The document provides a history of microbiology, from early observations of microorganisms in the 17th century to modern techniques. It discusses key figures like Hooke, Leeuwenhoek, Redi, and Pasteur and their experiments disproving spontaneous generation. Pasteur developed the germ theory of disease. Koch established criteria to identify disease-causing pathogens. The document also outlines techniques in phenotypic and genotypic taxonomy as well as microbial nutrition and culture media.
This document provides definitions and information related to microbiology. It defines key terms like microbiology, microorganisms, microscope, antibiotics, and antiseptics. It discusses the early history of microbiology including Leeuwenhoek's discovery of microbes and debates around spontaneous generation. It summarizes Louis Pasteur's experiments which disproved spontaneous generation and established the germ theory of disease. The document also discusses the golden age of microbiology and contributions of scientists like Jenner, Koch, and others that advanced the field.
This document provides an introduction to the field of microbiology. It discusses the following key points in 3 sentences:
1. Microbiology is the study of microorganisms like bacteria, fungi, algae, protozoa, and viruses. Major groups include bacteria, algae, fungi, protozoa, and viruses. Microorganisms play important roles in nature, industries, causing diseases, and more.
2. The discovery of microorganisms began in the 1600s with Anton van Leeuwenhoek's microscope observations of "animalcules". However, microbiology emerged as a science in the late 1800s with advances like germ theory and pure culture techniques.
3. Louis P
This document discusses the history and scope of microbiology. It begins by defining microbiology as the study of microorganisms, which are tiny creatures that can only be seen under a microscope. It then describes the branches of microbiology, including pure microbiology which focuses on taxonomy and integration of microbes, and applied microbiology which examines medical, veterinary, industrial, and other applications. The document continues by outlining the major groups of microorganisms and how they are named and classified. It concludes with an overview of the key discoveries and scientists that helped establish microbiology as a field, including the germ theory of disease and development of antibiotics.
INTRODUCTION TO MICROBIOLOGY - LECTURE 1.pptxaburageoffrey
Microbiology is the study of microorganisms too small to be seen with the naked eye. The document introduces key terms and provides a brief history of microbiology, including early theories of spontaneous generation and biogenesis. It describes important early scientists like van Leeuwenhoek, Redi, Spallanzani, and Pasteur and their experiments disproving spontaneous generation. The development of the germ theory of disease by Koch and the classification of microorganisms into domains, kingdoms, and taxa is summarized.
MICROBIOLOGY QUICK LEARNFood MicrobiologyIntroduction and DevelopmentSaajida Sultaana
Microbiology is the study of microorganisms. The development of microbiology involved early observations of microbes using microscopes in the 1600s. However, the germ theory of disease was established in the late 1800s by scientists like Pasteur and Koch, who proved microbes cause specific diseases. Major advances included developing techniques to isolate and grow pure cultures of microbes, and discovering antibiotics and vaccines. Today, microbiology remains important for medicine, public health, genetics, and industrial applications like producing antibiotics and other products using microbes.
This document provides an introduction to life science concepts that will be covered in the module. It outlines five key learning objectives, including identifying organisms and conditions that enable their existence, explaining evolution based on evidence, describing classic experiments that model early life conditions, describing unifying themes in life science studies, and showing connections between living things. The document then provides examples of content that will be discussed to meet these objectives, such as a description of the 2009 H1N1 influenza outbreak, the process of genetic reassortment in viruses, definitions of pandemics, and examples of evolution at work.
Introduction of Microbiology by Dr. Shujaat Ali (1).pptxhdjjd1
The document provides a history of microbiology, beginning with the discovery of microorganisms in the 1670s using Antonie van Leeuwenhoek's microscope. It discusses early debates around spontaneous generation and the experiments of Francesco Redi, Louis Pasteur, and others proving the theory of biogenesis. Major developments included Robert Koch's postulates identifying specific pathogens, Louis Pasteur's germ theory of disease, and Edward Jenner's smallpox vaccine. The molecular age saw uses of microbes to study genetics and cellular structure, while Alexander Fleming's discovery of penicillin launched modern antimicrobials. Current challenges include antibiotic resistance and emerging infectious diseases.
Van Leeuwenhoek was the first to observe microorganisms using self-made microscopes in the 1670s. Throughout the 17th-18th centuries, scientists debated whether microorganisms arose spontaneously or from other organisms. Redi provided evidence against spontaneous generation by showing that flies lay eggs on meat. Spallanzani strengthened this by showing microbes did not grow in sterilized broth. Pasteur disproved spontaneous generation through experiments isolating microbes from air. Koch and others established the germ theory of disease in the late 1800s, showing specific microbes cause specific illnesses. Jenner developed the smallpox vaccine in 1796, providing the first example of disease prevention through inoculation
This document provides definitions and information related to microbiology. It defines key terms like microbiology, microorganisms, microscope, antibiotics, and antiseptics. It discusses the early history of microbiology including Leeuwenhoek's discovery of microbes and debates around spontaneous generation. It summarizes Louis Pasteur's experiments which disproved spontaneous generation and established the germ theory of disease. The document also discusses the golden age of microbiology and contributions of scientists like Jenner, Koch, and others that advanced the field.
This document provides an introduction to the field of microbiology. It discusses the following key points in 3 sentences:
1. Microbiology is the study of microorganisms like bacteria, fungi, algae, protozoa, and viruses. Major groups include bacteria, algae, fungi, protozoa, and viruses. Microorganisms play important roles in nature, industries, causing diseases, and more.
2. The discovery of microorganisms began in the 1600s with Anton van Leeuwenhoek's microscope observations of "animalcules". However, microbiology emerged as a science in the late 1800s with advances like germ theory and pure culture techniques.
3. Louis P
This document discusses the history and scope of microbiology. It begins by defining microbiology as the study of microorganisms, which are tiny creatures that can only be seen under a microscope. It then describes the branches of microbiology, including pure microbiology which focuses on taxonomy and integration of microbes, and applied microbiology which examines medical, veterinary, industrial, and other applications. The document continues by outlining the major groups of microorganisms and how they are named and classified. It concludes with an overview of the key discoveries and scientists that helped establish microbiology as a field, including the germ theory of disease and development of antibiotics.
INTRODUCTION TO MICROBIOLOGY - LECTURE 1.pptxaburageoffrey
Microbiology is the study of microorganisms too small to be seen with the naked eye. The document introduces key terms and provides a brief history of microbiology, including early theories of spontaneous generation and biogenesis. It describes important early scientists like van Leeuwenhoek, Redi, Spallanzani, and Pasteur and their experiments disproving spontaneous generation. The development of the germ theory of disease by Koch and the classification of microorganisms into domains, kingdoms, and taxa is summarized.
MICROBIOLOGY QUICK LEARNFood MicrobiologyIntroduction and DevelopmentSaajida Sultaana
Microbiology is the study of microorganisms. The development of microbiology involved early observations of microbes using microscopes in the 1600s. However, the germ theory of disease was established in the late 1800s by scientists like Pasteur and Koch, who proved microbes cause specific diseases. Major advances included developing techniques to isolate and grow pure cultures of microbes, and discovering antibiotics and vaccines. Today, microbiology remains important for medicine, public health, genetics, and industrial applications like producing antibiotics and other products using microbes.
This document provides an introduction to life science concepts that will be covered in the module. It outlines five key learning objectives, including identifying organisms and conditions that enable their existence, explaining evolution based on evidence, describing classic experiments that model early life conditions, describing unifying themes in life science studies, and showing connections between living things. The document then provides examples of content that will be discussed to meet these objectives, such as a description of the 2009 H1N1 influenza outbreak, the process of genetic reassortment in viruses, definitions of pandemics, and examples of evolution at work.
Introduction of Microbiology by Dr. Shujaat Ali (1).pptxhdjjd1
The document provides a history of microbiology, beginning with the discovery of microorganisms in the 1670s using Antonie van Leeuwenhoek's microscope. It discusses early debates around spontaneous generation and the experiments of Francesco Redi, Louis Pasteur, and others proving the theory of biogenesis. Major developments included Robert Koch's postulates identifying specific pathogens, Louis Pasteur's germ theory of disease, and Edward Jenner's smallpox vaccine. The molecular age saw uses of microbes to study genetics and cellular structure, while Alexander Fleming's discovery of penicillin launched modern antimicrobials. Current challenges include antibiotic resistance and emerging infectious diseases.
Van Leeuwenhoek was the first to observe microorganisms using self-made microscopes in the 1670s. Throughout the 17th-18th centuries, scientists debated whether microorganisms arose spontaneously or from other organisms. Redi provided evidence against spontaneous generation by showing that flies lay eggs on meat. Spallanzani strengthened this by showing microbes did not grow in sterilized broth. Pasteur disproved spontaneous generation through experiments isolating microbes from air. Koch and others established the germ theory of disease in the late 1800s, showing specific microbes cause specific illnesses. Jenner developed the smallpox vaccine in 1796, providing the first example of disease prevention through inoculation
This document provides an overview of the history and scope of microbiology. It discusses key figures like Hooke, van Leeuwenhoek, Redi, Needham, Spallanzani, Pasteur, Tyndall, and Koch and their important contributions. Robert Hooke first observed cells using microscopy in 1665. Van Leeuwenhoek is considered the father of microbiology for his observations of microorganisms like bacteria in the 1670s using simple microscopes he developed. Pasteur disproved spontaneous generation and established germ theory through experiments in the 1860s. Koch developed techniques for isolating bacteria in pure culture and established criteria for proving causation between microbes and disease. These scientists helped establish
Microbiology is the study of microorganisms, which are tiny living organisms too small to be seen without a microscope. Key developments in microbiology included Anton van Leeuwenhoek's discovery of microbes in the 1600s, Louis Pasteur's experiments in the 1800s disproving spontaneous generation and establishing that microbes cause fermentation and disease, and Robert Koch's work in the late 1800s demonstrating specific diseases are caused by specific microbes through his postulates. The discovery of antibiotics and development of molecular genetics, including determining the structure of DNA and sequencing microbial genomes, further advanced the field of microbiology.
Microorganisms play an important role in human health and disease. The document discusses the history of microbiology from early ideas of spontaneous generation to experiments disproving this theory by Redi, Spallanzani, and Pasteur. It also outlines Koch's postulates for linking microbes to specific diseases and notes pioneering microbiologists like Semmelweis, Lister, Koch, Chamberland, Jenner, and Pasteur and their contributions to understanding the role of microbes in infections and developing vaccines. Major groups of microbes are also introduced along with their characteristics.
This document provides an overview of the history and development of microbiology. It discusses early theories on the causes of disease and key experiments and discoveries that helped establish microbiology as a science. These include the work of Leeuwenhoek, Pasteur, Lister, Koch and others who helped prove that microorganisms cause disease and developed methods to study and culture them. The document also describes the classification, identification and laboratory testing of bacteria through examination of morphology, staining, biochemical reactions and other methods.
Microbiology is the study of organisms that are usually too small to be seen by the unaided eye; it employs techniques—such as sterilization and the use of culture media—that are required to isolate and grow these microorganisms.
This document provides an overview of the history of microbiology. It discusses early observations of microorganisms using microscopes in the 1600s. It describes debates around spontaneous generation and key experiments disproving this theory by Pasteur in the 1800s. Major developments included establishing microbiology as a science, discoveries of germ theory and specific bacteria causing diseases, advances in vaccination, and the birth of chemotherapy and discovery of antibiotics like penicillin.
1 bio265 introduction to microbiology_dr di bonaventura_instructorShabab Ali
This document provides an overview of key topics in microbiology discussed in a Bio 265 lecture. It begins with Antoni van Leeuwenhoek and his discovery of microorganisms in the late 1600s using microscopes. Next, it discusses the early debates around spontaneous generation versus biogenesis. Major figures from the Golden Age of Microbiology are then outlined, including Louis Pasteur's experiments disproving spontaneous generation and Robert Koch's work establishing the germ theory of disease. Other topics covered include staining techniques, taxonomy, identifying microbes, case studies of disease, and the importance of handwashing in hospitals.
1. History and Scope of microbiology (1).pptxShaikh Ayesha
This document provides an overview of the history and scope of microbiology. It discusses how microbiology began with Anton van Leeuwenhoek's discovery and observation of microbes in the late 1600s. Important early experiments disproving spontaneous generation include Redi's meat experiment and Pasteur's swan neck flask experiment. Robert Koch and others established the germ theory of disease and techniques like staining and culturing. Modern microbiology is interdisciplinary and studies diverse microbes and their roles in fields like medicine, industry, and biotechnology using techniques like genetics and electron microscopy. Microbiology has applications in human health, agriculture, biotechnology, and other areas.
Robert Hooke first observed cells under a microscope in the 1600s and coined the term "cell". Anton van Leeuwenhoek was the first to observe bacteria and protozoa in the 1670s using single-lens microscopes. Louis Pasteur's experiments in the 1800s definitively disproved the theory of spontaneous generation and established that microorganisms are present everywhere and can contaminate previously sterile environments. Robert Koch developed methods to isolate and grow bacteria in pure culture in the late 1800s, establishing the germ theory of disease and identifying the specific bacteria that cause anthrax, cholera, and tuberculosis.
Contributions of renowned scientists in MicrobiologySaajida Sultaana
This document summarizes the contributions of several renowned scientists in microbiology, including Anton van Leeuwenhoek who was the first to observe bacteria and protozoa using microscopes he developed, Robert Koch who isolated the bacteria that cause tuberculosis, cholera, and anthrax and developed staining techniques, Louis Pasteur who disproved spontaneous generation and developed pasteurization, and Edward Jenner who discovered vaccination for smallpox. It also discusses the work of Robert Hooke, Francesco Redi, John Needham, and their experiments related to spontaneous generation and microorganisms.
The Biogenesis Theory states that all living things originate from other living things, opposing the idea of spontaneous generation from nonliving matter. Key figures in developing biogenesis include Antoni van Leeuwenhoek, who discovered microorganisms using an early microscope; Francesco Redi, who demonstrated that maggots come from flies; Louis Pasteur, whose experiments with swan neck flasks showed that sterile broth remained sterile, disproving spontaneous generation.
Distinguish between cellular and acellular. Give examples of microorg.pdfarjuntiwari586
Distinguish between cellular and acellular. Give examples of microorganisms in each category.
Describe the distinguishing features of each type of cell. What are the three domains of life?
Describe features of each domain. Escherichia coli is a bacterial species. Identify the genus and
the species. Escherichia coli has different strains. What is the significance of the strain
designation? What contributes to the emergence and/or re-emergence of infectious diseases?
Define the divisions of microbiology: bacteriology, mycology, virology, parasitology, serology,
molecular biology. The following made significant contributions to the field of microbiology,
identify the contribution of each: Leeuwenhoek, Holmes, Semmelweis, Lister, Pasteur, Koch,
Jenner
Solution
2.Unicellular organism is made up of one cell, a being with a cell wall, that gets along fine on its
own (like amoebas, protozoa or bacteria that usually move about all on their own) or which
could get along fine on its own (like yeasts or algae, which usually grow in bunches or
strings).Acellular organisms do not divide into discrete cells following the division of the
nucleus - they just carry on growing and producing more nuclei.Eg:Viruses, viroids, satellites,
plasmids, phagemids, cosmids, transposons and prions.
3. please specify the cells,in human or microbes?
4.The three domains of life are:
(a)EUKARYOTA
The Eukaryota include the organisms that most people are most familiar with - all animals,
plants, fungi, and protists. They also include the vast majority of the organisms that
paleontologists work with. Although they show unbelievable diversity in form, they share
fundamental characteristics of cellular organization, biochemistry, and molecular biology. Eg:
dinoflagellate,single-celled photosynthetic protist; plants; animals; and fungi.
(b)BACTERIA
Bacteria are often maligned as the causes of human and animal disease (like this one, Leptospira,
which causes serious disease in livestock). However, certain bacteria, the actinomycetes, produce
antibiotics such as streptomycin and nocardicin; others live symbiotically in the guts of animals
(including humans) or elsewhere in their bodies, or on the roots of certain plants, converting
nitrogen into a usable form. Bacteria put the tang in yogurt and the sour in sourdough bread;
bacteria help to break down dead organic matter; bacteria make up the base of the food web in
many environments. Bacteria are of such immense importance because of their extreme
flexibility, capacity for rapid growth and reproduction, and great age - the oldest fossils known,
nearly 3.5 billion years old, are fossils of bacteria-like organisms.
(c)ARCHEA
Archaeans include inhabitants of some of the most extreme environments on the planet. Some
live near rift vents in the deep sea at temperatures well over 100 degrees Centigrade. Others live
in hot springs, or in extremely alkaline or acid waters. They have been found thriving inside the
digestive tracts of cows, t.
This document provides an introduction to the field of microbiology. It discusses the scope and history of microbiology, including key figures and discoveries. Some of the major topics covered include the spontaneous generation theory being disproven by Louis Pasteur, Robert Koch establishing the germ theory of disease and Koch's postulates, the identification of antibiotics by Alexander Fleming and Selman Waksman, and the isolation and study of various microorganisms by scientists like Beijerinck and Winogradsky. The document serves as an overview of the emergence and development of microbiology as a scientific discipline.
This document outlines the course contents for a basic microbiology class. It covers topics such as the introduction and history of microbiology, classification of microorganisms, bacterial cell structure, growth and genetics, viruses, the immune system, and materials required for the class. Key figures in the history and development of microbiology are also mentioned, including Hooke, van Leeuwenhoek, Redi, Pasteur, Koch, Fleming, and Watson and Crick. Classification of microbes from domain to species level is reviewed.
The document provides a history of microbiology from its early beginnings to modern applications. It describes key early scientists like Van Leeuwenhoek who first observed microbes, and Linnaeus who developed a taxonomy system. Later, scientists like Pasteur and Koch established germ theory and methods to study microbes. Their work led to understanding fermentation and the microbial causes of disease. Today, microbiology involves understanding biochemical reactions, genetics, molecular biology, and applications like bioremediation, disease prevention, and recombinant DNA technology. The future of microbiology relies on continued scientific questioning and discovery.
This document discusses the history and development of microbiology. It covers key topics such as:
- The early discovery of microorganisms in the 1600s by Antonie Van Leeuwenhoek.
- Louis Pasteur's experiments in the 1800s that disproved spontaneous generation and established germ theory.
- Robert Koch's work in the late 1800s isolating specific bacteria that cause diseases and establishing his postulates for proving causation.
- Early pioneers like Edward Jenner and developments like vaccines, antibiotics like penicillin, and the golden age of microbiology from 1857-1914.
Microbiology is the study of microorganisms that are too small to be seen with the naked eye, such as bacteria, fungi, protozoa, algae, and viruses. Microbes play both beneficial and pathogenic roles. The history of microbiology began in the 17th century with the first observations of microbes using microscopes. Important figures who contributed to the field include Anton van Leeuwenhoek, Louis Pasteur, Robert Koch, Edward Jenner, Alexander Fleming. Their work established germ theory, microbial fermentation and disease causation, vaccination, and the discovery of the first antibiotic - penicillin.
This document provides an introduction to microbiology and outlines important historical developments in the field. It discusses key figures like Antony van Leeuwenhoek, who was the first to observe microorganisms using microscopes, and Louis Pasteur, one of the founders of medical microbiology. Some of their major contributions are summarized, such as Leeuwenhoek's discovery of bacteria and Pasteur's disproving of spontaneous generation and development of pasteurization. The document also reviews the work of other scientists who helped establish microbiology as a field of study.
To understand the basic concepts of the biology of microorganisms and its mechanism of action in host cells.
-Dr SUBASHKUMAR R
Associate Professor in Biotechnology
Sri Ramakrishna College of Arts and Science, Coimbatore
Brown algae are characterized by cell walls containing cellulose and alginic acid. They reproduce sexually and asexually and have an alternation of generations life cycle. Brown algae are divided into three classes based on their life cycles: isogamous, heterogamous, and oogamous. Ectocarpus is a filamentous brown alga that is a model organism. Kelps are large brown algae with a diploid sporophyte generation and haploid gametophyte. Fucus is dioecious and releases gametes using tidal movements, with sperm chemotaxing towards eggs. Brown algae are used as sources of iodine, alginate, food, and
The document discusses various methods for controlling microbial growth, including moist heat sterilization methods like pasteurization, boiling, steaming, and tyndalization. It also discusses dry heat sterilization and chemical methods using agents like phenol, halogens, alcohols, heavy metals, soaps/detergents, aldehydes, ethylene oxide, and food preservatives. The document then discusses mechanisms of antibiotic resistance in bacteria, including antibiotic inactivation, target modification, efflux pumps, and changes to outer membrane permeability.
This document provides an overview of the history and scope of microbiology. It discusses key figures like Hooke, van Leeuwenhoek, Redi, Needham, Spallanzani, Pasteur, Tyndall, and Koch and their important contributions. Robert Hooke first observed cells using microscopy in 1665. Van Leeuwenhoek is considered the father of microbiology for his observations of microorganisms like bacteria in the 1670s using simple microscopes he developed. Pasteur disproved spontaneous generation and established germ theory through experiments in the 1860s. Koch developed techniques for isolating bacteria in pure culture and established criteria for proving causation between microbes and disease. These scientists helped establish
Microbiology is the study of microorganisms, which are tiny living organisms too small to be seen without a microscope. Key developments in microbiology included Anton van Leeuwenhoek's discovery of microbes in the 1600s, Louis Pasteur's experiments in the 1800s disproving spontaneous generation and establishing that microbes cause fermentation and disease, and Robert Koch's work in the late 1800s demonstrating specific diseases are caused by specific microbes through his postulates. The discovery of antibiotics and development of molecular genetics, including determining the structure of DNA and sequencing microbial genomes, further advanced the field of microbiology.
Microorganisms play an important role in human health and disease. The document discusses the history of microbiology from early ideas of spontaneous generation to experiments disproving this theory by Redi, Spallanzani, and Pasteur. It also outlines Koch's postulates for linking microbes to specific diseases and notes pioneering microbiologists like Semmelweis, Lister, Koch, Chamberland, Jenner, and Pasteur and their contributions to understanding the role of microbes in infections and developing vaccines. Major groups of microbes are also introduced along with their characteristics.
This document provides an overview of the history and development of microbiology. It discusses early theories on the causes of disease and key experiments and discoveries that helped establish microbiology as a science. These include the work of Leeuwenhoek, Pasteur, Lister, Koch and others who helped prove that microorganisms cause disease and developed methods to study and culture them. The document also describes the classification, identification and laboratory testing of bacteria through examination of morphology, staining, biochemical reactions and other methods.
Microbiology is the study of organisms that are usually too small to be seen by the unaided eye; it employs techniques—such as sterilization and the use of culture media—that are required to isolate and grow these microorganisms.
This document provides an overview of the history of microbiology. It discusses early observations of microorganisms using microscopes in the 1600s. It describes debates around spontaneous generation and key experiments disproving this theory by Pasteur in the 1800s. Major developments included establishing microbiology as a science, discoveries of germ theory and specific bacteria causing diseases, advances in vaccination, and the birth of chemotherapy and discovery of antibiotics like penicillin.
1 bio265 introduction to microbiology_dr di bonaventura_instructorShabab Ali
This document provides an overview of key topics in microbiology discussed in a Bio 265 lecture. It begins with Antoni van Leeuwenhoek and his discovery of microorganisms in the late 1600s using microscopes. Next, it discusses the early debates around spontaneous generation versus biogenesis. Major figures from the Golden Age of Microbiology are then outlined, including Louis Pasteur's experiments disproving spontaneous generation and Robert Koch's work establishing the germ theory of disease. Other topics covered include staining techniques, taxonomy, identifying microbes, case studies of disease, and the importance of handwashing in hospitals.
1. History and Scope of microbiology (1).pptxShaikh Ayesha
This document provides an overview of the history and scope of microbiology. It discusses how microbiology began with Anton van Leeuwenhoek's discovery and observation of microbes in the late 1600s. Important early experiments disproving spontaneous generation include Redi's meat experiment and Pasteur's swan neck flask experiment. Robert Koch and others established the germ theory of disease and techniques like staining and culturing. Modern microbiology is interdisciplinary and studies diverse microbes and their roles in fields like medicine, industry, and biotechnology using techniques like genetics and electron microscopy. Microbiology has applications in human health, agriculture, biotechnology, and other areas.
Robert Hooke first observed cells under a microscope in the 1600s and coined the term "cell". Anton van Leeuwenhoek was the first to observe bacteria and protozoa in the 1670s using single-lens microscopes. Louis Pasteur's experiments in the 1800s definitively disproved the theory of spontaneous generation and established that microorganisms are present everywhere and can contaminate previously sterile environments. Robert Koch developed methods to isolate and grow bacteria in pure culture in the late 1800s, establishing the germ theory of disease and identifying the specific bacteria that cause anthrax, cholera, and tuberculosis.
Contributions of renowned scientists in MicrobiologySaajida Sultaana
This document summarizes the contributions of several renowned scientists in microbiology, including Anton van Leeuwenhoek who was the first to observe bacteria and protozoa using microscopes he developed, Robert Koch who isolated the bacteria that cause tuberculosis, cholera, and anthrax and developed staining techniques, Louis Pasteur who disproved spontaneous generation and developed pasteurization, and Edward Jenner who discovered vaccination for smallpox. It also discusses the work of Robert Hooke, Francesco Redi, John Needham, and their experiments related to spontaneous generation and microorganisms.
The Biogenesis Theory states that all living things originate from other living things, opposing the idea of spontaneous generation from nonliving matter. Key figures in developing biogenesis include Antoni van Leeuwenhoek, who discovered microorganisms using an early microscope; Francesco Redi, who demonstrated that maggots come from flies; Louis Pasteur, whose experiments with swan neck flasks showed that sterile broth remained sterile, disproving spontaneous generation.
Distinguish between cellular and acellular. Give examples of microorg.pdfarjuntiwari586
Distinguish between cellular and acellular. Give examples of microorganisms in each category.
Describe the distinguishing features of each type of cell. What are the three domains of life?
Describe features of each domain. Escherichia coli is a bacterial species. Identify the genus and
the species. Escherichia coli has different strains. What is the significance of the strain
designation? What contributes to the emergence and/or re-emergence of infectious diseases?
Define the divisions of microbiology: bacteriology, mycology, virology, parasitology, serology,
molecular biology. The following made significant contributions to the field of microbiology,
identify the contribution of each: Leeuwenhoek, Holmes, Semmelweis, Lister, Pasteur, Koch,
Jenner
Solution
2.Unicellular organism is made up of one cell, a being with a cell wall, that gets along fine on its
own (like amoebas, protozoa or bacteria that usually move about all on their own) or which
could get along fine on its own (like yeasts or algae, which usually grow in bunches or
strings).Acellular organisms do not divide into discrete cells following the division of the
nucleus - they just carry on growing and producing more nuclei.Eg:Viruses, viroids, satellites,
plasmids, phagemids, cosmids, transposons and prions.
3. please specify the cells,in human or microbes?
4.The three domains of life are:
(a)EUKARYOTA
The Eukaryota include the organisms that most people are most familiar with - all animals,
plants, fungi, and protists. They also include the vast majority of the organisms that
paleontologists work with. Although they show unbelievable diversity in form, they share
fundamental characteristics of cellular organization, biochemistry, and molecular biology. Eg:
dinoflagellate,single-celled photosynthetic protist; plants; animals; and fungi.
(b)BACTERIA
Bacteria are often maligned as the causes of human and animal disease (like this one, Leptospira,
which causes serious disease in livestock). However, certain bacteria, the actinomycetes, produce
antibiotics such as streptomycin and nocardicin; others live symbiotically in the guts of animals
(including humans) or elsewhere in their bodies, or on the roots of certain plants, converting
nitrogen into a usable form. Bacteria put the tang in yogurt and the sour in sourdough bread;
bacteria help to break down dead organic matter; bacteria make up the base of the food web in
many environments. Bacteria are of such immense importance because of their extreme
flexibility, capacity for rapid growth and reproduction, and great age - the oldest fossils known,
nearly 3.5 billion years old, are fossils of bacteria-like organisms.
(c)ARCHEA
Archaeans include inhabitants of some of the most extreme environments on the planet. Some
live near rift vents in the deep sea at temperatures well over 100 degrees Centigrade. Others live
in hot springs, or in extremely alkaline or acid waters. They have been found thriving inside the
digestive tracts of cows, t.
This document provides an introduction to the field of microbiology. It discusses the scope and history of microbiology, including key figures and discoveries. Some of the major topics covered include the spontaneous generation theory being disproven by Louis Pasteur, Robert Koch establishing the germ theory of disease and Koch's postulates, the identification of antibiotics by Alexander Fleming and Selman Waksman, and the isolation and study of various microorganisms by scientists like Beijerinck and Winogradsky. The document serves as an overview of the emergence and development of microbiology as a scientific discipline.
This document outlines the course contents for a basic microbiology class. It covers topics such as the introduction and history of microbiology, classification of microorganisms, bacterial cell structure, growth and genetics, viruses, the immune system, and materials required for the class. Key figures in the history and development of microbiology are also mentioned, including Hooke, van Leeuwenhoek, Redi, Pasteur, Koch, Fleming, and Watson and Crick. Classification of microbes from domain to species level is reviewed.
The document provides a history of microbiology from its early beginnings to modern applications. It describes key early scientists like Van Leeuwenhoek who first observed microbes, and Linnaeus who developed a taxonomy system. Later, scientists like Pasteur and Koch established germ theory and methods to study microbes. Their work led to understanding fermentation and the microbial causes of disease. Today, microbiology involves understanding biochemical reactions, genetics, molecular biology, and applications like bioremediation, disease prevention, and recombinant DNA technology. The future of microbiology relies on continued scientific questioning and discovery.
This document discusses the history and development of microbiology. It covers key topics such as:
- The early discovery of microorganisms in the 1600s by Antonie Van Leeuwenhoek.
- Louis Pasteur's experiments in the 1800s that disproved spontaneous generation and established germ theory.
- Robert Koch's work in the late 1800s isolating specific bacteria that cause diseases and establishing his postulates for proving causation.
- Early pioneers like Edward Jenner and developments like vaccines, antibiotics like penicillin, and the golden age of microbiology from 1857-1914.
Microbiology is the study of microorganisms that are too small to be seen with the naked eye, such as bacteria, fungi, protozoa, algae, and viruses. Microbes play both beneficial and pathogenic roles. The history of microbiology began in the 17th century with the first observations of microbes using microscopes. Important figures who contributed to the field include Anton van Leeuwenhoek, Louis Pasteur, Robert Koch, Edward Jenner, Alexander Fleming. Their work established germ theory, microbial fermentation and disease causation, vaccination, and the discovery of the first antibiotic - penicillin.
This document provides an introduction to microbiology and outlines important historical developments in the field. It discusses key figures like Antony van Leeuwenhoek, who was the first to observe microorganisms using microscopes, and Louis Pasteur, one of the founders of medical microbiology. Some of their major contributions are summarized, such as Leeuwenhoek's discovery of bacteria and Pasteur's disproving of spontaneous generation and development of pasteurization. The document also reviews the work of other scientists who helped establish microbiology as a field of study.
To understand the basic concepts of the biology of microorganisms and its mechanism of action in host cells.
-Dr SUBASHKUMAR R
Associate Professor in Biotechnology
Sri Ramakrishna College of Arts and Science, Coimbatore
Brown algae are characterized by cell walls containing cellulose and alginic acid. They reproduce sexually and asexually and have an alternation of generations life cycle. Brown algae are divided into three classes based on their life cycles: isogamous, heterogamous, and oogamous. Ectocarpus is a filamentous brown alga that is a model organism. Kelps are large brown algae with a diploid sporophyte generation and haploid gametophyte. Fucus is dioecious and releases gametes using tidal movements, with sperm chemotaxing towards eggs. Brown algae are used as sources of iodine, alginate, food, and
The document discusses various methods for controlling microbial growth, including moist heat sterilization methods like pasteurization, boiling, steaming, and tyndalization. It also discusses dry heat sterilization and chemical methods using agents like phenol, halogens, alcohols, heavy metals, soaps/detergents, aldehydes, ethylene oxide, and food preservatives. The document then discusses mechanisms of antibiotic resistance in bacteria, including antibiotic inactivation, target modification, efflux pumps, and changes to outer membrane permeability.
Bioinformatics is an interdisciplinary field that uses computer science and information technology to analyze and interpret biological data. It involves developing databases to store biological information and computational tools to analyze data. The key aims of bioinformatics are to store biological data in organized databases, develop tools to analyze the data, and use these tools to interpret results in a biologically meaningful way. It has applications in areas like genome sequencing and annotation, gene expression analysis, protein structure prediction, and understanding biological pathways and networks.
The fluid mosaic model proposes that the cell membrane is a bilayer of phospholipids with integral and peripheral proteins scattered throughout. The phospholipid molecules are arranged with their hydrophobic tails facing inward and hydrophilic heads facing outward, forming a selectively permeable barrier. Integral proteins firmly embed in the membrane, while peripheral proteins attach to the exterior surface. This structure allows for passive diffusion of small hydrophobic molecules but requires membrane proteins like pumps, carriers, and channels to regulate the passage of ions and larger molecules into and out of the cell.
Coleochaete is a genus of about 10 species of freshwater algae. They grow either as epiphytes on various aquatic plants and algae or as endophytes within the cells of certain green algae. The plant body of Coleochaete is multicellular and heterotrichous, with both erect and prostrate filaments. Some species have well-developed erect systems while others have prominent prostrate systems, resulting in discoid thalli that resemble a single layer of parenchyma tissue.
Volvox is a genus of multicellular green algae that forms spherical colonies called coenobia. The coenobia contain many individual cells connected by cytoplasmic strands. Volvox is found in freshwater throughout the world. It reproduces both sexually and asexually. Asexual reproduction occurs through the formation of daughter coenobia inside the parent coenobium. Sexual reproduction involves the formation of male antheridia and female oogonia, with fertilization occurring when the sperm from the antheridia fuse with the eggs in the oogonia to form zygotes. The zygotes develop into new coenobia, completing the life cycle.
Chara is a freshwater green alga found in shallow ponds, lakes, and slow rivers. It reproduces both sexually and asexually. Sexually, the male globule contains sperm that fertilize the female nucule, forming a hardy diploid oospore. The oospore's nucleus undergoes meiosis to produce four haploid nuclei, restarting the life cycle. Asexually, bulbils, amylum stars, and secondary protonema can form new plants. Overall, Chara's life cycle is predominantly haploid, with only the oospore being diploid briefly before meiosis.
Fritsch classified algae into 11 classes based on their pigments, reserve foods, and modes of reproduction. The classes are Chlorophyceae, Xanthophyceae, Chrysophyceae, Bacillariophyceae, Cryptophyceae, Dinophyceae, Chloromonodineae, Euglinineae, Phaeophyceae, Rhodophyceae, and Myxophyceae. Each class is distinguished by characteristics such as their occurrence, pigments, reserve foods, structures, and modes of reproduction. Fritsch's classification was published in his 1935 book "The Structure and Reproduction of Algae".
Viruses are small infectious particles that can only replicate inside living host cells. They contain nucleic acid surrounded by a protein coat and infect all types of organisms. Viruses enter host cells, release their genetic material, and use the host cell's machinery to produce new viral components and assemble new virus particles, which then exit the cell. Viruses are classified based on characteristics like nucleic acid type, structure, and host organisms. Their replication cycles involve entry, uncoating, expression and replication of genes, assembly of new viral particles, and release.
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
The technology uses reclaimed CO₂ as the dyeing medium in a closed loop process. When pressurized, CO₂ becomes supercritical (SC-CO₂). In this state CO₂ has a very high solvent power, allowing the dye to dissolve easily.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
1. History of Microbiology
Early Studies
Before 17th century, study of microbiology was hampered
by the lack of appropriate tools to observe microbes.
Robert Hooke: In 1665 built a compound light microscope
and used it to observe thin slices of cork. Coined the word cell.
Anton van Leeuwenhoeck: In 1673 was the first person to
observe live microorganisms which he called “animalcules”
(bacteria, protozoa), using single-lens microscopes that he
designed.
2. Before 1860s many scientists believed in Spontaneous
generation, i.e.: That living organisms could arise
spontaneously from nonliving matter:
Mice come from rags in a basket.
Maggots come from rotting meat.
Ants come from honey.
Microbes come from spoiled broth.
Spontaneous Generation vs Biogenesis
3. Francesco Redi: In 1668 proved that maggots do not arise
spontaneously from decaying meat.
Lazaro Spallanzani: In 1765 found that nutrient broth that
had been heated in a sealed flask would not become
contaminated with microbes.
Some proponents of spontaneous generation argued that
boiling had destroyed the “life force” of air in flask.
Others argued that microbes were different from other life
forms.
4. Redi's Experiment
In 1668, Francesco Redi, an Italian scientist, designed a scientific
experiment to test the spontaneous creation of maggots.
He placed fresh meat in each of two different jars.
One jar was left open; the other was covered with a cloth.
Days later, the open jar contained maggots, whereas the covered jar
contained no maggots.
He did note that maggots were found on the exterior surface of the cloth
that covered the jar.
Redi successfully demonstrated that the maggots came from fly eggs and
thereby helped to disprove spontaneous generation
Redi's Experiment and Needham's Rebuttal
5. In England, John Needham challenged Redi's
findings by conducting an experiment in which he placed
a broth, or “gravy,” into a bottle, heated the bottle to kill
anything inside, then sealed it. Days later, he reported the
presence of life in the broth and announced that life had
been created from nonlife.
In actuality, he did not heat it long enough to kill all
the microbes.
Needham's Rebuttal
6. Lazzaro Spallanzani, also an Italian scientist, reviewed both
Redi's and Needham's data and experimental design and concluded
that perhaps Needham's heating of the bottle did not kill everything
inside.
He constructed his own experiment by placing broth in each of
two separate bottles, boiling the broth in both bottles, then sealing
one bottle and leaving the other open.
Spallanzani's Experiment
7. Days later, the unsealed bottle was teeming with small living
things that he could observe more clearly with the newly invented
microscope.
The sealed bottle showed no signs of life.
This certainly excluded spontaneous generation as a viable
theory.
Scientists of that day deprived Spallanzani that the sealed bottle
was deprived of air.
So although his experiment was successful, a strong rebuttal
blunted his claims.
8. Louis Pasteur, the notable French scientist, accepted the
challenge to re-create the experiment of Lazzaro Spallanzani.
He designed two types of flasks, one with long S shaped necks
and another with straight necks.
He placed a nutrient-enriched broth in both the jars, boiled the
broth inside the jars and left them open.
Kept both the jars open for long time.
Straight necked flasks showed the presence of life whereas S
necked flasks showed no life up to one year.
Pasteur's Swan necked flask Experiment
9. He then broke off the top of the bottle, exposing it more directly
to the air, and noted life-forms in the broth within days
The reason behind it was that the air paricles carrying minute
life forms were trapped at the deepest portion of the neck because
of gravity.
11. Pasteur’s Contributions:
Pasteurization: Developed a process in which liquids are
heated (at 65oC) to kill most bacteria responsible for spoilage.
Disease Causes: Identified three different microbes that caused
silkworm diseases.
Vaccine: Developed a vaccine for rabies from dried spinal
cords of infected rabbits.
Directed Pasteur Institute until his death in 1895.
History of Microbiology
Golden Age: 1857-1914
12. History of Microbiology
Golden Age: 1857-1914
Germ Theory of Disease: Belief that microbes cause diseases.
Before, most people believed diseases were caused by divine
punishment, poisonous vapors, curses, witchcraft, etc.
Agostino Bassi (1835): Found that a fungus was responsible for
a silkworm disease.
Ignaz Semmelweis (1840s): Demonstrated that childbirth fever
was transmitted from one patient to another, by physicians who
didn’t disinfect their hands. He was ostracized by colleagues.
13. Before Pasteur disproved spontaneous generation, he decided to
determine why some bottles of wine soured over time. He observed wine that
had soured and compared it to wine that had not. He determined that all
soured wines contained a large number of cells. Yeast cells are required for
wine fermentation, so even good wine would have yeast cells. But, sour wine
was full of many smaller cells that were not yeast. Pasteur reasoned that sour
wines had been contaminated with microbes, and these contaminating
microbes were causing the poor quality.
Based on this, Pasteur postulated the germ theory of disease, which
states that microorganisms are the causes of infectious disease.
The Germ Theory of Disease
14. Pasteur's attempts to prove the germ theory were
unsuccessful. However, the German scientist Robert Koch
provided the proof by cultivating anthrax bacteria apart from
any other type of organism. He then injected pure cultures of
the bacilli into mice and showed that the bacilli invariably
caused anthrax. The procedures used by Koch came to be
known as Koch's postulates.
Koch's postulates
15.
16. Four criteria that were established by Robert Koch to
identify the causative agent of a particular disease, these
include:
•the microorganism or other pathogen must be present in all
cases of the disease.
•the pathogen can be isolated from the diseased host and grown
in pure culture.
•the pathogen from the pure culture must cause the disease
when inoculated into a healthy, susceptible laboratory animal.
•the pathogen must be reisolated from the new host and shown
to be the same as the originally inoculated pathogen.
17. Modern Taxonomy for Microbial Diversity
Microorganisms are actually composed of very different
and taxonomically diverse groups of communities: archaea,
bacteria, fungi and viruses. The members of these groups or taxa
are distinct in terms of their morphology, physiology and
phylogeny and fall into both prokaryotic and eukaryotic domains.
They constitute a broad group of life system inhabiting the
known ecosystems on earth: terrestrial and marine; including
geographical locations considered to be extreme or inimical to
life.
18.
19.
20. Phenotypic techniques
The phenotypic methods are all those that do not include the
DNA/RNA sequencing or their typing methods. Study of
morphological characteristics and chemotaxonomic profiles is broadly
associated with phenotypic characterization.
21. Classical: Colony characteristics, biochemical and physiological analyses
The phenotypic features are the foundation for description of taxa. The
morphological, biochemical and physiological characteristics provide in-depth
information on a taxon. The morphology can include the colony characteristics
(colour, shape, pigmentation, production of slime etc.). Further, the features of
the cell are described as to shape, size, Gram reaction, extracellular material like
capsule, presence of endospores, flagella presence and location, motility and
inclusion bodies. Light microscopy is generally used to describe the broad cell
features; however electron microscopy is recommended for high resolution
images.
22. Numerical taxonomy
Analysis of huge volumes of phenotypic data to derive meaningful
relationships amongst a large number of microorganisms can be carried out
using computer programs . This system of analysis is called numerical
taxonomy. Giving numerical weightage to each trait is followed by analysis
of the data by the computer programs generating data matrices between each
pair of isolates according to the degree of similarity. Based on the similarity
data, cluster analysis are carried out (based on different algorithms) and
dendrograms (‘trees’) are generated showing the overall pattern of
similarity/dissimilarity amongst the various organisms being studied.
23. Cell wall composition
The peptidoglycan component of cell walls of bacteria does not
provide much information except for classifying into Gram-positive,
Gram-negative and acid-fast bacterial types. However, those in Gram-
positive cells contain different types of peptidoglycan depending on the
genus or species. The peptidoglycan structure can be analysed by
determining its type (A or B), mode of cross-linking (whether it is directly
linked or via interpeptide bridge and with amino acids in the bridge), and
the composition of amino acids (especially the diaminoacid) of the side
chain.
24. Fatty acid analyses
Different types of lipids are present in bacterial cells. Polar lipids are
present in the lipid bilayer of the cytoplasmic membrane. The diversity of polar
lipids is known to be large and many are yet to be structurally elucidated. While
in archaea, polar lipids are of types phospholipids, aminophospholipids,
glycolipids and phosphoglycolipids, in bacteria, apart from the ones seen in
archaea, there are also lipids derived from amino acids, capnines, sphingolipids
(glycol or phosphosphingolipids) and hopanoids . In Gram-negative bacteria,
lipopolysaccharides are present in the outer membranes. The type of sugar
present and the fatty acid type, the linkage of the fatty acid to the sugar (amide or
ester linkage) provide information on characteristic of the cell.
25. Genotypic techniques
Modern taxonomy has been influenced by genetic methods
and indeed, much of the classification and identification is predicated
on specific gene sequences. All the techniques involving DNA or RNA
fall under genotypic methods.
26. 16S rDNA-based analyses
The technique, which is very nearly a gold standard for taxonomic
purposes today, is sequencing of the 16S rRNA gene of bacteria. The 23S
rRNA gene sequence is also considered in many studies but lack of
comprehensive databases for comparison is a drawback. Since the 16S
rRNA is present in all bacteria, is functionally constant and is composed
of conserved and variable regions, it has consistently served as a good
taxonomic marker for deriving taxonomic relationships
27. DNA base content
Determination of moles percent guanosine and cytosine
constitutes a classical method of establishment of genomic content. This
is now being used along with other genotyping methods to establish
taxonomic position of an organism. Within species, the G+C content
ranges within 3% and within genera 10%. Overall, the G+C content
ranges from 24-76% in bacteria.
28. DNA-DNA hybridization
This method is an indirect measurement of sequence similarity between
genomes. A cut-off value of 70% similarity is considered for establishment
of species. However, the method has to be reproducible between
laboratories and performed under standardized conditions, which is often a
drawback. Hence it is applied only where 16S rRNA gene sequences show
similarity values above 98%. There have been reports where 16S rRNA
gene sequence has shown 99% similarity and yet DNA-DNA hybridization
values have been 60% or less. Hence, this method has to be used with
caution and performed under highly standardized conditions.
29. Other genotyping methods
Earlier, sub-typing was done on the basis of biochemical profile
(biotyping), serological profile (serotyping), phase susceptibility (phage
typing) or antibiotic susceptibility. But currently DNA-typing methods are
preferred due to their reproducibility, ease of performance and high level of
discrimination between strains [1]. Genotyping methods such as Restriction
Fragment Length Polymorphism (RFLP), Randomly Amplified Polymorphic
DNA (RAPD), Amplified Fragment Length Polymorphism (AFLP),
Amplified Ribosomal DNA Restriction Analysis (ARDRA), Repetitive
Element-Polymerase Chain Reaction (REP-PCR), Ribotyping and Multi
Locus Sequence Analyses (MLSA) are some of the newer methods to
characterize a taxon.
30. Taxonomy of viruses
The definition of a virus ‘species’ is: "A virus species is a polythetic
class of viruses that constitutes a replicating lineage and occupies a particular
ecological niche". A virus isolate can refer to any virus as long as the virus has
existed for some time. Viruses are not considered to be either prokaryotes or
eukaryotes but have implication from health point of view; hence
characterization of viruses has increased considerably. Where earlier, only
electron microscopy was used, today sequencing of viral genomes constitutes
advancements and the database is increasing. According to International
Committee on Taxonomy of Viruses (ICTV), proposals are afoot to accept
online descriptions of viral taxa based on taxonomical details such as : dsDNA,
ssDNA, rtDNA, rtRNA, dsRNA, ssNRNA, ssPRNA, SAT (Satellites), VIR
(Viroids), UN (unassigned).
31. MICROBIAL NUTRITION
The microbial cells are extremely complex and in
addition to oxygen and hydrogen they contain four other
major elements such as carbon, nitrogen, phosphorus and
sulphur. The microorganisms in general do not need only
these six elements but also others, which are found in
lesser -quantity. Such elements are potassium, magnesium,
calcium, sodium, iron, manganese, cobalt copper,
molybdenum and zinc.
32. Most of the microorganisms need molecular oxygen for respiration. In
these, the oxygen serves as terminal electron acceptor and, such organisms
are referred to as ‘obligate aerobes’. As opposed to this there are a few
organisms, which do not use molecular oxygen as terminal electron acceptor.
These microbes are called ‘obligate anaerobes’. In fact, molecular oxygen is
toxic to these organisms. Aerobes, which can grow in the absence of oxygen,
are called ‘facultative anaerobes’ and the anaerobes which can grow in the
presence of oxygen are referred to as ‘facultative aerobes’. In addition to
these major classes, there are organisms, which grow best at reduced oxygen
pressure but are obligate aerobes and these are called ‘Microaerophilic’.
33. Some microorganisms manufacture their foods from inorganic
supplies to them and thus are able to subsist in an exclusively
inorganic environment: They are collectively called autotrophs.
Other micro organic metabolites; they must absorb from the
environment in certain minimum amounts and kinds of prefabricated
organic metabolites (the foods). Such microorganisms are collectively
called heterotrophs.
34. Autotrophic microorganisms, which manufacture foods from
inorganic sources, require not only external source of appropriate nutrient
raw materials but also external sources of energy. In some cases, external
energy for food manufacture is obtained from light and such
microorganisms are collectively called photosynthesizers. In other cases,
some inorganic nutrients serve as raw materials for food manufacture and
other inorganic nutrients, i.e., chemicals, serve as external energy sources.
Such microorganisms are collectively called chemosynthesizers.
35. Major nutritional types of microbes
Microbes can be categorized under four nutritional types depending
upon the source of carbon, electron and energy-
Light as a source of energy
Photolithoautotrophs: these microbes use light as the source of
energy, inorganic compounds as electron source and CO2 as carbon
source. Example: Green and Purple sulphur bacteria, cyanobacteria.
Photoorganoheterotrophs: these microbes use light as energy source
and organic compounds as electron and carbon source. Example: Green
and Purple non sulphur bacteria.
36. Inorganic or organic compounds as source of energy
Chemolithoautotrophs: These microbes use inorganic
compounds as source of energy as well as electrons. They also
use carbon-dioxide as a source of carbon. Example: Sulphur
oxidizing bacteria, hydrogen bacteria.
Chemoorganoheterotrophs: They use organic compounds as
the source of carbon, electrons and energy. Example: Fungi,
nonphotosynthetic bacteria, nitrifying bacteria.
37. CULTURE MEDIA
Substrates or mixtures of nutrients that provide proper growth of
microorganisms in laboratory are referred as culture media. The use of diverse kinds of
culture media made the cultivation of microbes easy and these culture media may be
divided into following tyoes
Natural media: These types media contain simple ingredients having
nutrients of unknown composition like peptone, beef extract, yeast extract, potato etc.
which provide a wide range of nutrients Ilike amino acids, peptides, nucleotides,
itamins, minerals, carbon source etc.) for better growth of different kinds of microbes.
Eg. Nutrient agar, potato dextrose agar.
Synthetic media: These media are constructed using specific chemicals in
their exact proportions. It is commonly used for growth of microbes haing simple
nutritional requirements. Eg. Czapek dox agar.
38. Basal media or minimal : It supplies only the minimal nutritional
requirements of a particular microorganism. These types of media support the
growth of most non-fastidious organisms. Eg. Nutrient agar and nutrient broth.
Enriched media: When extra nutrients like blood, serum, egg yolk etc are
added to a minimal medium it becomes enriched medium. It supports the
growth of nutritionally fastidious bacteria. Eg. Blood agar, chocolate agar.
All purpose media: This type of media is rich with wide varieties of nutrients
including growth factors and therefore supports the growth of wide number of
bacteria. Eg. Plate count agar, Heart infusion agar.
Selective media: The media that encourage the growth of only some specic
microbes and inhibit the growth of others. Eg. Pseudomonas agar
Differential media: The media used to identify different groups of microbes.
Eg. Blood agar, skim milk agar.
39. MICROBIAL GROWTH
As most of the microorganisms are unicellular in nature, microbial
growth does not refer to the growth of the cell size, but it denotes the
growth of cell number in a specific period.
Microbial growth curve:
The growth curve has four distinct phases as mentioned in the figure.