SlideShare a Scribd company logo
1 of 25
Download to read offline
INTRODUCTION TO MICROBIOLOGY
(BSPH 112)
LECTURE # 1
Dr. Siachinji K. Matthews
Introduction
• Microbiology (Micro=Small, Biology= Study of life), thus it is the study
of agents too small to be seen with the naked eye.
• Microorganisms consist of Bacteria, Fungi, Protozoa, Viruses, and
Parasites among many others.
• Microorganisms are present everywhere as their presence can be
marked in geothermal vents in the ocean depths to the person’s skin.
• They are also present in soil, air, and water
Intro…
• Microorganisms are involved in the production of 50% of Carbon and 90%
of Nitrogen.
• They are involved in different processes like biodegradation, the process of
photosynthesis, the process of digestion, and many other production
processes.
• Society gets to benefit from microorganisms through their use in bread,
cheese, beer, vaccines, and antibiotics production
History of Microbiology
One of the most important discoveries of biology occurred in 1665, with the
help of a crude microscope, when Robert Hooke stated that life’s smallest
structural units were cells.
Antony Van Leeuwenhoek (1632-1723) was the first one to provide
somewhat accurate information about microorganisms.
His microscope had a magnification of 50 – 300X.
NB: He is considered by many as the “Father of Microbiology”
Theory of Spontaneous Generation
• Early beliefs that some forms of life could arise from “Vital forces”
present in nonliving or decomposing matter – Abiogenesis.
• Or simply, organisms can arise from non-living matter.
• Many scientists challenged this theory
Francesco Redi (1626 – 1697)
• John Needham and Lazzaro Spallanzani were still supporting the theory of
spontaneous generation by proving that air carried the germs to the
culture media.
• Schwann, Friedrich Schroder and Von Dusch (1830s) disproved them by
allowing air to enter the flask but only after passing through a heated tube
or sterile wool, so no growth appeared.
• But still some scientists believed in the theory of spontaneous generation.
Pasteur’s Experiment
• These assumptions provoked Louis Pasteur (1822-1895) to settle the
matter once and for all.
• He trapped airborne organisms in cotton, then showed that the piece
of cotton caused microbial growth when placed in a sterile medium.
Then he did another experiment to solve the controversy.
• Louis Pasteur inverted the process of Pasteurization.
• John Tyndall (1820-1893) – dealt a final blow to spontaneous
generation theory in 1877 by demonstrating that omission of dust →
no growth of microorganisms.
• He also provided evidence for heat-resistant forms of bacteria.
• A German botanist Ferdinand Cohn (1828-1898) discovered the
existence of bacterial endospores.
Demonstrations that microorganisms cause
disease
• The first direct demonstration of the role of bacteria in causing
disease came from the study of anthrax by German Physician Robert
Koch (1843-1910).
• His criteria (is still used) to establish the link between a
microorganism and a particular disease that it causes, it is known as
Koch’s postulates.
Koch’s Postulates
• The causative agent must be present in all affected organisms but absent in
healthy individuals.
• The agent must be capable of being isolated and cultured in pure form.
• When the cultured agent is introduced to a healthy organism, the same
disease must occur.
• The same causative agent must be isolated again from the affected host.
Classification
• Classifying microorganisms has always been a challenge for
taxonomists, as they are diverse.
• Some microorganisms are motile like animals, but also have cell walls
and are photosynthetic like plants…
• These observations eventually led them to the development of a
classification scheme, that divided organisms into five kingdoms.
Five Kingdom System
1. Monera
2. Protista
3. Fungi
4. Animalia
5. Plantae
Three Domain System
1. Bacteria
2. Archea
3. Eucarya
Carl Woese in the 1970s proposed
this system.
Bacteria
• Prokaryotes
• They are single-celled organisms
• The cell wall is made of Peptidoglycan
• Abundant in the soil, water, and air and are the normal resident of the skin,
nose, mouth, and intestine.
• Some live in extreme temperatures.
• They have harmful aspects but are usually beneficial as well
Archaea
• These are bacteria but different due to their rRNA sequences
• Cell wall composition is changed as they lack peptidoglycan but contain
lipids.
• Unique feature is that some are methanogens.
• Archaea are found in environments that are too hostile for other life forms.
• No pathogens archaea have yet been identified
Eucarya
• They are multicellular organisms
• The true nucleus is one of the distinguishing features of eukaryotes.
• Contains microbes classified as protists or fungi.
• Animals and plants are also included in this group.
Protists
• These are larger than prokaryotes.
• It includes unicellular algae, protozoa, slime molds and water molds.
Algae
• Most algal species are unicellular, though other algae may form extremely
large multicellular structures.
• All algae contain Chlorophyll in their chloroplast.
• A number of algae produce toxins that are poisonous to humans and other
animals.
• Of note is that, together with cyanobacteria (blue-green algae), it produces
about 75% of the planet’s oxygen
• It also forms the foundation of aquatic food chains.
Protozoa
• They are unicellular nonphotosynthetic protists.
• It seems likely that the ancestors of these protozoa were algae that became
heterotrophs – the nutritional requirements of such organisms are met by organic
compounds.
• Adaptation to a heterotrophic mode of life was somewhat accompanied by loss of
chloroplasts, and algae thus giving rise to the closely related protozoa.
• Similar events have been observed in the laboratory to be the result of either
mutation or physiological adaptation.
Fungi
• They are a diverse group of microorganisms that range from unicellular
fungi (yeasts) to multicellular fungi (molds and mushrooms).
• They absorb nutrients from the environment including organic molecules –
that they use as carbon and energy source.
• They have metabolic capabilities, so many fungi are beneficial in making
bread rise, producing antibiotics, and decomposition of dead organic
matter.
• Though some cause diseases in Humans, Animals, and Plants
• The fungi are nonphotosynthetic protists growing as a mass of branching,
interlacing filaments “Hyphae” known as mycelium.
• The tubes, are made of polysaccharides such as chitin and are homologous
with cell walls. Yeasts, do not form a mycelium but are easily recognized as
fungi by the nature of their sexual reproductive processes.
• The fungi probably represent an evolutionary offshoot of the protozoa;
they are unrelated to the actinomycetes, mycelial bacteria that they
superficially resemble. The major subdivision (phyla) of fungi are
Chytridiomycota, Zygomycota (the Zygomycetes), Ascomycota (the
ascomycetes), Basidiomycota (the basidiomycetes), and the
“deuteromycetes” (or imperfect fungi).
What is the scope of
Microbiology???
Microbiology has both Basic and Applied aspects.
The Basic aspects are concerned with the Biology of microorganisms
themselves and include fields like:
✓ Bacteriology
✓Mycology
✓Phycology
✓Protozoology
✓Microbial cytology and physiology
✓Microbial genetics
✓Molecular biology
✓Microbial ecology
✓Microbial Taxonomy
The applied aspects are concerned with practical problems.
These are;
✓ Disease study
✓ Water and wastewater treatment
✓Food spoilage and food production
✓ Industrial uses of microbes
NB: Medical microbiology, Immunology, Industrial Microbiology, and
Agricultural Microbiology are also widely studied fields of microbiology.

More Related Content

Similar to 1. INTRODUCTION TO MICROBIOLOGY.pdf hpp@

History of microbiology
History of microbiologyHistory of microbiology
History of microbiologyRinaldo John
 
1. Introduction to Microbiology.pdf
1. Introduction to Microbiology.pdf1. Introduction to Microbiology.pdf
1. Introduction to Microbiology.pdfJamesChabu1
 
MICROBIOLOGY QUICK LEARN Food Microbiology Introduction and Development
MICROBIOLOGY QUICK LEARNFood MicrobiologyIntroduction and DevelopmentMICROBIOLOGY QUICK LEARNFood MicrobiologyIntroduction and Development
MICROBIOLOGY QUICK LEARN Food Microbiology Introduction and DevelopmentSaajida Sultaana
 
INTRODUCTION TO MICROBIOLOGY.pptx
INTRODUCTION TO MICROBIOLOGY.pptxINTRODUCTION TO MICROBIOLOGY.pptx
INTRODUCTION TO MICROBIOLOGY.pptxaburageoffrey
 
Bmb 103(Agriultural microbiology)
Bmb 103(Agriultural  microbiology)Bmb 103(Agriultural  microbiology)
Bmb 103(Agriultural microbiology)shivendra kumar
 
Micro1microbiologythescience 1
Micro1microbiologythescience 1Micro1microbiologythescience 1
Micro1microbiologythescience 1Conrad Garan
 
Unit 1 Introduction to Microbiology BSN new.pdf
Unit 1 Introduction to Microbiology BSN new.pdfUnit 1 Introduction to Microbiology BSN new.pdf
Unit 1 Introduction to Microbiology BSN new.pdfDr. Faiza Munir Ch
 
Microbes-Introduction and significance.pptx
Microbes-Introduction and significance.pptxMicrobes-Introduction and significance.pptx
Microbes-Introduction and significance.pptxyogesh301636
 
1.Introduction to Microbiology MRT.pptx
1.Introduction to Microbiology MRT.pptx1.Introduction to Microbiology MRT.pptx
1.Introduction to Microbiology MRT.pptxhabtamu biazin
 
History & Scope of Microbiology SMG
History &  Scope of Microbiology   SMGHistory &  Scope of Microbiology   SMG
History & Scope of Microbiology SMGsajigeorge64
 
History and Scope of Microbiology
History and Scope of MicrobiologyHistory and Scope of Microbiology
History and Scope of MicrobiologyPharmacy Universe
 
CHAPTER 1.docx Microbiology for 2nd year pharm d
CHAPTER 1.docx Microbiology for 2nd year pharm dCHAPTER 1.docx Microbiology for 2nd year pharm d
CHAPTER 1.docx Microbiology for 2nd year pharm dtehseenmalik450
 
1. History and Scope of microbiology (1).pptx
1. History and Scope of microbiology (1).pptx1. History and Scope of microbiology (1).pptx
1. History and Scope of microbiology (1).pptxShaikh Ayesha
 

Similar to 1. INTRODUCTION TO MICROBIOLOGY.pdf hpp@ (20)

History of microbiology
History of microbiologyHistory of microbiology
History of microbiology
 
1. Introduction to Microbiology.pdf
1. Introduction to Microbiology.pdf1. Introduction to Microbiology.pdf
1. Introduction to Microbiology.pdf
 
MICROBIOLOGY QUICK LEARN Food Microbiology Introduction and Development
MICROBIOLOGY QUICK LEARNFood MicrobiologyIntroduction and DevelopmentMICROBIOLOGY QUICK LEARNFood MicrobiologyIntroduction and Development
MICROBIOLOGY QUICK LEARN Food Microbiology Introduction and Development
 
INTRODUCTION TO MICROBIOLOGY.pptx
INTRODUCTION TO MICROBIOLOGY.pptxINTRODUCTION TO MICROBIOLOGY.pptx
INTRODUCTION TO MICROBIOLOGY.pptx
 
Bmb 103(Agriultural microbiology)
Bmb 103(Agriultural  microbiology)Bmb 103(Agriultural  microbiology)
Bmb 103(Agriultural microbiology)
 
Micro1microbiologythescience 1
Micro1microbiologythescience 1Micro1microbiologythescience 1
Micro1microbiologythescience 1
 
Microbial world
Microbial worldMicrobial world
Microbial world
 
Unit 1 Introduction to Microbiology BSN new.pdf
Unit 1 Introduction to Microbiology BSN new.pdfUnit 1 Introduction to Microbiology BSN new.pdf
Unit 1 Introduction to Microbiology BSN new.pdf
 
I_Introduction.pptx
I_Introduction.pptxI_Introduction.pptx
I_Introduction.pptx
 
Microbes-Introduction and significance.pptx
Microbes-Introduction and significance.pptxMicrobes-Introduction and significance.pptx
Microbes-Introduction and significance.pptx
 
1.Introduction to Microbiology MRT.pptx
1.Introduction to Microbiology MRT.pptx1.Introduction to Microbiology MRT.pptx
1.Introduction to Microbiology MRT.pptx
 
History & Scope of Microbiology SMG
History &  Scope of Microbiology   SMGHistory &  Scope of Microbiology   SMG
History & Scope of Microbiology SMG
 
History and Scope of Microbiology
History and Scope of MicrobiologyHistory and Scope of Microbiology
History and Scope of Microbiology
 
The Microbial World
The Microbial WorldThe Microbial World
The Microbial World
 
Ambe 101 @ lec 2
Ambe 101 @ lec 2Ambe 101 @ lec 2
Ambe 101 @ lec 2
 
CHAPTER 1.docx Microbiology for 2nd year pharm d
CHAPTER 1.docx Microbiology for 2nd year pharm dCHAPTER 1.docx Microbiology for 2nd year pharm d
CHAPTER 1.docx Microbiology for 2nd year pharm d
 
1. History and Scope of microbiology (1).pptx
1. History and Scope of microbiology (1).pptx1. History and Scope of microbiology (1).pptx
1. History and Scope of microbiology (1).pptx
 
Microsoft word bs5 bp303-t_pmb_unit_i
Microsoft word   bs5 bp303-t_pmb_unit_iMicrosoft word   bs5 bp303-t_pmb_unit_i
Microsoft word bs5 bp303-t_pmb_unit_i
 
Microbiology 1st
Microbiology 1stMicrobiology 1st
Microbiology 1st
 
Introduction to microbiology
Introduction to microbiologyIntroduction to microbiology
Introduction to microbiology
 

Recently uploaded

Sulphonamides, mechanisms and their uses
Sulphonamides, mechanisms and their usesSulphonamides, mechanisms and their uses
Sulphonamides, mechanisms and their usesVijayaLaxmi84
 
DiskStorage_BasicFileStructuresandHashing.pdf
DiskStorage_BasicFileStructuresandHashing.pdfDiskStorage_BasicFileStructuresandHashing.pdf
DiskStorage_BasicFileStructuresandHashing.pdfChristalin Nelson
 
6 ways Samsung’s Interactive Display powered by Android changes the classroom
6 ways Samsung’s Interactive Display powered by Android changes the classroom6 ways Samsung’s Interactive Display powered by Android changes the classroom
6 ways Samsung’s Interactive Display powered by Android changes the classroomSamsung Business USA
 
MS4 level being good citizen -imperative- (1) (1).pdf
MS4 level   being good citizen -imperative- (1) (1).pdfMS4 level   being good citizen -imperative- (1) (1).pdf
MS4 level being good citizen -imperative- (1) (1).pdfMr Bounab Samir
 
Indexing Structures in Database Management system.pdf
Indexing Structures in Database Management system.pdfIndexing Structures in Database Management system.pdf
Indexing Structures in Database Management system.pdfChristalin Nelson
 
Employablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptxEmployablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptxryandux83rd
 
Jason Potel In Media Res Media Component
Jason Potel In Media Res Media ComponentJason Potel In Media Res Media Component
Jason Potel In Media Res Media ComponentInMediaRes1
 
Farrington HS Streamlines Guest Entrance
Farrington HS Streamlines Guest EntranceFarrington HS Streamlines Guest Entrance
Farrington HS Streamlines Guest Entrancejulius27264
 
The role of Geography in climate education: science and active citizenship
The role of Geography in climate education: science and active citizenshipThe role of Geography in climate education: science and active citizenship
The role of Geography in climate education: science and active citizenshipKarl Donert
 
Paul Dobryden In Media Res Media Component
Paul Dobryden In Media Res Media ComponentPaul Dobryden In Media Res Media Component
Paul Dobryden In Media Res Media ComponentInMediaRes1
 
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 11 (CẢ NĂM) - FRIENDS GLOBAL - NĂM HỌC...
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 11 (CẢ NĂM) - FRIENDS GLOBAL - NĂM HỌC...BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 11 (CẢ NĂM) - FRIENDS GLOBAL - NĂM HỌC...
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 11 (CẢ NĂM) - FRIENDS GLOBAL - NĂM HỌC...Nguyen Thanh Tu Collection
 
CHUYÊN ĐỀ ÔN THEO CÂU CHO HỌC SINH LỚP 12 ĐỂ ĐẠT ĐIỂM 5+ THI TỐT NGHIỆP THPT ...
CHUYÊN ĐỀ ÔN THEO CÂU CHO HỌC SINH LỚP 12 ĐỂ ĐẠT ĐIỂM 5+ THI TỐT NGHIỆP THPT ...CHUYÊN ĐỀ ÔN THEO CÂU CHO HỌC SINH LỚP 12 ĐỂ ĐẠT ĐIỂM 5+ THI TỐT NGHIỆP THPT ...
CHUYÊN ĐỀ ÔN THEO CÂU CHO HỌC SINH LỚP 12 ĐỂ ĐẠT ĐIỂM 5+ THI TỐT NGHIỆP THPT ...Nguyen Thanh Tu Collection
 
4.11.24 Poverty and Inequality in America.pptx
4.11.24 Poverty and Inequality in America.pptx4.11.24 Poverty and Inequality in America.pptx
4.11.24 Poverty and Inequality in America.pptxmary850239
 
The Emergence of Legislative Behavior in the Colombian Congress
The Emergence of Legislative Behavior in the Colombian CongressThe Emergence of Legislative Behavior in the Colombian Congress
The Emergence of Legislative Behavior in the Colombian CongressMaria Paula Aroca
 
DBMSArchitecture_QueryProcessingandOptimization.pdf
DBMSArchitecture_QueryProcessingandOptimization.pdfDBMSArchitecture_QueryProcessingandOptimization.pdf
DBMSArchitecture_QueryProcessingandOptimization.pdfChristalin Nelson
 
Shark introduction Morphology and its behaviour characteristics
Shark introduction Morphology and its behaviour characteristicsShark introduction Morphology and its behaviour characteristics
Shark introduction Morphology and its behaviour characteristicsArubSultan
 

Recently uploaded (20)

Sulphonamides, mechanisms and their uses
Sulphonamides, mechanisms and their usesSulphonamides, mechanisms and their uses
Sulphonamides, mechanisms and their uses
 
DiskStorage_BasicFileStructuresandHashing.pdf
DiskStorage_BasicFileStructuresandHashing.pdfDiskStorage_BasicFileStructuresandHashing.pdf
DiskStorage_BasicFileStructuresandHashing.pdf
 
CARNAVAL COM MAGIA E EUFORIA _
CARNAVAL COM MAGIA E EUFORIA            _CARNAVAL COM MAGIA E EUFORIA            _
CARNAVAL COM MAGIA E EUFORIA _
 
6 ways Samsung’s Interactive Display powered by Android changes the classroom
6 ways Samsung’s Interactive Display powered by Android changes the classroom6 ways Samsung’s Interactive Display powered by Android changes the classroom
6 ways Samsung’s Interactive Display powered by Android changes the classroom
 
MS4 level being good citizen -imperative- (1) (1).pdf
MS4 level   being good citizen -imperative- (1) (1).pdfMS4 level   being good citizen -imperative- (1) (1).pdf
MS4 level being good citizen -imperative- (1) (1).pdf
 
Indexing Structures in Database Management system.pdf
Indexing Structures in Database Management system.pdfIndexing Structures in Database Management system.pdf
Indexing Structures in Database Management system.pdf
 
Employablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptxEmployablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptx
 
Jason Potel In Media Res Media Component
Jason Potel In Media Res Media ComponentJason Potel In Media Res Media Component
Jason Potel In Media Res Media Component
 
Israel Genealogy Research Assoc. April 2024 Database Release
Israel Genealogy Research Assoc. April 2024 Database ReleaseIsrael Genealogy Research Assoc. April 2024 Database Release
Israel Genealogy Research Assoc. April 2024 Database Release
 
Farrington HS Streamlines Guest Entrance
Farrington HS Streamlines Guest EntranceFarrington HS Streamlines Guest Entrance
Farrington HS Streamlines Guest Entrance
 
The role of Geography in climate education: science and active citizenship
The role of Geography in climate education: science and active citizenshipThe role of Geography in climate education: science and active citizenship
The role of Geography in climate education: science and active citizenship
 
Paul Dobryden In Media Res Media Component
Paul Dobryden In Media Res Media ComponentPaul Dobryden In Media Res Media Component
Paul Dobryden In Media Res Media Component
 
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 11 (CẢ NĂM) - FRIENDS GLOBAL - NĂM HỌC...
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 11 (CẢ NĂM) - FRIENDS GLOBAL - NĂM HỌC...BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 11 (CẢ NĂM) - FRIENDS GLOBAL - NĂM HỌC...
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 11 (CẢ NĂM) - FRIENDS GLOBAL - NĂM HỌC...
 
CHUYÊN ĐỀ ÔN THEO CÂU CHO HỌC SINH LỚP 12 ĐỂ ĐẠT ĐIỂM 5+ THI TỐT NGHIỆP THPT ...
CHUYÊN ĐỀ ÔN THEO CÂU CHO HỌC SINH LỚP 12 ĐỂ ĐẠT ĐIỂM 5+ THI TỐT NGHIỆP THPT ...CHUYÊN ĐỀ ÔN THEO CÂU CHO HỌC SINH LỚP 12 ĐỂ ĐẠT ĐIỂM 5+ THI TỐT NGHIỆP THPT ...
CHUYÊN ĐỀ ÔN THEO CÂU CHO HỌC SINH LỚP 12 ĐỂ ĐẠT ĐIỂM 5+ THI TỐT NGHIỆP THPT ...
 
Spearman's correlation,Formula,Advantages,
Spearman's correlation,Formula,Advantages,Spearman's correlation,Formula,Advantages,
Spearman's correlation,Formula,Advantages,
 
4.11.24 Poverty and Inequality in America.pptx
4.11.24 Poverty and Inequality in America.pptx4.11.24 Poverty and Inequality in America.pptx
4.11.24 Poverty and Inequality in America.pptx
 
The Emergence of Legislative Behavior in the Colombian Congress
The Emergence of Legislative Behavior in the Colombian CongressThe Emergence of Legislative Behavior in the Colombian Congress
The Emergence of Legislative Behavior in the Colombian Congress
 
DBMSArchitecture_QueryProcessingandOptimization.pdf
DBMSArchitecture_QueryProcessingandOptimization.pdfDBMSArchitecture_QueryProcessingandOptimization.pdf
DBMSArchitecture_QueryProcessingandOptimization.pdf
 
Teaching Critical AI Literacies - Maha Bali
Teaching Critical AI Literacies - Maha BaliTeaching Critical AI Literacies - Maha Bali
Teaching Critical AI Literacies - Maha Bali
 
Shark introduction Morphology and its behaviour characteristics
Shark introduction Morphology and its behaviour characteristicsShark introduction Morphology and its behaviour characteristics
Shark introduction Morphology and its behaviour characteristics
 

1. INTRODUCTION TO MICROBIOLOGY.pdf hpp@

  • 1. INTRODUCTION TO MICROBIOLOGY (BSPH 112) LECTURE # 1 Dr. Siachinji K. Matthews
  • 2. Introduction • Microbiology (Micro=Small, Biology= Study of life), thus it is the study of agents too small to be seen with the naked eye. • Microorganisms consist of Bacteria, Fungi, Protozoa, Viruses, and Parasites among many others. • Microorganisms are present everywhere as their presence can be marked in geothermal vents in the ocean depths to the person’s skin. • They are also present in soil, air, and water
  • 3. Intro… • Microorganisms are involved in the production of 50% of Carbon and 90% of Nitrogen. • They are involved in different processes like biodegradation, the process of photosynthesis, the process of digestion, and many other production processes. • Society gets to benefit from microorganisms through their use in bread, cheese, beer, vaccines, and antibiotics production
  • 4. History of Microbiology One of the most important discoveries of biology occurred in 1665, with the help of a crude microscope, when Robert Hooke stated that life’s smallest structural units were cells. Antony Van Leeuwenhoek (1632-1723) was the first one to provide somewhat accurate information about microorganisms. His microscope had a magnification of 50 – 300X. NB: He is considered by many as the “Father of Microbiology”
  • 5. Theory of Spontaneous Generation • Early beliefs that some forms of life could arise from “Vital forces” present in nonliving or decomposing matter – Abiogenesis. • Or simply, organisms can arise from non-living matter. • Many scientists challenged this theory
  • 7. • John Needham and Lazzaro Spallanzani were still supporting the theory of spontaneous generation by proving that air carried the germs to the culture media. • Schwann, Friedrich Schroder and Von Dusch (1830s) disproved them by allowing air to enter the flask but only after passing through a heated tube or sterile wool, so no growth appeared. • But still some scientists believed in the theory of spontaneous generation.
  • 8. Pasteur’s Experiment • These assumptions provoked Louis Pasteur (1822-1895) to settle the matter once and for all. • He trapped airborne organisms in cotton, then showed that the piece of cotton caused microbial growth when placed in a sterile medium. Then he did another experiment to solve the controversy. • Louis Pasteur inverted the process of Pasteurization.
  • 9.
  • 10. • John Tyndall (1820-1893) – dealt a final blow to spontaneous generation theory in 1877 by demonstrating that omission of dust → no growth of microorganisms. • He also provided evidence for heat-resistant forms of bacteria. • A German botanist Ferdinand Cohn (1828-1898) discovered the existence of bacterial endospores.
  • 11. Demonstrations that microorganisms cause disease • The first direct demonstration of the role of bacteria in causing disease came from the study of anthrax by German Physician Robert Koch (1843-1910). • His criteria (is still used) to establish the link between a microorganism and a particular disease that it causes, it is known as Koch’s postulates.
  • 12. Koch’s Postulates • The causative agent must be present in all affected organisms but absent in healthy individuals. • The agent must be capable of being isolated and cultured in pure form. • When the cultured agent is introduced to a healthy organism, the same disease must occur. • The same causative agent must be isolated again from the affected host.
  • 13. Classification • Classifying microorganisms has always been a challenge for taxonomists, as they are diverse. • Some microorganisms are motile like animals, but also have cell walls and are photosynthetic like plants… • These observations eventually led them to the development of a classification scheme, that divided organisms into five kingdoms.
  • 14. Five Kingdom System 1. Monera 2. Protista 3. Fungi 4. Animalia 5. Plantae Three Domain System 1. Bacteria 2. Archea 3. Eucarya Carl Woese in the 1970s proposed this system.
  • 15. Bacteria • Prokaryotes • They are single-celled organisms • The cell wall is made of Peptidoglycan • Abundant in the soil, water, and air and are the normal resident of the skin, nose, mouth, and intestine. • Some live in extreme temperatures. • They have harmful aspects but are usually beneficial as well
  • 16. Archaea • These are bacteria but different due to their rRNA sequences • Cell wall composition is changed as they lack peptidoglycan but contain lipids. • Unique feature is that some are methanogens. • Archaea are found in environments that are too hostile for other life forms. • No pathogens archaea have yet been identified
  • 17. Eucarya • They are multicellular organisms • The true nucleus is one of the distinguishing features of eukaryotes. • Contains microbes classified as protists or fungi. • Animals and plants are also included in this group.
  • 18. Protists • These are larger than prokaryotes. • It includes unicellular algae, protozoa, slime molds and water molds.
  • 19. Algae • Most algal species are unicellular, though other algae may form extremely large multicellular structures. • All algae contain Chlorophyll in their chloroplast. • A number of algae produce toxins that are poisonous to humans and other animals. • Of note is that, together with cyanobacteria (blue-green algae), it produces about 75% of the planet’s oxygen • It also forms the foundation of aquatic food chains.
  • 20. Protozoa • They are unicellular nonphotosynthetic protists. • It seems likely that the ancestors of these protozoa were algae that became heterotrophs – the nutritional requirements of such organisms are met by organic compounds. • Adaptation to a heterotrophic mode of life was somewhat accompanied by loss of chloroplasts, and algae thus giving rise to the closely related protozoa. • Similar events have been observed in the laboratory to be the result of either mutation or physiological adaptation.
  • 21. Fungi • They are a diverse group of microorganisms that range from unicellular fungi (yeasts) to multicellular fungi (molds and mushrooms). • They absorb nutrients from the environment including organic molecules – that they use as carbon and energy source. • They have metabolic capabilities, so many fungi are beneficial in making bread rise, producing antibiotics, and decomposition of dead organic matter. • Though some cause diseases in Humans, Animals, and Plants
  • 22. • The fungi are nonphotosynthetic protists growing as a mass of branching, interlacing filaments “Hyphae” known as mycelium. • The tubes, are made of polysaccharides such as chitin and are homologous with cell walls. Yeasts, do not form a mycelium but are easily recognized as fungi by the nature of their sexual reproductive processes. • The fungi probably represent an evolutionary offshoot of the protozoa; they are unrelated to the actinomycetes, mycelial bacteria that they superficially resemble. The major subdivision (phyla) of fungi are Chytridiomycota, Zygomycota (the Zygomycetes), Ascomycota (the ascomycetes), Basidiomycota (the basidiomycetes), and the “deuteromycetes” (or imperfect fungi).
  • 23. What is the scope of Microbiology??? Microbiology has both Basic and Applied aspects.
  • 24. The Basic aspects are concerned with the Biology of microorganisms themselves and include fields like: ✓ Bacteriology ✓Mycology ✓Phycology ✓Protozoology ✓Microbial cytology and physiology ✓Microbial genetics ✓Molecular biology ✓Microbial ecology ✓Microbial Taxonomy
  • 25. The applied aspects are concerned with practical problems. These are; ✓ Disease study ✓ Water and wastewater treatment ✓Food spoilage and food production ✓ Industrial uses of microbes NB: Medical microbiology, Immunology, Industrial Microbiology, and Agricultural Microbiology are also widely studied fields of microbiology.