This document discusses different branches of microbiology including bacteriology, virology, phycology, and mycology. It provides information on each branch such as: Bacteriology studies bacteria morphology, ecology, and biochemistry. Virology is the study of viruses and their classification into groups based on shape. Phycology is the study of algae, which are important primary producers. Mycology is the study of fungi and their characteristics such as being eukaryotic and reproducing through spores.

1. DIFFERENT BRANCHES OF
MICROBIOLOGY
INTRODUCTION TO MICROBIOLOGY
BACTERIOLOGY,VIROLOGY,PHYCOLOGY,MYCOLOGY
BY : ZULEKHA HAFSA
AKHTAR
BSC GENETICS AND
MICROBIOLOGY

2. BACTERIOLOGY

3. Microbiology

4. Branches of microbiology

5. Applications

6. BACTERIOLOGY
Bacteriology is the branch and specialty of biology that studies the morphology, ecology, genetics and biochemistry of bacteria as well as
many other aspects related to them. This subdivision of microbiology involves the identification, classification, and characterization of
bacterial species.
Because of the similarity of thinking and working with microorganisms other than bacteria, such as protozoa, fungi, and viruses, there has
been a tendency for the field of bacteriology to extend as microbiology.
Bacteria are single-celled microorganisms that lack a nuclear membrane, are metabolically active and divide by binary fission.
Medically they are a major cause of disease. Superficially, bacteria appear to be relatively simple forms of life; in fact, they are
sophisticated and highly adaptable. Many bacteria multiply at rapid rates, and different species can utilize an enormous variety of
hydrocarbon substrates, including phenol, rubber, and petroleum. These organisms exist widely in both parasitic and free-living forms.

7. classification
Though to have been the first organisms on earth,
bacteria are prokaryotic cells that lack membrane-
bound organelles. Based on the general structure,
therefore, bacteria are some of the simplest life forms
on earth.
Compared to other organisms, this group of
organisms is also one of the largest on earth
(estimated to be about 5 x 1030). One aspect of
bacteriology entails the identification,
characterization, and classification of these
organisms.
Currently, a number of systems continue to be used
for this classification for identification purposes.

8. Morphology and gram staining
Morphology and Gram staining are two of the most important systems when it comes to bacteria
classification. With regards to morphology, bacteria are classified into three major categories including
Cocci (spherical in shape), Bacilli (rod-shaped), Spiral, and Vibrio which is comma-shaped.
This system of classification makes it easier to identify bacteria based on their general appearance (shape).
On the other hand, Gram staining makes it possible to determine the nature of peptidoglycan of bacteria.
Whereas some bacteria are Gram-positive (bacteria with a thick layer of peptidoglycan) others are Gram-
negative which means that the peptidoglycan layer on their cell wall is very thin.
These characteristics are important in that they can allow bacteriologists to distinguish bacteria based on
their respective structure.

10. virology
Virology is the study of viruses. The first viruses were discovered in 1898 and were identified by
their ability to pass through filters that were too small to allow the passage of bacteria.
Viruses are the most abundant biological entities on Earth and infect all living things, and yet they
are not considered to be alive. They share several characteristics with living organisms, but are
unable to reproduce independently and maintain metabolic activities. In addition, they do not
undergo cell division, like living organisms do, but assemble newly made components from scratch
after gaining entry into a cell and its machinery.
viruses are found in surface and deep sea and lake waters, below the Earth surface, in any type of
soil, in deserts, and in most environments designated as extreme regarding ionic conditions and
temperature

11. classification
● Viruses are classified into four groups based on shape: filamentous, isometric (or icosahedral), enveloped, and head and tail.
● Many viruses attach to their host cells to facilitate penetration of the cell membrane, allowing their replication inside the cell.
● Non-enveloped viruses can be more resistant to changes in temperature, pH, and some disinfectants than are enveloped viruses.
● The virus core contains the small single- or double-stranded genome that encodes the proteins that the virus cannot get from the host
cell.
Key Terms
● capsid: the outer protein shell of a virus
● envelope: an enclosing structure or cover, such as a membrane
● filamentous: Having the form of threads or filaments
● isometric: of, or being a geometric system of three equal axes lying at right angles to each other (especially in crystallography)

12. morphology
Viruses are acellular, meaning they are biological entities that
do not have a cellular structure. Therefore, they lack most of
the components of cells, such as organelles, ribosomes, and
the plasma membrane. A virion consists of a nucleic acid
core, an outer protein coating or capsid, and sometimes an
outer envelope made of protein and phospholipid membranes
derived from the host cell. The capsid is made up of protein
subunits called capsomeres. Viruses may also contain
additional proteins, such as enzymes. The most obvious
difference between members of viral families is their
morphology, which is quite diverse. An interesting feature of
viral complexity is that host and virion complexity are
uncorrelated. Some of the most intricate virion structures are
observed in bacteriophages, viruses that infect the simplest
living organisms: bacteria.

14. phycology
* The word "Phycology" comes from the Greek word "Phykos" which means seaweed.
Cryptogamic plants and consequently, flowering plants originated from algae (prokaryotic
algae)
CLASSIFICATION
The classification of algae has proved to be a complex process that has experienced several revisions over the years.
Several systems have also been proposed based on different aspects of the organisms.
Algae are important as primary producers in aquatic ecosystems. Most algae are eukaryotic, photosynthetic organisms that live in a wet
environment. They are distinguished from the higher plants by a lack of true roots, stems or leaves. They do not flower. Many species are
single-celled and microscopic (including phytoplankton and other microalgae); many others are multicellular to one degree or another, some
of these growing to large size (for example, seaweeds such as kelp and Sargassum).

15. Morphology of algae
Algae exhibit a very wide range of
morphological diversity. The simplest forms
are unicellular, microscopic, motile or non-
motile eukaryotic cells. They may be
spherical (Protococcus, Chlorella), or
pyriform (Chlamydomonas). When motile
(Volvox, Chlamydomonas) the cells are
generally provided with a pair of eukaryotic
flagella. Diatoms show a characteristic type
of non-flagellar locomotion.

17. mycology
mycology, the study of fungi, a group that includes the mushrooms and yeasts. Many fungi are useful in
medicine and industry. Mycological research has led to the development of such antibiotic drugs as penicillin,
streptomycin, and tetracycline, as well as other drugs, including statins (cholesterol-lowering drugs).
Mycology also has important applications in the dairy, wine, and baking industries and in the production of
dyes and inks.

18. fungi
Fungi are highly diverse groups of eukaryotic microorganisms that vary greatly in size, shape, and
complexity. The branching architecture and indeterminate growth of mycelia of terrestrial fungi
optimize foraging ability to explore large soil volumes and exploit heterogeneous and patchily
distributed organic substrates. Various mycelial structures optimize this behavior and also provide
a hardy resting stage when conditions are adverse. Cytoplasmic continuity, even with septa,
provides a mosaic of genetic and phenotypic possibilities within the same organism. Spores are
produced sexually, asexually, or both. In the soil environment, fungi are important as food sources,
pathogens, beneficial symbionts, saprophytes to degrade crop residues, and biotic agents to
improve soil structure and aeration

19. Characteristics of fungi
1. Fungi are eukaryotic, non-vascular, non-motile and
heterotrophic organisms.
2. They may be unicellular or filamentous.
3. They reproduce by means of spores.
4. Fungi exhibit the phenomenon of alternation of
generation.
5. Fungi lack chlorophyll and hence cannot perform
photosynthesis.
6. Fungi store their food in the form of starch.
7. Biosynthesis of chitin occurs in fungi.
8. The nuclei of the fungi are very small.
9. The fungi have no embryonic stage. They develop from
the spores.
10. The mode of reproduction is sexual or asexual.
11. Some fungi are parasitic and can infect the host.
12. Fungi produce a chemical called pheromone which
leads to sexual reproduction in fungi.
13. Examples include mushrooms, moulds, yeast.