2. Introduction
• Microbiology is the study of micro-organisms, those
being unicellular (single cell), multicellular (cell colony),
or acellular (lacking cells).
• Microbiology encompasses numerous branches
including virology, bacteriology, protistology, mycology,
and parasitology.
• Eukaryotic microorganisms possess membrane-
bound organelles and include fungi and protists,
• Whereas prokaryotic organisms, all of which are microorganisms
are conventionally classified as lacking membrane-bound
organelles and include Bacteria and Archaea.
• These micro-organisms may be harmful or beneficial.
3. • The branch microbiology starts from the invention of
microscope.
• “Antonie van leeuwenhoek” invented the first microscope.
• “Robert Hooks” firstly observe the cells from microscope.
• “Antonie van leeuwenhoek” firstly observe the bacterialcells.
• “Ferdinand Cohn” developed the classification scheme of
bacteria, based on shaped.
Such as:
Spherobacteria- spherical shape
Microbacteria- rod shaped
• Desmobacteria- filamentous
• Spirobacteria- spiral shaped
History
4. • “Louis Pasteur” given pasteurization process, germ theory and
developed vaccines.
• “Robert koch” identified the anthrax and discovered the
Mycobacterium tuberculosis, cause tuberculosis. He developed
the agar growth medium.
• “Paul ehrlich” developed the chemotherapy method to cure
disease and antibiotics for sleeping sickness and syphlis.
• “Alexender flaming” discovered the penicillin antibiotic.
• “Ivanovaski” discovered the first virus TMV.
• “Hershey and Chase” identified the genetic material of
Bacteriophage.
5. Characters of M.or.
Morphological Characters
Chemical composition
Cultural Characters
Metabolic Characters
Antigenic Characters
Genetic Characters
Pathogenecity
Ecological characters
6. • Micro-organisms are classified according to particular
characters.
Three domain system of classification
Five kingdom system of classification
Eight kingdom system of classification
Classification of M.or.
7. • ‘Whitaker’ in 1969 given five kingdom classification.
• He classified the organism according to their cell anatomy and
energy yielding system in to five systems.
• Monera, Protista, Fungi, Plantae, Animalia
• All prokaryotic organism kept into monera kingdom
• Unicellular and multicellular organism kept in to protista
kingdom.
• Multicellular eukaryotic kept in fungi kingdom, it is based upon
absorptive mode of nutrition.
• Multicellular eukaryotes kept in animalia and it is based on
ingestion and nutrition mode.
• Plantae kingdom based on photosynthesis mode and it is also
multicellular.
Five kingdom classification
8.
9. • Eight kingdom
classification given by
‘Smith’.
• Organisms are classified
according to ultrastructure
and genetic organization
into two groups: Bacteria
and Eukaryota
• Eubacteria and
Archebacteria were kept in
bacteria group.
• In the eukaryota group,
archea, protozoa, plantae,
chromista, fungi, animalia
were kept.
Eight kingdom classification
10. • ‘Woese’ in 1990 developed the three domain system.
• Bacteria, Archea, Eukarya
Three domain system classification
12. • Micro- organisms are classified according to particular
phenotypic characters.
On the basis of morphology: M.Or. are divided into five
groups.
Bacteria: it may be cocci and bacilli shape.
Actinomycetes: it is filamentous structure.
Spirochaets: it is spiral shaped.
Mycoplasma: it is highly pleomorphic and indifinite shape.
Ricketsia: small, obligate parasite, related to virus.
Classification and Identification of Bacteria
13. On the basis of anatomical features:
Capsule:
• Capsulated- S. Pneumoniae
• Non- capsulated- Viridans streptococci
Flagilla:
• Flagillate - monotrichous, lophotrichous etc.
• Aflagillate - shigella species
Spore:
• Spore forming- bacillus species
• Non- spore forming – e.coli
14. On the basis of staining reaction:
Gram stain:
• Gram +ve cocci- S. aureus
• Gram –ve cocci – Neisseria gonorrhoeae
• Gram +ve rod- Clostridium sp.
• Gram –ve rod- E.coli
Acid fast stain:
• Acid fast bacilli- Mycobacterium tuberculosis
• Non acid fast bacilli- Staphylococcus aureus
15. On the basis of staining reaction:
Temperature:
• Psychrophiles- Pseudomonas fluorescence
• Mesophiles- E.coli, Salmonella enterica
• Thermophiles – Bacillus stearothermophiles
Oxygen dependent:
• Aerobic- require oxygen
• Obligate aerobes- strictly require oxygen for growth
• Facultative anaerobes- grow in the presence or absence of
oxygen
pH:
• Acidophiles- lactobacillus acidophiles
• Alkalophiles- Vibrio
• Neutrophiles- pH 6-8
