Classification of microorganism & their taxonomy

classification of microorganisms, bacilli, arrangement of bacteria, introduction of bacteria

1. Classification of microorganism & their taxonomy Mr.R.R.Patil Dr.Shivajirao Kadam College of Pharmacy, Kasabe digraj, Sangli

2. Classification of microorganisms Taxonomy is the science that deals with the logical arrangement of living thing into categories. The first to group all microorganisms & categories them as either plant or animal by Aristoles in 4 th centure B.C. In 1735 Carolus Linnaeus give the names to thousand of plants & animals & classified them in the kingdom planate & animalia .

3. Before the 18 th century the classification of living organism into two kingdoms one is plant & another is animal. E.H.Hackel (German zoologist) in 1866 was introduced a third kingdom ‘ Protista ’. In Protista included unicellular microorganism those are typically neither plants or animals. In protista contains cellular organisms such as bacteria, algae, fungi & protozoa but viruses (non-cellular organisms) are not included in protista.

4. In 1940 was discovered that, in some cells i.e bacteria the genetic material is not a part of nuclear membrane & it is possible with the help of electron microscope. In other cells i.e algae, fungi, protozoa the nucleus was enclosed in a membrane. On that result the organism was divided into Procaryotes & Eucaryotes . Bacteria are Procaryotic (absence of nuclear membrane) & Fungi, algae, protozoa, plant & animals are Eucarotic (Presence of nuclear membrane).

5. Whittaker’s Five-Kingdom Concept In 1969 Robert H. Whittaker was introduced the classification of living organism. He proposed that all living organisms can be classified under five kingdoms. Those five kingdoms was classified on bases of nutrition & absorption of food materials. The procaryotic organism are included under the kingdom of monera ( lower protista) Those lower protista organism do not have the ingestive mode of nutrition.

6. The unicellular eucaryotic microorganisms are placed in kingdom protista (higher protista). Whittakers explained that some organisms assimilate carbon dioxide by photosynthesis. Some organisms obtained nutrients absorbed from other organisms & some obtained nutrients by way of ingestion. He classified plants, animals, fungi in three separate kingdoms based on the mode of nutrition.

7. In five kingdom concept Whittakers placed all living things into five kingdoms based on cellular organisation & nutritional patterns. Five kingdoms are: Monera, Protista, Fungi, Animalia & Plantae . Kingdom Monera include: all unicellular procaryotes e.g bacteria, cynobacteria . Kingdom Protista include: unicellular eucaryotic cell e.g microalge , protozoa. The multicellular & multinucleate eucaryotic organisms are placed in the Kingdom fungi, Kingdom plante & Kingdom animalia . Those organisms utilized nutrients by absorption, photosynthesis & ingestion respectively.

8. Classification of microorganism into bacteria In 1923, David Bergey , professor of bacteriology at the University of Pennsylvania, and four colleagues published a classification of bacteria that could be used for identification of bacterial species. The Bergey’s Manual of Determinative Bacteriology published by williams & wilkins co. Baltimore, USA (1974). He introduced the classification of bacteria (19 parts) & also give description of all species.

9. Bergeys manual was revised betwn . 1984 & 1989 & published in 4 volumes with a new name as Bergey’s manual of systematic bacteriology. In these 4 volumes bacteria have been classified in 33 sections based on morphological & biochemical characteristics. Bacterial groups are divided into following 4 volumes: Gram-negative bacteria (1984)of general, medical & industrial important. Gram-positive bacteria (1986) other actinomycetes . Gram-negative bacteria (1989) with distinctive properties, cyanobacteria , & archaeobacteria . Actinomycetes (1989) as gram positive filamentous bacteria.

10. In bergey’s manual of systematic bacteriology places all bacteria in kingdom procaryotae which in turns divided into 4 divisions as follows… I st division: (Thin Skin) Gracilicutes In that division included those procaryotes have a complex cell wall structure characteristic of Gram-Negative bacteria (e.g. non-photosynthetic bacteria). II nd division: (Strong Skin) Firmicutes In that division included those procaryotes have a cell wall structure characteristic of Gram-Positive bacteria (e.g. rods, cocci , actinomycetes ).

11. III rd division: (Soft or Tender skin) Tenericutes In that procaryotes lack of cell wall (e.g. mycoplasma ) IV th division: (Skin with faults) Mendosicutes In that procaryotes with unusual cell walls ( e.g archeobacteria ) All the bacteria are classified as kingdom, divisions, class, order, family, tribe, genus, section, series, species & individual. The latest edition of ‘ Bergey’s Manual in 1994.

12. ACETINOMYCETES Acetinomycetes are gram-positive bacteria. It have branching filaments or asexual spores or hyphae . It is gram positive bacteria with fungal morphology. They are non-motile, non-capsulated & filamentous that break into bacillary & coccoid elements forming aerial mycelium & substrate mycelium.

13. Significance of Actinomycetes : They are predominantly the inhabitants of soil & are distribute widely. They play important role in the cycling of organic matter in the soil ecosystem. They stimulate the plant growth & help in the biodegradation of agricultural. They are rich source of antibiotics, enzymes, biosurfactants & enzyme inhibitors. Those are found in soil, water, compost & other extreme environments.

14. BACTERIA Bacteria defined as microscopic single celled organism that can penetrate into healthy tissues & start multiplying into vast numbers. These are unicellular, free living small microorganism which are visible under the light microscope. Those are belongs to kingdom prokaryotae (Monera). They occur in water, soil, air & all natural environments.

15. Size & Shape of Bacteria The size & shape vary between the dimensions of 0.75 to 4.0 µm. The cocci diameter near about 1 µm & bacilli are 1 to 8 µm. They are found in spherical shape i.e coccoid forms or as cylindrical form i.e rod shaped forms.

16. Another tendency of coccoid cells to exhibit growth in aggregates. Accordingly that assembly they again exist in following five manners: As pairs or diplococci . As group of four systematically arranged in a cube or sarcinae . As unorganized array like a bunch of grapes or staphylococci. As chain like a string of beads or streptococci. In that cocci divided into two planes & remain in group of four that is tetrads.

17. Many bacterial species can cause diseases in plants, animals & human begins. Some species plays important role in the natural cycling of elements ( soil fertility). Some species useful in industries for preparation of different compounds.

18. RICKETTSIA Rickettsia was first discovered by Howard Taylor Ricketts in 1909. They are small gram negative bacilli. They have properties of both bacteria & viruses. They usually reside in blood sucking arthropods viz. ticks & lice that essentially serve as either as vector or as primary host. They are obligate intracellular parasites & multiply by binary fission.

19. VIRUSES Viruses are 10 to 100 times smaller than bacteria. Those are non-cellular small microorganism near about 20 to 30 nm in size. Those are only seen under electron microscope. They are obligated intracellular parasites. In viruses contains nucleic acid, DNA or RNA surrounded by sheath of protein. They are responsible for various disease viz. AIDS, hepatitis, polio & chickenpox.

20. THANK YOU