Eubacteria

Overview of Eubacteria kingdom

1. Manjunatha S I M.Sc.(Botany) University of Mysore Eubacteria an overview

2. Contents Introduction General characteristics Classification Distribution Shapes Cellular organization Flagella Bacterial growth Nutrition Reproduction Economic importance Conclusion Reference

3. Introduction B acteria are the simplest, the smallest and the most successful prokaryotic microorganisms . Bacteria were among the first life forms to appear on Earth. The study of bacteria is known as bacteriology a branch of microbiology . The existence of microbial world was unknown until the invention of Microscope at the beginning of 17 th Century, which opened the realm of microorganisms to systematic scientific exploration.

4. General characteristics Cosmopolitan Microscopic in nature Size: 0.5-1.0 μ m Unicellular Prokaryotic type of cellular organization They may be Autotrophic, Heterotrophic, Saprophytic. Cell wall is made up of Peptidoglycan. All cell organelles are absent(except Ribosomes)

5. Chlorophyll pigments, if present, are located within involuted cytoplasmic membranes. Mesosomes are present Ribosomes are abundant (70S) Binary fission is the common method of multiplication T rue sexual reproduction is absent Motile Bacteria may possess one or more flagella.

6. Classification According to Bergey’s Manual of Systematic Bacteriology , 2 nd Edition Eubacteria is divided into 23 Phyla Volume-I covers Deeply branching bacterial groups and Phototrophes Volume-II covers Proteobacteria Volume-III covers The Low G+C Gram Positive Bacteria Volume-IV covers The High G+C Gram Positive Bacteria Volume-V covers Planctomycetes , Spirochaetes , Fibrobacters , Bacteriodetes & Fusobacteria

7. Exists everywhere….!!!!!!! Apart from normal E nvironmental conditions….. Occur in atmosphere to an height of about 6 KM & on the sea floor 5 KM below the mean sea level Exist in Hot springs Can survive below Freezing point of water Tolerate to pH range from 0-11 Can tolerate Pressure of 3000-6000 atm Exist as Free living, Parasitic, Symbiotic

8. Shapes of Eubacteria

9. Cellular organization

10. Cell wall Cell wall is made up of Peptidoglycan or mucopeptide. Thickness varies f rom 50-100 A° Function is purely Mechanical On the basis of cell wall character and Staining technique Bacteria’s are classified into a) Gram Positive Bacteria. b) Gram Negative Bacteria.

11. Surface appendages FLAGELLA : May be many times longer than the bacterial cell. It is a hollow cylindrical strand , made up of protein ‘ flagellin ’ Consists of 3 morphological parts-basal body , hook & filament Based on the number & arrangement of flagella , bacteria are classified into Atrichous ( Lactobacillus ) Monotrichous ( Vibrio ) Cephalotrichous ( Pseudomonas spp ) Lophotrichous ( Spirillum volutans ) Amphitrichous ( Nitrosomonas ) Peritrichous (Salmonella) Flagella

12. Pili : long & sparse , rigid & tubular-made up of special protein called ‘ Pilin ’ used for cell to cell or cell to surface attachment Spinae : Rigid & tubular appendages found in some Gram Positive bacteria . Formed of a single molecule of protein ’ S pinin ’ Helps the bacterium to resist S alinity, pH. temperature etc . PILI FIMBRIAE

13. Bacterial growth Involves 4 stages Lag phase Exponential phase Stationary phase Death phase

14. Nutrition

15. reproduction Asexual reproduction Binary Fission Budding Conidia Cysts & Endospores True sexual reproduction is absent, But sexuality is accomplished by interchange of genetic material. Conjugation Transformation Transduction

16. Binary Fission Budding & Conidia

17. Cysts Endospore

18. Transformation

19. Transduction

20. Conjugation

21. Economic importance Harmful activities Causes many diseases Plants Ring spot of Potato --- Xanthomonas solanacearum Citrus canker --- Xanthomonas citri Soft rot of Mango --- Bacterium cartovorus Tundu of Wheat --- Corynebacterium tritici Blight of Bean --- Pseudomonas phaseolicola Animals Plague --- Yersinia pestis Cholera --- Vibrio cholerae Tuberculosis --- Mycobacterium tuberculosis Typhoid --- Salmonella typhi Gastro-enteritis --- Escherichia coli 2. Food spoilage 3. Denitrification by Bacillus licheniformis , Pseudomonas aeruginosa .

22. Useful activities. Increases soil fertility through Ammonification, Nitrification & Nitrogen fixing process. Used in Dairy industries Degradation of Petroleum Hydrocarbons Used in Retting process Decomposition of Dead organisms Insect control Used in Biotechnology for production of various useful products. To control the Pollution.

23. conclusion Bacteria are the smallest living organism s on the Earth. Though having Prokaryotic cellular organization, they show a greater success in survival than any other living organism . We must give credit to Antony van Leeuwenhoek for his discovery which opened the doors of scientific exploration in microbial world. Through their activities Humans are getting many benefits Economically

24. references Prescott−Harley− Klein, Microbiology , 5 th Edition The McGraw−Hill Companies , 2002 Singh Pande Jain, Textbook of Botany, 4 th Edition, Rastogi Publications, Meerut 2011 www.googleimages.com

25. Thank you