CLASSIFICATION OF BACTERIA BASED ON SHAPE

1. CLASSIFICATION OF BACTERIA BASED ON SHAPE Dr. K. Thamaraiselvi, Dept. of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli – 620 024, Tamil Nadu, India

2. Bacteria is classified into different types based on their shape • Cocci • Bacilli • Vibrios • Spirilla • Spirochetes • Actinomycetes • Mycoplasmas Source: https://www.quora.com/What-are-the-various-shapes-of-bacteria Dr. K. Thamaraiselvi, Dept. of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli – 620 024, Tamil Nadu, India

3. Cocci cont’d Cocci is derived from kokkos meaning berry in Greek Spherical / Oval cells Mostly spherical and sometimes elongated oval in shape Diameter ranges from 0.5 to 1.0 micrometers. Flat, elongated and oval-shape allows them to have a larger surface area, which allows the bacteria to easily absorb more amount of nutrients. Dr. K. Thamaraiselvi, Dept. of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli – 620 024, Tamil Nadu, India

4. Cocci Cocci is derived from kokkos meaning berry in Greek Spherical / Oval cells Mostly spherical and sometimes elongated oval in shape Diameter ranges from 0.5 to 1.0 micrometers. Flat, elongated and oval-shape allows them to have a larger surface area, which allows the bacteria to easily absorb more amount of nutrients. Dr. K. Thamaraiselvi, Dept. of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli – 620 024, Tamil Nadu, India

5. Coccus • These bacteria are spherical /oval in shape • They are further sub divided into different types based on their arrangement - i) Diplococcus: Coccus in pair. Eg, Neissseria gonorrhoae, Pneumococcus ii) Streptococcus: Coccus in chain. Eg. Streptococcus salivarius iii) Staphylococcus: Coccus in bunch. Eg. Staphylococcus aureus iv) Tetrad: Coccus in group of four. v) Sarcina: Cocus in cubical arrangement of cell. Eg. Sporosarcin Source: https://en.wikipedia.org/wiki/Bacillus_%28shape%29 Dr. K. Thamaraiselvi, Dept. of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli – 620 024, Tamil Nadu, India

6. Bacilli • These are rod shaped bacteria • They are further classified as- i) Coccobacilli ii) Streptobacilli: chain of rod shape bacteria: iii) Comma shaped iv) Chinese letter shaped Source: https://en.wikipedia.org/wiki/Bacillus_%28shape%29 Dr. K. Thamaraiselvi, Dept. of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli – 620 024, Tamil Nadu, India

7. Mycoplasma • They are cell wall lacking bacteria • Also known as PPLO (Pleuropneumonia like organism) • Eg: Mycoplasma pneumoniae Source: http://www.biologydiscussion.com/cell/mycoplasma/mycoplasma-history-habitat-characters-and-cell-structure/23800 Dr. K. Thamaraiselvi, Dept. of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli – 620 024, Tamil Nadu, India

8. Spirochaetes: • They are spiral shaped bacteria Source: http://cronodon.com/BioTech/Bacteria_motility3.html Dr. K. Thamaraiselvi, Dept. of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli – 620 024, Tamil Nadu, India

9. Rickettsiae and Chlamydiae • They are obligate intracellular parasites resemble more closely to viruses than bacteria Dr. K. Thamaraiselvi, Dept. of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli – 620 024, Tamil Nadu, India

10. Actinomycetes • They have filamentous or branching structure • They resemble more closely to fungi than bacteria • Example: Streptomyces Dr. K. Thamaraiselvi, Dept. of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli – 620 024, Tamil Nadu, India