Divisions of Microbial World

1. MAJOR DIVISIONS OF
MICROBIAL WORLD
By
Nayakanti Bhasker Babu
Research Scholar
CES College of Pharmacy, Kurnool
ANDHRAPRADESH

3. THE WORLD OF BACTERIA I:
ORDINARY GRAM NEGATIVE BACTERIA

4. THE SPIROCHETES
• Flexible, Helical, Periplasmic flagella, Saprophytes or parasites Ex: Treponema,
Borrelia, Leptospira

5. AEROBIC/ MICROAEROPHILIC, MOTILE, HELICAL/VIBRIOD, GRAM-NEGATIVE
• Rigid; motile by polar flagella, oxidative type of metabolism, saprophytes or
parasites Ex: Azospirillum

6. NONMOTILE (RARELY MOTILE), GRAM-NEGATIVE,CURVED BACTERIA
• Rigid; curved, ring-shaped or helical cells lacking flagella; Saprophytes
Ex: Spirosoma, Runella, Flectobacillus

7. AEROBIC GRAM NEGATIVE RODS AND COCCI
• Rigid; Straight or slightly curved (but not helical) rods, cocci; oxidative type of
metabolism; saprophytes and parasites Ex: Pseudomonas

8. FACULTATIVELY ANAEROBIC GRAM – NEGATIVE RODS
• Rigid; straight or curved rods; have both oxidative and fermentative type of
metabolism; saprophytes and parasites Ex: Shigella, Salmonella, Enterobacter

9. ANAEROBIC GRAM-NEGATIVE STRAIGHT, CURVED AND HELICAL RODS
• Rigid ; obtain energy by fermentation or by an anaerobic respiration that does nor
use sulfur compounds as electron acceptors; parasites Ex: Bacteroids fragilis

10. DISSIMILATORY SULFATE OR SULFUR REDUCING BACTERIA
• Rigid; anaerobic; use sulfur compounds as electron acceptors; saprophytes an
parasites Ex:Desulfococcus

11. ANEAROBIC GRAM-NEGATIVE COCCI
• Rigid; nonmotile; fermentative; parasites Ex: Veillonella

12. THE RICKETTSIAS AND CHLAMYDIAS
• Rigid; tiny cells; intracellular parasites of humans, other animals and arthropods, can
be isolated and cultivated in host cells and sometimes on culture media
• Ex: Coxiella

13. THE MYCOPLASMAS
• Soft and plastic; nonmotile; lack cell walls; parasites and saprophytes Ex:
Mycoplasma pneumoniae

14. ENDOSYMBIONTS
• Bacteria – like forms that are obligate parasites of protozoa, arthropods or other
hosts; often beneficial to their hosts; have not been isolated or cultivated
• Ex: Lyticum flagellatum