Bacteria are prokaryotic microorganisms, unicellular and without any true branching except in higher bacteria (Actinomycetales) Cocci : Spherical or oval shape Bacilli : Rod shaped cells Vibrios : comma shaped, curved rods possessing vibratory motility Spirilla : rigid forms Spirochete :flexous spiral forms Actinomycetes : branching filamentous bacteria Mycoplasma: cell wall deficient bacteria

1. MORPHOLOGY OF
BACTERIA

2.  Bacteria are prokaryotic microorganisms,
unicellular and without any true branching
except in higher bacteria (Actinomycetales)

4. Shape of Bacteria
 Cocci : Spherical or oval shape
 Bacilli : Rod shaped cells
 Vibrios : comma shaped, curved rods
possessing vibratory motility
Spirilla : rigid forms
Spirochete :flexous spiral forms
Actinomycetes : branching filamentous
bacteria
Mycoplasma: cell wall deficient bacteria

6. Cellular Arrangement
 Cocci arranged in ;
 In pairs : Diplococci
 Group of Four : Tetrad
 Group of eight : Sarcina
 In chains : Streptococci
 In clusters : Staphylococci

7.  Bacilli arranged in;
 Angle to each other or Chinese letter
arrangement
 In chains : Streptobacilli

8. Cell Wall
 Accounts for the shape of bacterial cell and
confers its rigidity and ductility
 10-25nm thick, about 20-30% of dry weight
 Composed of mucopeptide, scaffolding
formed by N-acetyl glucosamine and N-acetyl
muramicacid
 On the basis of staining procedure bacteria
divided into two majour groups and this is
due to their cell wall structure, these are

9. Gram Positive cell wall
 Peptidoglycan: 16-80 nm thick
 Teichoic acid : majour surface antigen, water
soluble polymers, containing Ribotol or
glycerol polymers
 Lipoteichoic acid

11. Gram Negative cell wall
 Lipoprotien layer
 Outer membrane protien (OMP)
 Lipopolysaccharides (LPS)
 Periplasmic space
 Peptidoglycan layer

13. Cell Membrane
 5-10 nm thick
 Chemically it consists of lipid and protien
molecules, steroids are absent, except in
mycoplasma

15. Cytoplasm
 Protoplasmic straming is abent
 Contain ribosomes, mesosomes, inclusions
and vacoules

16. Nucleiod
 No nuclear membrane and nucleolus
 Does not contain basic protein
 Double stranded DNA
 Also contain extra nuclear genetic material in
the cytoplasm known as Plasmid or Episome

17. Capsule and slime layer
 Present in some bacteria
 Demonstrated by negative staining with India
ink
 Enhance virulence
 Protection


19. Flagella
 Made up of Flagellin protein
 3-20 micro meter long
 Arrangement
 Monotrichous
 Amphitrichous
 Lophotrichous
 Peritrichous
 Antigenic

22. Fimbriae
 Hair like appendages
 8 types on the basis of function
 Monmer of Pillin
 Function as organ of adhesion
 Antigenic

24. Spore
 Dormant stage of bacteria
 Produce by Gram positive bacteria only