MORPHOLOGY OF BACTERIA

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