BIOLOGY OF MICRO-ORGANISM

BIOLOGY OF MICRO-ORGANISM
@ Bacteria :-
       Prokaryotic, unicelluler, microscopic organism
# Character :-
- Presence of rigid cell wall
- Sometime presence of cell wall
- Cell wall contain acetyl glucosamine and acetyl muronic acid
# Size :-
    Bacteria can be measured - - In micrometer, which is one thousand part of one millimeter
- In millimicron or nanometre is equal to one million of a millimetre
- In angstron unit one tenth part of nanometre
In General, Bacteria are generally 0.2-1.5 micrometre diameter  to 3-5 micrometre in length
# Shape of bacteria :-
1. Cocci = Spherical or oval shaped ,following type
- Diplococci
- Streptococci :-
           In chain group
- Straphylococci :-
         In grape form like cluster
2. Bacilli = Rod shaped cell
- Streptobacillus :-
         Bacilli arranged in chain
3. Vibrio = Comma shaped
4. Spirilla = Rigid spiral form
5. Mycoplasm :-
            Bacteria that have cell wall deficient and hence do not posses a stable morphology, They are round or oval body as interlacing filament
@ Prokaryotic Bacterial Anatomy :-
* Cell wall= Rigid cell wall beneath cytoplasm
* Cell Envelope = Which encloses Protoplasm
* Ribosome present
* Mesosomes present
* Flagella = For locomotion
* Fimbriae = Organ for adhesion
# Cell wall :-
     - which is responsible for bacterial rigidity, ductility. Cell wall can't seen by microscope and not see after staining also,  bUt
1.) demonstrated by plasmolysis when placed in hypertonic solution,  by this cytoplasm loses water by osomosis and get shrink, while the cell wall retain it's original shape and size
2.) By microsussection, in this reaction of specific antibody mechanical rupture of cell differential staining procedure
3.) By electron microscopy bacterial cell wall account for dry weight
Cell wall, carries bacterial antigen that are important in virulance and immunity
# Cytoplasmic Membrane :-
      - It is type of layer linings present inner surface of cell wall
- It form cytoplasm,
- It act as semipermeable membrane  help in controlling inflow and outflow of material
- Chemically this membrane consist lipoprotein and small amount of carbohydrate,
# Ribosome :-
         - it is center of protein synthesis
- 70s type
- With mRNA this Ribosome form linear chain called polysomes
# Mesosomes :-
    -  Vasicular, convoluted or multilaminated structure formed by invagination of plasma Membrane
  - Act as principles sites of respiratory enzyme in bacteria
- They are more prominent in gram positive bacteria
- also called Chondroids
# Nucleus :-
- Demonstrated by Ribonuclease Hydrolysis  ,b'coz in bacteria RNA present as Genetic material
- They seen as Oval, elongated bodies under microscope
- Cell wall consist two or more nuclear body
- Don't have any nuclear membrane
- Genome consist of a single molecule of double standed  Circuler DNA arranged
- Bacterial chromosome is haploid
- Replication by  simple fission
# Capsule :-
   - Viscoid material around cell surface,
- Capsule not stained by basic dye and not visible in gram stain
- Capsule may be readily demonstrated by negative staining in wet films with India ink
# Flagella :-
     -  Long, unbranched, sinouses fluid filament called flagella
- They are organ for locomotion
- They having the distinct part
i) Filament
ii) Hook
iii) Basal body
@ Fungi :-
- They are Eukaryotic protist
- They posses rigid cell wall contain chitin
- Cytoplasmic membrane contain sterols
- They posses true nucleus
- Simplest budding fungus is yeast
- Elongation of cell produces tubular,  thread like structure called hyphae
- Hyphae May be septate or non-septate
- If septa present they have hole for cytoplasmic material
@ Type :-
   On Basis of morphology
1. Yeast :-
      Unicelluler fungi which mainly divide by budding, form smooth colonies
2. Moulds :-
        Filamentous fungi with true mycelium ,which reproduce by different type of spores
Ex:- Dermatophytes
3. Yeast like fungi :-
       Fungi which partly grow on yeast and partly as elongated cell which resemble hyphae
4. Dimorphic Fungi :-
       Fungi causing systematic infection, in host tissue they occur as yeast and in soil they culture as mould
@ Fungi Classification :-
A) On Bases of Spore formation :-
1. Phycomycetes :-
         Fungi having nonseptate hyphae which form endogenous asexual spore
2. Ascomycetes :-
          Are those both yeast and filamentous fungi
3. Basidiomycetes:-
          Are those which form basidiospore.
4. Deuteronomycetes :-
                 This group include fungi whose sexual phase not identified
@ Viruses :-
          Extracelluler inert, microscopic infectious organism which lack tRNA
# Character :-
- Without host they are inert in nature
- Completely depend on host for their reproduction ,multiplication and energy
# Size :-
They are when small so that they can be filterated so they put in separate class which are filterable
- Ultra microscopic :-
         Small can be seen under light microscope
- Elementary Bodies :-
        Larger viruses, can be seen under light microscope
Ex:- Poxvirus
Note:-
Extracelluler infectious virus particle called virion
# Structure and Shape :-
Different shape of virus are
+ Spherical
+ Irregular.
+ Pleomorphic
+ Bullet shape
+ Brick shape
- TMV is Rod shape bacterial virus
# Point :-
         Virion consist essentially of nucleic acid surrounded by a protein coat, the capsid. The capsid with the enclosed nucleic acid is known as the nucleocapsid. The function of the capsid is to protect the nucleic acid form inactivation by nuclease and other delecterous agents in the environment. The capside is composed of a large number of capsomes which form it's morphological unit. The chemical  are polypeptide molecule which are arranged symmetrical to form an inventrabl shell around the nucleic acid core. One of the major function of the capsid is to introduce viral genome into host cell by absorbing readily to cell surface
@ Bacterial differential by Staining :-
1. Simple Staining :-
        Cell stain by single stain reagent to determine shape, size and arrangement
2. Negative Staining :-
        -Staining used to gaining Information about cell shape, cell breakage and refractile inclusion
- This staining technique doesn't stain bacteria but stain background
- Nigrosin or acidic stain used to separated negative charge carrying bacteria from positive charge carrying bacteria
# Advantage :-
      *  In this stain no heat fixing required so cell appear less shrived or distorted
* Capsuled bacteria can be observed by this method
3. Gram Staining :-
            Differential stain developed by Dr. Hans Christian , characterized into 2 type
-

# Staining Differences :-
          Staining responses to the gram stain can be related to chemical and physical differences in their cell wall. The gram negative bacterial cell wall is thin ,complex multilayered structure and contain relatively a high lipid content in addition to protein and mucopeptides .The higher amount of lipid is readily dissolved by alcohol resulting in the formation of larger pore in cell wall which do not close appreciably on dehydration of cell wall protein, thus facilitating the leakage of crystal violets of the bacterium. Which later takes the counter stain and appear red,
- in contrast the gram positive cell wall are thick and chemically simple composed mainly of protein and cross linked mucopolypeptide. When treated with alcohol cause dehydration and closure of cell wall pores thereby not allowing the loss of complex and cell remain purple
# Staining of Endospores ;-
        Some bacteria are capable of changing into dormant structure that are morphologically inactive and do not grow or reproduce, since these structure are formed inside Cell called Endospores in bacteria. These are remarkably resistant to heat radiation, chemical and other agents that are typically lethal to the organism the heat resistance of spores has been linked to their high content of calcium and diplocolinic acid, A single bacterium forms a single spore by process called sporulation, During unfavorable condition Endospores surround impermeable layer of cell spore coat
# Capsule Staining :-
         -Viscous coat around cell structure called capsule
- Structure referred as capsule when stranded arranged in oval and round shape
- capsule usually composed of Polysaccheride
- It gives bacteria resist against phagocytosis cell and also protect from desiccation
# Flagella staining :-
      Locomotory,  fine thread, filamentous structure used for locomotion, originate in cytoplasm and protect out form cell wall are of 4 type
i) monotrichous :-
       Posses single Flagella at one end of cell
ii) Lophotrichous :-
              Flagella at both side
iii) Amphitrichous :-
               Flagella in both side either singly or in tufts
iv) Peritrichous :-
           Possessing Flagella all over surface