Spore (bacterial, fungal) Cells 2 types.
1. Vegetative cells
2. Endo spores (spore cells)
1. Vegetative cells:
· Reproductive cells
· Is a metabolically active and growing phase
2. Endo spores :
· Is a dormant stage. (inactive phase)
· They do not have role of reproduction Because:
1. Dryness Heat (temperature) 2. moisture
3. Poor nutrient.
· 4. Metabolically in active, but high resistensive
· When the environmental becomes more favorable the endo spores can reactive itself
vegetative cell.
· Endo spores can survive with out nutrients.
· They are resistance to ultra violet radiation high temperature, extreme freezing and chemical disinfectants
· They are highly resistance environmental stress such as temperature, irradiation, strong acids, disinfection -----etc.
(some endo spores can be boiled for hours and retain their viability)
· Favorable condition back to vegetative cells.
· Endo spore productive bacteria’s
1. Bacillus spp (gram positive rod shaped bacteria)
2. Clostridium spp (Anaerobic gram positive rod shaped bacteria)
Characteristics Vegetative cells Endo spores
1.
|
Water content
|
80-90%
|
10-25%
|
2.
|
pH
|
7
|
5.5 -6.0
|
3.
|
Heat resistance
|
Low
|
high
|
4.
|
Radiation resistance
|
Low
|
high
|
5.
|
Resistance to chemicals
|
Low
|
high
|
(H2O2)and acids.
|
low
|
(thick spore coat
| |
6.
|
Calcium content
|
peptide glycan cell wall)
| |
· Staining Endo spores – (Schaeffer –Fulton method)
