My vlog is Bacterial spores or endospore are formed by the bacteria in order to survive the adverse environmental conditions.Tge spores are not reproductive structure as a single bacterium will produce only one spores and,in turn,a single spores will produce only single bacterium.The spores are metabolically in active.Tgey are resistant to various environmental conditions like heat, chemical desiccation and starvation.Fgey can. Survive for many years.Once the spores is exposed to favourable environmental conditions like water and nutrients,they will germinate in to the vegetative bacterial cell.

A typical endo spores contain a core which contains the bacterial DNA with small amount of cytoplasm,a cortex, spores coat and exo sporium.The resistance is due to the presence of dipicolinic acid in the core.

Two medically important gram positive bacteria,viz.Bacillus and clostridium,produce endospore.

Bacterial growth

The bacterial growth means the increase in number of bacterial cell.The bacteria multiply by a process called called binary fission.The mean generation time of bacterium is the average time taken by the bacterium to become double. The bacterial growth can be measured by looking into either cell concentration or biomass.The cell concentration may be determined by viable count in which serial dilution of bacterial sample is plated on the bacterial growth medium and finding the colony forming units.Each colony forming unit give the measures of one viable bacterium.On the other hand, the total count is determined by measuring the turbidity of the bacterial sample or counting the cells in the counting chamber under the microscope.

Bacterial Nutrition

A typical bacterial cell contain around 80% of water, protein, polysaccharides, lipids, nucleic acid and other minerals.The basic nutrient that are required for its growth are water, carbon source, nitrogen source and inorganic salts.The water act as the vehicle for the entry of nutrients and elimination of waste material. The bacteria can be classified based on energy requirements as follows

Phototrophs thes are the bacteria that derive energy from sunlight.

Chemotrophs these bacteria derive their energy from chemical reactions.

The bacteria can be classified based on nutritional requirements as follows

Autotrophs these are the bacteria that can synthesis their organic compounds on their own.

Heterotrophs these bacteria cannot synthesis their own organic compounds.Hence they depend on preformed organic compounds from other sources.Most of the pathogenic bacteria belong to heterotrophs.thank you