Germination of Endospores

Germination of Endospores

Germination of Endospores - Bacterial spores have no metabolic activity and are adapted for prolonged survival under adverse conditions.spores can remain dormant for several years

Although viability of spores decreases with the passage of time, organisms have been cultured from spores of baciili over 300 years old.

The process by which a spore is converted into a germinative cell is called germination.

Three stages of germination have been distinguished, activation, initiation (germination proper) and outgrowth, or post germinative development.

Activation:

Some bacterial spores germinate spontaneously in a favourable medium.

Others remain dormant even if placed in optimal conditions for germination. Activation may be brought about by traumatic agents such as heat, low pH or an SH compound.

Certain chemicals such as L-alanine, adenosine, glucose and some reducing agents can also bring about activation: Heat shock or heat activation appears to be the most general mechanism for activating spores.

Heating of spores in an aqueous fluid for 15-60 minutes at 65°C results in the activation of most spores. Higher temperatures of 105 to 120°C are requited for thermophilic spores.

Heat activation is a reversible process. The induced germ inability declines if spores are returned to lower temperatures for some days.

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