Unit III

Two main categories of Growth Requirements

Cold loving microbes

Lowest temperature at which species will grow

Moderate temperature loving microbes

Heat loving microbes

More common than psychrophiles; optimum growth temperature at 20-30°C

Bacteria growing near neutral pH 6.5-7.5

Bacteria tolerant of acidity;thrives on pH 1-5

Process of contraction or shrinkahe of protoplasm and causes cell water loss

Requires high salt concentration for growth

Do not require high salt concentration, but are able to grow at salt concentration higher than normal e.g. 2%—a concentration that inhibits the growth of many other organisms

Half the dry weight of cell

14% and 4% of the total dry weight

Gets most of their carbon source from their energy sources

Structural backbone of all living matter

Essential for the synthesis of nucleic acids

Microbes that use molecular Oxygen (O2)

Organisms that require oxygen to live

Aerobic bacteria that has developed the ability to continue growing in the absence of oxygen

A toxic form of Oxygen that is a normal molecular Oxygen boosted into a higher energy state

Superoxide anions; formed in small amounts during normal respiration

Are bacteria unable to use molecular Oxygen for energy-yielding reaction

Fermentative anaerobes; cannot use oxygen for growth

used to synthesize sulfur-containing amino acids and vitamins such as thiamine and biotin.