Mesophile

A mesophile is an organism that grows best in moderate temperature, neither too hot nor too cold, typically between 20 and 45 °C (68 and 113 °F). The optimal temperature is 37 °C.The term is mainly applied to microorganisms. Organisms that prefer extreme environments are known as extremophiles. Mesophiles have diverse classifications, belonging to two domains: Bacteria, Archaea, and to kingdom Fungi of domain Eucarya. Mesophiles belonging to the domain Bacteria can either be gram-positive or gram-negative. Gram-positive bacteria have a cell layer made of peptidoglycan and stains purple. Gram-negative bacteria does not contain peptidoglycan and stains red or pink. Oxygen requirements for mesophiles are not just confined to aerobic or anaerobic. There are three basic shapes of mesophiles: coccus, bacillus, and spiral.

The habitats of mesophiles can include cheese and yogurt. They are often included during fermentation of beer and wine making. Since normal human body temperature is 37 °C, the majority of human pathogens are mesophiles, as are most of the organisms comprising the human microbiome.

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