Mesophile

A mesophile is an organism that grows best in moderate temperature, neither too hot nor too cold (typically between 15 and 40 °C). The term is mainly applied to microorganisms. It is also used to describe mesophilic anaerobic digestion, which takes place optimally around 37 to 41 °C or at ambient temperatures between 20 to 45 °C, where mesophiles are the primary microorganisms present.