Mesophilen

Mesophilen, in microbiology, refers to organisms that prefer moderate temperatures and grow best in a range roughly between 20 and 45 degrees Celsius, with many having their optimum around 30 to 40 degrees. The term is commonly expressed as mesophile in English, and mesophilic organisms can include bacteria, fungi, and other microbes. Because human body temperature is about 37°C, many mesophiles are adapted to environments associated with animals and humans, including pathogens that cause disease at body temperature.

Mesophilen habitats are diverse. They are found in soil, freshwater and marine environments, decaying organic matter, and a wide range of foods stored at ambient or moderate temperatures. In industry and research, mesophiles are frequently cultured for fermentation, biotechnology, and diagnostic purposes. Notable examples include bacteria such as Escherichia coli, Staphylococcus aureus, and Bacillus subtilis, as well as yeasts like Saccharomyces cerevisiae and molds such as Aspergillus species. These organisms are generally distinguished from psychrophiles, which prefer cold environments, and thermophiles, which thrive at higher temperatures.

The term is used across microbiology and biotechnology to describe growth preferences rather than a strict taxonomic group. Understanding mesophilen organisms aids in predicting their behavior in food safety, clinical contexts, and industrial processes. In some languages, mesophilen is used synonymously with mesophile, reflecting a shared concept of life forms adapted to moderate thermal conditions.