Q. Physiological Characteristics of molds?

The physiological characteristics of molds will be reviewed only briefly here and will be discussed in more detail subsequently. Moisture Requirements: In general most molds require less available moisture than do most yeasts and bacteria. It has been claimed that below 14 to 15
percent total moisture in flour or some dried fruits will prevent or greatly delay mold growth.

Temperature Requirements: Most molds would be considered mesophillic i.e. able to grow well at ordinary temperature. The optimal temperature for most molds is around 25 to 30°C, but some grow well at 35 to 37°C or above, e.g. Aspergillus spp. And some at still higher temperatures. A number of molds are psychrotophic or psychroduric i.e. they grow fairly well at temperatures of refrigeration, and some can grow slowly at temperatures below freezing. Growth has been reported at as low as - 5 to 10°C. A few are thermophillic; i.e. they have a high optimal temperature.