Microbes that grow in refrigeration but are not human pathogens are categorized as what?

The correct categorization for microbes that can grow in refrigeration temperatures but are not human pathogens is psychrophiles. These microorganisms thrive at low temperatures, typically between 0°C and 20°C, which allows them to survive and grow in refrigerated environments.

Psychrophiles possess specific adaptations in their cellular structures and metabolic processes that enable them to remain active and reproduce in cold conditions. This characteristic makes them well-suited to environments like refrigerators, where other pathogens that thrive at warmer temperatures may not be able to grow. Their presence is often beneficial for certain food processes, as they can carry out fermentation and spoilage without posing significant health risks to humans.

Other categories such as thermophiles, which prefer high temperatures, and mesophiles, which grow optimally at moderate temperatures (typically around human body temperature), do not apply in this case. Psychrotolerant organisms are similar to psychrophiles but can typically grow at higher temperatures than psychrophiles can tolerate; however, the key distinction is that psychrophiles are specifically adapted to cold environments and encompass those which grow at refrigeration temperatures without being harmful.