Plates are incubated at temperatures designed to simulate ambient
environmental conditions. For example, polar and deep-sea samples should be
incubated at ∼5°C. Temperature required for temperate and tropical samples often
result in overgrowth by filamentous fungi, which can be reduced by incubation at
temperatures ∼12°C (Fell, 2001). For taxonomic tests, yeasts are usually incubated
at 25ºC (Buhagiar and Barnett, 1971), although optimum temperatures for growth
are higher for some yeast and lower for others (Watson, 1987).