In general, the higher the temperature, the more easily microorganisms can grow up to a certain point. Very high and low temperatures both obstruct the enzyme processes microorganisms depend on to survive. Microbes play an important role in climate because they release carbon dioxide into the atmosphere when they eat. Bacteria and their main predators, protists, account for more than 40 times the biomass of all animals on Earth. As a result, they have a huge effect on carbon dioxide emissions. Bacteria break down dead organisms, animal waste, and plant litter to obtain nutrients. But microbes don't just eat nature's waste, they recycle it. The process of decomposition releases chemicals that can be used to build new plants and animals.
Incorrect. We use warmer temps in the lab as the microbes typically studied are from clinical sources. Microbes from soils and the environment grow well at their native temperatures.
e.g. Article A New Medium for the Enumeration and Subculture of Bacteria ...