At what temperature do mesophilic organisms grow optimally?

Mesophilic organisms thrive optimally at temperatures between 30℃ and 38℃. These microorganisms play a crucial role in biological wastewater treatment processes, such as activated sludge systems and anaerobic digestion. The term "mesophilic" refers to heat-loving organisms that prefer moderate temperatures, which provide an ideal environment for their metabolic activities.

At temperatures within this range, mesophilic bacteria can effectively decompose organic matter, which is vital for reducing the biochemical oxygen demand (BOD) in wastewater treatment. The activity of these organisms is not only influenced by temperature but also by factors like pH, nutrient availability, and the presence of toxic substances. Therefore, ensuring that the temperature remains within the optimal range fosters the health and efficiency of the microbial community responsible for breaking down pollutants in water treatment systems.

In contrast, the other temperature ranges are either too low or too high for mesophilic growth. Temperatures below 30℃ may slow down microbial activity, while those above 38℃ could shift the environment to favor thermophilic organisms instead, which thrive at higher temperatures and have different metabolic processes.