Which of the following bacteria types would thrive in a temperature range suitable for mesophilic digestion?

Mesophilic bacteria are specifically adapted to thrive in moderate temperature ranges, typically between 20°C to 45°C (68°F to 113°F). This temperature range is optimal for the microbial digestion processes commonly employed in wastewater treatment and biogas production. These bacteria play a crucial role in the breakdown of organic materials, making them highly effective in anaerobic digestion.

In contrast, psychrophilic bacteria prefer colder temperatures, usually below 20°C, and are not efficient at breaking down organic matter in warmer conditions. Thermophilic bacteria, on the other hand, thrive at higher temperatures, generally between 45°C to 75°C (113°F to 167°F), which can lead to different digestion characteristics that may not be as efficient for all types of organic materials as mesophilic processes. Hyperthermophilic bacteria require even more extreme temperatures, typically above 80°C (176°F), where mesophilic digestion would not be effective.

Therefore, the correct choice indicates the specific type of bacteria that is best suited for mesophilic digestion in wastewater treatment environments.