*7.3. Temperature*

The temperature influences the efficacy of MFCs because it affects ORR catalyzed by Pt on the cathode, bacterial kinetics, and the rate of mass transfer of protons through the liquid. MFC experiments are often conducted at about room temperature or somewhat higher (20–35 ◦C). At low temperatures in the range of 4–30 ◦C, MFC functionality requires a longer starting time to provide consistent power cycles and performance. MFCs could not generate significant electricity at temperatures below 15 ◦C, even after a month of operation [151]. Researchers are now focusing their efforts on creating effective MFCs based on thermophilic bacteria as it has an advantage over agri-waste as it also promotes pre-treatment. Thermophilic microorganisms have a high rate of metabolic processes and electron generation, which may be advantageous for their use in MFCs operating at elevated temperatures [152]. Choi et al. (2004) constructed an efficient MFC using thermophilic microorganisms. The authors utilized thermophilic bacteria (*Bacillus licheniformis* and *Bacillus thermoglucosidasius*) to investigate various operational parameters in the MFC system, including redox mediators, temperature, pH, and carbon sources. The authors stated that they produced a significant quantity of power via the use of a redox mediator. Maximum performance was found at 50 ◦C, and cell productivity remained constant at this temperature [153].
