Integrating anaerobic digestion of potato peels to methanol production by methanotrophs immobilized on banana leaves.

In the present study, potato peels were subjected to anaerobic digestion (AD) to produce biogas (methane [CH4] and carbon dioxide), which was subsequently used as a substrate for methanol production by methanotrophs. AD resulted in high yields of up to 170 L CH4/kg total solids (TS) from 250 mL substrate (2% TS, w/v). Under optimized conditions, maximum methanol production of 4.97 and 3.36 mmol/L from raw biogas was observed in Methylocella tundrae and Methyloferula stellata, respectively. Immobilization of methanotrophs on banana leaves showed loading of up to 156 mg dry cell mass/g support. M. tundrae immobilized on banana leaves retained 31.6-fold higher methanol production stability, compared to non-immobilized cells. To the best of our knowledge, this is the first study on immobilization of methanotrophs on banana leaves for producing methanol from potato peels AD-derived biogas. Such integrative approaches may be improved through process up-scaling to achieve sustainable development.