Coupling aerobic biodegradation of methanol vapors with heterologous protein expression of endochitinase Ech42 from Trichoderma atroviride in Pichia pastoris

Methanol is included among the most hazardous air pollutants, and an effort of vapors biofiltration by using microbial consortiums has been reported. The aim of this work was to couple the methanol vapors biodegradation with the production of recombinant endochitinase (ech42) from Trichoderma atroviride in Pichia pastoris transformed with the pPIC-ech42 plasmid. After carrying out batch experiments at 0.5% (w/v) of methanol concentration, the recombinant P. pastoris Mut+ strain was selected because it showed methanol biodegradation rates similar to those of wild type GS115 strain (39 g/m3 h), but 15% higher than the transformed MutS strain. In addition, the recombinant Ech42 protein production was higher in Mut+ than MutS. After various methanol vapor concentrations were evaluated, the maximum recombinant protein recovery was 317 mg/l and the volumetric methanol consumption rate was 88.7 g/m3 h at 0.5% (w/v) of methanol concentration. This research underlines the promising application of linking methanol vapors biodegradation with the production of recombinant protein with high biotechnological interests.