Evaluation of an Ethanol-Tolerant Acetobacter pasteurianus Mutant Generated by a New Atmospheric and Room Temperature Plasma (ARTP)

A novel atmospheric and room temperature plasma (ARTP) which used helium as the working gas was employed to generate mutants of Acetobacter pasteurianus to improve the ethanol tolerance, which is a poorly characterized industrial strain. The best strain U1-1 was selected after mutagenesis. U1-1 could grow in liquid medium with 11 % ethanol. The production of acetic acid reached 32.83 ± 0.75 g/L, 385.7 % higher than that of the parent strain, meanwhile, U1-1 has stable production. Moreover, the cell membrane permeability were measured by PI assay and the results show that the cell membrane permeability of starting strain (AP-1.01) is significantly higher than U1-1. The better ethanol tolerance of strain U1-1 was maybe due to the decreased membrane permeability.