UV-ARTP combined mutagenesis selection of lignin-degrading strain and enzymatic characterization of the resultant organisms

In this study, we selected a strain JC-28 after mutagenesis in preliminary identification. The Ultraviolet-Atmospheric and Room Temperature Plasma (UV-ARTP) combined mutagenesis time was 60 seconds for each, resulting in the screening of 6 positively mutated strains. The enzyme activity and lignin degradation rate of these strains were determined. Eventually, two optimal strains, JC-28-UA26 and JC-28-UA12, were identified. Following genetic stability testing, strain JC-28-UA12 was ultimately chosen, exhibiting a 16.18% increase in lignin degradation rate and relatively good genetic stability. The optimal temperatures for the enzymes Lip, Mnp, and Lac of this strain were 40°C, 40°C, and 50°C, respectively, with optimal pH values of 4, 5, and 3, and relatively good stability. Additionally, metal ions Mg2+, Mn2+, and K+ all enhanced the activity of these three enzymes, while Fe2+ and Hg2+ exhibited some inhibitory effects on them. This study provides valuable insights into the breeding of lignin-degrading bacterial strains.