Combined fermentation and ARTP mutagenesis to enhance lipase activity of Penicillium camembertii and its application for high-purity 1,3-diacylglycerol preparation.

Penicillium camembertii lipase (PCL) is a glycerol-biased enzyme isolated from P. camembertii, exhibiting high esterification activity. The PCL activity was enhanced by combining fermentation optimization with atmospheric and room temperature plasma (ARTP) mutagenesis. Following multiple rounds of high-throughput screening and serial passages, a genetically stable mutant, P12, was obtained. In shake flask culture, P12 exhibited a lipase activity of 1600 U/g, representing an 800 % increase compared to the wild type (WT), with improved thermostability and methanol stability. Subsequently, P12 was used as a whole-cell biocatalyst to catalyze the esterification of oleic acid with glycerol in a solvent-free system to prepare 1,3-diacylglycerol (1,3-DAG). With an oleic acid /glycerol molar ratio of 4:1, 8 % biocatalyst, and a reaction temperature of 40 °C, the content of 1,3-DAG was 74.7 % after 24 h. These results suggest that the mutant P12 demonstrates considerable potential as a whole-cell biocatalyst for synthesizing high-purity 1,3-DAG.