Breeding of Esterified Monascus Compound Mutagenesis and Optimization of Solid State Fermentation Conditions

In order to obtain high-esterification Monascus,laboratory-prepared Monascus strains were mutated using UV combined with atmospheric pressure room temperature plasma compound mutagenesis,and their solid-state fermentation conditions were optimized through single-factor tests and response surface analysis. Improve the ability of strains to produce esterase. The starting strain N3 was subjected to compound mutagenesis,and the transparent circle method was used for preliminary screening and the esterification enzyme activity determination method was re-screened to obtain a mutant strain Z14 with high esterification enzyme activity and good genetic stability. The enzyme activity was stable to 34.44 U/g,which was 74% higher than the starting strain. The optimized solid-state fermentation conditions obtained by response surface analysis were:Inoculation amount was 5%,water content was 70%,and culture time was 7 days. Under these conditions,the esterase activity of Z14 reached 38.53 U/g,which was 95% higher than the starting strain.