高产洛伐他汀红曲菌的选育及其在红腐乳中的应用

硫酸软骨素酶（ChSase）是一类能将硫酸软骨素（CS）催化裂解为小分子多糖的酶，根据结合的底物种类可分为ChSase ABC，ChSase AC，ChSase B和ChSase C。将普通变形杆菌（Proteus vulgaris）KCTC 2579的硫酸软骨素酶ABC I（ChSase ABC I）与麦芽糖结合蛋白（MBP）融合表达，构建了pMAL-c2x-ChSase ABC I重组载体，并成功在大肠杆菌（Escherichia coli）BL21(DE3)宿主中高效表达。将麦芽糖结合蛋白-硫酸软骨素酶（MBP-ChSase）ABC I固定在聚苯胺载体上，制备生物传感器，并利用循环伏安法对其进行检测。结果表明，MBP-ChSase ABC I酶活和比酶活分别为3 180 IU/L发酵液和76 IU/mg蛋白。选择硫酸软骨素A（CS A）作为酶的反应底物，在最适反应条件下，反应的峰值电流与CS A在浓度0.1 nmol/L～0.1 μmol/L范围内呈线性关系。该生物传感器对底物反应迅速，具有较高的灵敏度，可以进行有效检测。

Screening of high-yield lovastatin Monascus sp. strain and its application in red sufu

Five strains of Monascus sp. (M1-M5) from red kojic rice were identified by morphological observation, physiological and biochemical tests and molecular biology techniques, and the production of lovastatin and citrinin was determined by UPLC-MS/MS, in order to screen excellent strain with high-producing lovastatin and low-producing citrinin. On this basis, the functional red sufu was developed using the strain, and its quality was evaluated by sensory, physical and chemical, and microbial indexes. The results showed that the strains M1, M3, M4, and M5 were all identified as Monascus purpureus, and the strain M2 was identified as Monascus pilosus. Among them, the production of lovastatin in the fermentation broth of strain M2 (15.67 mg/L) was the highest, which was an excellent strain with high-yield lovastatin. The quality indexes of the functional red sufu developed by strain M2 met the requirements of relevant national standards.