产阿魏酸酯酶菌株的筛选及其酚酸释放研究

本文采用平板筛菌和牛津杯透明圈试验法筛选具有产阿魏酸酯酶的菌株,将其接种于麸皮中进行固态发酵,采用分光光度法和HPLC法分析发酵麸皮其阿魏酸酯酶活力、总酚酸以及阿魏酸的释放量,并进行个体形态、菌落特征和TIS测序鉴定,结果表明:筛选出一株菌株的阿魏酸酯酶酶活优于其他菌株,在发酵第4 d该菌株的阿魏酸酯酶酶活达最高为163.5 m U/g;而且发酵麸皮释放总酚酸的能力较高,将麸皮的总酚酸量提高6.6倍,其中阿魏酸的量达到0.697%,比没有发酵的麸皮阿魏酸的含量增加了0.22%。对其进行分子鉴定,该菌株与烟曲霉(Aspergillus clavatus)同源性达100%,确认为烟曲霉命名为烟青。将该菌应用于麸皮发酵提高阿魏酸含量,是农副产品增值利用以及药用功能开发的主要研究方向。

Selection of Feruloyl Esterase-producing Strains and Estimation of Phenolic Acid Production

The agar plate screening and Oxford cup testing methods were used to select microorganisms that could produce feruloyl esterase. The isolated strains were inoculated into wheat bran for solid-phase fermentation. Spectrophotometry and High Performance Liquid Chromatorgphy (HPLC) were used to analyze the activity of feruloyl esterase as well as the quantity of total phenolic acid and ferulic acid released in the fermented wheat bran. The individual morphology, colony characteristics, and iternally transcribed spacer (TIS) sequencing analysis, and identification of the strains was performed. The results identified one screened strain with highest feruloyl esterase activity, with a peak value of 163.5 mU/g on the 4th day. In addition, this strain yielded higher amounts of total phenolic acids, with 6.6× increase in fermented wheat bran. Among the total phenolic acids, ferulic acid accounted for 0.697% and its production was enhanced by 0.22% compared to that in unfermented wheat bran. Molecular identification revealed 100% homology of this strain with Aspergillus clavatus, and it was named Yanqing. This strain has potential applications in improving ferulic acid content during wheat bran fermentation in the fields of agriculture, value-adding utilization of sideline products, and medicine.