湘西陈年腊肉微生物群落分析及高产脂肪酶细菌的筛选

Microbial Flora Analysis of Aged Cured Pork in Western Hunan Province and Screening of a High-Yield Lipase-Producing Strain

为筛选肉源高产脂肪酶菌株,本研究以湘西陈年腊肉为样品,采用稀释平板计数法分析湘西腊肉的微生物结构,利用产脂肪菌株在罗丹明B筛选平板上形成变色圈的方法进行初筛,采用对硝基苯酚棕榈酸酯比色法比较初筛菌株脂肪酶活力进行复筛,通过形态学和分子生物学相结合的方法鉴定复筛菌株。结果表明:湘西陈年腊肉有丰富的微生物群落,是产脂肪酶菌株的良好菌源,酵母菌、霉菌和微球菌是其主要微生物群落;腊肉中的微生物经罗丹明B平板初筛后得1号菌株,变色圈最大为2.6 cm,11、12号菌株次之,为2.4 cm;复筛得酶活力最高的菌株为1号菌株达13.8 U/mL,与初筛预测结果一致,经构建其16S rD NA区域系统发育树,鉴定1号目的菌株为寡养单胞菌属。

To screen a high-yield lipase strain derived from processed meat,the bacterial community structure in aged cured pork in western Hunan province was analyzed by the dilution plate count method and the isolated strains were subjected to two rounds of screening on rhodamine B plates for lipase activity.Lipase activity was colorimetrically determined using p-NPP as a substrate.The screened isolates were identified by morphology and molecular biology techniques.The results showed that abundant microbial communities existed in aged cured pork in western Hunan province,which was a good source of microbial lipase with yeasts,molds and Micrococcus being predominant.Primary screening indicated that strain 1 produced the largest zones（2.6 cm diameter）of discoloration on rhodamine B plates,followed by strains 11 and 12（2.4 cm）.Secondary screening confirmed strain 1 to have the highest lipase activity of 13.8 U/mL.At last a phylogenetic tree was built for the screened strain to identify it as Stenotrophomonas sp.