一株玉米肠致腐菌的16S rDNA鉴定及其防腐剂复配优化

Identification of A Microorganism Strain Isolated from the Corn Sausage by 16S rDNA Sequence Analysis and Optimization of Preservative Mixture

【目的】从发黏、黏稠汁液渗出败坏的玉米肠中分离获得1株导致产品腐败的菌株ym11,为构建控制技术,提高玉米肠安全水平,对该菌进行鉴定和防腐剂优化。【方法】采用16S rDNA序列分析对该菌进行鉴定,并通过MIC测定其对不同防腐剂的敏感性,利用响应曲面法对防腐剂复配进行优化。【结果】该菌属枯草芽孢杆菌属,同源性相似度达97%。对乳酸链球菌素、聚赖氨酸、尼泊金乙酯较敏感,MIC分别为39、39和125mg·L-1。响应曲面优化结果显示,当乳酸链球菌素、聚赖氨酸、尼泊金乙酯浓度分别为11.30、10.90和4.80mg·L-1时,可使基质中的ym11降低2个数量级。【结论】该菌属于枯草芽孢杆菌属,利用复合防腐剂可有效对其杀灭。

【Objective】 A microorganism strain ym11 causing corn sausage to corrupt and become soft and sticky was isolated from the surface of corn sausage in order to construct control technology to assure safety of corn sausage.Authenticate and optimization of preservatives were studied with the ym11 stain.【Method】 The microorganism stain was identified by using the 16S rDNA sequence analysis,and different preservatives were determined by MICs and optimization of preservatives mixture was also studied.【Result】 The result indicated that it was Bacillus subtilis and homologous similarity was 97%.It was more sensitive to nisin,polylysine,ethylparaben,whose MICs were 39mg·L-1,39 mg·L-1,125 mg·L-1,respectively.Optimization result showed that ym11 in the medium could be reduced two logs when the concentrations of nisin,polylysine,and ethylparaben were 11.30 mg·L-1,10.90 mg·L-1,and 4.80 mg·L-1,respectively.【Conclusion】 The ym11 strain belongs to Bacillus subtilis.It can be sterilized effectively by using preservatives mixture.