产共轭亚油酸植物乳杆菌的筛选、鉴定与诱变

Screening,Identification and Breeding of Conjugated Linoleic Acid-producing Lactobacillus plantarum by Mutation

从传统泡菜中筛选得到1株乳酸菌lp15能够合成共轭亚油酸(CLA),经16SrRNA全序列分析法和API系统鉴定法鉴定为植物乳杆菌(Lactobacillus plantarum)。利用人工诱变方法,以lp15为出发菌株,采用紫外线、硫酸二乙酯(DES)依次诱变处理,经进一步液体发酵复筛获得多株突变菌株,CLA合成能力较出发菌株提高了29.3%～52.2%。其中lp15-2-1突变菌株为CLA生成能力最高菌株,MRS培养液中添加0.2mg/mLLA培养48h,CLA产量达30.13μg/mL。经气相色谱(GC)检测分析,产物中cis9,trans11-共轭亚油酸(c9,t11-CLA)占76.5%,trans10,cis12-共轭亚油酸(t10,c12-CLA)占23.5%。

A lactic acid bacterial strain,lp15,having the ability to synthesize conjugated linoleic acid（CLA） was isolated from pickle juice samples.The strain lp15 was identified as Lactobacillus plantarum based on full-length 16S rRNA sequence analysis and API system.This strain was treated by ultraviolet and DES to obtain several mutant strains,which exhibited 29.3%-52.2% enhancement for CLA production.The strain lp15-2-1 exhibited the highest CLA productivity,which was up to 30.13 μg/mL after 48 h culture in the MRS medium added with LA at 0.2 mg/mL level.According to gas chromatographic analysis,cis9,trans11-CLA was the predominant compound in the fermentation product,with a relative content of up to 76.5%.trans10,cis12-CLA approximately accounted for 23.5% of the fermentation product.