耐受重金属铅乳酸菌的分离筛选及鉴定

Isolation,screening and identification of lactic acid bacteria tolerance to heavy metal lead

通过对包头尾矿库区、白云鄂博采矿区重金属污染严重区域土壤样品中的乳酸菌进行分离、筛选，共得到62株乳酸菌，并对分离得到的乳酸菌进行耐受铅离子的测定，62株乳酸菌对铅离子均有-定的耐受能力，不同菌株对铅离子的耐受能力有所不同；铅离子浓度为1200~9600mg／L时，随着培养时间的增长，菌株对耐受铅离子的修复能力逐渐增强；30℃下分离得到的菌株对铅离子的修复能力明显优于37℃下分离得到的菌株；菌株BY—Fa4、BG-5193、BG-862等13株菌可在铅离子浓度为7200mg／L的环境下生长，菌株BY—Fal、BY—Fc2、BG-6bl可在铅离子浓度为8400mg/L的环境下生长。实验结果得出筛选得到的13株乳酸菌对铅离子不仅具有较强的耐受能力，而且还具有较强的修复能力。对筛选出13株高耐受铅离子的菌株进行16SrRNA序列分析，鉴定结果为戊糖片球菌2株、清酒乳杆菌1株、食窦魏斯氏菌5株、戊糖乳杆菌2株、植物乳杆菌3株。

A total of 62 strains of lactic acid bacteria was isolated from the soil sample which was polluted by heavy metal collected at Baotou and Baiyun Ebo mine.And by the test of the tolerance of lead ions,the 62 strains of lactic acid bacteria all had the tolerance of lead ions, but different stains had different tolerance capability.With the increasing of culturing time, the capability of strains to repair the lead ions had increased gradually when the concentration of lead ions was 1：200-9600 mg/L. The strains which were isolated at 30 ℃ had better repair capability of lead ions than the strains isolated at 37 ℃.There were 13 strains could survive under the condition of 7200 mg/L concentration of lead ions, and the strains of BY-Fa4, BG-Sb3, BG-Sb2 could survive under the condition of 8400 mg/L concentration of lead ions.It indicated that there were 13 stains of all the lactic acid bacteria which isolated had better capability of both tolerance and repair to lead ions.The 16S rRNA gene of 13 strains was amplified by PCR and were identified as 2 strains of Pediococcus pentosaceus, 1 strain of Lactobacillus sake, 5 strains of Weissella cibaria,2 strains of Lactobacillus pentosus,3 strains of Lactobacillus plantarum.