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

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 1200～9600 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 of7200 mg / L concentration of lead ions,and the strains of BY- Fa4、BG- 5b3、BG- 8b2 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.