Isolation of Heavy Metal Scavenging Lactic Acid Bacteria

Nowadays micro-dust is a serious problem in Korea. In particular micro-dust contains heavy metals such as Pb (lead) and Cd (cadmium) which negatively effect on human health. In this study, we intended to isolate lactic acid bacteria which can scavenge the heavy metals. Firstly we isolated two lactic acid bacteria which were resistant to Ag, Cu, and Zn (30-100 mM AgNO 3, CuSO 4, ZnSO 4 in MRS broth). The two lactic acid bacteria CJNU 1877 and JG 15 were identified Lactobacillus paracasei and Enterococcus faecium, respectively. Subsequently the strains were inoculated in MRS broth and agar plate where 100 ppm of Pb(NO 3 ) 2 and CdSO 4 were added, respectively. They did grow in the conditions and we found aggregations from 24 h cultures, indicating the strains can absorb the heavy metals, which was further proved by scanning electron microscopy (SEM) and Inductively Coupled Plasma-Optical Emission Spectrometer. Therefore the isolated lactic acid bacteria can be used as a probiotics harboring heavy metal scavenging activity.