Abstract

It has been demonstrated that certain lactic acid bacteria (LAB) can sequester metal ions by binding them to their surfaces. In the present study, lead (Pb)-resistant LAB were isolated from kimchi, a Korean fermented food. A total of 96 different LAB strains were isolated, and 52 strains showed lead resistance. Among them, an LAB strain-96 (L-96) iden-tified as Leuconostoc mesenteroides showed remarkable Pb resistance and removal capacity. The maximum adsorption capacity of this strain calculated using the Langmuir isotherm was 60.6 mg Pb/g. In an in vivo experiment, young male mice were provided with water (A), Pb-water (B), or Pb-water+ L-96 (C) during puberty. Lower glutamate oxaloacetate trans-aminase (GOT) and glutamate pyruvate transaminase (GPT) levels in Pb-exposed male mice that received strain L-96 as a probiotic were suggestive of reduced hepatotoxicity. More-over, feces from mice treated with L-96 contained more Pb than feces from untreated mice. Increased Pb elimination likely reduced internal accumulation, and this hypothesis was supported by significantly lower Pb concentrations in kid-neys and testes of the mice treated with strain L-96. The mo-tility and ATP content of epididymal spermatozoa were par-tially restored if strain L-96 was administered. In conclusion, isolated L-96 LAB had lead-biosorption activity and effi-ciently detoxified lead-poisoned male mice, resulting in re-covering male reproductive function. These results suggest the potential use of LAB as a probiotic to protect humans from the adverse effects of Pb exposure.

• Keywords: fermentation; exopolysaccharides; environmental health; bioremediation; lactic acid bacteria