Screening and identification of Lactic acid bacteria from Ya'an pickle water to effectively remove Pb²

Heavy metal lead, which enters the human body through food intake, endangers human health. Microbe has the ability of adsorbing heavy metal, among which lactic acid bacteria are promising microbes to adsorb and remove Pb²⁺. The purpose of this study was to screen lactic acid bacteria from Ya'an pickle water to effectively remove Pb²⁺. The 7 strains having strong ability to effectively remove Pb²⁺ were detected. These strains were identified by microscopic examination and 16S rDNA sequencing, 4 strains of Lactobacillus plantarum and 3 strains of Lactobacillus brevis were obtained. Then the bacteria had a blind adsorption effect on Pb²⁺. After microwave digestion, the Pb²⁺ concentration was measured by flame atomic absorption spectrometry. The highest removal reached 82.25%. The adsorption mechanism of lactic acid bacteria was mainly divided into biosorption and bioaccumulation. The 7 strains of lactic acid bacteria could provide potential for detoxification of contaminated foods and reduction of the Pb²⁺ accumulation in the human diet and animal feed. At the same time, this study was helpful to further understand the mechanism of Pb²⁺ being adsorbed by lactic acid bacteria.