Biosorption of heavy metals by lactic acid bacteria and identification of mercury binding protein

Hideki Kinoshita, Yui Sohma, Fumika Ohtake, Mitsuharu Ishida, Yasushi Kawai, Haruki Kitazawa, Tadao Saito, Kazuhiko Kimura

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73 Citations (Scopus)

Abstract

Heavy metals cause various health hazards. Using lactic acid bacteria (LAB), we tested the biosorption of heavy metals e.g. cadmium (Cd) (II), lead (Pb) (II), arsenic (As) (III), and mercury (Hg) (II). Cd (II) sorption was tested in 103 strains using atomic absorption spectrophotometery (AAS). Weissella viridescens MYU 205 (1×108cells/ml) decreased Cd (II) levels in citrate buffer (pH 6.0) from one ppm to 0.459±0.016ppm, corresponding to 10.46μg of Cd (II). After screening, 11 LAB strains were tested using various pH (pH 4.0, 5.0, 6.0, 7.0) showing the sorption was acid sensitive; and was cell concentration dependent, where the Cd (II) concentration decreased from one ppm to 0.042 (max)/0.255 (min) ppm at 1×1010cells/ml. Additionally, the biosorption of Pb (II), As (III), and Hg (II) were tested using an inductively coupled plasma mass spectrometer (ICP-MS). The Hg (II) concentration was reduced the most followed by Pb (II) and As (III). Many of the bacterial cell surface proteins of W. viridescens MYU 205 showed binding to Hg (II) using the Hg (II) column assay. Having a CXXC motif, a ~14kDa protein may be one of the Hg (II) binding proteins. LAB biosorption may aid the detoxification of people exposed to heavy metals.

Original languageEnglish
Pages (from-to)701-709
Number of pages9
JournalResearch in Microbiology
Volume164
Issue number7
DOIs
Publication statusPublished - 2013 Sep 1

Keywords

  • Biosorption
  • Cadmium
  • Detoxification
  • Heavy metal
  • Lactic acid bacteria
  • Mercury

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology

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