Investigation of Cr(VI) reduction potential and mechanism by Caldicellulosiruptor saccharolyticus under glucose fermentation condition

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

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Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)585-592
Journal / PublicationJournal of Hazardous Materials
Volume344
Early online date29 Oct 2017
Publication statusPublished - 15 Feb 2018

Abstract

This study examined the microbial reduction of hexavalent chromium [Cr(VI)] by an extremely thermophilic bacterium, Caldicellulosiruptor saccharolyticus, under glucose fermentation conditions at 70 °C. Experimentation with different initial Cr(VI) concentrations confirmed that C. saccharolyticus had the ability to reduce Cr(VI) and immobilize Cr(III). At a concentration of 40 mg/L, Cr(VI) was completely reduced within 12 h, and 97% of the reduction product Cr(III) precipitated on the cell surface. Cr(VI) reduction was accelerated by the addition of neutral red (NR, an electron mediator), resulting in the reduction time shortened to 1 h. The addition of CuCl2, a Ni-Fe hydrogenase inhibitor, also enhanced Cr(VI) reduction. Additionally, analysis of the relationship between Cr(VI) reduction and glucose fermentation suggested that different electron sources acted during CuCl2 and NR conditions. Hydrogen served as an electron donor under normal fermentation and NR conditions with the catalysis of Ni-Fe hydrogenase. However, when the activity of Ni-Fe hydrogenase was inhibited by CuCl2, C. saccharolyticus directly used reduction equivalents during glucose fermentation for intracellular Cr(VI) reduction. Therefore, our findings demonstrated high Cr(VI) reduction ability and different electron transfer pathways during Cr(VI) reduction by C. saccharolyticus.

Research Area(s)

  • Caldicellulosiruptor saccharolyticus, Cr (VI) reduction, Electron transfer, Glucose fermentation, Reduction equivalents

Citation Format(s)

Investigation of Cr(VI) reduction potential and mechanism by Caldicellulosiruptor saccharolyticus under glucose fermentation condition. / Bai, Ya-Nan; Lu, Yong-Ze; Shen, Nan; Lau, Tai-Chu; Zeng, Raymond Jianxiong.

In: Journal of Hazardous Materials, Vol. 344, 15.02.2018, p. 585-592.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review