Cr(VI) removal by Penicillium oxalicum SL2: Reduction with acidic metabolites and form transformation in the mycelium

Bibo Long; Jien Ye; Zhe Ye; Junyu He; Yating Luo; Yige Zhao; Jiyan Shi

doi:10.1016/j.chemosphere.2020.126731

Cr(VI) removal by Penicillium oxalicum SL2: Reduction with acidic metabolites and form transformation in the mycelium

Chemosphere. 2020 Aug:253:126731. doi: 10.1016/j.chemosphere.2020.126731. Epub 2020 Apr 7.

Authors

Bibo Long¹, Jien Ye², Zhe Ye², Junyu He³, Yating Luo², Yige Zhao², Jiyan Shi⁴

Affiliations

¹ Department of Environmental Engineering, Zhejiang University, Hangzhou, Zhejiang, 310058, China; Guangdong Bioengineering Institute (Guangzhou Sugarcane Industry Research Institute), Guangzhou, Guangdong, 510316, China; MOE Key laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
² Department of Environmental Engineering, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
³ Ocean College, Zhejiang University, Zhoushan, Zhejiang, 316021, China.
⁴ Department of Environmental Engineering, Zhejiang University, Hangzhou, Zhejiang, 310058, China; MOE Key laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, Zhejiang, 310058, China. Electronic address: shijiyan@zju.edu.cn.

PMID: 32302907
DOI: 10.1016/j.chemosphere.2020.126731

Abstract

Bioremediation of Cr(VI) contamination using microorganisms is a promising method for reducing its environmental risks. The objective of this study was to clarify Cr(VI) removal by Penicillium oxalicum SL2 in terms of indirect Cr(VI) reduction by metabolites, interaction sites, and form transformation of chromium. Strain SL2 could sequentially remove Cr(VI) in the bioreactor. Oxalic acid produced by the fungus contributed to Cr(VI) reduction. Scanning transmissiony X-ray microscop (STXM) analysis suggested strain SL2 could partly reduce Cr(VI) to Cr(III) in the cell. Amine, carboxyl, and phosphate groups were related to Cr(VI) removal. Chromium K-edge X-ray absorption near edge structure (XANES) analysis implied Cr(III)-Cys potentially acted as an intermediate for the formation of chromium oxalate complexes during the process of treatment. This study would support the application of strain SL2 in Cr(VI) bioremediation and expand knowledge on the interaction of chromium with fungus.

Keywords: Chromium speciation; Cr(VI) reduction; Fungus; Oxalic acid; STXM; XANES.

MeSH terms

Biodegradation, Environmental
Bioreactors / microbiology*
Chromium / analysis*
Chromium / metabolism
Environmental Pollutants / analysis*
Environmental Pollutants / metabolism
Mycelium / metabolism*
Oxalic Acid / analysis*
Oxalic Acid / metabolism
Oxidation-Reduction
Penicillium / metabolism*
Phosphates / analysis

Substances

Environmental Pollutants
Phosphates
Chromium
chromium hexavalent ion
Oxalic Acid