Development of whole-cell catalyst system for sulfide biotreatment based on the engineered haloalkaliphilic bacterium

Manqi Zhang; Qiong Xue; Shengjie Zhang; Heng Zhou; Tong Xu; Jian Zhou; Yanning Zheng; Ming Li; Sumit Kumar; Dahe Zhao; Hua Xiang

doi:10.1186/s13568-021-01302-9

Development of whole-cell catalyst system for sulfide biotreatment based on the engineered haloalkaliphilic bacterium

AMB Express. 2021 Oct 24;11(1):142. doi: 10.1186/s13568-021-01302-9.

Authors

Manqi Zhang^{1

2}, Qiong Xue^{1

2}, Shengjie Zhang^{1

2}, Heng Zhou¹, Tong Xu¹, Jian Zhou¹, Yanning Zheng¹, Ming Li¹, Sumit Kumar³, Dahe Zhao⁴, Hua Xiang^{5

6}

Affiliations

¹ State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China.
² University of Chinese Academy of Sciences, 100049, Beijing, China.
³ Enzyme and Microbial Biochemistry Lab, Department of Chemistry, Indian Institute of Technology, Delhi, India.
⁴ State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China. zhaodh@im.ac.cn.
⁵ State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China. xiangh@im.ac.cn.
⁶ University of Chinese Academy of Sciences, 100049, Beijing, China. xiangh@im.ac.cn.

Abstract

Microorganisms play an essential role in sulfide removal. Alkaline absorption solution facilitates the sulfide's dissolution and oxidative degradation, so haloalkaliphile is a prospective source for environmental-friendly and cost-effective biodesulfurization. In this research, 484 sulfide oxidation genes were identified from the metagenomes of the soda-saline lakes and a haloalkaliphilic heterotrophic bacterium Halomonas salifodinae IM328 (=CGMCC 22183) was isolated from the same habitat as the host for expression of a representative sequence. The genetic manipulation was successfully achieved through the conjugation transformation method, and sulfide: quinone oxidoreductase gene (sqr) was expressed via pBBR1MCS derivative plasmid. Furthermore, a whole-cell catalyst system was developed by using the engineered strain that exhibited a higher rate of sulfide oxidation under the optimal alkaline pH of 9.0. The whole-cell catalyst could be recycled six times to maintain the sulfide oxidation rates from 41.451 to 80.216 µmol·min^-1·g^-1 dry cell mass. To summarize, a whole-cell catalyst system based on the engineered haloalkaliphilic bacterium is potentiated to be applied in the sulfide treatment at a reduced cost.

Keywords: Genetic modification; Haloalkaliphilic heterotrophic bacterium; Hydrogen sulfide treatment; Process optimization; Sulfide: quinone oxidoreductase; Whole-cell catalysis.

Abstract

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