Enhanced growth-driven stepwise inducible expression system development in haloalkaliphilic desulfurizing Thioalkalivibrio versutus

Moustafa Mohamed Sharshar; Nadia Abdrabo Samak; Xuemi Hao; Tingzhen Mu; Wei Zhong; Maohua Yang; Sumit Peh; Sadaf Ambreen; Jianmin Xing

doi:10.1016/j.biortech.2019.121486

Enhanced growth-driven stepwise inducible expression system development in haloalkaliphilic desulfurizing Thioalkalivibrio versutus

Bioresour Technol. 2019 Sep:288:121486. doi: 10.1016/j.biortech.2019.121486. Epub 2019 May 15.

Authors

Moustafa Mohamed Sharshar¹, Nadia Abdrabo Samak², Xuemi Hao¹, Tingzhen Mu³, Wei Zhong¹, Maohua Yang³, Sumit Peh¹, Sadaf Ambreen⁴, Jianmin Xing⁵

Affiliations

¹ Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences (CAS), Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences (CAS), Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China; Processes Design and Development Department, Egyptian Petroleum Research Institute, Nasr City, 11727 Cairo, Egypt.
³ Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences (CAS), Beijing 100190, China.
⁴ University of Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Genomics and Precision Medicine, Institute of Genomics, CAS, Beijing 100101, China.
⁵ Key Laboratory of Green Process and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences (CAS), Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: jmxing@ipe.ac.cn.

PMID: 31128536
DOI: 10.1016/j.biortech.2019.121486

Abstract

Highly toxic and flammable H₂S gas has become an environmental threat. Because of its ability to efficiently remove H₂S by oxidation, Thioalkalivibrio versutus is gaining more attention. Haloalkaliphilic autotrophs, like the bio-desulfurizing T. versutus, grow weakly. Weak growth makes any trial for developing potent genetic tools required for genetic engineering far from achieved. In this study, the fed-batch strategy improved T. versutus growth by 1.6 fold in maximal growth rate, 9-fold in O.D₆₀₀ values and about 3-fold in biomass and protein productions. The strategy also increased the favorable desulfurization product, sulfur, by 2.7 fold in percent yield and 1.5-fold in diameter. A tight iron-inducible expression system for T. versutus was successfully developed. The system was derived from fed-batch cultivation coupled with new design, build, test and validate (DPTV) approach. The inducible system was validated by toxin expression. Fed-batch cultivation coupled with DPTV approach could be applied to other autotrophs.

Keywords: Bio-desulfurization; Fed-batch cultivation; Inducible regulation system; Promoter engineering; Thioalkalivibrio versutus.

MeSH terms

Biomass
Ectothiorhodospiraceae*
Oxidation-Reduction
Sulfur

Substances

Sulfur