SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2024, Vol. 74 ›› Issue (10): 74-82.DOI: 10.1016/j.cjche.2024.05.023

• Full Length Article • 上一篇    下一篇

Identification of genes involved in cadmium-ion tolerance in evolutionary Synechocystis sp. PCC 6803 tolerant to both cadmium and high light

Jie Xiong1,2, Zhengxin Dong1,2, Yaru Xie1,2, Weiwen Zhang1,2,3, Tao Sun1,2,3, Lei Chen1,2   

  1. 1 Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, China;
    2 Frontier Science Center for Synthetic Biology & Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, China;
    3 Center for Biosafety Research and Strategy, Tianjin University, Tianjin 300072, China
  • 收稿日期:2024-04-06 修回日期:2024-05-26 接受日期:2024-05-27 出版日期:2024-10-28 发布日期:2024-06-24
  • 通讯作者: Tao Sun, Tel:+86 22 2740 6394;Fax:+86 22 2740 6364.E-mail:tsun@tju.edu.cn;Lei Chen,E-mail:lchen@tju.edu.cn
  • 基金资助:
    This research was supported by grants from the National Key Research and Development Program of China (2018YFA0903600) as well as the National Natural Science Foundation of China (32371486 and 32270091).

Identification of genes involved in cadmium-ion tolerance in evolutionary Synechocystis sp. PCC 6803 tolerant to both cadmium and high light

Jie Xiong1,2, Zhengxin Dong1,2, Yaru Xie1,2, Weiwen Zhang1,2,3, Tao Sun1,2,3, Lei Chen1,2   

  1. 1 Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, China;
    2 Frontier Science Center for Synthetic Biology & Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, China;
    3 Center for Biosafety Research and Strategy, Tianjin University, Tianjin 300072, China
  • Received:2024-04-06 Revised:2024-05-26 Accepted:2024-05-27 Online:2024-10-28 Published:2024-06-24
  • Contact: Tao Sun, Tel:+86 22 2740 6394;Fax:+86 22 2740 6364.E-mail:tsun@tju.edu.cn;Lei Chen,E-mail:lchen@tju.edu.cn
  • Supported by:
    This research was supported by grants from the National Key Research and Development Program of China (2018YFA0903600) as well as the National Natural Science Foundation of China (32371486 and 32270091).

摘要: Photosynthetic cyanobacteria have shown great potential as “autotrophic cell factories” for the synthesis of fuels and chemicals. However, poor tolerance to various environmental stressors such as high light and heavy metals is an important factor limiting their economic viability. While numerous studies have focused on the tolerance mechanism of cyanobacteria to individual stressors, their response to simultaneous stresses remains to be recovered. To investigate the mechanism of cross tolerance to heavy-metal Cd2+ and high light, the model cyanobacterium Synechocystis sp. PCC 6803 tolerant to both Cd2+ and high light was obtained via about 800 days’ cross-adaptive laboratory evolution. Three evolutionary strains capable of tolerating both 5.5 μmol·L-1 Cd2+ and 600 μmol·m-2·s-1 high light were successfully obtained, achieving about 83% enhancement of Cd2+ tolerance compared with the parent strain. The different response of parent and evolutionary strains to Cd2+ was elucidated via metabolomics. Furthermore, a total of 15 genes that were mutated during evolution were identified by whole-genome re-sequencing. Finally, by single-gene knockout and complementation analysis, four genes including ssl2615, sll1732, ssr1480, and sll1659 involved in the improvement of Cd2+ tolerance under high-light condition were successfully identified. This work explored the tolerance mechanism of Synechocystis sp. PCC 6803 to cadmium under high-light condition and provided valuable reference for deciphering multi-tolerance mechanism of cyanobacteria in the future.

关键词: Synechocystis, Adaptive laboratory evolution, Cross tolerance, Cadmium-ion tolerance

Abstract: Photosynthetic cyanobacteria have shown great potential as “autotrophic cell factories” for the synthesis of fuels and chemicals. However, poor tolerance to various environmental stressors such as high light and heavy metals is an important factor limiting their economic viability. While numerous studies have focused on the tolerance mechanism of cyanobacteria to individual stressors, their response to simultaneous stresses remains to be recovered. To investigate the mechanism of cross tolerance to heavy-metal Cd2+ and high light, the model cyanobacterium Synechocystis sp. PCC 6803 tolerant to both Cd2+ and high light was obtained via about 800 days’ cross-adaptive laboratory evolution. Three evolutionary strains capable of tolerating both 5.5 μmol·L-1 Cd2+ and 600 μmol·m-2·s-1 high light were successfully obtained, achieving about 83% enhancement of Cd2+ tolerance compared with the parent strain. The different response of parent and evolutionary strains to Cd2+ was elucidated via metabolomics. Furthermore, a total of 15 genes that were mutated during evolution were identified by whole-genome re-sequencing. Finally, by single-gene knockout and complementation analysis, four genes including ssl2615, sll1732, ssr1480, and sll1659 involved in the improvement of Cd2+ tolerance under high-light condition were successfully identified. This work explored the tolerance mechanism of Synechocystis sp. PCC 6803 to cadmium under high-light condition and provided valuable reference for deciphering multi-tolerance mechanism of cyanobacteria in the future.

Key words: Synechocystis, Adaptive laboratory evolution, Cross tolerance, Cadmium-ion tolerance