Biotechnology Bulletin ›› 2022, Vol. 38 ›› Issue (11): 269-276.doi: 10.13560/j.cnki.biotech.bull.1985.2022-0329

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Screening and Identification of Ethylene-forming Enzymes with High Activity and Thermostability

ZHANG Chen1,2(), ZHANG Tong-tong2,3, LIU Hai-ping2,3()   

  1. 1. Tianjin University of Science and Technology,College of Biotechnology,Tianjin 300457
    2. Center for Chemical Biology,Tianjin Institute of Industrial Biotechnology,Chinese Academy of Science,Tianjin 300308
    3. National Technology Innovation Center of Synthetic Biology,Tianjin 300308
  • Received:2022-03-19 Online:2022-11-26 Published:2022-12-01
  • Contact: LIU Hai-ping E-mail:zhangchen@tib.cas.cn;liu_hp@tib.cas.cn

Abstract:

The ethylene-forming enzyme(EFE)is the potential key enzyme for bioethylene production. Enzyme activity and thermostability are essential for the industrial application. Six candidate genes of ethylene-forming enzymes based on the evolution tree were selected, their expressions and purifications were conducted successfully, and their activity and thermostability were measured. EFEs from Streptomyces bottropensisSbEFE)and Streptomyces turgidiscabiesStEFE)were found to have the highest activity and thermostability. The specific activities of SbEFE and StEFE were 3.23 and 4.23 times of the reported PsEFE, and enzymatic activity remained 95.73% and 88.22%, while PsEFE was completely inactivated under the same condition. Analysis of enzymatic kinetics indicated that by-product catalyzed by SbEFE and StEFE was obviously lower than that by PsEFE. Therefore, SbEFE and StEFE are the enzymes with the highest activity and thermostability in currently found EFEs, which may provide novel foundation for deeply studying catalytic mechanism of EFE and application process.

Key words: ethylene-forming enzyme, catalytic activity, thermostability, ethylene, kinetic parameters