1. Academic Validation
  2. Mechanism of 2,3-butanediol stereoisomers formation in a newly isolated Serratia sp. T241

Mechanism of 2,3-butanediol stereoisomers formation in a newly isolated Serratia sp. T241

  • Sci Rep. 2016 Jan 12;6:19257. doi: 10.1038/srep19257.
Liaoyuan Zhang 1 Zewang Guo 1 Jiebo Chen 1 Quanming Xu 1 Hui Lin 1 Kaihui Hu 1 Xiong Guan 1 Yaling Shen 2
Affiliations

Affiliations

  • 1 Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, College of Life Science, Fujian Agriculture and Forestry University, FuZhou, Fujian province, 350002, PR China.
  • 2 State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, PR China.
Abstract

Serratia sp. T241, a newly isolated xylose-utilizing strain, produced three 2,3-butanediol (2,3-BD) stereoisomers. In this study, three 2,3-butanediol dehydrogenases (BDH1-3) and one glycerol dehydrogenase (GDH) involved in 2,3-BD isomers formation by Serratia sp. T241 were identified. In vitro conversion showed BDH1 and BDH2 could catalyzed (3S)-acetoin and (3R)-acetoin into (2S,3S)-2,3-BD and meso-2,3-BD, while BDH3 and GDH exhibited the activities from (3S)-acetoin and (3R)-acetoin to meso-2,3-BD and (2R,3R)-2,3-BD. Four encoding genes were assembled into E. coli with budA (acetolactate decarboxylase) and budB (acetolactate synthase), responsible for converting pyruvate into acetoin. E. coli expressing budAB-bdh1/2 produced meso-2,3-BD and (2S,3S)-2,3-BD. Correspondingly, (2R,3R)-2,3-BD and meso-2,3-BD were obtained by E. coli expressing budAB-bdh3/gdh. These results suggested four Enzymes might contribute to 2,3-BD isomers formation. Mutants of four genes were developed in Serratia sp. T241. Δbdh1 led to reduced concentration of meso-2,3-BD and (2S,3S)-2,3-BD by 97.7% and 87.9%. (2R,3R)-2,3-BD with a loss of 73.3% was produced by Δbdh3. Enzyme activity assays showed the decrease of 98.4% and 22.4% by Δbdh1 and Δbdh3 compared with the wild strain. It suggested BDH1 and BDH3 played important roles in 2,3-BD formation, BDH2 and GDH have small effects on 2,3-BD production by Serratia sp. T241.

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