Synthesis of Ectoine by Whole-cell Catalysis from Recombinant Escherichia Coli

Ectoine is a cyclic amino acid derivative of aspartic acid, which is widely used in the fields such as cosmetics, food, medicine and so on. In this paper, by comparing the synthetic gene clusters ectABC of ectoine from five different sources, it was found that the recombinant strain pYB1s-BPectABC/BW25113 obtained from Bacillus pseudofirmus OF4 had the best ability to produce ectoine when it was integrated into Escherichia coli BW25113. The conditions for whole-cell catalysis of pYB1s-BPectABC/BW25113 were preliminarily optimized by single factor experiment:the pYB1s-BPectABC/BW25113 was reacted with 100 mmol·L^-1 sodium aspartate and 100 mmol·L^-1 glycerine as the substrates in the conversion solution (pH=7.0) of 100 mmol·L^-1 KCl for 24h at 30℃, and the final production of ectoine reached 3.10 g·L^-1, and the transformation efficiency reached 0.129 g·L^-1·h^-1. In this experiment, the ectoine synthetic recombinant strain pYB1s-BPectABC/BW25113 was preliminarily obtained, which laid a foundation for the subsequent researches on ectoine.