Enhancement of haloacetate dehalogenase production by strain mutation and condition optimization |
| |
Authors: | Chun-jiao Lin Li-rong Yang Gang Xu Jian-ping Wu |
| |
Institution: | 1.Department of Chemical and Biological Engineering,Zhejiang University,Hangzhou,China |
| |
Abstract: | Enhancement of the activity of an inducible chloroacetate dehalogenase was carried out by efficient and safe mutation with
UV and microwave irradiation along with optimization of culture conditions. First, a stable mutant of Pseudomonas sp. CGMCC 3267-MW6 with chloroacetate dehalogenase activity of 2.77 U/mL (3-fold higher activity than the wild strain) was
produced by mutation. The maximum activity of this inducible enzyme was measured as 29.41 U/mL when Pseudomonas sp. CGMCC 3267-MW6 was cultured with 4 g/L 3-hydroxybutyrate for 12 h followed by 40 mM 3-chlorobutyrate for an additional
20 h. Production of the enzyme was found to be associated with growth of the bacterium. According to these results, we determined
that the optimum inducer of chloroacetate dehalogenase activity would be a hard degradable substrate. The optimum auxiliary
carbon source would be the primary metabolite of the substrate or the precursor of the metabolite. The optimum time of inducer
supplementation would be during the middle stage of exponential phase. The optimum concentration of substrate would be sufficient
but would not induce inhibition. Finally, the optimum collection time would be at the later stage of exponential phase. This
work provides further knowledge of chloroacetate dehalogenase and the optimization of inducible enzyme production. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|