Identification of nitrile hydratase-producing Rhodococcus ruber TH and characterization of an amiE-negative mutant
Identification of nitrile hydratase-producing Rhodococcus ruber TH and characterization of an amiE-negative mutant
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DOI：
10.1016/j.biortech.2009.07.057
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发表时间：
2010-01-01
影响因子：
11.4
通讯作者：
Shen, Zhongyao
中科院分区：
文献类型：
--
作者：
Ma, Yuchao;Yu, Huimin;Shen, Zhongyao
微生物腈水合酶催化丙烯腈转化为丙烯酰胺是绿色化学研究的热点。在转化过程中，丙烯酸通常通过酰胺酶的生物催化作为副产物积累。从土壤中分离到一株腈水合酶活性较高的菌株，经形态学观察和16 S rRNA基因分析鉴定为红色红球菌（Rhodococcus ruber TH）。一个酰胺酶阴性的重组体，R.橡胶TH 3的研制。其腈水合酶活性比野生型高25%，达到490 +/- 29.2 U/mg干细胞重，而酰胺酶活性低60%。在18 ℃下使用游离细胞作为生物催化剂的丙烯腈水合6小时后。TH 3的丙烯酰胺产量比野生型高23%，而副产物丙烯酸的产量比野生型低87%。这一结果表明菌株TH 3可能具有工业应用价值。(C)2009爱思唯尔有限公司版权所有。
Microbial transformation of acrylonitrile to acrylamide by nitrile hydratase is of great interest to green chemistry. During the transformation, acrylic acid is generally accumulated as a by-product through biocatalysis of amidase. A novel strain with high nitrile hydratase activity was isolated from soil and identified as Rhodococcus ruber TH by morphology and 16S rRNA gene analysis. An amidase-negative recombinant, R. ruber TH3 was constructed. Its nitrile hydratase activity was 25% higher than that of the wild type, reaching 490 +/- 29.2 U/mg dry cell weight, while the amidase activity was 60% lower. After 6 h hydration of acrylonitrile using free cells as biocatalysts at 18 degrees C. acrylamide production by TH3 was 23% higher and the production of the by-product, acrylic acid, was 87% lower than that of the wild type. This result demonstrates that the strain TH3 could be valuable for industrial applications. (C) 2009 Elsevier Ltd. All rights reserved.