Enzymatic degradation of aliphatic nitriles by Rhodococcus rhodochrous BX2, a versatile nitrile-degrading bacterium
Enzymatic degradation of aliphatic nitriles by Rhodococcus rhodochrous BX2, a versatile nitrile-degrading bacterium
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红红球菌 BX2（一种多功能腈降解细菌）对脂肪族腈的酶促降解
DOI：
10.1016/j.biortech.2015.02.078
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发表时间：
2015-06-01
影响因子：
11.4
通讯作者：
Li, Chunyan
中科院分区：
文献类型：
--
作者：
Fang, Shumei;An, Xuejiao;Li, Chunyan
腈类化合物是常见的环境污染物，其去除越来越受到人们的关注。微生物降解被认为是最可接受的去除方法。本文研究了紫红红球菌BX 2对三种脂肪腈（乙腈、丙烯腈和巴豆腈）的生物降解及其代谢酶的表达。这种微生物可以利用所有三种脂肪族腈作为唯一的碳源和氮源，导致这些化合物的完全降解。降解动力学采用一级动力学模型进行描述。降解效率按t（1/2）排序为：乙腈>反式丁烯腈>丙烯腈>顺式丁烯腈。只有氨积累后的三种腈降解，而酰胺和羧酸是短暂的，并在试验结束时消失。mRNA表达和酶活性表明，测试的脂肪族腈降解通过诱导型腈水解酶/酰胺酶和组成型腈水解酶途径，与前者最有可能首选。(C)2015爱思唯尔有限公司版权所有。
Nitriles are common environmental pollutants, and their removal has attracted increasing attention. Microbial degradation is considered to be the most acceptable method for removal. In this work, we investigated the biodegradation of three aliphatic nitriles (acetonitrile, acrylonitrile and crotononitrile) by Rhodococcus rhodochrous BX2 and the expression of their corresponding metabolic enzymes. This organism can utilize all three aliphatic nitriles as sole carbon and nitrogen sources, resulting in the complete degradation of these compounds. The degradation kinetics were described using a first-order model. The degradation efficiency was ranked according to t(1/2) as follows: acetonitrile > trans-crotononitrile > acrylonitrile > cis-crotononitrile. Only ammonia accumulated following the three nitriles degradation, while amides and carboxylic acids were transient and disappeared by the end of the assay. mRNA expression and enzyme activity indicated that the tested aliphatic nitriles were degraded via both the inducible NHase/amidase and the constitutive nitrilase pathways, with the former most likely preferred. (C) 2015 Elsevier Ltd. All rights reserved.