Brandão Pedro F B, Bull Alan T
Research School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK.
Antonie Van Leeuwenhoek. 2003;84(2):89-98. doi: 10.1023/a:1025409818275.
Nitrile metabolising actinomycetes previously recovered from deep-sea sediments and terrestrial soils were investigated for their nitrile transforming properties. Metabolic profiling and activity assays confirmed that all strains catalysed the hydrolysis of nitriles by a nitrile hydratase/amidase system. Acetonitrile and benzonitrile, when used as growth substrates for enzyme induction experiments, had a significant influence on the biotransformation activities towards various nitriles and amides. The specific activities of selected deep-sea and terrestrial acetonitrile-grown bacteria against a suite of nitriles and amides were higher than those of the only other reported marine nitrile-hydrolysing R. erythropolis, isolated from a shallow sediment. The increase of nitrile chain length appeared to have negative influence on the nitrile hydratase activity of acetonitrile-grown bacteria, but the same was not true for benzonitrile-grown bacteria. The nitrile hydratases and amidases were constitutive in 10 of the 16 deep-sea and terrestrial actinomycetes studied, and one strain showed an inducible hydratase and a constitutive amidase. Most of the deep-sea strains had constitutive activities and showed some of the highest activities and broadest substrate specificities of organisms included in this study.
对先前从深海沉积物和陆地土壤中分离出的腈代谢放线菌的腈转化特性进行了研究。代谢谱分析和活性测定证实，所有菌株均通过腈水合酶/酰胺酶系统催化腈的水解。在酶诱导实验中，当乙腈和苯甲腈用作生长底物时，它们对各种腈和酰胺的生物转化活性有显著影响。所选的深海和陆地乙腈生长细菌对一系列腈和酰胺的比活性高于唯一另一种已报道的从浅海沉积物中分离出的海洋腈水解红平红球菌。腈链长度的增加似乎对乙腈生长细菌的腈水合酶活性有负面影响，但对苯甲腈生长细菌则不然。在所研究的16株深海和陆地放线菌中，有10株的腈水合酶和酰胺酶是组成型的，一株显示出可诱导的水合酶和组成型的酰胺酶。大多数深海菌株具有组成型活性，并且在所研究的生物中表现出一些最高的活性和最广的底物特异性。
