Heterotrophic nitrification in an acid forest soil: isolation and characterisation of a nitrifying bacterium
Heterotrophic nitrification in an acid forest soil: isolation and characterisation of a nitrifying bacterium
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DOI：
10.1016/s0038-0717(01)00045-1
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发表时间：
2001-08-01
影响因子：
9.7
通讯作者：
Wood, M
中科院分区：
文献类型：
--
作者：
Brierley, EDR;Wood, M
细菌和真菌分离自酸性森林土壤，其中硝化作用通过异养途径发生。在含有β-丙氨酸作为C和N的唯一来源的液体无机盐介质中，土壤的富集导致NO2-和NO3-的形成。在纯培养物中，β-丙氨酸不是所有分离物的硝化作用的合适底物，但当一种细菌（B-D）与真菌共培养时，β-丙氨酸确实支持硝化作用。这种细菌是革兰氏阳性和杆状的，并暂时确定为节杆菌属。细菌B-D能够硝化乙酸铵，并在较小程度上蛋白胨，在纯培养。乙酸铵的硝化作用在无菌土壤溶液中比在无机盐限定培养基中更强。在还原性较低的N中，α-酮戊二肟支持最高的硝化速率，但乙酰丙酮肟和酮丁酸肟的硝化水平低于还原性N。该生物体能够在pH 3下存活和硝化，尽管它与pH小于或等于10的非常酸性的环境隔离。提出由非硝化微生物产生的β-丙氨酸的代谢产物为硝化细菌提供了合适的底物。(C)2001爱思唯尔科技有限公司版权所有。
Bacteria and fungi were isolated from an acid forest soil in which nitrification occurred via a heterotrophic pathway. Enrichment of soil in a liquid inorganic salts medium, containing beta -alanine as the sole source of C and N, led to formation of NO2- and NO3-. In pure culture, beta -alanine was not a suitable substrate for nitrification by my of the isolates, but did support nitrification when one bacterium (B-D) was cocultured with a fungus. This bacterium was gram-positive and rod-shaped and identified provisionally as an Arthrobacter sp. The bacterium B-D was able to nitrify ammonium acetate and, to a lesser extent peptone, in pure culture. Nitrification of ammonium acetate was greater in sterile soil solution than in defined media of inorganic salts. From a less reduced form of N, alpha -ketoglutaric oxime supported the highest rates of nitrification, but nitrification of pyruvic and ketobutyric oximes was at levels lower than from reduced N. The organism was able to survive and nitrify at pH 3, and despite its isolation from a very acidic environment, at pH less than or equal to 10. It is proposed that a metabolic product of beta -alanine produced by a non-nitrifying microorganism provided a suitable substrate for the nitrifying bacterium. (C) 2001 Elsevier Science Ltd. All rights reserved.