Sorokin Dimitry Y, van Pelt Sander, Tourova Tatjana P
Winogradsky Institute of Microbiology, Russian Academy of Sciences, Moscow, Russia.
FEMS Microbiol Lett. 2008 Nov;288(2):235-40. doi: 10.1111/j.1574-6968.2008.01353.x. Epub 2008 Sep 16.
Enrichment with isobutyronitrile as the sole carbon, energy and nitrogen source at pH 10, using soda solonchak soils as an inoculum, resulted in the selection of a binary culture consisting of two different spore-forming phenotypes. One of them, strain ANL-iso4, was capable of growth with isobutyronitrile as a single substrate, while the other phenotype only utilized products of isobutyronitrile hydrolysis, such as isobutyroamide and isobutyrate. Strain ANL-iso4 is an obligate alkaliphile and a moderately salt-tolerant bacterium. Apart from isobutyronitrile, it grew on other (C3-C6) aliphatic nitriles at pH 10. Resting cells of ANL-iso4 actively hydrolyzed a number of aliphatic and arylaliphatic nitriles and their corresponding amides. The latter, together with the intermediate formation of amides during nitrile hydrolysis, indicated the presence of a nitrile hydratase/amidase system in the novel bacterium. Although present in an alkaliphilic bacterium, both nitrile- and amide-hydrolyzing activities had a pH optimum within the neutral range, probably due to their intracellular localization. On the basis of phenotypic and phylogenetic analyses, strain ANL-iso4 is proposed as a new species Bacillus alkalinitrilicus sp. nov.
以异丁腈作为唯一的碳源、能源和氮源，在pH值为10的条件下，使用苏打盐土作为接种物进行富集培养，结果筛选出一种由两种不同产孢表型组成的二元培养物。其中之一，菌株ANL-iso4，能够以异丁腈作为单一底物生长，而另一种表型仅利用异丁腈水解产物，如异丁酰胺和异丁酸。菌株ANL-iso4是一种专性嗜碱菌和中度耐盐细菌。除了异丁腈外，它在pH值为10时还能在其他（C3 - C6）脂肪族腈类化合物上生长。ANL-iso4的静止细胞能积极水解多种脂肪族和芳基脂肪族腈类化合物及其相应的酰胺。后者以及腈水解过程中酰胺的中间形成，表明这种新型细菌中存在腈水合酶/酰胺酶系统。尽管存在于嗜碱细菌中，但腈水解和酰胺水解活性的最适pH值都在中性范围内，这可能是由于它们定位于细胞内。基于表型和系统发育分析，菌株ANL-iso4被提议为芽孢杆菌属的一个新物种，命名为嗜碱腈芽孢杆菌（Bacillus alkalinitrilicus sp. nov.）。
