Ehrich S, Behrens D, Lebedeva E, Ludwig W, Bock E
Institut für Allgemeine Botanik, Universität Hamburg, Germany.
Arch Microbiol. 1995 Jul;164(1):16-23. doi: 10.1007/BF02568729.
A gram-negative, non-motile, non-marine, nitrite-oxidizing bacterium was isolated from an enrichment culture initiated with a sample from a partially corroded area of an iron pipe of a heating system in Moscow, Russia. The cells were 0.9-2.2 microns x 0.2-0.4 microns in size. They were helical- to vibroid-shaped and often formed spirals with up to three turns 0.8-1.0 micron in width. The organism possessed an enlarged periplasmic space and lacked intracytoplasmic membranes and carboxysomes. The cells tended to excrete extracellular polymers, forming aggregates. The bacterium grew optimally at 39 degrees C and pH 7.6-8.0 in a mineral medium with nitrite as sole energy source and carbon dioxide as sole carbon source. The optimal nitrite concentration was 0.35 mM. Nitrite was oxidized to nitrate stoichiometrically. The doubling time was 12 h in a mineral medium with 7.5 mM nitrite. The cell yield was low; only 0.9 mg protein/l was formed during oxidation of 7.5 mM nitrite. Under anoxic conditions, hydrogen was used as electron donor with nitrate as electron acceptor. Organic matter (yeast extract, meat extract, peptone) supported neither mixotrophic nor heterotrophic growth. At concentrations as low as 0.75 g organic matter/l or higher, growth of nitrite-oxidizing cells was inhibited. The cells contained cytochromes of the b- and c-type. The G+C content of DNA was 56.9 +/- 0.4 mol%. The chemolithoautotrophic nitrite-oxidizer differed from the terrestrial members of the genus Nitrobacter with regard to morphology and substrate range and equaled Nitrospira marina in both characteristics. The isolated bacterium is designated as a new species of the genus Nitrospira.(ABSTRACT TRUNCATED AT 250 WORDS)
从俄罗斯莫斯科一个供暖系统铁管部分腐蚀区域的样本所启动的富集培养物中，分离出了一种革兰氏阴性、无运动性、非海洋性、亚硝酸盐氧化细菌。细胞大小为0.9 - 2.2微米×0.2 - 0.4微米。它们呈螺旋状至弧状，常形成宽度达0.8 - 1.0微米、多达三圈的螺旋。该生物体有扩大的周质空间，缺乏胞内膜和羧酶体。细胞倾向于分泌胞外聚合物，形成聚集体。该细菌在以亚硝酸盐为唯一能源、二氧化碳为唯一碳源的矿物培养基中，于39℃和pH 7.6 - 8.0条件下生长最佳。最佳亚硝酸盐浓度为0.35 mM。亚硝酸盐按化学计量比氧化为硝酸盐。在含有7.5 mM亚硝酸盐的矿物培养基中，倍增时间为12小时。细胞产量低；在7.5 mM亚硝酸盐氧化过程中，仅形成0.9 mg蛋白质/升。在缺氧条件下，氢气用作电子供体，硝酸盐用作电子受体。有机物（酵母提取物、肉提取物、蛋白胨）既不支持兼养生长也不支持异养生长。在低至0.75 g有机物/升或更高浓度时，亚硝酸盐氧化细胞的生长受到抑制。细胞含有b型和c型细胞色素。DNA的G + C含量为56.9±0.4摩尔%。这种化能自养型亚硝酸盐氧化菌在形态和底物范围方面与硝化杆菌属的陆生成员不同，在这两个特征上与海洋硝化螺菌相当。分离出的细菌被指定为硝化螺菌属的一个新物种。（摘要截断于250字）
