Urios Laurent, Michotey Valérie, Intertaglia Laurent, Lesongeur Françoise, Lebaron Philippe
Observatoire Océanologique de Banyuls, Laboratoire ARAGO, Université Pierre et Marie Curie - Paris 6, UMR 7621, F-75005 Paris, France.
Int J Syst Evol Microbiol. 2008 Oct;58(Pt 10):2336-41. doi: 10.1099/ijs.0.64592-0.
Two novel Gram-negative bacteria, designated strains DR41_21(T) and DR41_18(T), were isolated from coastal, surface waters of the north-western Mediterranean Sea. The cells were motile, pleomorphic rods, 2.9 microm long and 0.9 microm wide and formed cream colonies on marine agar medium. The G+C content of the genomic DNA was 60 mol%. Phylogenetic analysis of 16S rRNA gene sequences positioned the isolates in the class Alphaproteobacteria within the family Rhodospirillaceae. The 16S rRNA gene sequence similarity of the two strains was 98.8 % but DNA-DNA hybridization indicated only 55 % relatedness. Strain DR41_21(T) was able to denitrify and possessed nirK and nosZ genes, unlike strain DR41_18(T), which possessed only nirK. These isolates represent two novel species of a new genus, Nisaea gen. nov., for which the names Nisaea denitrificans sp. nov. and Nisaea nitritireducens sp. nov. are proposed. The type strain of Nisaea denitrificans is DR41_21(T) (=DSM 18348(T)=CIP 109265(T)=OOB 129(T)) and the type strain of Nisaea nitritireducens is DR41_18(T) (=DSM 19540(T)=CIP 109601(T)=OOB 128(T)).
从地中海西北部沿海表层水体中分离出两株新的革兰氏阴性菌，分别命名为菌株DR41_21(T)和DR41_18(T)。细胞呈运动性、多形性杆状，长2.9微米，宽0.9微米，在海洋琼脂培养基上形成奶油色菌落。基因组DNA的G+C含量为60摩尔%。16S rRNA基因序列的系统发育分析将这些分离菌株定位在红螺菌科的α-变形菌纲内。两株菌株的16S rRNA基因序列相似性为98.8%，但DNA-DNA杂交显示它们的相关性仅为55%。与仅含有nirK基因的菌株DR41_18(T)不同，菌株DR41_21(T)能够进行反硝化作用，并拥有nirK和nosZ基因。这些分离菌株代表了一个新属——尼萨菌属（Nisaea gen. nov.）的两个新物种，为此提出了反硝化尼萨菌（Nisaea denitrificans sp. nov.）和亚硝酸盐还原尼萨菌（Nisaea nitritireducens sp nov.）这两个名称。反硝化尼萨菌的模式菌株是DR41_21(T)（=DSM 18348(T)=CIP 109265(T)=OOB 129(T)），亚硝酸盐还原尼萨菌的模式菌株是DR41_18(T)（=DSM 19540(T)=CIP 109601(T)=OOB 128(T)）。
