Department of Biology, Pacific Lutheran University, Tacoma, WA 98447, USA.
Department of Special Bacteriology, Washington State Department of Health, Shoreline, WA 98155, USA.
Int J Syst Evol Microbiol. 2010 Jan;60(Pt 1):84-92. doi: 10.1099/ijs.0.007773-0. Epub 2009 Jul 31.
A gas-vacuolate bacterium, strain 174(T), was isolated from a sea-ice core collected from Point Barrow, Alaska, USA. Comparative analysis of 16S rRNA gene sequences showed that this bacterium was most closely related to Psychromonas ingrahamii 37(T), with a similarity of >99 %. However, strain 174(T) could be clearly distinguished from closely related species by DNA-DNA hybridization; relatedness values determined by two different methods between strain 174(T) and P. ingrahamii 37(T) were 58.4 and 55.7 % and those between strain 174(T) and Psychromonas antarctica DSM 10704(T) were 46.1 and 33.1 %, which are well below the 70 % level used to define a distinct species. Phenotypic analysis, including cell size (strain 174(T) is the largest member of the genus Psychromonas, with rod-shaped cells, 8-18 microm long), further differentiated strain 174(T) from other members of the genus Psychromonas. Strain 174(T) could be distinguished from its closest relative, P. ingrahamii, by its utilization of D-mannose and D-xylose as sole carbon sources, its ability to ferment myo-inositol and its inability to use fumarate and glycerol as sole carbon sources. In addition, strain 174(T) contained gas vacuoles of two distinct morphologies and grew at temperatures ranging from below 0 to 10 degrees C and its optimal NaCl concentration for growth was 3.5 %. The DNA G+C content was 40 mol%. Whole-cell fatty acid analysis showed that 16 : 1omega7c and 16 : 0 comprised 44.9 and 26.4 % of the total fatty acid content, respectively. The name Psychromonas boydii sp. nov. is proposed for this novel species, with strain 174(T) (=DSM 17665(T) =CCM 7498(T)) as the type strain.
一株气液泡细菌，菌株 174(T)，从美国阿拉斯加巴罗角采集的海冰芯中分离得到。16S rRNA 基因序列的比较分析表明，该细菌与 Psychromonas ingrahamii 37(T)最为密切相关，相似度>99%。然而，通过 DNA-DNA 杂交，菌株 174(T)可以与密切相关的物种清楚地区分开来；通过两种不同方法确定的菌株 174(T)与 P. ingrahamii 37(T)之间的相关性值分别为 58.4%和 55.7%，菌株 174(T)与 Psychromonas antarctica DSM 10704(T)之间的相关性值分别为 46.1%和 33.1%，这些值均远低于用于定义不同物种的 70%水平。表型分析，包括细胞大小（菌株 174(T)是 Psychromonas 属中最大的成员，具有杆状细胞，长 8-18 微米），进一步将菌株 174(T)与 Psychromonas 属的其他成员区分开来。菌株 174(T)可以通过其利用 D-甘露糖和 D-木糖作为唯一碳源、发酵肌醇的能力以及不能利用富马酸和甘油作为唯一碳源来与最接近的亲缘种 P. ingrahamii 区分开来。此外，菌株 174(T)含有两种不同形态的气液泡，可在 0 至 10°C 的温度范围内生长，其生长的最佳 NaCl 浓度为 3.5%。DNA G+C 含量为 40mol%。全细胞脂肪酸分析表明，16:1omega7c 和 16:0 分别占总脂肪酸含量的 44.9%和 26.4%。提议将这种新物种命名为 Psychromonas boydii sp. nov.，菌株 174(T)（=DSM 17665(T)=CCM 7498(T)）为模式株。
