Novel, attached, sulfur-oxidizing bacteria at shallow hydrothermal vents possess vacuoles not involved in respiratory nitrate accumulation
Novel, attached, sulfur-oxidizing bacteria at shallow hydrothermal vents possess vacuoles not involved in respiratory nitrate accumulation
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DOI：
10.1128/aem.70.12.7487-7496.2004
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发表时间：
2004-12-01
影响因子：
4.4
通讯作者：
Nelson, DC
中科院分区：
文献类型：
--
作者：
Kalanetra, KM;Huston, SL;Nelson, DC
在加利福尼亚州白点附近的浅水热液喷口发现了新的空泡状硫磺细菌。在那里，这些细丝紧密地附着在不同的生物和非生物底物上，并向周围环境延伸一到几厘米，在那里它们交替暴露在硫化物和含氧海水中。从该地点收集的本地细丝的表征表明，这些细丝与迄今为止表征的所有其他空泡细菌相比，具有新颖的形态和生理特性。附着丝的直径从4微米到100微米或更大，由圆柱形细胞组成，每个细胞含有一个围绕着一个大的中央液泡的充满硫磺球的细胞质的细环。获得了一个接近完整的16S rRNA基因序列，并经荧光原位杂交证实只与直径为10微米或更大的细丝有关。系统发育分析表明，这些更宽的附着丝在伽马蛋白细菌中形成，这是一个单一的类群，包括所有先前描述的空泡型硫磺细菌(Beggiatae属、Thiopoca属和Thiomargarita属)，而不包括非空泡型属。然而，与之前描述的所有真空细菌不同，对两年多收集的样本的细胞裂解产物的重复测量表明，附着的白点细丝不存储内部硝酸盐。这些液泡可能参与了氧气的瞬时储存，或者对这些细丝的相对浮力有贡献。
Novel, vacuolate sulfur bacteria occur at shallow hydrothermal vents near White Point, Calif. There, these filaments are attached densely to diverse biotic and abiotic substrates and extend one to several centimeters into the surrounding environment, where they are alternately exposed to sulfidic and oxygenated seawater. Characterizations of native filaments collected from this location indicate that these filaments possess novel morphological and physiological properties compared to all other vacuolate bacteria characterized to date. Attached filaments, ranging in diameter from 4 to 100 mum or more, were composed of cylindrical cells, each containing a thin annulus of sulfur globule-filled cytoplasm surrounding a large central vacuole. A near-complete 16S rRNA gene sequence was obtained and confirmed by fluorescent in situ hybridization to be associated only with filaments having a diameter of 10 mum or more. Phylogenetic analysis indicates that these wider, attached filaments form within the gamma proteobacteria a monophyletic group that includes all previously described vacuolate sulfur bacteria (the genera Beggiatoa, Thioploca, and Thiomargarita) and no nonvacuolate genera. However, unlike for all previously described vacuolate bacteria, repeated measurements of cell lysates from samples collected over 2 years indicate that the attached White Point filaments do not store internal nitrate. It is possible that these vacuoles are involved in transient storage of oxygen or contribute to the relative buoyancy of these filaments.