Cultivation and growth characteristics of a diverse group of oligotrophic marine Gammaproteobacteria
Cultivation and growth characteristics of a diverse group of oligotrophic marine Gammaproteobacteria
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DOI：
10.1128/aem.70.1.432-440.2004
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发表时间：
2004-01-01
影响因子：
4.4
通讯作者：
Giovannoni, SJ
中科院分区：
文献类型：
--
作者：
Cho, JC;Giovannoni, SJ
采用高通量培养方法，从太平洋沿海和远洋地区培养了44株新的伽马变形杆菌，这些方法依赖于在极低营养物质的介质中稀释到灭绝。系统发育分析表明，分离株可分为5个rRNA分支，均含有海水环境基因克隆文库中已报道的rRNA基因序列(SAR92、OM60、OM182、BD1-7和K189A)。系统发育可靠性的Bootstrap分析不支持将这五个分支折叠成一个单独的分支，因此它们被命名为寡营养海洋伽马蛋白细菌(OMG)群。在液体培养中连续纯化了代表5个支系的12个菌种，测定了它们在不同温度和不同溶解有机碳浓度下的生长特性。OMG组中的菌株是生理多样性的异养菌，它们的生理特性通常遵循它们的系统发育关系。OMG组的菌株在第一次从海水中分离时没有在低营养或高营养琼脂上形成菌落，而12个培养用于实验室检测的菌株中有7个最终在1/10 R2a琼脂上产生了菌落。菌株在天然海水培养基中生长相对较慢(1.23~2.63天)，在高营养(~GT；351 mg C L~(-1))中无一生长。这些分离株是冷嗜性到中嗜性和必需的寡养性；它们中的许多是超微生物大小(
Forty-four novel strains of Gammaproteobacteria were cultivated from coastal and pelagic regions of the Pacific Ocean using high-throughput culturing methods that rely on dilution to extinction in very low nutrient media. Phylogenetic analysis showed that the isolates fell into five rRNA clades, all of which contained rRNA gene sequences reported previously from seawater environmental gene clone libraries (SAR92, OM60, OM182, BD1-7, and K189A). Bootstrap analyses of phylogenetic reliability did not support collapsing these five clades into a single clade, and they were therefore named the oligotrophic marine Gammaproteobacteria (OMG) group. Twelve cultures chosen to represent the five clades were successively purified in liquid culture, and their growth characteristics were determined at different temperatures and dissolved organic carbon concentrations. The isolates in the OMG group were physiologically diverse heterotrophs, and their physiological properties generally followed their phylogenetic relationships. None of the isolates in the OMG group formed colonies on low- or high-nutrient agar upon their first isolation from seawater, while 7 of 12 isolates that were propagated for laboratory testing eventually produced colonies on 1/10 R2A agar. The isolates grew relatively slowly in natural seawater media (1.23 to 2.63 day), and none of them grew in high-nutrient media (>351 mg of C liter(-1)). The isolates were psychro- to mesophilic and obligately oligotrophic; many of them were of ultramicrobiall size (