Molecular characterization of the nonphotosynthetic partner bacterium in the consortium "Chlorochromatium aggregatum"
Molecular characterization of the nonphotosynthetic partner bacterium in the consortium "Chlorochromatium aggregatum"
复制标题
DOI：
10.1128/aem.71.11.7434-7441.2005
复制
发表时间：
2005-11-01
影响因子：
4.4
通讯作者：
Overmann, J
中科院分区：
文献类型：
--
作者：
Kanzler, BEM;Pfannes, KR;Overmann, J
光合菌群是研究不同细菌间信号转导和协同进化的重要模式系统。光养菌群“Chlorochromatium aggregatum”由一个无色的中心杆状细菌组成，周围有大约20个绿色的附着生物。虽然被确定为一个成员的绿色硫细菌，最近分离和纯培养的特点，中央无色细菌已被确定为一个成员的β-变形菌，但到目前为止不能进一步的特点。在本研究中，“C。通过化学活性富集了“aggregatum”的16 S rRNA基因，并对中心菌的16 S rRNA基因序列进行了分析。基于序列信息，荧光原位杂交探针针对16 S rRNA的四个不同区域的设计，并显示出专门杂交到中央细菌的细胞。对1,437 bp长序列的系统发育分析表明，“C.聚集菌”代表了迄今为止分离的与Rhodoferax spp.相关的系统发生谱系，Polaromonas vacuolata和Variovorax paradoxus，属于丛枝藻科。这一谱系的大多数亲属尚未培养，并在低温水生环境或含有异生物质或碳氢化合物的水生环境中发现。在氯化铯-双苯并咪唑平衡密度梯度中，聚集绿染色菌的基因组DNA形成一条特异性条带，可通过特异性引物进行定量PCR检测。用此方法测定中心菌的G+C含量为55.6mol%。
Phototrophic consortia represent valuable model systems for the study of signal transduction and coevolution between different bacteria. The phototrophic consortium "Chlorochromatium aggregatum" consists of a colorless central rod-shaped bacterium surrounded by about 20 green-pigmented epibionts. Although the epibiont was identified as a member of the green sulfur bacteria, and recently isolated and characterized in pure culture, the central colorless bacterium has been identified as a member of the beta-Proteobacteria but so far could not be characterized further. In the present study, "C. aggregatum" was enriched chemotactically, and the 16S rRNA gene sequence of the central bacterium was elucidated. Based on the sequence information, fluorescence in situ hybridization probes targeting four different regions of the 16S rRNA were designed and shown to hybridize exclusively to cells of the central bacterium. Phylogenetic analyses of the 1,437-bp-long sequence revealed that the central bacterium of "C. aggregatum" represents a so far isolated phylogenetic lineage related to Rhodoferax spp., Polaromonas vacuolata, and Variovorax paradoxus within the family Comamonadaceae. The majority of relatives of this lineage are not yet cultured and were found in low-temperature aquatic environments or aquatic environments containing xenobiotica or hydrocarbons. In CsCl-bisbenzimidazole equilibrium density gradients, genomic DNA of the central bacterium of "Chlorochromatium aggregatum" formed a distinct band which could be detected by quantitative PCR using specific primers. Using this method, the G+C content of the central bacterium was determined to be 55.6 mol%.