Tiquia S M, Schleibak M, Schlaff J, Floyd C, Benipal B, Zakhem E, Murray K S
Department of Natural Sciences, The University of Michigan, Dearborn, MI 48128, USA.
Environ Technol. 2008 Jun;29(6):651-63. doi: 10.1080/09593330801986998.
This study was conducted to elucidate microbiological characteristics of river water and groundwater communities in order to improve our conceptual and predictive understanding of river and groundwater ecosystem processes, functioning and management. Rouge River bacterial communities from shallow groundwater and river water were screened using Biolog Ecoplates, which test for oxidation of selected carbon sources and by culturing heterotrophic bacteria. The isolates cultured from the samples were also characterized using the 16SrRNA gene-based approach. The patterns of utilization of the groups of carbon substrates by the microbial communities revealed differences between river water and groundwater samples. Carbohydrates, polymers, carboxylic acids and amino acids were highly utilized by the microbial communities in the river samples, while carbohydrates, polymers, amino acids and phenolic compounds were metabolized in the groundwater samples. Sequence comparison results showed that the most prevalent phylum in all sites was the Firmicutes (low G+C, mostly gram-positive bacteria). The dominant isolates from this phylum were similar to Bacillus spp., (98% nucleotide identity), which represented approximately 62% of the total number of unique isolates. Also prevalent were the gamma-Proteobacteria, which were dominated by 16S rRNA sequences 98-99% similar to that of Pseudomonas spp. The observed profile of carbon sources metabolized reflected the catabolic potential of the river water and groundwater community. Many of the isolates recovered have been known to metabolize several organic substrates, and may have potential use in remediation organic contaminants from the Rouge River. Direct incubation water samples in Biolog Ecoplates produced patterns of metabolic response useful in the classification and characterization of river water and groundwater microbial communities. Heterotrophic bacteria isolated from the sites may play important roles in the fate of many organic and inorganic contaminants from the Rouge River, although future studies are needed to understand their response to these contaminants.
开展本研究是为了阐明河水和地下水群落的微生物特征，以增进我们对河流和地下水生态系统过程、功能及管理的概念性和预测性理解。使用Biolog生态板对鲁日河浅层地下水和河水中的细菌群落进行筛选，该生态板可检测特定碳源的氧化情况并培养异养细菌。还采用基于16SrRNA基因的方法对从样本中培养出的分离株进行了特征分析。微生物群落对碳底物组的利用模式揭示了河水和地下水样本之间的差异。碳水化合物、聚合物、羧酸和氨基酸在河水样本中的微生物群落中被大量利用，而碳水化合物、聚合物、氨基酸和酚类化合物在地下水样本中被代谢。序列比较结果表明，所有采样点最普遍的菌门是厚壁菌门（低G+C含量，大多为革兰氏阳性菌）。该菌门的优势分离株与芽孢杆菌属相似（核苷酸同一性为98%），约占独特分离株总数的62%。同样普遍的是γ-变形菌门，其16S rRNA序列与假单胞菌属的序列相似度为98-99%。观察到的碳源代谢概况反映了河水和地下水群落的分解代谢潜力。许多分离出的菌株已知可代谢多种有机底物，可能在修复鲁日河的有机污染物方面具有潜在用途。将水样直接接种到Biolog生态板中产生的代谢反应模式，有助于对河水和地下水微生物群落进行分类和特征分析。从这些采样点分离出的异养细菌可能在鲁日河许多有机和无机污染物的归宿中发挥重要作用，不过还需要进一步研究来了解它们对这些污染物的反应。
