Jiménez L
Environmental Sciences Section, Westinghouse Savannah River Company, Aiken, South Carolina 29808-0001.
Appl Environ Microbiol. 1990 Jul;56(7):2108-13. doi: 10.1128/aem.56.7.2108-2113.1990.
Bacterial isolates from deep-sediment samples from three sites at the Savannah River site, near Aiken, S.C., were studied to determine their microbial community composition and DNA structure by using total DNA hybridization and moles percent G + C. Standard phenotypic identification underestimated the bacterial diversity at the three sites, since isolates with the same phenotype had different DNA structures in terms of moles percent G + C and DNA homology. The G + C content of deep-subsurface bacteria ranged from 20 to 77 mol%. More than 60% of the isolates tested had G + C values similar to those of Pseudomonas spp., and 12% had values similar to those of Acinetobacter spp. No isolates from deeper formations showed the same DNA composition as isolates from upper formations. Total-DNA hybridization and DNA base composition analysis provided a better resolution than phenotypic tests for the understanding of the diversity and structure of deep-subsurface bacterial communities. On the basis of the moles percent G + C values, deep-subsurface isolates tested seemed to belong to the families Pseudomonadaceae and Neisseriaceae, which might reflect a long period of adaptation to the environmental conditions of the deep subsurface.
对取自南卡罗来纳州艾肯附近萨凡纳河场地三个地点的深层沉积物样本中的细菌分离株进行了研究，通过全DNA杂交和鸟嘌呤与胞嘧啶的摩尔百分比来确定其微生物群落组成和DNA结构。标准表型鉴定低估了这三个地点的细菌多样性，因为具有相同表型的分离株在鸟嘌呤与胞嘧啶的摩尔百分比和DNA同源性方面具有不同的DNA结构。深层地下细菌的鸟嘌呤与胞嘧啶含量范围为20至77摩尔%。超过60%的测试分离株的鸟嘌呤与胞嘧啶值与假单胞菌属的相似，12%的与不动杆菌属的相似。来自更深地层的分离株没有显示出与上层地层分离株相同的DNA组成。全DNA杂交和DNA碱基组成分析比表型测试在理解深层地下细菌群落的多样性和结构方面提供了更好的分辨率。根据鸟嘌呤与胞嘧啶的摩尔百分比值，测试的深层地下分离株似乎属于假单胞菌科和奈瑟菌科，这可能反映了对深层地下环境条件的长期适应。
