不同生境中沼泽红假单胞菌基因型多样性分析

The Genotype Diversity of Rhodopseudomonas palustris in Different Habitats

摘要:

沼泽红假单胞菌(Rhodopseudomonas palustris, R. palustris)是一种分布广泛的紫色非硫细菌, 代谢方式的多样性赋予了它们重要的生态学意义和应用价值。从湖泊、池塘和河流的11个底泥样品中富集培养紫色非硫细菌, 利用基于pufM基因的PCR-DGGE技术鉴定为R. palustris, 再利用rep-PCR技术进行基因型指纹图谱分析。结果发现相近生境, 即湖泊中的菌株基因型相似度较高, ＞80%, 而差异越大的生境中菌株基因型指纹图谱差异也越大。这种基因型差异性分析不仅可以帮助研究者更全面地了解不同环境中R. palustris基因型多样性, 也为进一步揭示其生态学意义和进化过程提供基础。

Abstract:

Rhodopseudomonas palustris (R. palustris) is a common type of purple phototrophic bacteria found in a wide variety of environments. As a result of the diverse metabolism mechanisms, they are ecologically important and have valuable applications. In this study, we collected eleven sediment samples from lakes, ponds and streams. Samples were cultivated for purple nonsulfur bacteria enrichment. With PCR-DGGE based on pufM gene fraction, the enriched bacteria were phylogenetically identified as R. palustris. Genotypes from these bacteria were differentiated with rep-PCR for cluster analysis. We found that R. palustris from similar habitats, eg. lakes, can be categorized into a group with > 80% fingerprinting similarity. On the contrary, the genotypes of R. palustris from distinct habitats are distant. Our results suggest a relationship between the genotype diversity of R. palustris and their habitat variances. This finding allows a foundation for further studies on the ecological importance and evolution pathway of such purple nonsulfur bacteria.