The Genotype Diversity of Rhodopseudomonas palustris in Different Habitats

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.