Analysis Of Bacterial Communities Diversity In Sediments Of Lake Dongping

Microbial community diversity and composition at six stations of Lake Dongping in two seasons were investigated using molecular approaches (Terminal restriction fragment length polymorphisam (T-RFLP) and 16S rDNA clone libraries). Statistical methods, such as PCA (Redundance Analysis), CCA (Canonical Correspondence Analysis), and RDA (Redundance Analysis), was used to investigate the relationship between bacterial communities of Lake Dongping sediment and environmental factors.Members of sediment bacterial communities in Lake Dongping included 16 phyla (or subphylum): Proteobacteria (includingα-Proteobacteria,β-Proteobacteria,δ-Proteobacteria,ε-Proteobacteria,γ-Proteobacteria), Acidobacteria, Planctomycetes, Bacteroidetes, Firmicutes, Verrucomicrobia, Nitrospira, Chloroflexi, Gemmatimonadetes, Chlorobi, Cyanobacteria, Deferribacteres, Actinobacteria, OP8, Spirochaetes and OP11. Bacterial diversity and composition displayed noticeable spatial and temporal variations at 6 stations. Beta-, delta-, and gamma-proteobacterial sequences were dominated in 11 of 12 clone libraries derived from sediments. The greatest bacterial diversity was present in samples collected in station 1 and station 4 in July and the least diversity in those collected in station 2 in October. The results of CCA and RDA indicated that TP (Total phosphorus) was the most important environmental factor to influence the structure of bacterial communities in sediments of Lake Dongping. Total phosphorus concentration significantly correlated to the distribution of bacterial communities in sediments of Lake Dongping. RDA was used to analysis the relationships between bacterial species and environmental factor. Planctomycetes showed the highest positive correlation with concentration of TP.β-Proteobacteria, δ-Proteobacteria,ε-Proteobacteria, Bacteroidetes, and Gemmatimonadetes were all positively correlated with TP. Additionally, Acidobacteria,γ-Proteobacteria,α-Proteobacteria, Firmicutes, Verrucomicrobia, Nitrospira, Chloroflexi, Chlorobi, Cyanobacteria, and Deferribacteres were all negatively correlated with TP. The results of CCA based on T-RFLP suggested that the abundance of 558, 64.5, 164, and 509 bp T-RFs were significant affected by environmental factors, while other 14 T-RFs were not significant correlated with environmental factors.Our results suggest that different environmental stressors contribute to spatial and temporal variations of physiochemical features and bacterial communities in sediments of Lake Dongping.