Comparison of bacterial diversity of polluted and unpolluted sediment by Brominated Flame Retardant

Abstract:

Abatract [Objective] By using brominated flame retardant we compared the bacterial diversity of highly polluted river sediment with that of nearby unpolluted lake. [Method] Total DNA was extracted from unpolluted and highly polluted sediment sample by brominated flame retardant in Guiyu of China. The 16S rRNA gene was amplified by PCR using bacterial primer 27F and 1500R. The plasmid libraries of the amplicons were constructed. The positive clones with insert were screened on plates with IPTG/X-gal/Ap. Amplified ribosmal DNA restriction analysis (ARDRA) was carried out with restriction enzymes HhaⅠand HinfⅠ. Representative clones of each operational taxonomic unit based on the ARDRA patterns were selected to be sequenced. After proof reading and careful comparison to remove the chimeric sequences, the partial sequence of 16S rRNA gene were used for construction of the phylogenetic tree. [Result] The result of blast searching showed that clones from unpolluted sediment sample belonged to α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, δ-Proteobacteria, Planctomycetes, Acidobacteria, Actinobacteria, Chloroflexi, Verrucomicrobia, Firmicutes, the predominant bacteria (30.2% of total clones) is Acidobacteria; most clones from polluted sediment belonged to α-Proteobacteria, β-Proteobacteria, ε-Proteobacteria, δ-Proteobacteria, Planctomycetes, Acidobacteria, Actinobacteria, Chloroflexi, Bacteroidetes, Firmicutes, candidate division OP01, candidate division OP08, the predominant bacteria (44.9% of total clones) are ε-Proteobacteria and Chloroflexi. [Conclusion] Bacterial community structure of polluted sediment has distinguished feature and obviously different from the unpolluted sediment sample, which is mainly reflected in the dominant position of ε-Proteobacteria and Chloroflexi in the bacterial flora.