Analysis of Bacterial Community Composition by 16S rDNA Clone Library Sampling from Constructed Rapid Infiltration System(CRI)

Abstract:

In order to analyze the bacterial population diversity in surface layer(10 cm depth) of CRI, a bacterial 16S rDNA gene clone library was constructed. The results indicated that the bacterial community composition in surface Layer of CRI was high diversity and could be divided into 7 groups. The uncultured Acidobacteria and uncultured bacteria were the largest fraction(53.72% of total clones), followed by uncultured planctomycete (13.89%) and β-proteobacterium (8.33%); In clone library, the proportion of denitrifying bacteria was larger than that of nitrosobacteria and Nitrospira-like bacteria wasn’t found. The high percentage of uncultured bacterial clones predominated in clone library, but by plating culture method the majority colonies were only Pseudomonas aeroginosa and Chromobacterium sp., Which were the minority presented in clone library. The results demonstrated that either the bacterial community composition diversity or the abundance of phytogenetic groups analyzed by 16S rDNA clone library were much higher than those by plating culture method. The bacterial population diversity shown by 16S rDNA gene library is certain meaningful to reveal the activity profile of biodegradation in CRI.

Key words:Constructed Rapid Infiltration system (CRI), 16S rDNA clone library, Bacterial community composition