Comparative Analysis of Community Structure and Activity of Wastewater Treatment Biofilm Cultivated Under Different Conditions

Abstract:

The effect of phenol concentration on the structure and function of microbial communities, which were cultured in different conditions using coking wastewater biofilm as seeding, was investigated by Biolog and denaturing gradient gel electrophoresis (DGGE) methods. The less number of bands of cultivated samples on the denaturing gradient gel electrophoresis fingerprint of 16S rRNA gene indicated reduction of diversity after enrichment and cultivation. Some bands on the DGGE gel were significantly influenced by the phenol concentration in medium. The results of Biolog showed that the original biofilm sample had the highest substrate utility capacity as measured by average well color development (AWCD). But low concentration of phenol enriched sample S7 showed more diverse activity on the utility of Carboxylic acids. The principal component analysis (PCA) of Biolog data revealed that the metabolic patterns were similar when using the same phenol concentration, although the sample S7 much less similar to other cultivated samples. These results suggested that the enrichment and cultivation with phenol supplemented decreased the diversity and also changed the metabolic function of the microbial community. Lower phenol concentration increased the microbial community metabolic activity. The phenol degrading capacity of isolates from each samples indicated that the enrichment and cultivation condition had changed the type and property of cultruable bacteria. Based on these results, we concluded that the different microorganisms will be isolated under different cultivation condition.

Key words:Phenol, Bacteria, Denaturing gradient gel electrophoresis, Enrichment and cultivation