Assessment of functional diversity of heterotrophic microbial communities in polluted environments through community level physiological profiles

Abstract

The community level physiological profiles (CLPP) of bacterial communities inhabiting polluted environments (acid mine drainage water and sediments, soils contaminated with tannery waste and oil refinery effluents) were assessed using the Biolog Ecoplates™ in comparison to non-contaminated sites (water and sediments from a recreational lake and soil from anopen space). Although the polluted sites were characterized by typically high metal concentrations, CLPP fingerprints of the different bacterial communities from these sites were indicative of versatile metabolic potentials. These microbial communities could differentially utilize all the different groups of carbon substrates. However, the rates of utilization were significantly lower, and the number of utilized substrates were fewer than those of microbial communities from non-contaminated sites. This was confirmed by cluster analysis in which the dendrogram showed two clusters of microbial communities from contaminated environments and another for those from non-contaminated sites. Nonetheless, the indices of diversity calculated did not show a reduction of diversity or evenness in the microbial communities from contaminated sites. This study confirms the usefulness of the CCLP method in untangling the functional diversity of microbial diversity in contaminated environments.