Classification and Characterization of Heterotrophic Microbial Communities on the Basis of Patterns of Community-Level Sole-Carbon-Source Utilization

TLDR

The BLOLOG redox technology, using tetrazolium dye reduction, was evaluated as a rapid, community‑level method to characterize and classify heterotrophic microbial communities. Whole environmental samples were incubated in BIOLOG plates with 95 carbon sources, and the resulting dye‑reduction patterns were correlated to principal components to functionally distinguish communities. Principal‑component analysis of the color responses revealed distinct patterns across habitats and spatial gradients, demonstrating that this technique can produce ecologically relevant classifications of heterotrophic microbial communities.

Abstract

The BLOLOG redox technology based on tetrazolium dye reduction as an indicator of sole-carbon-source utilization was evaluated as a rapid, community-level method to characterize and classify heterotrophic microbial communities. Direct incubation of whole environmental samples (aquatic, soil, and rhizosphere) in BIOLOG plates containing 95 separate carbon sources produced community-dependent patterns of sole-carbon-source utilization. Principal-component analysis of color responses quantified from digitized images of plates revealed distinctive patterns among microbial habitats and spatial gradients within soil and estuarine sites. Correlation of the original carbon source variables to the principal components gives a functional basis to distinctions among communities. Intensive spatial and temporal analysis of microbial communities with this technique can produce ecologically relevant classifications of heterotrophic microbial communities.