Evaluation of soil-microbial communities by their CLPP. Standardization of a laboratory technique to replace commercial available microplates

Variation of soil-microbial communities are good bioindicators of human impacts in soils, such as different soils management or contamination. Considering that traditional methods of isolation and taxonomic analysis do not consider the functionality of the microbial community, Community-Level Physiological Profi les (CLPP) emerged as a complementary methodology to study microbial communities. Several studies have shown that Biolog® EcoPlates® are very useful for determining physiological differences between communities from different samples. However, commercial microplates have some disadvantages which led us to the idea of replacing them by microplates prepared in the laboratory (Laboratory’s). Here, we compared both types of microplates using soil samples from a bioremediation assay. We compared a) the average well color development for each sample, b) the averages of absorbance values for each type of microplate, c) Principal Components, and d) Shannon-Weaver’s diversity index (H). Although Laboratory’s showed signifi cantly lower Average absorbance values than EcoPlates®, the principal component analysis and diversity index did not differ between types of microplates. In conclusion, both types of microplates showed a relatively similar ability to detect differences in the CLPP of the treatments studied. Consequently, microplates prepared in laboratory are a reliable and economical tool to study the physiology of soil microbial communities. [