Characterization of pristine and agricultural soils by catabolic profiling of microbial communities

RUIZ DE; MONTECCHIA MS; CORREA OS; PUCHEU NL; SORIA MA; GARCÍA AF

Villa Carlos Paz, Córdoba

Congreso; XLIV Reunión anual de la Sociedad argentina de Investigación en Bioquímica y Biología Molecular; 2008

Sociedad argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

The advance of the agriculture frontier in Northwestern Argentina affects soils, especially those that were subjected to deforestation followed by monoculture agriculture. In this work we analyzed the community level physiological profiling (CLPP) of microbial communities to compare soils from the low-altitude pristine forests of the Yungas eco-region with soils under 40 and 100 years of sugarcane monoculture. Two techniques were applied, a BD oxygen biosensor system (BDOxy) and a variant of the Biolog system. The BDOxy method allows the direct measurement of microbial respiration using a fluorescent dye, while the cheaper but less sensitive Biolog system estimates metabolic activity indirectly through color change of a redox dye. The multivariate dataset was summarized using Analysis of Principal Components. Both methods showed differences in the catabolic profiles for the three soils tested, with the agricultural soils sharing a higher similarity between them. Using microcosm experiments we found that the microbial community of the pristine soil was more resilient to environmental stresses, specifically changes in temperature. Although it can be argued that the BDOxy and the Biolog methods estimate the catabolic activities of different community fractions, our results suggest that both can be used as indicator of soil characteristics and community dynamics .