CONICET | Buscador de Institutos y Recursos Humanos

In this study we compared the capacity of three microbial community profiling methods to describe differences in the soil microbial community associated with deforestation and agriculture.We used biochemical (phospholipid fatty acid analysis, PLFA), physiological (community level physiological profiling, CLPP, using a BD oxygen biosensor system), and molecular (16S rDNA polymerase chain reaction-denaturing gradient gel electrophoresis, PCR-DGGE) fingerprinting methods. We analyzed samples from pristine soils, as well as adjacent deforested and agricultural soils with different land-use histories (40 or 100 yrs sugarcane and 20 yrs soybean monocultures).All fingerprinting methods distinctly characterized the microbial community structure of each soil and detected changes in the soil microbial population related to land use. PLFA analysis revealed that total microbial biomass was much more abundant in pristine forest soils than in those under agricultural use or that had been recently deforested, where the microbial biomass was severely reduced. Analysis of CLPP and DGGE profiles indicated that microbial communities from soils under agricultural management were functionally and genetically different from those characterizing pristine soils.The structure of microbial communities was different between the soils analyzed and these differences were detected by all the approaches used.