|402-1||CARBENDAZIME DEGRADATION AND THEIR EFFECT ON COMMUNITY LEVEL PHYSIOLOGICAL PROFILING AND MICROBIAL COMMUNITIES IN THE BIOMIXTURE OF A BIOBED.|
|Autores:||Gonzalo Tortella (UFRO - Universidad de La Frontera) ; Olga Rubilar (UFRO - Universidad de La Frontera) ; Rodrigo Mella Herrera (UFRO - Universidad de La Frontera) ; Cristina Diez (UFRO - Universidad de La Frontera) |
The biobed is a simple biological system composed by a biomixture of top soil, peat and straw (1:1:2 vv-1), providing a matrix to adsorb and facilitate the pesticide biodegradation. The biomixture in the biobed system is a principal element controlling the degradation efficacy of the biobed, and information about community level physiological profiling (CLPP) and microbial diversity is important for understanding the role of the microbial populations in this system. In this work, the effects of carbendazime on CLPP and microbial communities in the biomixture of biobed were evaluated. Moreover, carbendazime degradation was also evaluated. The biomixture was contaminated with 40 mg kg-1 in three successive applications and incubated at 25 °C for 90 days. CLPP was determined using 31 different simple organic substrates contained in 96-well microtiter plates (Biolog Ecoplate). The plates were inoculated with 150µl of a bacterial suspension (105), incubated at 25 °C and the color development was monitored for 72 hrs at 590nm. Changes in the bacterial and fungal community structure were monitored by denaturing gradient gel electrophoresis (PCR-DGGE). Residual carbendazime was extracted of the biomixture with methanol and quantified by HPLC. The results obtained showed that carbendazime caused variation in CLPP, and the numbers of substrates that were used were reduced after pesticide application. However, microbial communities monitored by DGGE revealed not great variation in microbial and fungal communities after pesticide application. Although was possible to observe a variation in CLPP and microbial communities in the biomixture due to the pesticide, was found that the biomixture was capable of to degrade carbendazime at a rate greater than 90% after of three successive application. In conclusion, carbendazime caused variation in CLPP and microbial communities in the biomixture, however, this does not represent a change in the microbiological robust of the biomixture in the long time, allowing for efficient degradation of the pesticide.
Acknowledgements: This work was financed supported by the Chilean FONDECYT Project 11100236.
Palavras-chave: BIOBED, COMMUNITY LEVEL PHYSIOLOGICAL PROFILING, DGGE, PESTICIDE DEGRADATION