Briceño Gabriela
Universidad de La Frontera Chile
Title: Selection of an actinobacteria consortium for enhancing diazinon degradation
Biography
Biography: Briceño Gabriela
Abstract
The biological treatment of pesticides constitutes a promising alternative for a safe, efficient and economical elimination of pesticides. In this way, biological treatments for removing organophosphorus pesticides, toxic and worldwide used pesticides, from contaminated matrices are needed. The aim of this work was to select an actinobacteria consortium to enhance the diazinon degradation. For this, organophosphorus-degrading actinobacteria identified as Streptomyces sp. strains AC5, AC6, AC7, AC9, GA3, GA11, ISP4 and ISP13 were used. In 30mL of minimal medium containing 50 mg L-1 diazinon as only carbon source, single strains of actinobacteria were added. After 96 h of incubation, microbial growth, intracellular protein content, protein profile and the concentration of diazinon and their metabolite 2-isopropyl-6-methyl-4-pyrimidinol (IMHP) were analyzed. The results showed that biomass and protein content increased with the diazinon addition. Thus, some of the actinobacteria showed prominent bands of proteins enhanced in response to diazinon application. About 10-30% of diazinon degradation for single actinobacteria was observed and only three strains showed IMHP production. However, when mixed cultures of two, three, four and five actinobacteria strains were evaluated, the diazinon degradation was increased, reaching values close to 90%. The quadruple culture composed by the strains AC5, AC9, GA11 and ISP13 presented the best diazinon degradation, which occurs during the first 72 h with a decrease of IMHP over time. Therefore, we conclude that the selected actinobacteria consortium is a promising alternative to increase the diazinon degradation. Acknowledgement: Fondecyt Project Nº 11130716.