Actinobacteria consortia as a bioremediation tools of systems contaminated with pesticides

Abstract

The agriculture sector is a very important part of the global economy, and provides human and animal food, and raw materials for the industries. To increase the yield and the productivity, this sector use resources as pesticides, chemical fertilizers, equipment and machines. Among these resources, the pesticides are applied simultaneously or one after another for crop protection, and this practice often leads a combined contamination of their residues in the soil environment. The organochlorine pesticides represent one of the biggest environmental problems, because of their high toxicity, persistence and ability to bioaccumulate in the food chain. Although these compounds are banned and/or restricted in different countries, nowadays pose a risk to both health and the environment, because assuming its disuse, their presence is ignored in living beings and the environment. Current studies demonstrated the organochlorine pesticides presence in organisms and environment of Argentine. The bioremediation by using consortia of actinobacteria is an attractive approach to remove this kind of compounds, because of the actinobacteria ability to degrade pesticides and the advantage to use microbial consortia able to increase the metabolic pathways to achieve it. Different actinobacteria isolated from contaminated sites were selected by their ability to growth, in presence of organochlorine pesticides such as lindane, methoxychlor and chlordane, and for their ability to remove it, from the culture media. These actinobacteria enhanced the pesticides removal when were combined as defined microbial consortia, especially of three or four actinobacteria strains. After to select an actinobacteria consortium by each pesticide, it was demonstrated their versatility to remove each one, in soil and slurries systems, reaching removal values between 25-21% for lindane, 56-46% for methoxychlor and 21-35% for chlordane, respectively. These results highlight the advantages to use actinobacteria consortia as a promising tool for pesticide bioremediation in soil and slurry systems.