Biodegradation of herbicide atrazine by bacteria isolated from agricultural soils

Abstract

Atrazine is one of the most widely used herbicides worldwide in corn, sorghum, sugarcane, pineapple and others, belongs to the family of s-triazine to present a heterocyclic ring that confers high stability. It is considered by the EPA, WHO, OSPAR, WWF as hormonal disruptor and its environmental persistence, ability to seep into the soil, is a contaminant of groundwater reservoirs, rivers and lakes. The present work is evaluated efficiency of atrazine degradation by bacteria isolated from agricultural soils. 7 microbial consortia MIG-AI, MIG-AS-BS MIG MIG-DI, MIGE,-F and MIG MIG-G selected by growth and progressive solubility of the herbicide over 4 subcultures in minimal medium as a sole atrazine carbon and nitrogen source. The MIG-AI consortium selected for best performance presents a specific growth rate of 0.31 h-1 atrazine solubilizing in 2 days and generating areas of clearance in 4 days in liquid and solid medium, respectively. It was identified by analysis of 16S rRNA gene of strain Stenotrophomonas maltophilia MIG-AI/2 having ability to degrade atrazine.