Metabolic ability and individual characteristics of an atrazine-degrading consortium DNC5

Abstract

A stable four-member bacterial consortium, DNC5 that was capable of metabolizing atrazine was isolated from corn-planted soil. The main objective of this paper is to characterize the individual metabolic characteristics and the mutualism of the cultivable members in the consortium DNC5. Substrates utilizing character of each community member indicate that the primary organism in this consortium is Arthrobacter sp. DNS10, which was the only strain capable of mineralizing atrazine to cyanuric acid. Two secondary strains (Bacillus subtilis DNS4 and Variovorax sp. DNS12) utilized cyanuric acid during the atrazine degradation process. Meanwhile, we found that a metabolite (isopropylamine) inhibited the atrazine degrading species Arthrobacter sp. DNS10. The last strain (Arthrobacter sp. DNS9) of this consortium played a role in reducing this inhibition by utilizing isopropylamine for its growth. Altogether this is a new combination of isolates in an atrazine degrading consortium. The growth and the degradation rate of consortium DNC5 were faster than that of the single strain DNS10. The high degradation ability of the consortium showed good potential for atrazine biodegradation. This study will contribute toward a better understanding about metabolic activities of atrazine degrading consortium, which are generally considered to be responsible for atrazine mineralization in the natural environment.