LAUSR

Abstract Pure strains of Paecilomyces variotii, Paecilomyces lilacinus and Sphingobacterium sp. were investigated in this work for their capability of degrading a commercial formulation of endosulfan (Tridane 350) and reagent grade endosulfan (α and β isomers), at an initial concentration of 25 mg L−1. In the tests with Tridane 350, P. lilacinus was able to degrade 38.4% and 79.5% of α- and β-endosulfan, respectively, and P. variotii degraded only 21% of α-endosulfan, while degradation of β isomer was marginal. Nonetheless, in the tests performed with reagent-grade endosulfan, P. variotii showed the ability to degrade 26.4% and 31.4% of α and β isomers of endosulfan, followed by Sphingobacterium sp. with 14.34% and 21.14%, and finally P. lilacinus with 10.87% and 8.99% respectively. Moreover, a correlation was observed between the production of CO2 and the degradation of endosulfan, indicating the possible mineralization of the latter. In general, the studied strains showed a moderate capability of using endosulfan as a carbon source, but their potential use in the remediation of endosulfan contaminated soils and the elimination of obsolete pesticide residues was evidenced. To the best of our knowledge, this is the first report on P. variotii and P. lilacinus used in the degradation of endosulfan.