DEGRADATIVE POTENTIAL OF HEXACHLOROCYCLOHEXANE ISOMERS WITH WOOD FUNGI

Estelvina Rodríguez Portillo, Dra. Araceli Amaya and Dr. Jaime Moreno

Science and Technology School, National University of Itapúa, María Auxiliadora, Paraguay

Abstract

Because of the extensive microbial biodiversity, it was long believed that micro-organisms could degrade any substance if they were preserved in favorable environmental conditions. Nonetheless, the massive increase in the synthesis of organic chemicals of xenobiotic origin led to a high persistence (Singleton 1994). One of the major causes of persistent chemical compounds in nature is attributed to the low ability of organisms to degrade. Therefore, it is necessary to explore new biodegradable agents on recalcitrant substances. On the other hand, the widespread use of Hexachlorocyclohexane HCH, its high persistence in the environment and its low degradability imply a potential hazard. The research explored the potential degradative fungi wood rot Trametes versicolor and Bjerkandera adusta on a- y β isomers of Hexachlorocyclohexane in contaminated soil, through tests noting their growth rate and tolerance capability to different concentrations of HCH and degradation. The results indicate that the genus B. adusta showed a higher growth rate as well as a high production of ligninolytic enzymes, achieving a 22% degradation after 20 days of treatment. It is determined that rot fungi have the capability to degrade HCH isomers, and β-HCH being the most recalcitrant.

Keywords: Biodegradation, fungi, HCH isomers.