Enzymatic Degradation of Organochlorine Insecticide Chlordane by Phlebia brevispora.

[Objective] This study aimed to clarify the mechanism of enzymatic degradation of organochlorine insecticide chlordane by the white rot fungus Phlebia brevispora. [Method] The degradation characteristics of chlordane were determined by the crude enzyme extracted from P. brevispora strain by pure culture, ultrasonic fragmentation and centrifuge separation. [Result] About 33.2% and 10.4% of chlordane were degraded respectively by intracellular enzyme and extracellular enzyme within 20 min. At pH 5.0 and 32 °C, the crude enzyme showed the greatest degradation activity (49.9%), with its Michaelis-Mentns constant (Km) and maximum degradation rate (Vmax) of 3.49 and 8.38 [xmol/min, respectively. [Conclusion] Extracellular enzyme can degrade chlordane through dehydrogenation or dehydrochlorination. Intracellular enzyme plays a major role in chlordane degradation. It can transform chlordane to some hydroxylated metabolites through hydroxylation or substitution of chlorine atom by hydroxyl group. [ABSTRACT FROM AUTHOR]