Application of microscopic fungi isolated from polluted industrial areas for polycyclic aromatic hydrocarbons and pentachlorophenol reduction.

Abstract

The growth abilities of fifteen fungal strains isolated from contaminated areas, in the presence of xenobiotics compounds mixture (overworked cutting fluid, crude and waste oil) were examined. Strains with the richest growth were chosen for anthracene, phenanthrene and pentachlorophenol biodegradation in Sabouraud medium (with initial xenobiotic concentration 250 mg/l in cultures with polycyclic aromatic hydrocarbons and 10 mg/l for the chlorinated substrate). Strains IM 1063 and IM 6325 were able to attack phenanthrene forming its derivative 9-phenanthrenol with the yields 5.22 mg/l and 2.82 mg/l, respectively. Strain IM 1063 and IM 6325 transformed pentachlorophenol to an intermediate compound--pentachloromethoxybenzene. Final content of pentachloromethoxybenzene reached 3.46 mg/l and 3.2 mg/l, respectively. Strain IM 6203 (contrary to other strains) released an intermediate product of pentachlorophenol metabolism--2,3,5,6-tetrachlorohydroquinone (8.73 mg/l substrate remaining and 1.2 mg/l 2,3,5,6-tetrachlorohydroquinone forming). The IM 6203 strain was identified as Mucor ramosissimus. The chlorinated pesticide degradation by M. ramosissimus was improved significantly on a medium with overworked oil. Only 8.3% of pentachlorophenol and 4.3% of 2,3,5,6-tetrachlorohydroquinone in relation to the introduced substrate (10 mg/l) were found, after 7 days of incubation. The growth of M. ramosissimus on medium with overworked oil in pentachlorophenol presence was associated with oil emulgation, which enhanced fungal growth and the pesticide degradation.