Polycyclic Aromatic Hydrocarbon Biodegradation by a Subtropical White Rot Fungus in Packed Bed and Suspended Carrier Bioreactor Systems

Abstract

Application of a biotreatment system utilising immobilised white rot fungi can become an alternative for treating water or effluent contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAHs). The application of the packed bed and suspended carrier bioreactor systems for the degradation of PAHs in synthetic polluted media using a subtropical white rot fungal isolate DSPM95 was evaluated. The white rot fungal isolate, DSPM95 could reduce a mixture of selected PAHs namely; fluorene, phenanthrene, anthracene, pyrene and benzo(a)anthracene by 50 to 96 % over the reactor operation time of 31 days and when the concentration of each PAH in the feed medium was 1 mg l⁻¹. High manganese peroxidase and laccase activities were detectable during PAH biodegradation in both the bioreactor systems, however the maximum enzyme activities could not be sustained in the bioreactors for extended periods of time. Varying concentrations of glucose to nutrient nitrogen in the feed medium could not help sustain high enzyme production in the bioreactor. It can be concluded that the white rot fungi used here could efficiently degrade the PAH compounds in both the packed bed and suspended carrier bioreactor system, which compares well with other studies as highlighted in this report.

Keywords:

• LIGNINOLYTIC FUNGI
• BIODEGRADATION
• PAHS
• BIOREACTORS