Biodegradation of polyvinyl alcohol by Phanerochaete chrysosporium after pretreatment with Fenton's reagent

Polyvinyl alcohol (PVA) solutions (BP05 and BF17; 5.0%, wt v(-1)) were degraded by a combination of chemical (Fenton's reagent) and fungal (Phanerochaete chrysosporium) treatments. The overall degradations of BP05 and BF17 were 74.4 and 72.8%, respectively, as determined by chemical oxygen demand (COD) analysis, and 63.7% and 57.7%, respectively, as determined by total organic carbon (TOC) analysis. Increased retention times and changes in the intensity of the PVA peaks on gel permeation chromatograms indicated that PVA molecules of greater molecular weights were degraded to lower molecular weights by both the chemical and fungal treatments. The predominant enzyme secreted by P. chrysosporium in medium containing 2% (wt v(-1)) ground cereal bran in 60 mM phosphate buffer (pH 6.0) was manganese peroxidase. Neither laccase nor lignin peroxidase activity was detected. Manganese peroxidase was probably involved in the biodegradation of the PVA solutions.