Effect of glucose on enzyme activity and color removal by Trametes versicolor for high strength landfill leachate

Abstract

This research was carried out to study the treatment of landfill leachate by immobilized Trametes versicolor BCC 8725. Leachate was collected from Nonthaburi disposal site of Thailand from a pipe as discharged from landfill to the stabilization pond. Batch experiments were conducted to determine the effects of carbon source (glucose) on the biomass growth of fungi and the treatment of leachate in terms of color, Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) removal. Enzymes produced by Trametes versicolor BCC 8725 were also analyzed. Experimental results indicated a higher biomass growth when glucose was added, indicating that the growth of fungi is dependent on the co-substrate. The percentage of color removal is approximately 58% and 12%, respectively, with and without glucose. BOD and COD removals were 37% and 40% with glucose addition within 12 days at optimum conditions. Enzyme analysis indicated that laccase was the main enzyme produced. In addition, Manganese Peroxidase (MnP) and Lignin Peroxidase (LiP) were also detected. The fungi were able to produce the enzymes. The peak concentrations of LiP, MnP and laccase activity were found to be 384, 1,241, 2,534 unit/litre (U/L) with glucose, indicating that the color removal rates were proportional to the enzyme activity.