Decolorization of Maxilon-Red by Kissiris Immobilized Phanerochaete Chrysosporium in a Trickle-Bed Bioreactor-Involvement of Ligninolytic Enzymes

The decolorization of Maxilon-red dye by Kissiris immobilized Phanerochaete chrysosporium in the trickle-bed reactor (TBR) using the basal nitrogen-limited growth medium was studied. The influence of the superficial liquid velocity (SLV) on the decolorizing ability of the fungus was examined at four SLVs (cm sec-۱): ۰.۰۵, ۰.۰۷۵, ۰.۱, and ۰.۱۵. Maximum level of the decolorizing activity was about ۹۴ % by day ۴-۵ of the process when the TBR operated at SLV=۰.۰۷۵  to  ۰.۱ cm sec-۱. At these SLVs, the maximum activities of the lignin peroxidase (LiP) and the manganese peroxidase (MnP) were (UL-۱): ۸۷ and ۲۰۷, respectively. In a successive decolorization of the tested dye in a continuous dye addition in the TBR when glucose level decreased to ۲ gL-۱, significant reduction in the characteristics of the interest were observed. While by controlling the glucose concentration, these properties were improved considerably: The decolorizing ability of the Kissiris immobilized mycelia was more than ۸۵ % after nearly ۲۰ days of the process while the maximum activities of the LiP and the MnP were (UL-۱): ۳۲۰ and ۱۵۱, respectively. Considerable levels of the enzyme activities were detected by day ۱۹ and after ۱۱ times of the dye additions.

کلیدواژه ها:

Ligninolytic enzymes ، Kissiris-immobilized Phanerochaete chrysosporium ، Decolorization ، Maxilon-red synthetic dye ، Trickle-bed bioreactor