Enhanced catalytic potentiality of Ganoderma lucidum IBL-05 manganese peroxidase immobilized on sol-gel matrix

• MnP was immobilized successfully in sol-gel matrix by entrapment method.
• Insolubilized MnP with remarkable catalytic behavior and storage stability was obtained.
• Biodegradation of textile wastewater effluents with in a shortest time period of 5 h.
• Recycling and re-use of the insolubilized MnP display a high potential for biotechnological applications.
• Toxicity evaluation demonstrated the nontoxic nature of immobilized MnP treated effluent solutions.

Sol-gel immobilization is an efficient approach to improve the catalytic and life-time properties of biocatalyst. A monomeric 43 kDa manganese peroxidase (MnP) from Ganoderma lucidum IBL-05 was immobilized using hydrophobic sol-gel matrix of tetramethoxysilane and propyltrimethoxysilane. The method led to very effective MnP immobilization (91.0%), and imparted remarkable stability to the enzyme (82.7 ± 0.9% after 2 months of storage at 4 °C). The optimum pH was 5.0 and 4.0 for soluble and sol-gel immobilized MnP, respectively. Sol-gel encapsulated MnP exhibited 43% residual activity at 50 °C, whereas the free enzyme lost its activity completely after 72 h. After 5 h reaction time, textile wastewater effluents were decolorized to different extents (with a maximum of 93.92%) by immobilized MnP. Operational stability of the entrapped MnP was significantly improved after immobilization, and it retained more than 70% of original activity after three repeated uses for the tested effluents. The chemical oxygen demand (COD) and total organic carbon (TOC) of maximally decolorized effluents were below the permissible limits. The cytotoxicity evaluated through Allium cepa and brine shrimp lethality tests was considerably reduced after treatment with immobilized MnP. The broader pH stability, better thermo-and storage stability, and high catalytic activity are the attractive features of immobilized MnP that make it a promising candidate for environmental biotechnology.

Agro-industrial based lignocellulosic waste material i.e. wheat bran was used as a fermentation feed-stuff for manganese peroxidase (MnP) production. A promising and environmentally friendlier immobilization approach was adopted to incorporate the purified MnP into the sol-gel matrix. The resulted modified biocatalyst was used for the degradation and detoxification of dye-contaminated real textile wastewater effluents.Figure optionsDownload as PowerPoint slide