Bioconversion of orange peel residue for the production of pectinase using Calocybe indica and its application in biomedical research

Abstract

Conversion of organic material to valuable products like pectinase by biological agents like fungi and bacteria has been a leading approach in recent times. Production of pectinases for various commercial uses by a cheaper method is a big challenge. An edible mushroom Calocybe indica cultivated under solid state fermentation using orange peel residue as substrate can produce significant amount of pectinase. Since, orange peel is highly rich in pectin could be used for the growth of many fungi. Calocybe indica seed was inoculated on PDA agar medium and allowed to grow on the plate for seed inoculum production, then; it was inoculated onto the substrate as orange peel residue. Five different substrate concentrations were prepared using orange peel residue with wheat bran and rice bran as subsidiary with moisture content of 1:2.The growth was stopped on 25^th day of fermentation by mixing distilled water and enzyme was extracted. Among substrates, substrate type-1 (only residue) and 4 (residue + wheat bran + rice bran) showed higher enzyme activity 0.3435 and 0.335µmol/min respectively this was determined by DNS method. Molecular weight of crude pectinase was determined by SDS-PAGE which showed band of 30kDa which indicated the presence of pectinase in substrate. In this study, we found out that orange peel residue could be cheaper and better substrate for production of pectinase using Calocybe indica an edible fungus and make the pectinase enzymes commercially viable.