Production and characterization of carboxymethyl cellulase from Paenibacillus polymyxa using mango peel as substrate

Mango peel, a solid mango processing waste, comprises 15-20% of total fruit weight. This, being a rich source of lignocelluloses, was used as substrate for carboxymethyl cellulase (CMCase) production using Paenibacillus polymyxa. Maximum CMCase production (7.814 U mg(-1)) was observed in a medium containing 7% mango peel (w/v) with 1.5% ammonium sulphate (w/v) at 37 degrees C and pH 5.5. Purification to an extent of 28.24 fold was achieved by affinity column chromatography. Bands corresponding to 26.5 and 34.0 kDa molecular sizes were observed on 12% denaturing Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) while of 72 kDa on 10% non-denaturing Native-PAGE, proving its heteromeric multienzyme nature. The enzyme was stable over a range of 20-60 degrees C and pH of 4.0-7.5. Michaelis-Menten equation constant (Km and Vmax) values of purified CMCase were 8.73 mg ml(-1) and 17.805 mM ml(-1) min(-1), respectively.