Abstract

Polygalacturonase (PGases) production from Rhizomucor pusillus was enhanced when various production parameters were optimized. Maximum PGases activity was obtained after 120 h at 45°C and pH 5.0 with pectin (pure) (1.5% w/v) as carbon source, urea (0.3% w/v) as nitrogen source and MnSO4 (0.2% w/v) as mineral supplement. PGases from R.pusillus was partially purified and subjected to characterization studies. Maximum PGases specificity was observed when polygalacturonic acid was used as the substrate. The PGases was stable at 50°C up to 4 h of incubation and pH condition of between 4.0-5.0. The stability of PGase decrease rapidly above 60°C and above pH 5.0. To our knowledge, it was the first time that a polygalacturonase enzyme was purified in this species. It would be worthwhile to exploit this strain for polygalacturonase production. Polygalacturonase from this strain can be recommended for commercial production because of its constitutive and less catabolically repressive nature, thermo stability and wide range of pH. However, scales up studies are needed for better output for commercial production.

Key words: Thermophilic fungi, Rhizomucor pusillus, pectinase, polygalacturonase