Characterization of a neutral pectin lyase produced by Oidiodendron echinulatum MTCC 1356 in solid state fermentation

Abstract

A neutral pectin lyase produced by a new fungal strain Oidiodendron echinulatum MTCC 1356 under solid state fermentation using wheat bran as agro waste has been studied. The enzyme was purified by ammonium sulphate precipitation (30-60%), DEAE anion exchange and Sephadex G-100 column chromatographies. The SDS-PAGE and native PAGE revealed two bands of sizes 42 and 47 kDa. The enzyme was purified 37 fold with specific activity of 4.5 U/mg and 2.25% yield. The K(m) and V(max) values determined using citrus pectin were 1.2 mg/ml and 0.36 IU/min respectively. The pH and temperature optima were pH 7.0 and 50 °C, respectively. The pH stability was around 5.0 for 24 h at 20 °C. The purified enzyme retained maximum activity for 30 min upto 50 °C. The activation energy for thermal denaturation of the purified enzyme was found to be 60.0 kJ/Mol. The effects of various metal ions and protein inhibitors on enzyme activity have revealed total inhibition of the enzyme activity in the presence of Ag(+) and Cu(+) and KMnO(4) at 1 mM. The neutral pectin lyase showed retting of Crotalaria juncea fibre in the presence of EDTA.