Production and characterization of a thermo-pH stable pectinase from Bacillus licheniformis UNP-1: A novel strain isolated from Unapdev hot spring

摘要

An efficient thermostable pectinase producer was isolated from the hot water spring of Unapdev and identified as Bacillus licheniformis UNP-1 using culture-dependent techniques by its morphological, microscopic, biochemical, physiological and molecular characteristics. Thermostable pectinase production was optimized in a submerged fermentation system using modified fermentation medium (MFM). The optimized components of MFM performed by changing one parameter at a time were pectinase defined liquid medium containing (g/L) 10 pure Pectin, 2.0 KH2PO4, 6.0 K2HPO4, 2.0 MgSO4 center dot 7H(2)O Optimized culture conditions were used for thermostable pectinase production. Bacillus licheniformis UNP-1 produced 55.2 U/mL of pectinase. Optimum pH and temperature for the production were 9 and 60 degrees C, respectively with 48 hours of incubation. The pectinase enzyme showed maximum activity at pH 11 and at 80 degrees C. Pectinolytic activity was the highest in the presence of Fe3+ metal ion. Optimum catalytic activity was recorded at substrate concentration of polygalacturonic acid of 3.5% after 90 min of incubation. The molecular mass of the dialyzed thermostable pectinase was 35 kDa. Partially purified pectinase enzyme was used for fruit juice extraction and clarification.