Optimization, purification and characterization of pectinases from pectinolytic strain, Aspergillus foetidus MTCC 10559.

A strain (MPUAT-2), isolated from coconut hull and identified as Aspergillus foetidus MTCC 10559, was used for pectinase production. Optimum pectinase production was obtained at pH 8.0 and temperature 35 degrees C under static conditions in submerged fermentation after 5 days of incubation. Orange peel, a byproduct of fruit industry, was used as a sole carbon source (3% w/v) to produce high pectinase, thus making the process cost effective. The culture filtrate was analyzed for pectin methyl esterase (PME) and endopolygalacturonase (endo-PG) enzymes. The enzymes, PME and endo-PG were purified using ammonium sulphate precipitation and molecular exclusion chromatography (Sephadex G-75) with corresponding recovery of 39.3 and 44.3%. The partially purified enzymes were also characterized for their kinetic properties.

Modified amylopectin based flocculant for the treatment of synthetic effluent and industrial wastewaters.

Herein, we report the application of an efficient polymeric flocculant based on amylopectin grafted with poly (acrylic acid) (g-AP) for the treatment of synthetic effluent as well as various industrial wastewaters. The flocculation characteristics of g-AP have been explored in different pH conditions using silica suspension by measurement of residual turbidity as well as floc size. Results suggest that in acidic pH, patching mechanism is predominating while at neutral and alkaline pH, bridging is the main mechanism. In addition, aggregation of particles and particle collision models confirm that bridging mechanism is the key mechanism at alkaline condition. Further, g-AP demonstrates excellent potential as flocculant for the treatment of paper effluent, textile wastewater and shows better flocculation performance than that of commercially available flocculant. Besides, the pilot scale study of mine processwater suggests excellent efficacy of g-AP as flocculant.

Antioxidative enzymatic profile of mushrooms stored at low temperature.

Fruiting bodies of 6 mushrooms including Agaricus bisporus, Hyspizygus ulmarius, Pleurotus florida PF-01, Pleurotus florida PF-01 R5, Pleurotus platypus and Pleurotus sajor-caju PSC-04 were analyzed for antioxidative enzymatic profile during low temperature storage. Colour, rehydration ratio and moisture were taken as indices of accessing their shelf-life/marketability, of which, colour contributed significantly while rehydration ratio and moisture did not change considerably during storage. Mushrooms were stored at 5 and 10 °C and activities and isozyme profile of antioxidative enzymes, superoxide dismutase (SOD) and peroxidase (POX) were analyzed after every 48 h interval till the fruiting bodies remained marketable. SOD activity increased generally at 5 and 10 °C while POX activity first increased and then decreased under similar conditions. Isozyme profile of SOD and POX did not show any new isozyme during storage, the only difference was in the intensity of bands.