02401nas a2200205 4500008004100000022001400041245011800055210006900173260010200242300001400344490000600358520153300364653003201897653003201929653003101961100001901992700003002011700002602041856012802067 2011 eng d a1930-212600aHyper-production of beta-glucosidase and beta-xylosidase by aspergillus niger NCIM 1207 In Xylan-Containing Media0 aHyperproduction of betaglucosidase and betaxylosidase by aspergi aCAMPUS BOX 8005, RALEIGH, NC 27695-8005 USAbNORTH CAROLINA STATE UNIV DEPT WOOD & PAPER SCIcJAN a2066-20760 v63 a
Aspergillus niger NCIM 1207 produced significantly high levels of beta-glucosidase and beta-xylosidase activities in submerged fermentation. Cellulose induced only beta-glucosidase, while xylan induced both beta-glucosidase and beta-xylosidase activities. Both the enzymes of this strain were found to undergo catabolite repression in the presence of high concentrations of glucose and glycerol. The sudden drop in pH of the fermentation medium below 3.5 caused the inactivation of enzymes when the fungus was grown in glycerol-containing media at lower temperatures. The growth of the organism at 36 degrees C led to an increase in pH of the fermentation above 6.0 that affected beta-xylosidase activity significantly. Highest levels of beta-glucosidase ((19 IU mL(-1) or 633 IU g(-1) of substrate) and beta-xylosidase (18.7 IU/mL(-1) or 620 IU g(-1) of substrate) activities were detected when A. niger was grown at 30 degrees C for first five days followed by further incubation at 36 degrees C. Such a process of growing the organism at lower temperatures (growth phase) followed by producing the enzymes at higher temperatures (production phase) in case of fungal systems has not been reported so far. The zymogram staining of the beta-glucosidase demonstrated that A. niger produced only single species of beta-glucosidase. We feel that A. niger NCIM 1207 is a potential candidate to produce both beta-glucosidase and beta-xylosidase in high amounts that can be used to supplement commercial cellulase preparations.
10aAspergillus niger NCIM 120710abeta-glucosidase production10abeta-xylosidase production1 aKhisti, Ujwala1 aBastawade, Kulbhushan, B.1 aGokhale, Digambar, V. uhttp://library.ncl.res.in/content/hyper-production-beta-glucosidase-and-beta-xylosidase-aspergillus-niger-ncim-1207-xylan-0