A strain of Aspergillus giganteus cultivated in a medium with xylan produced two xylanases (xylanase I and II) which were purified to homogeneity. Their molar mass, estimated by SDS-PAGE, were 21 and 24 kDa, respectively. Both enzymes are glycoproteins with 50 degrees C temperature optimum; optimum pH was 6.0-6.5 for xylanase I and 6.0 for xylanase II. At 50 degrees C xylanase I exhibited higher thermostability than xylanase II. Hg2+, Cu2+ and SDS were strong inhibitors, 1,4-dithiothreitol stimulated the reaction of both enzymes. Both xylanases are xylan-specific; kinetic parameters indicated higher efficiency in the hydrolysis of oat spelts xylan. In hydrolysis of this substrate, xylotriose, xylotetraose and larger xylooligosaccharides were released and hence the enzymes were classified as endoxylanases.

• MeSH
• aktivátory enzymů analýza   farmakologie   MeSH
• Aspergillus enzymologie   růst a vývoj   MeSH
• dextrany MeSH
• dithiothreitol MeSH
• dodecylsíran sodný MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• endo-1,4-beta-xylanasy chemie   izolace a purifikace   metabolismus   MeSH
• frakční precipitace MeSH
• fungální proteiny chemie   izolace a purifikace   metabolismus   MeSH
• gelová chromatografie MeSH
• glykoproteiny chemie   izolace a purifikace   metabolismus   MeSH
• inhibitory enzymů analýza   farmakologie   MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• kultivační média chemie   MeSH
• měď analýza   farmakologie   MeSH
• molekulová hmotnost MeSH
• síran amonný chemie   MeSH
• sloučeniny rtuti analýza   farmakologie   MeSH
• stabilita enzymů MeSH
• substrátová specifita MeSH
• teplota MeSH
• xylany metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aktivátory enzymů MeSH
• dextrany MeSH
• dithiothreitol MeSH
• dodecylsíran sodný MeSH
• endo-1,4-beta-xylanasy MeSH
• fungální proteiny MeSH
• glykoproteiny MeSH
• inhibitory enzymů MeSH
• kultivační média MeSH
• měď MeSH
• sephadex MeSH Prohlížeč
• síran amonný MeSH
• sloučeniny rtuti MeSH
• xylany MeSH

beta-Glucosidase from the fungus Thermoascus aurantiacus grown on semi-solid fermentation medium (using ground corncob as substrate) was partially purified in 5 steps--ultrafiltration, ethanol precipitation, gel filtration and 2 anion exchange chromatography runs, and characterized. After the first anion exchange chromatography, beta-glucosidase activity was eluted in 3 peaks (Gl-1, Gl-2, Gl-3). Only the Gl-2 and Gl-3 fractions were adsorbed on the gel matrix. Gl-2 and Gl-3 exhibited optimum pH at 4.5 and 4.0, respectively. The temperature optimum of both glucosidases was at 75-80 degrees C. The pH stability of Gl-2 (4.0-9.0) was higher than Gl-3 (5.5-8.5); both enzyme activities showed similar patterns of thermostability. Under conditions of denaturing gel chromatography the molar mass of Gl-2 and Gl-3 was 175 and 157 kDa, respectively. Using 4-nitrophenyl beta-D-glucopyranoside as substrate, Km values of 1.17 +/- 0.35 and 1.38 +/- 0.86 mmol/L were determined for Gl-2 and Gl-3, respectively. Both enzymes were inhibited by Ag+ and stimulated by Ca2+.

• MeSH
• Ascomycota enzymologie   MeSH
• beta-glukosidasa antagonisté a inhibitory   chemie   izolace a purifikace   metabolismus   MeSH
• chemická precipitace MeSH
• chromatografie iontoměničová MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• gelová chromatografie MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• molekulová hmotnost MeSH
• stříbro farmakologie   MeSH
• ultrafiltrace MeSH
• vápník farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Brazílie MeSH
• Názvy látek
• beta-glukosidasa MeSH
• stříbro MeSH
• vápník MeSH

Polysaccharide hydrolase activity was assayed in a group of 28 selected Rhizopus strains. The production of lichenases, mannanases, cellulases, xylanases, amylases and pullulanases was demonstrated using the gel-testing method during growth of the strains on suitably meshed polysaccharide gels.

• MeSH
• fermentace MeSH
• polysacharidy metabolismus   MeSH
• Rhizopus enzymologie   MeSH
• xylosidasy metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• polysacharidy MeSH
• xylosidasy MeSH

Xylanase, beta-glucosidase, beta-xylosidase, endoglucanase and polygalacturonase production from Curvularia inaequalis was carried out by means of solid-state and submerged fermentation using different carbon sources. beta-Glucosidase, beta-xylosidase, polygalacturonase and xylanase produced by the microorganisms were characterized. beta-Glucosidase presented optimum activity at pH 5.5 whereas xylanase, polygalacturonase and beta-xylosidase activities were optimal at pH 5.0. Maximal activity of beta-glucosidase was determined at 60 degrees C, beta-xylosidase at 70 degrees C, and polygalacturonase and xylanase at 55 degrees C. These enzymes were stable at acidic to neutral pH and at 40-45 degrees C. The crude enzyme solution was studied for the hydrolysis of agricultural residues.

• MeSH
• Ascomycota enzymologie   růst a vývoj   MeSH
• fermentace MeSH
• glykosidhydrolasy metabolismus   MeSH
• hydrolýza MeSH
• koncentrace vodíkových iontů MeSH
• kultivační média MeSH
• polysacharidy metabolismus   MeSH
• teplota MeSH
• zemědělské plodiny metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• Názvy látek
• glykosidhydrolasy MeSH
• kultivační média MeSH
• polysacharidy MeSH