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
• Enzyme Activators analysis   pharmacology   MeSH
• Aspergillus enzymology   growth & development   MeSH
• Dextrans MeSH
• Dithiothreitol MeSH
• Sodium Dodecyl Sulfate MeSH
• Electrophoresis, Polyacrylamide Gel MeSH
• Endo-1,4-beta Xylanases chemistry   isolation & purification   metabolism   MeSH
• Fractional Precipitation MeSH
• Fungal Proteins chemistry   isolation & purification   metabolism   MeSH
• Chromatography, Gel MeSH
• Glycoproteins chemistry   isolation & purification   metabolism   MeSH
• Enzyme Inhibitors analysis   pharmacology   MeSH
• Kinetics MeSH
• Hydrogen-Ion Concentration MeSH
• Culture Media chemistry   MeSH
• Copper analysis   pharmacology   MeSH
• Molecular Weight MeSH
• Ammonium Sulfate chemistry   MeSH
• Mercury Compounds analysis   pharmacology   MeSH
• Enzyme Stability MeSH
• Substrate Specificity MeSH
• Temperature MeSH
• Xylans metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Enzyme Activators MeSH
• Dextrans MeSH
• Dithiothreitol MeSH
• Sodium Dodecyl Sulfate MeSH
• Endo-1,4-beta Xylanases MeSH
• Fungal Proteins MeSH
• Glycoproteins MeSH
• Enzyme Inhibitors MeSH
• Culture Media MeSH
• Copper MeSH
• sephadex MeSH Browser
• Ammonium Sulfate MeSH
• Mercury Compounds MeSH
• Xylans MeSH

Seventy-five fungal strains from different groups of basidiomycetes, newly isolated from rotten wood, were screened for pectinolytic activity. Despite the fact that basidiomycetes are scarcely referred to as pectinase producers, the polygalacturonase (PG) activity was detected in 76% of the strains; 16% with activity higher than 40 nkat/g, 40% between 13.3 and 40 nkat/g, and 44% with activity lower than 13.3 nkat/g. The highest productions were obtained among the fungi from order Aphyllophorales, family Polyporaceae. The characterization of the enzymes from the highest PG producers (Lentinus sp., Gloeophyllum striatum, Pycnoporus sanguineus, Schizophyllum commune) showed optimum temperature for catalytic activity at 60-70 degrees C and two peaks of pH optimum (3.5-4.5 and 8.5-9.5). The enzymes exhibited high pH stability (3.0-11.0) but after incubation at 40 degrees C for 1 h their activity dropped by 18-73%.

• MeSH
• Basidiomycota enzymology   isolation & purification   metabolism   MeSH
• Wood * MeSH
• Hydrogen-Ion Concentration MeSH
• Lentinula enzymology   isolation & purification   metabolism   MeSH
• Environmental Microbiology MeSH
• Pectins metabolism   MeSH
• Polygalacturonase metabolism   MeSH
• Polyporaceae enzymology   isolation & purification   metabolism   MeSH
• Schizophyllum enzymology   isolation & purification   metabolism   MeSH
• Enzyme Stability MeSH
• Temperature MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Pectins MeSH
• Polygalacturonase MeSH

Plastic waste disposal is a huge ecotechnological problem and one of the approaches to solving this problem is the development of biodegradable plastics. This review summarizes data on their use, biodegradability, commercial reliability and production from renewable resources. Some commercially successful biodegradable plastics are based on chemical synthesis (i.e. polyglycolic acid, polylactic acid, polycaprolactone, and polyvinyl alcohol). Others are products of microbial fermentations (i.e. polyesters and neutral polysaccharides) or are prepared from chemically modified natural products (e.g., starch, cellulose, chitin or soy protein).

• MeSH
• Bacteria metabolism   MeSH
• Biodegradation, Environmental MeSH
• Biotechnology methods   MeSH
• Cellulose chemistry   metabolism   MeSH
• Fungi metabolism   MeSH
• Plastics chemical synthesis   metabolism   MeSH
• Polyesters metabolism   MeSH
• Polymers MeSH
• Plants metabolism   MeSH
• Starch chemistry   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Cellulose MeSH
• Plastics MeSH
• Polyesters MeSH
• Polymers MeSH
• Starch MeSH

Synthesis of ethylene in static cultures as well as the effect of endogenous and exogenous ethylene on the synthesis of polygalacturonase by Aspergillus niger were determined. This strain produced maximum ethylene amounts when cultured at 30 degrees C for 3 d. The effect of adding ethylene precursors (citrate-cycle intermediates) on ethylene production was investigated. Best intracellular and extracellular polygalacturonase production was obtained with 2-oxoglutaric, pyruvic and fumaric acids, and with glutamic acid too. Addition of ethylene to the culture medium also increased the synthesis of polygalacturonase, although to a lower degree than when glutamic acid was added.

• MeSH
• Aspergillus niger drug effects   enzymology   growth & development   metabolism   MeSH
• Biomass MeSH
• Citric Acid Cycle MeSH
• Ethylenes biosynthesis   pharmacology   MeSH
• Fumarates pharmacology   MeSH
• Kinetics MeSH
• Culture Media MeSH
• Glutamic Acid pharmacology   MeSH
• Pyruvic Acid pharmacology   MeSH
• Ketoglutaric Acids pharmacology   MeSH
• Polygalacturonase biosynthesis   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• ethylene MeSH Browser
• Ethylenes MeSH
• Fumarates MeSH
• fumaric acid MeSH Browser
• Culture Media MeSH
• Glutamic Acid MeSH
• Pyruvic Acid MeSH
• Ketoglutaric Acids MeSH
• Polygalacturonase 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 enzymology   MeSH
• beta-Glucosidase antagonists & inhibitors   chemistry   isolation & purification   metabolism   MeSH
• Chemical Precipitation MeSH
• Chromatography, Ion Exchange MeSH
• Electrophoresis, Polyacrylamide Gel MeSH
• Chromatography, Gel MeSH
• Kinetics MeSH
• Hydrogen-Ion Concentration MeSH
• Molecular Weight MeSH
• Silver pharmacology   MeSH
• Ultrafiltration MeSH
• Calcium pharmacology   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Brazil MeSH
• Names of Substances
• beta-Glucosidase MeSH
• Silver MeSH
• Calcium MeSH

The production of beta-1,3-glucanases and chitinases by three strains of Trichoderma in submerged cultures was determined. The synthesis of enzymes was induced by cell wall biopolymers of phytopathogenic fungi (Botrytis cinerea, Fusarium culmorum and F. oxysporum). T. hamatum produced the highest beta-1,3-glucanase activity; the most effective inducer of enzyme synthesis was the biomass of F. oxysporum. All examined strains of Trichoderma inhibited phytopathogen growth in biotic tests. The diffusion tests showed that the lytic enzymes take part in growth inhibition of phytopathogenic fungi.

• MeSH
• beta-Glucosidase pharmacology   physiology   MeSH
• Botrytis drug effects   MeSH
• Chitinases pharmacology   MeSH
• Fusarium drug effects   MeSH
• Glucan 1,3-beta-Glucosidase MeSH
• Microbial Sensitivity Tests MeSH
• Plant Diseases microbiology   MeSH
• Substrate Specificity MeSH
• Trichoderma enzymology   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• beta-Glucosidase MeSH
• Chitinases MeSH
• Glucan 1,3-beta-Glucosidase 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 enzymology   growth & development   MeSH
• Fermentation MeSH
• Glycoside Hydrolases metabolism   MeSH
• Hydrolysis MeSH
• Hydrogen-Ion Concentration MeSH
• Culture Media MeSH
• Polysaccharides metabolism   MeSH
• Temperature MeSH
• Crops, Agricultural metabolism   MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Glycoside Hydrolases MeSH
• Culture Media MeSH
• Polysaccharides MeSH