Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.21 (beta-glucosidase)
 3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the course of screening amylase inhibitor producing, microorganisms, a strain identified as Streptomyces nigrifaciens NTU-3314 was found to have the highest inhibitor-producing ability among the other isolated strains. This strain was aerobically cultured at 30 degrees C in a 5l jar fermentor with a working volume of 2l. The optimum cultural medium consisted of defatted soybean flake 3.0%, potato starch 4.0%, casein 0.6%, sucrose 0.6%, serine 0.02% and NaCl 0.8% (pH 7.0). With an aeration rate of 1.5 vvm, an agitation speed of 300 rpm and an inoculum of 15% seed (previously grown in seed medium 3), the highest amount of inhibitor was obtained after 24 hours of cultivation. The amylase inhibitor produced had inhibitory effects on both alpha-amylase and glucoamylase, but not on beta-amylase, alpha-glucosidase, beta-glucosidase or dextranase. It was quite stable in 0.1M phosphate buffer (pH 7.0) and nearly 100% of its activity was retained even after boiling at 100 degrees C for 20 min.
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PMID:The microbial production of amylase inhibitor and its application. I. Isolation and cultivation of Streptomyces nigrifaciens NTU-3314. 608 1

Shake-flask cultivation of T. lanuginosus strain SSBP on coarse corn cobs yielded beta-xylanase levels of 56,500 nkat/ml at 50 degrees C, whereas other hemicellulases (beta-xylosidase, beta-glucosidase, and alpha-L-arabinofuranosidase) were produced at levels less than 7 nkat/ml. Cultivation on D-xylose yielded much lower levels of xylanase (350 nkat/ml), although other hemicellulase levels were similar to those produced on corn cobs. The influence of agitation rate and dissolved oxygen tension (DOT) on hemicellulase production was studied further in a bioreactor. On xylose, xylanase activities of 4,330 nkat/ml and 4,900 nkat/ml were obtained at stirrer speeds up to 1,400 rpm to control DOT. At a constant stirrer speed of 400 rpm, xylanase activities of 10,930 nkat/ml and 15,630 nkat/ml were obtained when cultivated on xylose and beechwood xylan respectively, despite DOT levels below 5% for the duration of fermentation. The results indicate that there is an interaction between agitation rate and DOT, impacting on xylanase and accessory enzyme production. Higher agitation rates favoured the production of xylosidase, arabinofuranosidase and glucosidase by T. lanuginosus strain SSBP, whereas the lower agitation rates favoured xylanase production. Rheological difficulties precluded cultivation on corn cobs in the bioreactor. Volumetric xylanase productivities of 1,060,000 nkat/l x h and 589,000 nkat/l x h obtained on beechwood xylan and xylose indicate that T. lanuginosus strain SSBP is a hyperxylanase producer with considerable industrial potential.
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PMID:The production of hemicellulases by Thermomyces lanuginosus strain SSBP: influence of agitation and dissolved oxygen tension. 1113 98

Softwood is an interesting raw material for the production of fuel ethanol as a result of its high content of hexoses, and it has attracted attention especially in the Northern hemisphere. However, the enzymatic hydrolysis of softwood is not sufficiently efficient for the complete conversion of cellulose to glucose. Since an improvement in the glucose yield is of great importance for the overall economy of the process, the influence of various parameters on the cellulose conversion of steam-pretreated spruce has been investigated. The addition of beta-glucosidase up to 50 IU g(-)(1) cellulose to the enzymatic hydrolysis process resulted in increased cellulose conversion at a cellulase loading up to 48 FPU g(-)(1) cellulose. Despite very high enzyme loading (120 FPU g(-)(1) cellulose) only about 50% of the cellulose in steam-pretreated spruce was converted to glucose when all of the material following pretreatment was used in the hydrolysis step. The influence of temperature, residence time, and pH were investigated for washed pretreated spruce at a dry matter (DM) content of 5% and a cellulase activity of 18.5 FPU g(-)(1) cellulose. The optimal temperature was found to be dependent on both residence time and pH, and the maximum degree of cellulose conversion, 69.2%, was obtained at 38 degrees C and pH 4.9 for a residence time of 144 h. However, when the substrate concentration was changed from 5% to 2% DM, the cellulose conversion increased to 79.7%. An increase from 5% to 10% DM resulted, however, in a similar degree of cellulose conversion, despite a significant increase in the glucose concentration from 23 g L(-)(1) to 45 g L(-)(1). The deactivation of beta-glucosidase increased with increasing residence time and was more pronounced with vigorous agitation.
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PMID:Influence of enzyme loading and physical parameters on the enzymatic hydrolysis of steam-pretreated softwood. 1117 Apr 88

Shear deactivation of cellulase and its major component enzymes, viz., exoglucanase (exo-1,4-beta-D-glucan-4-cellobiohydrolase), endoglucanase (endo-1,4-beta-D-glucanhydrolase), and 1,4-beta-glucosidase, was carried out by exposing cellulase to shear in a mechanically agitated reactor in the presence as well as in the absence of the substrate cellulose. Cellulase was found to undergo deactivation when subjected to shear, and the extent of deactivation increased with increasing speed of agitation. Among the three major component enzymes of cellulase, exoglucanase showed rapid deactivation and contributed the most to cellulase deactivation. The presence of a substrate did not affect the deactivation of cellulase.
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PMID:Shear deactivation of cellulase, exoglucanase, endoglucanase, and beta-glucosidase in a mechanically agitated reactor. 1173 55

Thermostable cellulase was produced by Streptomyces sp. T3-1 grown in a 50-l fermenter. Maximum cellulase activity was attained on the fourth day when agitation speeds and aeration rates were controlled at 300 rpm and 0.75 vvm, respectively. Maximum enzyme activities were: 148 IU CMCase ml(-1), 45 IU Avicelase ml(-1), and 137 IU beta-glucosidase ml(-1) with productivity of 326 IU l(-1) h(-1), which were 10-32% higher than the values obtained in shake-flask cultures.
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PMID:Thermostable cellulases from Streptomyces sp.: scale-up production in a 50-l fermenter. 1574 43

The hydrolytic activity of fungal originated beta-glucosidase is exploited in several biotechnological processes to increase the rate and extent of saccharification of several cellulosic materials by hydrolyzing the cellobiose which inhibits cellulases. In a previous presentation, we reported the screening and liquid fermentation with Aspergillus niger, strain C-6 for beta-glucosidase production at shake flask cultures in a basal culture medium with mineral salts, corn syrup liquor, and different waste lignocellulosic materials as the sole carbon source obtaining the maximum enzymatic activity after 5-6 d of 8.5 IU/mL using native sugar cane bagasse. In this work we describe the evaluation of fermentation conditions: growth temperature, medium composition, and pH, also the agitation and aeration effects for beta-glucosidase production under submerged culture using a culture media with corn syrup liquor (CSL) and native sugar cane bagasse pith as the sole carbon source in a laboratory fermenter. The maximum enzyme titer of 7.2 IU/mL was obtained within 3 d of fermentation. This indicates that beta-glucosidase productivity by Aspergillus niger C-6 is function of culture conditions, principally temperature, pH, culture medium conditions, and the oxygen supply given in the bioreactor. Results obtained suggest that this strain is a potential microorganism that can reach a major level of enzyme production and also for enzyme characterization.
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PMID:Effect of media composition and growth conditions on production of beta-glucosidase by Aspergillus niger C-6. 1591 12

Cellulase producing activity of Trichoderma reesei QM9414 was examined under various agitation intensities and at the dissolved oxygen concentration above 3 ppm. The producing activity greatly depended upon the agitation intensity, and the dependence on the agitation was different for each cellulase-constituting component. The maximum producing activities of FPA, CM Case, and beta-glucosidase were obtained under different agitation conditions, 1.0, 0.7, and 1.4 m/s in tip velocity, respectively. Intensive agitation brought about remarkable reduction in all cellulase components. The mycelial transformation through agitation intensity was also observed. Comparatively mild agitation of 0.3-1.0 m/s caused pellet formation as the culture progressed, although the pelletization was delayed with increasing agitation intensity. The behavior of the pelletization did not occur at 1.3 and 1.7 m/s throughout the course of cultivation, and under the latter agitation condition hyphae were broken up into short fragments. The cellulase producing activity is discussed in relation to such morphological changes.
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PMID:Variation in cellulase-constituting components from Trichoderma reesei with agitation intensity. 1858 82

beta-Glucosidase production by Debaryomyces pseudopolymorphus UCLM-NS7A using a simple nutrient medium containing cellobiose was evaluated under several biochemical and physiological parameters in submerged fermentation. Enzyme induction was also examined using different carbon and nitrogen sources. Cellobiose and ammonium nitrate were the best C and N sources to enhance beta-glucosidase production. The addition of NaCl, MgSO(4), yeast extract, ethanol and Tween 80 to the nutrient medium before inoculation was also compared. A factorial design to optimize enzyme production was developed using four variables that most influenced beta-glucosidase production and data analyzed by the response surface method. Optimal conditions to produce beta-glucosidase in shake-flasks were 1.25% cellobiose, 0.05% Tween 80, 0.4% NH(4)NO(3) over 72 hours. In another factorial design to further increase enzyme production, a lab fermenter using prior-determined shake-flask optimized conditions resulted in higher beta-glucosidase titres at 72 hours, pH controlled at 6.25 and agitation of 200 rpm.
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PMID:Extracellular beta-glucosidase production by the yeast Debaryomyces pseudopolymorphus UCLM-NS7A: optimization using response surface methodology. 2049 76