Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: KEGG:D03434 (Cellulase)
 512 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A systematic method was designed for the isolation of a large number of protoplasts from an agarophyte alga Gracilaria verrucosa using agarase from a marine bacterium Vibrio sp. PO-303 and commercial enzymes (Cellulase Onozuka RS and Macerozyme R-10). Pretreatment of the tissue with 5% papain at 22 degreesC for 30 min before digestion with polysaccharide-degrading enzymes increased the protoplast yield. Suitable pH and temperature for the polysaccharide-degrading enzyme reaction were 6.5 and 22 degreesC, respectively. Mannitol (0.7 M) was found to be an excellent osmotic stabilizer. When the tissue (1 g, fresh wt.) of G. verrucosa pretreated with 5% papain solution (20 mM MES buffer, pH 7.5, containing 0.7 M mannitol) was digested with an enzyme mixture consisting of 4 units of agarase, 4% Cellulase Onozuka, 2% Macerozyme, and 0.7 M mannitol in 20 mM MES buffer (pH 6.5) with gentle agitation for 150 min at 22 degreesC, 1.03 x 10(8) protoplasts were obtained.
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PMID:Optimization of parameters for isolation of protoplasts from Gracilaria verrucosa (Rhodophyta). 970 45

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

A two-level fractional factorial design (FFD) was used to determine the effects of six factors, i.e. substrate (domestic wastewater sludge - DWS) and co-substrate concentration (wheat flour - WF), temperature, initial pH, inoculum size and agitation rate on the production of cellulase enzyme by Trichoderma harzianum in liquid state bioconversion. On statistical analysis of the results from the experimental studies, optimum process conditions were found to be temperature 32.5 degrees C, substrate concentration (DWS) 0.75% (w/w), co-substrate (WF) concentration 2% (w/w), initial pH 5, inoculum size 2% (v/w) and agitation 175 rpm. Analysis of variance (ANOVA) showed a high coefficient of determination (R2) of 0.975. Cellulase activity reached 10.2 FPU/ml at day 3 during the fermentation process which indicated about 1.5-fold increase in production compared to the cellulase activity obtained from the results of design of experiment (6.9 FPU/ml). Biodegradation of DWS was also evaluated to verify the efficiency of the bioconversion process as a waste management method.
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PMID:Statistical optimization of process conditions for cellulase production by liquid state bioconversion of domestic wastewater sludge. 1798 Oct 27

An ultrafiltration membrane reactor was used to investigate the recovery of biocatalysts during enzymatic hydrolysis of pretreated sallow. Product inhibition could be eliminated by continuous removal of products through the ultrafiltration membrane, thus retaining the macromolecular substrate and enzymes. In this way, the degree of conversion was improved from 40% in a batch hydrolysis to 95% (within 20 h), and the initial hydrolysis rate was increased up to seven times. The recovery studies were focused on mechanical deactivation and irreversible adsorption on to the nonconvertible fraction of the substrate. Cellulase deactivation during mechanical agitation was not significant, and the loss of activity was attributed mainly to strong adsorption of the enzymes onto undigested material. This process was studied in semicontinuous hydrolyses, where fresh substrate was added intermittently. The amount of reducing sugars produced in this experiment was 25.7 g/g enzyme, compared to 4.7 g/g enzyme in a batch hydrolysis.
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PMID:Enzymatic hydrolysis of sodium-hydroxide-pretreated sallow in an ultrafiltration membrane reactor. 1855 25

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

Numerical simulations and experimental validation were performed to understand the effects of hydrodynamics on pellet formation and cellulase production by filamentous T. reesei. The constructed model combined a steady-state multiple reference frame (MRF) approach describing mechanical mixing, oxygen mass transfer, and non-Newtonian flow field with a transient sliding mesh approach and kinetics of oxygen consumption, pellet formation, and enzyme production. The model was experimentally validated at various agitation speeds in a two-impeller Rushton turbine fermentor. Results from simulation and experimentation showed that higher agitation speeds led to increases in the pellet diameter and the proportion of pelletized (vs. filamentous) forms of the biomass. It also led to increase in dissolved oxygen mass transfer rate in shear-thinning fluid and cellulase productivity. The extent of these increases varied considerably among agitation speeds. Pellet formation and morphology were presumably affected within a viscosity-dependent shear-rate range. Cellulase activity and cell viability were shown to be sensitive to impeller shear. A maximum cellulase activity of 3.5 IU/mL was obtained at 400 rpm, representing a twofold increase over that at 100 rpm.
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PMID:Hydrodynamic and kinetic study of cellulase production by Trichoderma reesei with pellet morphology. 2225 72

Effects of nonionic surfactants on enzymatic hydrolysis of Avicel at different agitation rates and solid loadings and the mechanism were studied. Nonionic surfactants couldn't improve the enzymatic hydrolysis efficiency at 0 and 100rpm but could enhance the enzymatic hydrolysis significantly at high agitation rate (200 and 250rpm). Cellulase was easily deactivated at high agitation rate and the addition of nonionic surfactants can protect against the shear-induced deactivation, especially when the cellulase concentration was low. When 25mg protein/L of cellulase solution was incubated at 200rpm for 72h, the enzyme activity increased from 36.0% to 89.5% by adding PEG4600. Moreover nonionic surfactants can compete with enzyme in air-liquid interface and reduce the amount of enzyme exposed in the air-liquid interface. The mechanism was proposed that nonionic surfactants could enhance the enzymatic hydrolysis of Avicel by reducing the cellulase deactivation caused by shear force and air-liquid interface.
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PMID:Nonionic surfactants enhanced enzymatic hydrolysis of cellulose by reducing cellulase deactivation caused by shear force and air-liquid interface. 2903 26