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Cellulase Preparation (cellulase + preparation)
Kinds of Cellulase Preparation Selected AbstractsEffect of adsorption characteristics of a modified cellulase on indigo backstainingJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2004Diomi Mamma Abstract The effect of limited proteolysis (digestion) of a commercial cellulase preparation (Ecostone® L350) on backstaining with indigo was investigated. The influence of protease (papain) concentration on limited proteolysis of cellulase preparation was studied, applying different ratios of papain/cellulase (w/w). Changes in adsorption on Avicel cellulose of the non-digested compared with the papain-digested Ecostone® L350 were examined using the Langmuir adsorption isotherm. The non-digested Ecostone® L350 exhibited stronger interaction to Avicel cellulose compared with the digested form, while the maximum efficiency of cellulase adsorption to Avicel cellulose decreased after digestion. When papain-digested Ecostone® L350 was applied on cotton fabrics during the dyeing procedure with indigo, a reduction of indigo backstaining was obtained compared with the non-digested Ecostone® L350. Copyright © 2004 Society of Chemical Industry [source] Relationships between the addition rates of cellulase or glucose and silage fermentation at different temperaturesANIMAL SCIENCE JOURNAL, Issue 3 2010Jian-Guo ZHANG ABSTRACT The influence of the application rates of cellulase preparation and glucose on silage fermentation at different temperatures was studied with the straw of naked barley (Hordeum vulgare L. emand Lam) and guineagrass (Panicum maximum Jacq.). Addition rate of cellulase and glucose, temperature and their interaction had significant effects on pH value, lactic acid content, butyric acid content and propionic acid content of naked barley straw silage and significant effects on all the parameters of guineagrass silage (P < 0.01). Temperature and interaction had significant effect on acetic acid content (P < 0.05) and no significant effect on NH3 -N content of naked barley straw silage (P > 0.05). Under all the temperatures, the pH values of barley straw and guineagrass silages were reduced by cellulase and glucose addition even at the lowest rate (P < 0.05), compared with their corresponding control. Lactic acid contents of silages were the highest within the same temperature and same additive when glucose and cellulase were added at the highest rates, whereas the effect of cellulase and glucose addition on butyric acid production varied with their application rates and silage storage temperature. The addition rate of restricting butyric acid fermentation was lower at 20°C than that at 30°C, and it was the lowest at 40°C where cellulase and glucose addition restricted butyric acid fermentation even at 0.1 g/kg and 10 g/kg, respectively, when compared to the control. While the addition rate was lower than the above level, cellulase and glucose addition also promoted butyric acid fermentation. [source] Optimization of enzyme complexes for lignocellulose hydrolysisBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2007Alex Berlin Abstract The ability of a commercial Trichoderma reesei cellulase preparation (Celluclast 1.5L), to hydrolyze the cellulose and xylan components of pretreated corn stover (PCS) was significantly improved by supplementation with three types of crude commercial enzyme preparations nominally enriched in xylanase, pectinase, and ,-glucosidase activity. Although the well-documented relief of product inhibition by ,-glucosidase contributed to the observed improvement in cellulase performance, significant benefits could also be attributed to enzymes components that hydrolyze non-cellulosic polysaccharides. It is suggested that so-called "accessory" enzymes such as xylanase and pectinase stimulate cellulose hydrolysis by removing non-cellulosic polysaccharides that coat cellulose fibers. A high-throughput microassay, in combination with response surface methodology, enabled production of an optimally supplemented enzyme mixture. This mixture allowed for a ,twofold reduction in the total protein required to reach glucan to glucose and xylan to xylose hydrolysis targets (99% and 88% conversion, respectively), thereby validating this approach towards enzyme improvement and process cost reduction for lignocellulose hydrolysis. Biotechnol. Bioeng. 2007;97: 287,296. © 2006 Wiley Periodicals, Inc. [source] The effect of hydration time and ethanol concentration on the rate of hydrolysis of extracted vanilla beans by commercial cellulase preparationsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2005Sandy L. Ovando Summary The rate of producing reducing sugars from extracted vanilla beans by using cellulolytic enzymes was studied. The hydration of cellulose improved the efficiency of hydrolysis. The treatment using Crystalzyme PML-MX at a concentration of 2.64 International Filter Paper Units (IFPU) g,1 of bean was the most successful and the enzyme stable for up to 5:100 (weight:volume) of ethanol. After 48 h of prehydration and 26 h of enzymatic hydrolysis with this enzyme preparation, 196.6 mg g,1 reducing sugars containing 15.9 mg g,1 glucose were liberated. Less active enzyme products, Zymafilt L-300 and Novozym, had greater cellulolytic activity when 10 or 15:100 (weight:volume) of ethanol were added respectively. Because of their stability with ethanol, the enzyme products could be used in the pretreatment of botanical material that are rich in flavour compounds and in this manner improve the final extraction of valuable flavours. [source] Standard assays do not predict the efficiency of commercial cellulase preparations towards plant materialsBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2006Mirjam A. Kabel Abstract Commercial cellulase preparations are potentially effective for processing biomass feedstocks in order to obtain bioethanol. In plant cell walls, cellulose fibrils occur in close association with xylans (monocotyls) or xyloglucans (dicotyls). The enzymatic conversion of cellulose/xylans is a complex process involving the concerted action of exo/endocellulases and cellobiases yielding glucose and xylanases yielding xylooligomers and xylose. An overview of commonly measured cellulase-, cellobiase-, and xylanase-activity, using respectively filter paper, cellobiose, and AZCL-dyed xylan as a substrate of 14 commercially available enzyme preparations from several suppliers is presented. In addition to these standardized tests, the enzyme-efficiency of degrading native substrates was studied. Grass and wheat bran were fractionated into a water unsoluble fraction (WUS), which was free of oligosaccharides and starch. Additionally, cellulose- and xylan-rich fractions were prepared by alkaline extraction of the WUS and were enzymatically digested. Hereby, the capability of cellulose and xylan conversion of the commercial enzyme preparations tested was measured. The results obtained showed that there was a large difference in the performance of the fourteen enzyme samples. Comparing all results, it was concluded that the choice of an enzyme preparation is more dependent on the characteristics of the substrate rather than on standard enzyme-activities measured. © 2005 Wiley Periodicals, Inc. [source] Influence of xylan on the enzymatic hydrolysis of steam-pretreated corn stover and hybrid poplarBIOTECHNOLOGY PROGRESS, Issue 2 2009Renata Bura Abstract The focus of this study was to alter the xylan content of corn stover and poplar using SO2 -catalyzed steam pretreatment to determine the effect on subsequent hydrolysis by commercial cellulase preparations supplemented with or without xylanases. Steam pretreated solids with xylan contents ranging from ,1 to 19% (w/w) were produced. Higher xylan contents and improved hemicellulose recoveries were obtained with solids pretreated at lower severities or without SO2 -addition prior to pretreatment. The pretreated solids with low xylan content (<4% (w/w)) were characterized by fast and complete cellulose to glucose conversion when utilizing cellulases. Commercial cellulases required xylanase supplementation for effective hydrolysis of pretreated substrates containing higher amounts of xylan. It was apparent that the xylan content influenced both the enzyme requirements for hydrolysis and the recovery of sugars during the pretreatment process. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] | |||||||||||||