Enzymatic activities cellulasic

Dry bean curd refuse was used as the substrate in the lactic acid fermentation with simultaneous saccharification (SSF). The dry bean curd refuse was preliminarily sieved under a mesh size of 250 II m. It contained 12.3% water, 4.0% ash, 0.8% lipid, 29.3% protein, 53.6% carbohydrate, respectively, in weight basis. The cellulase derived from Aspergilltis niger with an enzymatic activity of 25,000 units/g (Tokyo Kasei Industry Inc.) was employed as the saccharification enzyme. 

The extracellular cellulolytic activities, CM-cellulase and Avicelase, are stable over 24 hr at 55°C in the pH range of 6.0-7.3, which suggests that no enzymatic activity would be lost in a saccharification under these conditions and that the enzymes would be recoverable. 

E. T. Reese We have found that nearly all cellulolytic organisms, where cellulase is induced, do produce small amounts of constitutive enzyme, very very low levels. Your measurements here indicate similar very low levels of enzymatic activity. Under the conditions that you use I notice that the glucose did not disappear very rapidly. In our work on cellulase induction, we actually try to reduce the rate at which the substrate is consumed. I am wondering whether your conditions, where it is obvious that the organism wasn t very happy with its environment, were actually limiting growth and so stimulating induction ... 

Table VI. Enzymatic Activities of Adsorbed, and Non-adsorbed Fractions in Tricboderma Cellulase...

Cellulolytic enzymes are common in marine lignicolous fungi [6,7]. Around 25% of the 40 species tested by Rohrmann [20] showed the same cellulase activity as Sporotrichum pulverulentum, a strongly cellulolytic terrestrial deuteromycotina. In salt-marsh species, enzymatic activity against carboxymethylcellulose was found in 100% of the 19 species... 

Enzymes acting on molecules like cellulose, which are insoluble and of similar, or even greater size than themselves, obviously require delicate tertiary structures comparison of the sequence of approximately 50 fungal and bacterial cellulase genes and of some other polysaccharide hydrolase (for review see [8]) has offered evidence that such proteins are composed of separate domains, which allow a spacial separation of the sites involved in substrate recognition and enzymatic activity. 

First evidence for a domain organization of the T. reesei cellulases came from the finding that partial proteolysis by papain can cleave CBH I and CBH II into an enzymatic active core , and a cellulose adsorbing tail domain [9,10]. These studies were complemented by data on the gene sequences of four main cellulase components from T. reesei (CBH I, CBH II, EG I, EG III), which revealed a strikingly conserved terminal domain in all four species [11], which is joined to the rest of the protein by a similarly conserved hinge domain (Fig. 1). 

The enzymatic activity and ethanol formation abilities of Fusarium oxysporum makes it ideal for a simultaneous saccharification and biological conversion process [82]. Birch wood containing high xylose content, was used for the simultaneous saccharification and biological conversion test [82]. The birch chips were steam-treated at 185 °C for 30 min. Cellulase from Trichoderma reesei and either Saccharomyces cerevisiae or Fusarium oxysporum were used for the simultaneous saccharification and biological conversion process. Rates of hydrolysis and bioconversion were studied by varying the amount of T. reesei cellulase, since the... 

Selective inactivation of cellulase activities is another method which has been applied to fungal culture filtrates to produce cellulase-free xylanase preparations. Cellulase inactivation of a crude enzymatic complex was achieved by Barnoud et al. (15) using a 1 mM mercuric chloride solution. In the presence of this sulfhydryl binding metal, complete inactivation of endocellulases was observed whereas the xylanases retained 80% of their activity. 

For enzymatic degradation, culture filtrates of selected strains of Trichoderma viride ( Cellulase T ) and Gliocladium spec. ( Cellulase G ) were used, strains being selected by screening with respect to Ci activity. Generally, 1-g samples of substrate were incubated at 40°C with a mixture of 80 ml of culture filtrate and 20 ml of acetate buffer (pH = 5.0) for 12 to 170 hours. 

The categories of substrates which are used for assays of cellulase enzymes are shown in Table I. The use of crystalline, insoluble forms of cellulose as substrates makes assays difficult and has led to such trivial names as Avicelase activity. These assays are useful as indications of the capacity of an enzyme system to degrade native cellulose and indicate the presence of CBH enzyme which cannot be assayed in the presence of endoglucanases or / -glucosidase. The susceptibility to enzymatic attack generally increases with the hydration of the polymer chains that accom-... 

Lignocellulosic biomass is a valuable and plentiful feedstock commodity and its high cellulose and hemicellulose content (about 80% of total) provides considerable potential for inexpensive sugars production. However, enzymatic deconstruction of these polysaccharides remains a costly prospect. Strides in cellulase cost reduction have been made, yet further improvements are needed to reach the goal of 0.10/gal of EtOH expected to enable this new industry. Strategies to reach this goal will combine reduction in the cost to produce the needed enzymes as well as efforts to increase enzyme efficiency (specific activity). As this work proceeds, the more easily attained achievements will be made first, and thus the overall difficulty increases with time. 

Although most cellulase enzyme complexes, including Celluclast, contain xylanase activity (data not shown), the amount of released xylose after enzymatic hydrolysis was negligible, especially compared with the amount of released xylose after pretreatment. 

Three enzymatic mixtures with predominantly cellulase and xylanase activity were used for the saccharification tests. To hydrolyse the cellulose, the mixtures Celluclast 1.5L and Novozym 188 from Novo Nordisk were... 

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