The cellulase of Penicillium pinophilum. Synergism between enzyme components in solubilizing cellulose with special reference to the involvement of two immunologically distinct cellobiohydrolases

Two immunologically unrelated cellobiohydrolases (I and II), isolated from the extracellular cellulase system elaborated by the fungus Penicillum pinophilum, acted in synergism to solubilize the microcrystalline cellulose Avicel; the ratio of the two enzymes for maximum rate of attack was approx. 1:1. A hypothesis to explain the phenomenon of synergism between two endwise-acting cellobiohydrolases is presented. It is suggested that the cellobiohydrolases may be two stereospecific enzymes concerned with the hydrolysis of the two different configurations of non-reducing end groups that would exist in cellulose. Only one type of cellobiohydrolase has been isolated so far from the cellulases of the fungi Fusarium solani and Trichoderma koningii. Only cellobiohydrolase II of P. pinophilum acted synergistically with the cellobiohydrolase of the fungi T. koningii or F. solani to solubilize Avicel. Cellobiohydrolase II showed no capacity for co-operating with the endo-1,4-beta-glucanase of T. koningii or F. solani to solubilize crystalline cellulose, but cellobiohydrolase I did. These results are discussed in the context of the hypothesis presented.

Isolation and characterization of the 1,4-beta-D-glucan glucanohydrolases of Talaromyces emersonii

Culture filtrates of Talaromyces emersonii were found to contain four endocellulases termed I, II, III and IV, the last having the greatest electrophoretic mobility towards the anode in homogeneous 5%-(w/v)-polyacrylamide gels at pH 4.5. All four are glycoproteins, the carbohydrate contents being: I, 27.7%; II, 29.0%; III, 44.7%; IV, 50.8. Each form is eluted as a single peak corresponding to an Mr value of 68000 on gel filtration at pH 3.5 and as a single band corresponding to an Mr value of 35000 on reductive sodium dodecyl sulphate/polyacrylamide-gradient-gel electrophoresis. However, we believe that the latter represents the native Mr value. The pI values for each lie between pH 2.8 and 3.2. Activity in each case is optimal at pH 5.5-5.8 and at 75-80 degrees C. Half-life values at pH5 and 75 degrees C were from 2 to 4h. The specific activity with any individual substrate was much the same for each enzyme, as was the ratio of activity from one substrate to the next. Possible reasons for the observation that plots of velocity versus substrate concentration are sigmoidal are discussed. We believe that the finding of four endocellulases reflects differential glycosylation of a single enzyme form rather than genetically determined differences in primary structure.

Some properties of the endo-(1 → 4)-β-D-glucanase synthesized by the anaerobic cellulolytic rumen bacterium Ruminococcus albus

The extracellular and cell-bound cellulase (CM-cellulase) elaborated by the rumen bacterium Ruminococcus albus SY3 in synthetic medium was an endo-(1 → 4)-β-glucanase in that (i) it produced a rapid fall in the degree of polymerisation (1900 → 300) of H3PO4-swollen cellulose, while causing only 0.5% hydrolysis, and (ii) it released large amounts of cellotriose and smaller amounts of cellotetraose from H3PO4-swollen cellulose. The enzyme appeared in a wide range of molecular weights, which varied according to the culture conditions, but nevertheless focused at pH 6.0–6.1 in all cases in a pH gradient supported in a polyacrylamide gel. Cell-bound enzyme, which was of very large molecular weight (> 1.5 × 106), was excluded from the polyacrylamide gel. Under certain conditions, cellulose swollen in H3PO4 was hydrolysed extensively, but highly ordered cellulosic substrates were poorly hydrolysed. The enzyme acted synergistically with an endwise-acting cellobiohydrolase from the fungus Trichoderma koningii in solubilizing a microcystalline wood α-cellulose preparation (Avicel): the same cooperation was not apparent when Avicel was swollen in H3PO4 or when cellulose in the form of cotton fibre was used.

Comparison of AOAC and Atomic Absorption Spectrophotometry Methods for Determining Sodium in Fertilizers: Collaborative Study

A collaborative study was carried out to compare AOAC method 2.147-2.150 for determining sodium in fertilizers with the atomic absorption spectrophotometric (AAS) method. Twelve synthetic NPK samples, 6 pairs of blind duplicates (0.06-8.5% Na), were sent to 22 collaborators; a total of 13 sets of results were received and evaluated by the modified matched pairs technique. The AAS method showed better performance in samples with low sodium content and high potassium content. The AAS method has been adopted official first action for determining sodium in fertilizers.

Preparation of the cellulase from the cellulolytic anaerobic rumen bacterium Ruminococcus albus and its release from the bacterial cell wall

1. Most of the cellulase (CM-cellulase) elaborated by the rumen bacterium Ruminococcus albus strain SY3, which was isolated from a sheep, was cell-wall-bound. 2. The enzyme could be released readily by washing either with phosphate buffer or with water. 3. The amount of enzyme released was affected by the pH and ionic strength of the phosphate buffer. 4. The cell-wall-bound enzyme was of very high molecular weight (>>1.5x10(6)) as judged by its chromatographic behaviour on Sephacryl S-300. 5. The molecular weight of the extracellular enzyme was variable and depended on the culture conditions. 6. When cellobiose was used as the energy source and the medium contained rumen fluid (30%), the extracellular enzyme was, in the main, of high molecular weight. 7. When cellulose replaced the cellobiose, the cell-free culture filtrate contained only low-molecular-weight enzyme (M(r) approx. 30000) in late-stationary-phase cultures (7 days). 8. Cultures that did not contain rumen fluid contained mainly low-molecular-weight enzyme. 9. Under some conditions the high-molecular-weight enzyme could be broken down to some extent into low-molecular-weight enzyme by treatment with dissociating agents. 10. Cell-free and cell-wall-bound enzymes showed the same relationship when the change in fluidity effected by them on a solution of CM-cellulose was plotted against the corresponding increase in reducing sugars, suggesting that the enzymes were the same. 11. It is possible that R. albus cellulase exists as an aggregate of low-molecular-weight cellulase components on the bacterial cell wall and in solution under certain conditions.

Physical activity and sport: attitudes and perceptions of young Canadian athletes

The failure of the literature to report consistent attitude-behaviour relationships or show evidence of stability in children's attitudes toward physical activity (CATPA) led to an examination of the construct physical activity as an attitude object. Five hundred and fifty young male and female athletes were surveyed to obtain the following information; CATPA, children's attitudes toward the specific sport (CATSS) in which they were involved, and the activities perceived to be representative of six physical activity subdomains. Significant differences among sport groups were found in three of the attitude subdomains, the most noticeable being for females in the Aesthetic subdomain. In general, the athletes' perceived physical activities represented the sport in which they were participating. The small differences between CATPA and CATSS mean scores, along with the results of both canonical analysis and factor analysis, led to the conclusion that children's attitudes toward the construct physical activity are essentially equivalent to their attitudes toward a specific sport. The validity of physical activity as a well defined attitude object ws substantiated for young Canadian athletes.

The isolation, purification and properties of the cellobiohydrolase component of Penicillium funiculosum cellulase

1. A cellobiohydrolase component was isolated from a Penicillium funiculosum cellulase preparation by chromatography on DEAE-Sephadex, and purified by isoelectric focusing. 2. Purified in this way, the enzyme was homogeneous as judged by electrophoresis on sodium dodecyl sulphate/polyacrylamide gels and isoelectric focusing in polyacrylamide gels. 3. Acting in isolation, the enzyme had little hydrolytic activity to highly ordered celluloses such as cotton fibre, but, when recombined in the original proportions with the other components [endo-(1 leads to 4)-beta-D-glucanase and beta-D-glucosidase] of the complex, 98% of the original activity was recovered. 4. Synergistic effects were also observed when the enzyme was acting in concert with endo-(1 leads to 4)-beta-D-glucanase from other fungal sources. 5. Less-well-ordered celluloses, such as that swollen in H3PO4, were extensively hydrolysed, the principal product being cellobiose. 6. Attack on carboxymethyl-cellulose (CM-cellulose), which is the substrate normally used to assay for endo-(1 leads to 4)-beta-D-glucanase activity, was minimal. 7. The enzyme was associated with 9% of neutral sugar, 88% of which was mannose. It was isoelectric at pH 4.36 (4 degrees C) and had a mol.wt. of 46 300 (determined by gel chromatography on a calibrated column of Ultrogel). 8. The enzyme was specific for the beta-(1 leads to 4)-linkage.

The cellulase of Trichoderma koningii. Purification and properties of some endoglucanase components with special reference to their action on cellulose when acting alone and in synergism with the cellobiohydrolase

1. Four principal endoglucanase components of Trichoderma koningii cellulase were separated and purified by gel filtration on Sephadex G-75, ion-exchange chromatography on DEAE- and sulphoethyl-Sephadex and isoelectric focusing. 2. All four endoglucanases hydrolysed CM-cellulose, H3PO4-swollen cellulose, cellotetraose and cellopentaose, but differed in the rate and mode of attack. 3. Attack on cotton fibre by the endoglucanases was minimal, but resulted in changes that were manifested by an increased capacity for the uptake of alkali, and a decrease in tensile strength. 4. All four endoglucanases acted synergistically with the exoglucanase [cellobiohydrolase; Wood & McCrae (1972) Biochem. J. 128, 1183-1192] of T. koningii during the early stages of the breakdown of cotton fibre, but only two could produce extensive solubilization of cotton cellulose when acting in admixture with the exoglucanase component. 5. The mode of action of the enzymes is discussed in relation to these synergistic effects. It is suggested that the results are compatible with the interpretation that the 'crystalline' areas of cotton cellulose are hydrolysed only by those endoglucanases capable of forming of forming an enzyme-enzyme complex with the cellobiohydrolase on the surface of the cellulose chains.

Cellulase from Fusarium solani: purification and properties of the C1 component

The C1 component from Fusarium solani cellulase was purified extensively by molecular-sieve chromatography on Ultrogel AcA-54 and ion-exchange chromatography on DEAE-Sephadex. The purified component showed little capacity for hydrolysing highly ordered substrates (e.g., cotton fibre), but poorly ordered substrates (e.g., H3PO4-swollen cellulose), and the soluble cello-oligosaccharides cellotetraose and cellohexaose, were readily hydrolysed; cellobiose was the principal product in each case. Attack on O(-carboxymethyl)cellulose, a substrate widely used for measuring the activity of the randomly acting enzymes (Cx enzymes) of the cellulase complex, was minimal, and ceased after the removal of a few unsubstituted residues from the end of the chain. These observations, and the fact that the rate of change of degree of polymerisation of H3PO4-swollen cellulose was very slow compared with that effected by the randomly acting endoglucanases (Cx, CM-cellulases), indicate that C1 is a cellobiohydrolase. Fractionation by a variety of methods gave no evidence for the non-identity of the cellobiohydrolase and the component that acted in synergism with the randomly acting Cx enzyme when solubilizing cotton fibre.

The purification and properties of the C 1 component of Trichoderma koningii cellulase

1. The C(1) component that was isolated from a Trichoderma koningii cellulase preparation (Wood, 1968) by chromatography on DEAE-Sephadex with a salt gradient was still associated with a trace of CM-cellulase activity (determined by reducing-sugar and viscometric methods). 2. Further chromatography on DEAE-Sephadex, with a pH gradient instead of a salt gradient, provided a C(1) component that could still produce reducing sugars from a solution of CM-cellulose (to a very limited extent), but which could no longer decrease the viscosity (i.e. under the assay conditions employed). 3. No evidence for the non-identity of C(1) component and the trace of CM-cellulase activity could be found when electrofocusing was done in a stabilized pH gradient covering three pH units (pH3-6) or, alternatively, only 0.5 pH unit (pH3.72-4.25). 4. The two protein peaks that were separated by electrofocusing in carrier ampholytes covering only 0.5 pH unit (isoelectric pH values of 3.80 and 3.95) were shown to be isoenzymes of the C(1) component: they differed in the extent to which they were associated with carbohydrate (9% and 33%). 5. The purified C(1) component had little ability to attack CM-cellulose or highly ordered forms of cellulose, but degraded phosphoric acid-swollen cellulose readily: cellobiose was the principal product of the hydrolysis (97%). 6. Dewaxed cotton fibre was degraded to the extent of 15% when exposed to high concentrations of C(1) component over a prolonged period: cellobiose was again the principal sugar present in the supernatant (96%). 7. Cellotetraose and cellohexaose were hydrolysed almost exclusively to cellobiose. 8. Evidence indicates that the C(1) component is a beta-1,4-glucan cellobiosylhydrolase.

The cellulase of Fusarium solani. Purification and specificity of the -(1-4)-glucanase and the -D-glucosidase components

1. Cell-free culture filtrates of the fungus Fusarium solani were examined for homogeneity with respect to beta-d-glucosidase and C(x) activities. 2. o-Nitrophenyl beta-d-glucoside and cellobiose were both used as substrates for beta-d-glucosidase activity. 3. No evidence for the non-identity of nitrophenyl beta-d-glucosidase and cellobiase activities could be found, either by heat treatment, gel filtration on Sephadex G-100 or by isoelectric focusing. 4. The beta-d-glucosidase component was also a feeble exo-beta-glucanase: it had a molecular weight of approx. 400000. 5. The fall in viscosity of a solution of CM-cellulose, the formation of reducing sugars in a solution of CM-cellulose and the solubilization of phosphoric acid-swollen cellulose (Walseth cellulose), were all used for the measurement of C(x) activity. 6. The ratio of the two types of CM-cellulase activity was not changed after gel filtration on Sephadex G-100 or after chromatography on DEAE-Sephadex. 7. Three peaks of C(x) activity were obtained after electrofocusing, but all three possessed the same ratio of the two types of CM-cellulase activity as well as the same CM-cellulase/Walseth activity ratio, as the unfractionated enzyme; all three isoenzymes (isoelectric points, 4.75, 4.80-4.85 and 5.15) acted in synergism with a mixture of the C(1) and the beta-d-glucosidase components to the same extent in the solubilization of cotton fibre. 8. The molecular weight of the C(x) component was approx. 37000.

The cellulase of Fusarium solani. Resolution of the enzyme complex

1. Culture filtrates from Fusarium solani were fractionated by ion-exchange chromatography on DEAE-Sephadex, followed by gel chromatography on Sephadex G-100, into a C(1) component, a C(x) component (CM-cellulase) and a beta-glucosidase (cellobiase) component. 2. The individual components showed little capacity for the solubilization of cotton fibre (cellulase activity), but when recombined in their original proportions 81% of the original cellulase activity was recovered. 3. The C(1) components of F. solani and Trichoderma koningii were similar in their pH optima, heat stabilities over the pH range 5-8 and elution volumes on Sephadex G-100. 4. The C(1) component of F. solani synergized with the C(x) component of T. koningii and conversely. 5. The C(1) and the beta-glucosidase components of F. solani were devoid of the swelling-factor (S-factor) activity associated with the C(x) component.

Cellulolytic enzyme system of Trichoderma koningii. Separation of components attacking native cotton

1. Cell-free culture filtrates from Trichoderma koningii were concentrated by precipitation with ammonium sulphate between the limits of 20% and 80% saturation. 2. Removal of a low-molecular-weight carboxymethylcellulase (CM-cellulase) component by chromatography on Sephadex G-75 had no effect on the ability of the enzyme complex to solubilize cotton. 3. Further chromatography on DEAE-Sephadex separated a component (C(1)) from the C(x) (CM-cellulase) and beta-glucosidase activities. Separately these components had little ability to produce soluble sugars from cotton, but when recombined in their original proportions this capacity was almost completely recovered. 4. The C(x) component was further fractionated on SE-Sephadex into a fraction containing only CM-cellulase and a fraction showing CM-cellulase and beta-glucosidase activities: the latter two components could be separated by heat treatment. 5. The C(1) component had no swelling factor (S-factor) activity (Marsh, Merola & Simpson, 1953; Reese & Gilligan, 1954) on its own, but it had a synergistic effect on the S-factor activity associated with the CM-cellulase and beta-glucosidase components.