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After several improvements in the electronmicroscopical procedure a satisfactory resolution was obtained of the ultrastructural features of the halotolerant yeast Debaryomyces hansenii. An elaborate system of compartmentation structure was revealed. By analysis of serial sections its origin in plasma membrane and extension into the vacuole could be followed. [ABSTRACT FROM AUTHOR]

The ultrastructure of the extreme halotolerant yeast Debaryomyces hansenii (Zopf) van Rij was similar whether the organism was grown under normal physiological conditions or at high concentrations of NaCl (12, 20 per cent w/v). A multitude of channels often seen in association with plasma membrane and/or vacuoles occur in the cytoplasm. The vacuoles contain lipid storage material. A decrease in mitochondrial size was observed with increasing salt concentration. The ultrastructure has been discussed with respect to halotolerance. [ABSTRACT FROM AUTHOR]

The growth conditions of Rhizina undulata Fr. have been studied. Under the prevailing culture conditions, the optimal temperature for growth is found to be 20°C, and the optimal pH about 3. Nitrate, ammonium and amino nitrogen can be assimilated, and several mono- and disaccharides, — except lactose — can be utilized, although galactose only slightly. The organism is auxoautotrophic. Yeast nucleic acids are found to have a growth-stimulating effect. Cellulolytic and pectinolylic enzymes are formed in induced synthesis, production of the latter being depressed by addition of casein hydrolysate or an amino acid mixture. [ABSTRACT FROM AUTHOR]

The activity of some fungal cellulases is investigated in shake cultures and stationary cultures, and stationary culltures, as well as in cultures of different volume. Trichoderma viride Pers. ex Fr. and various strains of Collybia velutipes (Curt. ex Fr.) Quel. are used as cellulase producers. Data are given on mycelial production, extracellular protein release and the cellulase activity, as disclosed in a turbimetric test. Only stationary cultures with a shallow liquid layer, providing an adequate oxygen supply, are found to result in cellulolytically active culture filtrates of all organisms tested. [ABSTRACT FROM AUTHOR]

1. It is found that gluconic acid and glucono-1:5-lactone in a concentration of 10-3 M completely inhibit p-nitrophenyl-β-glucosidase, and produce 50 per cent inhibition at a concentration of 10-5 M. 2. Cellobiase activity is inhibited by gluconic acid at the same concentration, the cellobiase activity of Polyporus annosus being much stronger than that of Trichoderma viride. 3. Cellulase activity on long anhydroglucose chains, measured in turbidimetric tests, is not inhibited by addition of gluconic acid or gbicono-1:5-lactone at a concentration of 10-3 M. 4. The cellulase activity of Trichoderma viride (F), measured in terms of reducing substances, is inhibited at a constant rate to about 15 per cent, tentatively explained as an inhibition of the endwise cellulase attack. 5. It is suggested that differences in the physical conditions of culture influence not only the degree of activity, but also the nature of the enzymes. [ABSTRACT FROM AUTHOR]

1. The minimum growth-inhibitory concentration of anisomycin, determined after an incubation time of 42 hours, and with a cell density of 106 cells/ml. at zero time, is found to be 25 μg/ml, in the case of C. pseudotropicalis and C. robusta, but more than 100 μg/ml, in all other strains tested. 2. Anisomycin is found to decrease the respiration. At a concentration of 200 μg/ml, and with glucose as substrate at pH 6.0 the decrease amounts to 50 per cent of that of the controls in the case of C. pulcherrima and C. parapsilopsis, to about 35 per cent in C. pseudotropicalis, and less in all other species. 3. The relative effect of anisomycin on the O2 uptake by whole cells, protoplasts, and a subcellular fraction has been measured. [ABSTRACT FROM AUTHOR]

1. Enzyme preparations from pure cultures of different strains of Collybia velutipes were tested turbidimetrically for activity against cellulose sol, and spectrophotometrically for β-glucosidase activity generally with p-nitrophenyl-β-glucoside as a substrate. 2. The extracellular enzyme activities, produced by mycelia of varying age in cellulose cultures, were followed by the above mentioned methods. 3. A comparison between the activities of corresponding preparations from culture solutions and mycelial extracts, called extracellular and intracellular activity, respectively, indicate the former to be predominant. 4. In some cases the β-glucosidase activity was also tested with the natural β-glucosides, salicin and cellobiose as substrates. In all tests the hydrolysis rate for β-niphegluc turned out to be somewhat higher than for salicin and cellobiose, but still of the same magnitude. 5. The results obtained indicate that at least two extracellular enzymes are involved in the breakdown of cellulose to glucose by different strains of Collybia velutipes. 6. The β-glucoside-splitting activity was practically eliminated by a heat-treatment at 60°C, whereas the cellulose-splitting activity partly resisted even a 100°C treatment. [ABSTRACT FROM AUTHOR]

1. Enzyme preparations from a pure culture of Polyporus annosus were tested for activity against cellulose sol, turbidimetrically, and for β-glucosidase activity with p-nitro-phenyl-β-glucoside as a substrate. 2. The amounts of enzyme, extracellular and intracellular, produced by mycelia of varying age in glucose, cellobiose, and cellulose cultures were followed by the abovementioned tests. 3. The results obtained indicate besides the extracellular cellulase, which can stand a heat-treatment of 80° and 100°C partly, an extracellular β-glucosidase completely inactivated by a treatment at 80°C, involved in the total breakdown of cellulose by Polyporus annosus. [ABSTRACT FROM AUTHOR]

1. The enzyme preparations tested for cellulolytic activity were from pure cultures of Streptomyces sp. QM B 814 and of four different Hymenomycetes, viz. Polyporus annosus Fr. and three strains of Collybia velutipes (Curt. ex Fr.) Quéll, i.e. two monocaryotic wildtypes L 1 and L 11, as well as the dicaryotic combination (F 29/157 X F 28/42) between two arginineless mutants. 2. The enzyme activity against cellulose sol has been measured turbidimetrically, the method being referred to as the photometric method in earlier papers. (Norkrans 1950 a, b). The activity has also been expressed in terms of reducing substances, glucose formed, and changes in average degree of polymerization (DP). Furthermore the enzyme attack has been studied by electron microscopy of the cellulose sol. 3. In all tests the preparation of Collybia velutipes (F 29/157 X F 28/42) showed the greatest total activity as well as the highest reaction rate. 4. According to the turbidimetrical readings, as to the DPn-determinations, the enzyme preparations had a great influence on the cellulose sol during the first hours of incubation. The Z-values increased rapidly, after the first twenty hours representing 60 to 90 per cent of the end-Z-values. The initial DPn-value of 338 decreased to 50-60 in four (or six) hours. 5. The paper chromatogram indicates the presence of cellobiose as well as another, slower-moving substance, presumably cellotriose, as breakdown products besides glucose. 6. A comparison between the DPn-values and the corresponding glucose values lend support to the theory of a random-splitting of the cellulose chain. 7. Expressed in terms of reducing substances, the breakdown did not in any case proceed to more than about 65 per cent of the total initial amount of cellulose. The polymerization seemed to proceed until a DPn of about 50. These limits seem to be related rather to the morphological structure of the cellulose sol particles than to the enzyme inactivation. Electron micrographs of such cellulose residues lend support to this conclusion, since they revealed a mass of distinct and fairly homogeneous particles about 300 Å long and about half as wide. These stood in clear contrast to those of the untreated cellulose sots, containing larger aggregates of longer disordered fibers forming an irregular network or unresolved lumps. [ABSTRACT FROM AUTHOR]

1. The cellulolytic capacity of wildtypes and mutants (both morphological and biochemical) has been tested after cultivation on different nutrient media. 2. All strains showing a strongly positive cellulolytic activity alter cultivation on a weak yeast-glucose-cellulose medium, I, hardly changed their cellulolytic activity (except for one morphological mutant F 29/173) when cultivated on a richer yeast extract medium, I a. On the glucosefree media, II, they showed about the same or a decreased reaction. 3. All strains weakly positive on I changed their capacity in a positive direction after cultivation on the enriched media l a and - in the case of biochemical mutants - also on IlI a, Ill b, and I b and also on the glucose free medium II. 4:. All biochemical strains negative on I behaved in the same way as the weakly positive ones, except F 31/170 deg. which aside from its biochemical character of adenineless, also shows a deviating morphological character. 5. All morphological strains negative on I. remained as the strongly mophologically deviating adenineless F 31/170,negative on all media, except F 31/230 which gave strong positive reaction on glucose-free medium. As yet it cannot be decided whether these negative strains are inherently incapable of forming cellulose splitting enzymes or whether a change in environment could supply the necessary elements for their formation. 6. The changes from negative to positive reaction connected with the enrichment of the substrate of certain limiting nitrogenous metabolites or with the removal of »start-glucose » has been discussed in the light of the competition between glucose and cellulose splitting enzymes for the limiting metabolites. [ABSTRACT FROM AUTHOR]

1.A comparison has been made between the growth effects of glutamic acid, aspartic acid, their corresponding ketoacids and half-amides, fumaric acid, glutathione, and casein hydrolysate on some Tricholoma species. 2. The stimulative effect of glutamic and aspartic acid does not seem to depend upon the diamino carboxylic acids as such, since their corresponding ketoacids have been found to accelerate growth to an almost equal degree. 3. Only in the case of T. imbricatum did fumaric acid have a growth stimulating effect comparable with that of α-ketoglutaric acid and oxaloacetic acid. 4. The two amides, glutamine and asparagine, greatly stimulated the growth of T. imambosum and T. imbricatum. This effect has been discussed in relation to the peptide synthesis. [ABSTRACT FROM AUTHOR]

The cellulolytic capacity of wildtypes and mutants (both morphological and biochemical) of Collybia velutipes has been investigated, both as regards mono- and dicaryotic mycelia. 2. A method for making quantitative measurements of the cellulolytic activity has been devised, using the agar-plate diffusion technique. The activity has usually been expressed in terms of (dx-do) mm. where d0 is the diameter of the test plug ( = 11 mm.), dx the diameter of the cleared zone + that of the test plug. The reprodncibility of this test method proved satisfactory. 3. The cellulolytic capacity of the testmycelia was found to depend on length of incubation time; the enzyme activity is dependent upon the temperature but independent of the pH within the range 4.5-7.0. 4. Monocaryotic (261) and dicaryolic (8) wildtype strains from 45 different fruitbodies have been tested for their cellulolytic capacity. A rather large variation in enzyme activity was found to exist between monocaryotic strains from the same fruit body, the difference between the (dx-do) values being as great as 6 mm. The mean value of cellulolytic activity for monocaryotic strains from different fruitbodies, expressed as (dx-do) also varied considerably, strains from different fruitbodies, expressed as (dx-do) also varied considerably, namely from 2.5 to 5.5 mm. In a few cases, the collulolytic activity was rather low, and for one monospore culture no cellulolytic activity at all was measurable by this method. 5. Biochomical (10) and morphological (55) mutants have been tested. Mutant mycelia occurred having (dx-do) values ranging from zero to a value more than twice as large as that of the wildtype, from which it had been derived. Expressed in terms of mg. decomposed cellulose, the cellulolytic capacity in the latter case was about 3 times that of the corresponding wild typo. 6. In eleven out of twelve cases, dicaryotic combinations of the typo (wildtype × mutant) gave a cellulolytic activity of about the same order as that found in the case of the dicaryotic wildtype. Combinations with an inactive mutant did not seem to lower the production of cellulolytic enzyme by the wildtype. Except for one case where the dicaryotic mycelia showed no activity at all, the wildtype dominates in the production of cellulolytic enzymes, under these particular experimental conditions. The latter case bas been thoroughly discussed. 7. Dicaryotic combinations between two biochemical mutants have been investigated in eleven different pairings. Under the standard test conditions in those experiments, most of these wore found to be as active as the original dicaryotic wildtype in producing cellulolytic enzymes. In three different cases, combination of two non-cellulolytic mutants gave rise to mycelia, the cellulolytic capacity of which was as great as that of the original wildtype. The cellulolytic capacity of one combination, however, proved to be considerably weaker than that of the dicaryotic wildtype, that of another combination considerably greater (ef. Figure 8). The latter strain also deviates from the others both as regards fruitbody production and morphology. 8. Neohaplonts probably of the same nuclear typo have been shown to differ in their capacity to produce cellulolytic enzymes. If nuclear differences exist they could only be explained by spontaneous mutations. [ABSTRACT FROM AUTHOR]

Cellobiose inhibits the hydrolysis of cellulose by filtrates of most of the organisms tested. Glucose does not inhibit the hydrolysis. The action of cellobiose is believed to be that of an end product inhibiting an enzymatic hydrolysis, in much the same manner that maltose inhibits hydrolysis of starch by α-amylase. Filtrates of seven organisms (of 36 tested) have been found where the hydrolysis of carboxymethyl cellulose is stimulated by low cellobiose concentrations. As the cellobiose concentration was increased, the stimulation decreased, and finally inhibition occurred. The hydrolysis of unsubstituted cellulose by these same filtrates is inhibited by cellobiose. [ABSTRACT FROM AUTHOR]

1. Cell-free solutions with cellulolytic activity were obtained from two soil-inhabiting hymenomycetes: Tricholoma fumosum and Tricholoma nudum. 2. The celluloytic enzyme activity was measured photometerically. 3. In addition to the extinction measurements, sugar-formation and loss in cellulosic matter were determined. 4. Comparisons between the cellulolytic effect on precipitated cellulose and micelle solution were made. A correlation between increased degree of crystallinity and increased resistance against enzymic attack has been established. 5. The enzymes split off soluble reducing sugars as well as longer chains of glucose anhydride. [ABSTRACT FROM AUTHOR]

1. It has been confirmed that Lactarius deliciosus is poorly developed in a nutrient solution containing glucose, mineral salts and NH4-tartrate (0.05-0.5%), supplemented with thiamine. 2. Extracts, which were prepared from sporophores of Hymenomycetes, generally exerted a very stimulating effect if they were added in suitable amounts. 3. Natural casein hydrolysate benefited the growth, although not so much as certain sporophore extracts. 4. A mixture of 18 amino acids in the proportions found in casein exerted an effect equivalent to the most beneficial sporophore extracts. [ABSTRACT FROM AUTHOR]