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A number of basidiomycetes were cultured on liquid media and tested for laccase activity. Among these, some closely related Polyporus species (Polystictus group) appeared to be the most promising material for production of high yields of laccase. Some Stereum and Marasmius species, although showing fairly good growth and giving strong reactions on Bavendamm's media, produced only strains of Poly pro small amounts of laces as determined by quantitative methods. Nine strains of polyporous versicolor showed great variation in laccase production on different media. Two strains (nos. 1 and 11a) were studied in more detail under varying culture conditions, In chemically defined media, the addition of special inducing compound was 2,5-xylidine which also greatly stimulated growth. The age of the culture when also important. The copper content of the medium must be kept sufficiently high to permit maximum production of lactase. On the basis of the results summarized above, a procedure has been adopted for the production of larger amounts of laccase from polyporus versicolor for enzyme purification. The crude enzyme solutions obtained by a simple ammonium sulfate precipitation of the culture media and subsequent dialysis, normally had Qo2values of around 20.000. [ABSTRACT FROM AUTHOR]

The ATP pool of growing fungal mycelia, particularly Fomes annosus, has been determined. The ATP level varied during the different growth phases and correlated with the variations in the economic coefficient. Common uncouplers (at concentrations similar to those used in mitochondrial tests) decreased the ATP pool very rapidly. The size of the pool often fell 50–80% before the O2 uptake decreased below that of the control and was accompanied by an increasing exudation of inorganic phosphate. Phenolic compounds added to the medium stimulated the lacease activity, generally in combination with a decrease in the ATP level. [ABSTRACT FROM AUTHOR]

This article presents a study related to inhibition of several ectoenzymes of Fomes annosus by wood and bark extracts from Picea abies. Methanol soluble extractives of sapwood, heartwood and reaction zone from Norway spruce as well as acetone soluble extractives of spruce bark were tested at a concentration of 0.05 percent for inhibition of Fomes annosus enzymes cellulase, pectinase and laccase. Laccase was inhibited only by acetone soluble extractives of bark, whereas the other ectoenzymes were inhibited by all the extractives used. Such an inhibition may be important during the spread of Fomes annosus in spruce in vivo.

Polyporus versicolor was cultured on different media and the formation of laccase was followed manometrically in Warburg experiments. It was found that in a non-synthetic substrate, like malt extract, considerable amounts of laccase were formed and secreted into the medium at an early stage of growth. In synthetic media the formation of laccase was delayed. A high activity was obtained in such media following autolysis of tbe mycelium. This was not connected with a release of preformed laccase in the mycelium, but the laccase was apparently formed during the autolysis process and directly secreted into the medium. Possible explanations of the findings are discussed. As a result of the investigations It may be stated that, if active laccase solutions from fungi are desired, great attention must be paid to the composition of the medium and the period of incubation of the fungi used. In the present work, the highest activity was obtained by culturing the fungi for 21 days or more in a synthetic medium containing ammonium salt as the source of nitrogen and sodium acetate as a buffer substance. [ABSTRACT FROM AUTHOR]