Extracellular Enzymes Content in Mycelium of Xylotrophic Fungi Nematoloma fasciculare (Huds.: Fr.) Karst. and Flammulina velutipes (Curt.: Fr.) Karst.

Badalian S.M.

Department of Botany, Yerevan State University, 1A Manoogian St., 375049, Yerevan, Armenia

Enzymatic system of xylotrophic fungi is characterized by large substrate specification. Fungi, provoking brown wood decay on the whole contain hydrolyse group of enzymes (cellulases). Species provoking white wood decay contain also oxido-reductase group of enzymes (phenol oxidases, peroxidases), catalysing oxido- restoring reactions and lignin degradation processes.

Enzymatic activity of fungi has strains-specific peculiarity. It not only depends on biosyntheses of enzymes, which is connecting with their ecology, but also on enzyme's activity and conformation stability (immobilization of enzymes). Preliminary screening of new species and their strains - producers extracellular enzymes (ECE) for obtaining mycelia biomass, is a important step in biotechnological using of Higher fungi.

ECE (lipase, laccase, caseinase, gelatinase, tyrosinase, peroxidase, alpha-amylase, cellulase, nitrate reductase, polygalacturonase, pectate transeliminase, chitinase, laminarinase, urease, xylanase, betta-glucosidase) were detected in mycelium of N. fasciculare and F. vellutipes growing on cultural medium (glucose 5.0 g, peptone 2.5 g, yeast extract 0.5 g, agar 16 g, water 1 L, pH 6.0). Present or absent of ECE were detected by secretion of specific compounds (direct test), and by added reagents in medium during the mycelia growth (indirect test). Enzymatic activity of mycelium was determined by the type and intensity of reaction (colouring, clearing or precipitation). Test-enzymes were selected by their industrial, ecological and metabolic significance and also by their rapid detection in vitro.

No differences between the extensivity of mycelium growth and enzymes synthetic activity were mentioned. Both species were similar by presence of laccase, peroxidase, amylase, nitrate reductase, cellulase, urease, betta-glucosidase and xylanase, and by absence of lipase, polygalacturonase, chitinase, laminarinase. Gelatinase and pectate transeliminase were present only within F. velutipes, and tyrosinase - only within N. fasciculare.

Thus, N. fasciculare and F. velutipes are not only source of biological active metabolites with large spectrum of action (antibiotic, immunomodulator, thrombolytic), as well as ECE.