Polyol Metabolism in the Basidiomycete Schizophyllum commune

1969

J Bacteriol

Erythritol uptake and metabolism were compared in wild-type mycelium and a dome morphological mutant of the wood-rotting mushroom Schizophyllum commune . Wild-type mycelium utilized glucose, certain hexitols, and pentitols including ribitol, as well as d -erythrose, erythritol, and glycerol as sole carbon sources for growth. The dome mutant utilized all of these compounds except d -erythrose and erythritol. Erythritol- or glycerol-grown wild-type mycelium incorporated erythritol into various cellular constituents, whereas glucose-grown cells lagged considerably before initiation of erythritol uptake. This acquisition was inhibited by cycloheximide. Dome mycelium showed behavior similar to wild-type in uptake of erythritol after growth on glucose or glycerol, except that erythritol was not further catabolized. Enzymes of carbohydrate metabolism were compared in cell extracts of glucose-cultured wild-type mycelium and dome . Enzymes of hexose monophosphate catabolism, nicotinamide adenine dinucleotide (NAD)-dependent sugar alcohol dehydrogenases, and reduced nicotinamide adenine dinucleotide phosphate (NADPH)-coupled erythrose reductase were demonstrated in both. The occurrence of erythrose reductase was unaffected by the nature of the growth carbon source, showed optimal activity at p H 7, and generated NAD phosphate and erythritol as products of the reaction. Glycerol-, d -erythrose-, or erythritol-grown wild-type mycelium contained an NAD-dependent erythritol dehydrogenase absent in glucose cells. Erythritol dehydrogenase activity was optimal at p H 8.8 and produced erythrulose during NAD reduction. Glycerol-growth of dome mycelium induced the erythritol uptake system, but a functional erythritol dehydrogenase could not be demonstrated. Neither wild-type nor dome mycelium produced erythritol dehydrogenase during growth on ribitol. Erythritol metabolism in wild-type cells of S. commune , therefore, involves an NADPH-dependent reduction of d -erythrose to produce erythritol, followed by induction of an NAD-coupled erythritol dehydrogenase to form erythrulose. A deficiency in erythritol dehydrogenase rather than permeability barriers explains why dome cannot employ erythritol as sole carbon source for mycelial growth.

Section: Resultsmentioning

confidence: 92%

mentioning

confidence: 99%

Erythritol Metabolism in Wild-Type and Mutant Strains of Schizophyllum commune

Braun

1969

J Bacteriol

“…Carbohydrates and polyols. The low-molecularweight carbohydrates were extracted with hot ethanol as described earlier (23,24). Glycogen was extracted with acetic acid (0.5 N at 80 C) as outlined by Wessels (39).…”

Section: Methodsmentioning

confidence: 99%

Ultrastructural Changes and Biochemical Events in Basidiospore Germination of Schizophyllum commune

Aitken

1970

J Bacteriol

Self Cite

Electron microscopic features and biochemical events were outlined in basidiospore germination of Schizophyllum commune. Normal ultrastructural changes included prominent vacuolization and more abundant endoplasmic reticulum. A lag phase in outgrowth included depletion of cellular reserves of trehalose, mannitol, and arabitol and subsequent increases in ribonucleic acid and protein. Depletion of polyols required exogenous carbon and nitrogen sources and was arrested by protein synthesis antagonists. Outgrowth subsequent to the lag period was accompanied by increased glycogen deposition and alkali-soluble glucan production.

Polyols in Schizophyllum Commune

Hunt

1967

American J of Botany

Self Cite

Sugars and sugar alcohols present in extracts of the wood‐rotting mushroom Schizophyllum commune were identified by paper chromatography during fruiting, basidiospore germination, and growth of vegetative mycelium. Homokaryotic fruitbodies and dikaryotic fruits derived from several compatible matings of S. commune contained mannitol and arabitol. Basidiospores shed from dikaryotic fruits also contained mannitol and arabitol while the latter disappeared during spore germination. Vegetative mycelium (strain 699) contained glucose, fructose, mannitol and glycerol while these compounds as well as arabitol occurred in mycelium of strain 845. Polyols are not, therefore, associated exclusively with the sporulation process in S. commune.