POLYOL METABOLISM IN THE BASIDIOMYCETE SCHIZOPHYLLUM COMMUNE.

Niederpruem, Donald J. (Indiana University Medical Center, Indianapolis), Amtul Hafiz, and Lyle Henry. Polyol metabolism in the basidiomycete Schizophyllum commune. J. Bacteriol. 89:954-959. 1965.-The polyol metabolism of intact cells and extracts of the wood-rotting mushroom Schizophyllum commune was investigated during the developmental cycle. Exogenous polyols stimulated the cellular respiration of germlings, but were without effect on that of ungerminated basidiospores. Requisite enzymes of polyol metabolism were demonstrated in extracts of spores and of subsequent stages of development. Oxidation of mannitol and sorbitol appeared to be coupled to nicotinamide adenine dinucleotide (NAD) reduction and was favored in alkaline medium. Ketohexose formation was shown during mannitol oxidation, and the NAD-dependent oxidation of xylitol yielded ketopentose. Xylitol oxidation with nicotinamide adenine dinucleotide phosphate (NADP) as hydrogen acceptor led to pentose formation. Oxidation of reduced NAD was enhanced by fructose but not by sorbose. Reduction of aldohexose and pentose was dependent upon reduced NADP, and pentose reductase was maximal at pH 6.8. The specific activity of mannitol dehydrogenase was highest in extracts of vegetative mycelium. Growth in either glucose or xylose media had no significant effect on enzymes of polyol metabolism.