Studies on the biochemistry of Penicillium charlesii. Influence of various dicarboxylic acids on galactocarolose synthesis.

1. It has been shown that Penicillium charlesii continues to synthesize galactocarolose when l-malic acid, malonic acid, succinic acid, fumaric acid, maleic acid or oxaloglycollic acid is substituted for dl-tartaric acid in the Raulin-Thom nutrient medium. 2. The quantity of galactocarolose synthesized per g. of mycelia was markedly decreased by substitution of l-malic acid, malonic acid, succinic acid, fumaric acid or maleic acid for dl-tartaric acid. Substitution of oxaloglycollic acid for dl-tartaric acid did not depress the galactocarolose synthesized/g. of mycelia; however, the quantity of fungal mass formed was decreased approximately fivefold. 3. Based upon (14)C incorporation into galactocarolose, succinic acid, fumaric acid or malonic acid did not serve as direct precursors of galactose as did tartaric acid. Oxaloglycollic acid, l-malic acid and maleic acid were not tested. 4. The relative quantity of galactocarolose synthesized per g. of mycelia decreased as the concentration of diammonium dicarboxylate added to the growth medium was increased. Tartaric acid, oxaloglycollic acid, fumaric acid and malonic acid were tested. 5. The quantity of mycelia formed and the quantity of galactocarolose synthesized per g. of mycelia were greater when the growth medium contained l-tartrate than when it contained d-tartrate.