Decomposition of L-Malic Acid by Schizosaccharomyces Pombe

Abstract

Schizosaccharomces pombe (IFO 0358) having intrinsically high ability of decomposing L-malic acid, when cultured in a synthetic growth medium, showed weaker ability to decompose L-malic acid than the ability cultured in apple juice, and it suggests that apple juice contains an unidentified factor or factors to promote the L-malic acid decomposition by the yeast. So, experiments were made to determine the nitrogen and mineral sources required to decompose L-malic acid by the yeast, and it became clear that the appearance of the L-malic acid decomposing ability was mainly due to the presence of L-asparagine which was contained in apple juice, and, in fact, Schizosaccharomyces pombe cultured in the synthetic growth medium with L-asparagine as a sole source of nitrogen, replacing ammonium salt, showed high ability to decompose L-malic acid.
Furthermore, experiments were made to determine the effects of nutritional materials -vitamins, mineral salts, nitrogenous compounds-on the formation of malate dehydrogenase by Schizosaccharomyces pombe, which might control the L-malic acid decomposition, and this series of experiments showed that the presence of nicotic acid, biotin, iron and L-asparagine was effective to promote the activity of malate dehydrogenase of the yeast.