Biosynthesis of hetero-polysaccharides by Pestalotiopsis microspora from various monosaccharides as carbon source

Pestalotiopsis microspora was cultured in media containing various monosaccharides as a carbon source. It was found that P. microspora metabolizes various monosaccharides and the composition of polysaccharides depends strongly on the monosaccharides used for carbon source. When D-glucose, D-mannose or D-galactose were used as the carbon source, hetero-polysaccharides of similar compositions containing a considerable amount of D-mannose units beside D-glucose units were formed. With D-xylose or N-acetyl-D-glucosamine as the carbon source, hetero-polysaccharides containing large amounts of D-mannose and D-galactose units beside D-glucose units were produced. Cultures with L-arabinose as the carbon source produced almost pure glucan, while with L-rhamnose, the yield and the composition of hetero-polysaccharide is the same as that obtained from the culture with D-glucose as the carbon source. The mechanism of biosynthesis of these hetero-polysaccharides is briefly discussed.