Extracellular Glucan Containing (1->3)- and (1->6)- Linkages Isolated from Monilinia fructigena

Abstract

Summary: Monilinia fructigena produced more extracellular polysaccharide when grown in liquid shake culture than in stationary culture, with greater quantities of the polysaccharide being secreted if ascorbic acid was present in the cultures. The polysaccharide was subsequently degraded during autolysis, eventually disappearing completely. After partial purification, the carbohydrate content was 96% and gel chromatography indicated a molecular weight of about 70000. Strong acid hydrolysis of the polysaccharide produced only glucose. Infrared spectroscopy indicated that the anomeric configuration of its d-glucose units was of the β-linkage type only. Periodate oxidation, Smith degradation and enzymic analysis indicated that the polysaccharide was a (1→3)-β-glucan having single (1→6)-β-glucosyl side-chains on every second d-glucose unit.