ABSTRACT:The nutrient assimilation profile of two non-pullulan-producing strains of Aureobasidium pullulans (NRRL 58539 and NRRL 58543) isolated in Thailand was investigated. Similar nutrient assimilation was observed between both strains and the pullulan-producing A. pullulans NRRL 58560. All three strains weakly assimilated methyl-α-D-glucoside and lactose. For the exopolysaccharide (EPS) production, NRRL 58539 and NRRL 58543 preferred NaNO3 as the sole nitrogen source. Enzyme sensitivity assays, infrared spectroscopy, and nuclear magnetic resonance analyses of the EPSs revealed a broad structural similarity to aubasidan and not to pullulan. This is the first report of an aubasidan-like β-glucan produced by A. pullulans in Thailand.