Deterioration potential of Aureobasidium pullulans on biodiesel, diesel, and B20 blend

A fungal species was isolated from 100% soybean methyl ester (B100 SME) and identified as Aureobasidium pullulans. The yeast was evaluated for its ability to grow in and to biodegrade B100 SME, B0 ultra-low-sulfur diesel (ULSD), and B20 ULSD (80% v/v ULSD + 20% B100 SME) in microcosms containing fuel over Bushnell-Haas mineral salts medium. The presence of SME affected the fungal cell morphology and metabolism. After 25 days, fungal biomass at the fuel/water interface in microcosms containing B100 SME and B20 ULSD were 0.98 ± 0.18 mg mL−1 and 0.16 ± 0.05 mg mL−1, respectively. In the B100 SME microcosms the esters concentrations fell by 10%. It was possible to observe that A. pullulans was biodeteriogenic in B100 and B20, but not in B0.