Transformation of corncob-derived xylose into intracellular lipid by engineered strain of Aureobasidium melanogenum P10 for biodiesel production

Lignocellulosic materials such as corn cob are an inexpensive, natural and the most abundant renewable resource in the nature. In this study, it was found that an oleaginous yeast-like fungal strain Aureobasidium melanogenum P10 could grow well on corncob-derived xylose and accumulate 38.27% (w/w) of lipids from it within 120 h. Removal of an oxidoreductase pathway and overexpression of an isomerase pathway from A. melanogenum P10 made the XI-15 strain accumulate 53.74% (w/w) of lipids from the same xylose within 108 h. All the properties of the prepared biodiesel obtained from the crude lipids produced by both P10 and XI-15 strains could totally meet the requirements of US biodiesel ASTM D6751 and EU biodiesel EN 14214. Especially, the cetane numbers (56.82 ± 1.2 and 57.32 ± 1.3 min) of the prepared biodiesels were much higher than those of US biodiesel ASTM D6751 and EU biodiesel EN 14214 and their iodine numbers (80.20 ± 2.1 and 74.71 ± 1.9) were much lower than those of US biodiesel ASTM D6751 and EU biodiesel EN 14214. These meant that the properties of the prepared biodiesels in this study were better than those of the standard ones and the prepared biodiesels had high potential applications in renewable fuel industries. At the same time, the prepared biodiesel was found to be burnt well.