Lipid profiles of green conversion from corn-ethanol co-product via Aspergillus niger

High-value recycling of agro-industrial by-products is the focus of global sustainable development. A method of the recovery and utilization of corn-ethanol co-product to produce functional lipids via Aspergillus niger (A. niger) was proposed. The lipid changes in distillers dried grains with solubles (DDGS) were monitored via lipidomics. 648 lipids (five classes, 29 subclasses) were identified, including 75 fatty acyls, 203 glycerolipids, 184 glycerophospholipids, 169 sphingolipids, and 17 glucosylsphingoshine. Glycerolipids were the most abundant lipids, accounting for 31%. As fermentation proceeded, the concentration of lipids with 1-9 unsaturated bonds steadily increased. Oleic acid and linoleic acid were the main accumulated fatty acids. The pathways enrichment results showed glycerophospholipid metabolism, glycerolipids metabolism, sphingolipid metabolism, and biosynthesis of unsaturated fatty acids were the key metabolic pathways involved during DDGS fermentation. These results provided a comprehensive knowledge of the lipid profiles in fermented DDGS and proposed a new approach for high-value utilization of DDGS.