Novel fungal lipids for the production of biodiesel resources by Mucor fragilis AFT7‐4

A newly isolated oleaginous fungus strain Mucor fragilis AFT7‐4 screened from farmland soil was shown to be a prospective producer of microbial lipid. To improve oil production, lipid collection techniques involving cell disruption and oil extraction were investigated, and fermentation conditions were also optimized by response surface methodology with a 3‐level 4‐factor Box‐Behnken Design. The results showed that the method, which is the combination of acid‐heating and freeze‐thawing worked best for cell disruption, and chloroform/methanol solution (2:1, v/v ) was the most suitable extraction system for oils extraction. Under the optimum conditions [glucose concentration 86 g/L, ammonium sulfate concentration 2.5 g/L, inoculum concentration ( v/v ) 11%, fermentation time 5 days], a lipid yield of 12.86 g/L and the lipid content of 46.80% could be achieved. These represented a 33.63% improvement in the lipid yield and a 44.44% increase in the lipid content compared with the original values (9.04 g/L and 32.41%). This work was firstly studied on a Mucor fragilis strain systematically for oil production.