Oil wastes management: medium optimization for the production of alpha-linolenic acid in Mucor circinelloides

The neutraceutical and pharmaceutical application of essential fatty acids is much cleared. Alpha-linolenic acid (ALA) is omega-3 fatty acid and generally known to have beneficial effects in CVS, CNS and other diseases. The purpose of the present investigation is to produce essential fatty acid, especially ALA by Mucor circinelloides from oil wastes. Five oil wastes collected from food industries were used as carbon sources, and the contents of total lipids, biomass and fatty acids were examined during 168 h. The ability of oil waste degradation was determined by measuring of biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Interestingly, 76 % reduction in BOD and 68 % reduction in COD by this strain were achieved, and M. circinelloides could be a good candidate for oil waste treatment. In order to enhance ALA production, fermentation variables were chosen in accordance with the fractional design and further optimized by the response surface method. The statistical model was constructed via central composite design. Following the optimization step, ALA production increased by approximately 44.3 %, when compared to the screening step. The results indicate that carrying out the fermentation under the conditions of oil waste 4.37 %, yeast extract at 0.65 g/l, (NH4)2SO4 at 0.38 g/l, an agitation rate of 180 rpm and fermentation time of 3 days will increase the ALA production up to 108.57 mg/l. In this study, a new renewable source of ALA was employed and optimized successfully for the production of valuable fatty acids.