A fermentation strategy for producing docosahexaenoic acid in Aurantiochytrium limacinum SR21 and increasing C22:6 proportions in total fatty acid

► Nitrogen and oxygen limiting, dual-phase culture are not necessary. ► This study applied low C/N ratio and 50% fluctuating dissolved oxygen level. ► C22:6 proportions in total fatty acids increase to 70%. ► C16:0 fatty acid ratios significantly decrease to below 5% of total fatty acids.