Two-stage continuous culture - Technology boosting erythritol production

Yield and product titer are two important parameters for economic evaluation of any biotechnological process. The published studies on erythritol biosynthesis are based mainly on batch and fed-batch cultures, which do not fully utilize the production potential of the cells. In the current work, a two-stage continuous process of erythritol production from glycerol by an industrially relevant strain of Yarrowia lipolytica is proposed. The proposed process significantly enhanced titer of secreted erythritol and reduced process costs compared to the conventional batch cultures on glycerol. The two-stage chemostat process with glycerol resulted in 199.4 g dm−3 of erythritol with overall yield of 0.66 g g−1 and productivity of 0.8 g dm−3 h−1. These results represent almost 2.5-fold higher titer of erythritol compared to commonly used batch cultures of Y. lipolytica and almost 2 times higher titer and 1.3-fold increase in the product yield compared to a previously published continuous process with glycerol as a substrate. This study showed the potential of a two-stage continuous process using a genetically unmodified strain of Y. lipolytica for efficient erythritol production from raw glycerol originating from different industries.