Enhancing the erythritol production by Yarrowia lipolytica from waste oil using loofah sponge as oil-in-water dispersant

Abstract

Waste oil is an economical alternative carbon resource in Yarrowia-based erythritol production, but the water insolubility limits its further utilization. Loofah sponge (LS), a natural polymer material and accessible agricultural waste, was selected as oil-in-water dispersant in this study. In the oil–erythritol cultivation system with LS addition, efficient oil dispersion and enhanced erythritol production (by ˜30%) were achieved, with high biomass and scarce residual oil in the medium. Up to 60.0 g/L of waste oil could be completely consumed under the effect of LS, resulting to an erythritol yield of 0.76 ± 0.03 g/g oil. Scanning electron microscopy (SEM) images and reusability experiments showed that the LS fiber was well preserved and could be stable for more than five continuous cycles in this process. The changes in activities of the metabolic enzymes suggested an enhanced carbon flux in erythritol synthesis pathway, which was accompanied with an improved oxygen consumption. Moreover, with LS addition, scale-up and fed-batch cultivations was well conducted, up to 114.3 ± 1.8 g/L of erythritol was produced from waste oil when the two cultivation strategies were combined. This study demonstrated an efficient and eco-friendly method for the utilization of waste oily substrates in production of microbial metabolites.