Polyol production from waste materials by genetically modified Yarrowia lipolytica

Erythritol as sweetener-wherefrom and whereto?

Erythritol is a naturally abundant sweetener gaining more and more importance especially within the food industry. It is widely used as sweetener in calorie-reduced food, candies, or bakery products. In research focusing on sugar alternatives, erythritol is a key issue due to its, compared to other polyols, challenging production. It cannot be chemically synthesized in a commercially worthwhile way resulting in a switch to biotechnological production. In this area, research efforts have been made to improve concentration, productivity, and yield. This mini review will give an overview on the attempts to improve erythritol production as well as their development over time.

Erythritol production by Yarrowia lipolytica from okara pretreated with the in-house enzyme pools of fungi

Okara (soybean residue) is an ideal erythritol feedstock due to its low price and high-nutrient content. Fungal-fermentations were carried out in okara using in-house enzyme pools generated by Mucor flavus or Trichoderma reesei to make okara more accessibility in the subsequent erythritol production using Yarrowia lipolytica. Mucor-fermented okara produced a high erythritol yield because of its special component and micromorphology. Five days is the optimal period for Mucor fermentation. Different fermentation modes were compared in terms of erythritol production and yield. The concentration of Mucor-fermented okara in erythritol fermentation medium was optimal at 30.0g/L. Moreover, 40.0g/L NaCl was added as the osmotic regulator. No extra ingredient was needed during this process. Results of 5-L fermentations showed that an erythritol titer of 14.7g/L, with a yield of 0.49g/g okara was obtained. These findings indicated that Mucor-fermented okara was an economically alternative feedstock for low-cost erythritol production.