Optimization of Erythritol Fermentation by High-Throughput Screening Assays

Abstract

In this research, the erythritol-producing ability of three Yarrowia lipolytica strains was investigated. The focus of our research was to achieve the highest possible erythritol concentration by examining and optimizing the cultivation conditions of erythritol fermentation. The complex utilization of the produced fermentation broth was also sought, e.g. the ergosterol extraction of yeast cells and isolation of a biodetergent from the foam formed during erythritol fermentation. Erythritol is a naturally occurring, widespread sugar alcohol that is gaining popularity, moreover, due to increases in usage, its demand among consumers is rising, which is why the importance of its biological production is becoming all the more critical in the food industry. Erythritol is 60-70% as sweet as sucrose and a low-calorie sweetener. Some microorganisms are capable of producing erythritol from glucose, meanwhile Yarrowia lipolytica strains have been reported as glycerol-consuming erythritol producers. These two sources of carbon were compared despite being subjected to further conditions like the initial pH, nitrogen sources and some additives. The largest production of erythritol was achieved by Y. divulgata resulting in 44g/L on glycerol compared to only 2g/L on glucose. The best supplementation was found to include ammonium nitrate and sodium citrate resulting in a product yield of 33%.