Study of polyols production by Yarrowia lipolytica in batch culture and optimization of growth condition for maximum production

Abstract

Background: Sugar alcohol erythritol is a non-caloric sweetener, non-cariogenic, and safe for diabetics because of no change to blood glucose and insulin levels after oral administration. Erythritol cannot be degraded by any enzymatic systems and must be eliminated from the blood through the kidney. Objectives: The aim of this study was production and optimization of erythritol from glucose by Yarrowia lipolytica. Materials and methods: Yarrowia lipolytica DSM70562 was cultivated at 30°C in a 250 mL Erlenmeyer containing 50 mL of production medium composed of 200 g/L glucose, 10 g/L yeast extract, 10 mg/L MnSO4.4H2O, and 2 mg/L CuSO4.5H2O. Erythritol was separated from the sugars and other polyols by thin layer chromatography. Total polyols was determined using colorimetric method of Bok and Demain, and erythritol was also eluted from the paper and determined by this colorimetric method. Results: In a batch culture with 200 g/L glucose at pH 5.5, an erythritol producer of Y.lipolytica capable to produce 27.8 g/L erythritol after seven days was selected, corresponding to a 21.52% yield and a productivity of 0.165 g/L/h. Conclusions: In this investigation we optimized the production medium and through altering medium components that resulted in a drastic change in polyol composition. Present study reports the production of erythritol for the first time by a Y. lipolytica strain DSM70562. Due to increasing demand for erythritol as a low caloric sweetener in food industry, its production via biological processes is becoming increasingly important.