Waste Conversion into a Sweetener—Development of an Innovative Strategy for Erythritol Production by Yarrowia lipolytica

Ludwika Tomaszewska-Hetman,Anita Rywińska,Waldemar Rymowicz

doi:10.3390/su12177122

Ludwika Tomaszewska-Hetman, Anita Rywińska + Show 1 more

Open Access

https://doi.org/10.3390/su12177122

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Abstract

The study proposed the innovative low-cost strategy for erythritol production by Yarrowia lipolytica through developing a simple medium based on industrial waste by-products and a natural method for culture broth purification. Results obtained proved that corn steep liquor might successfully replace traditional sources of nitrogen and other nutrients without compromising activities of the enzymes responsible for erythritol production and its production level. As a consequence, a production process was performed where Y. lipolytica A-6 was able to produce 108.0 g/L of erythritol, with a production rate of 1.04 g/Lh and a yield of 0.45 g/g of the medium containing exclusively 220 g/L of crude glycerol derived from biodiesel production and 40 g/L of corn steep liquor. Moreover, a comparable concentration of erythritol (108.1 g/L) was obtained when a part of crude glycerol was exchanged for the crude fraction of fatty acids in the two-steps process. Next, the collected post-fermentation broths were used in the culture with Y. lipolytica Wratislavia K1 for natural purification. The process resulted in a high increase of erythritol selectivity from 72% to 97% and in the production of 22.0 g/L of biomass with 40.4% protein content, which enables its use as an attractive animal feedstuff.

Highlights

IntroductionModern trends in nutrition led to the increased consumption of erythritol
In the last decade, modern trends in nutrition led to the increased consumption of erythritol
Two types of growth medium were used for seed culture preparation: glycerol-based growth medium (GGM) for the inoculation of mineral shake-flasks medium (MS-FM) and bioreactor media, and fatty acid crude fraction-based growth medium (FGM) to inoculate bioreactor cultures in which the production medium contained crude fraction of fatty acids (CFFA)

Summary

Introduction

Modern trends in nutrition led to the increased consumption of erythritol This polyol has many advantages, the primary of which includes low energy value (0.2 kcal/g), lack of bad aftertaste, not affecting insulin level in the blood, and very good tolerance in the human digestive system, which makes it one of the best sugar substitutes [1]. The environmental conditions, as well as the biochemical pathways of this polyol biosynthesis, have been widely described [2,15,16] This non-conventional yeast has low growth requirements, is able to assimilate a wide spectrum of substrates, and has fair resistance to impurities and changes in the composition of the culture medium [17]. Up to date, studies have employed substrates that required specific pretreatment or supplementation with complex nutrients, which, despite the non-expensive substrate application, might prove cost-ineffective

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