Sugar Alcohols and Organic Acids Synthesis in Yarrowia lipolytica: Where Are We?

Abstract

Sugar alcohols and organic acids that derive from the metabolism of certain microorganisms have a panoply of applications in agro-food, chemical and pharmaceutical industries. The main challenge in their production is to reach a productivity threshold that allow the process to be profitable. This relies on the construction of efficient cell factories by metabolic engineering and on the development of low-cost production processes by using industrial wastes or cheap and widely available raw materials as feedstock. The non-conventional yeast Yarrowia lipolytica has emerged recently as a potential producer of such metabolites owing its low nutritive requirements, its ability to grow at high cell densities in a bioreactor and ease of genome edition. This review will focus on current knowledge on the synthesis of the most important sugar alcohols and organic acids in Y. lipolytica.

Effect of Selenium on the Growth and Lipid Accumulation of Yarrowia lipolytica Yeast

“…Among them, the genus of Yarrowia has earned increasing attention by researchers, especially the non-conventional strain of Yarrowia lipolytica . Yarrowia lipolytica , possessing a rich enzymatic arsenal, has the ability to synthesize a variety of valuable cellular metabolites (e.g., SCOs, enzymes, proteins or recombinant proteins, polyols) and abundant lipid-free cell material and to excrete organic acids, while cultivated on hydrophobic (e.g., n -alkanes, oils, fats, and FAs) or hydrophilic substrates (e.g., glucose, raw glycerol, and other industrial and agro-industrial wastes) [ 35 – 38 ]. Thanks to its well-studied biochemistry of lipid accumulation and degradation, genetic profile, and the tools for its genetic manipulation, Y. lipolytica is characterized as a model microorganism for oleaginous microorganisms [ 23 ].…”

“…Acetyl-CoA is converted into malonyl-CoA, which is further converted into long-chain acyl-CoA [ 23 ]. Although, usually reducing power in the form of NADPH, required for FA synthesis, is provided either/both from PPP or/and from malic enzyme reaction, in Y. lipolytica , the main donor of NADPH is PPP [ 40 ], while recently, mannitol cycle is also suggested [ 38 ]. Then, the long-chain acyl-CoA is transported to the endoplasmic reticulum and esterified with glycerol-3P (G3P), generating structural and storage lipids.…”

Recent Advances in Producing Sugar Alcohols and Functional Sugars by Engineering Yarrowia lipolytica

“…Functional sugars generally refer to the sugars with unique structural and physiological characteristics, but occur in very low quantity in nature ( Bilal et al, 2020 ). Sugar alcohols and functional sugars have various applications in pharmaceutical, agro-food, and chemical industries ( Fickers et al, 2020 ). With the properties of same or better sweeting but less caloric value of sucrose, sugar alcohols and functional sugars are evolving as food ingredients ( Park et al, 2016 ).…”

“…Chemical approaches to sugar alcohols and functional sugars suffer from strict reaction conditions, limited yield, expensive raw starting feedstocks, and safety risks ( Huang et al, 2018 ). Engineering enzymes or whole-cell catalyst is emerging as the predominant alternative approach ( Fickers et al, 2020 ).…”

“…Promising results have been achieved by engineering Y. lipolytica into efficient producer of sugar alcohols and functional sugars due to its low nutritive requirements, feasibility of high cell density culture, and ease of genome editing ( Fickers et al, 2020 ). However, there remain some issues (inefficiency of enzyme activity and microbial cell factory, high cost of substrates, suboptimal bioprocess, and strain unstability) to be resolved before making the bioprocesses commercially feasible.…”