Biotechnological production of sugar-alcohols: Focus on Yarrowia lipolytica and edible/medicinal mushrooms

In the present review-article several aspects dealing with the biotechnological production of three major sugar-alcohols, viz. erythritol, mannitol and arabitol, are developed. Emphasis is given on the extra-cellular production of these sugar-alcohols by species of the yeast cell factory Yarrowia lipolytica and/or their intra-cellular accumulation in genera/species (mostly Agaricus and Pleurotus) of edible and medicinal mushrooms. Indications concerning the presence of soluble sugars inside the fungal mycelia and fruit-bodies of various types of mushrooms are also added. Initially, general information concerning the mentioned sugar-alcohols as well as others that are produced by biotechnological means, their roles, and their functionalities, are presented. The biochemistry of the synthesis of erythritol, mannitol and arabitol in the yeast cells and fungal mycelia when the main carbon sources employed in the Industrial Biotechnology (viz. glucose/fructose, lignocellulosic compounds/xylose, hydrophobic materials, glycerol) are used is presented and critically discussed. Given that the yeast Y. lipolytica is a major candidate that has been/is implicated in the production of the mentioned sugar-alcohols together with other compounds that are synthesized through similar metabolic pathways (viz. microbial lipids and citric acid, produced as the mentioned polyols during the imbalanced growth phase and after carbon-excess and nitrogen-limited conditions) various considerations concerning the biotechnological potential of this yeast species with emphasis of the production of sugar-alcohols are developed and assessed. Finally, presentations concerning the production of sugar-alcohols and other soluble sugars through the cultivation of various types of edible/medicinal mushrooms in several types of fermentation configurations are critically assessed.