title: Selective production of two diastereomers of disaccharide sugar alcohol, mannosylerythritol by Pseudozyma yeasts.
abstract: Mannosylerythritol (ME) is the hydrophilic backbone of mannosylerythritol lipids as the most promising biosurfactants produced by different Pseudozyma yeasts, and has been receiving attention as a new sugar alcohol. Different Pseudozyma yeasts were examined for the sugar alcohol production using glucose as the sole carbon source. P. hubeiensis KM-59 highly produced a conventional type of ME, i.e., 4-O-β-D-mannopyranosyl-D-erythritol (4-ME). Interestingly, P. tsukubaensis KM-160 produced a diastereomer of 4-ME, i.e., 1-O-β-D-mannopyranosyl-D-erythritol (1-ME). In shake flask culture with 200 g/l of glucose, strain KM-59 produced 4-ME at a yield of 33.2 g/l (2.2 g/l/day of the productivity), while strain KM-160 produced 1-ME at 30.0 g/l (2.0 g/l/day). Moreover, the two strains were found to produce ME from glycerol; the maximum yields of 4-ME and 1-ME from 200 g/l of glycerol were 16.1 g/l (1.1 g/l/day) and 15.8 g/l (1.1 g/l/day), respectively. The production of 1-ME as the new diastereomer was further investigated in fed batch culture using a 5-l jar-fermenter. Compared to the flask culture, strain KM-160 gave three times higher productivity of 1-ME at 38.0 g/l (6.3 g/l/day) from glucose and at 31.1 g/l (3.5 g/l/day) from glycerol, respectively. This is the first report on the selective production of two diastereomers of ME, and should thus facilitate the functional development and application of the disaccharide sugar alcohol in the food and relative industries.
authors.affiliation: Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5-2, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Yoshikawa
authors.forename: Tomotake
authors.initials: T
authors.lastname: Morita
authors.forename: Tokuma
authors.initials: T
authors.lastname: Fukuoka
authors.forename: Masaaki
authors.initials: M
authors.lastname: Konishi
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Imura
authors.forename: Koji
authors.initials: K
authors.lastname: Kakugawa
authors.forename: Dai
authors.initials: D
authors.lastname: Kitamoto
mesh_terms: D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D004896:Erythritol / Q000031:analogs & derivatives* / Q000378:metabolism*; D008362:Mannosides / Q000378:metabolism*; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D013237:Stereoisomerism; D013402:Sugar Alcohols / Q000378:metabolism*; D014587:Ustilaginales / Q000145:classification / Q000235:genetics / Q000378:metabolism*
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D008362:Mannosides; D013402:Sugar Alcohols; D004896:Erythritol