title: Microbial production of glyceric acid, an organic acid that can be mass produced from glycerol.
abstract: Glyceric acid (GA), an unfamiliar biotechnological product, is currently produced as a small by-product of dihydroxyacetone production from glycerol by Gluconobacter oxydans. We developed a method for the efficient biotechnological production of GA as a target compound for new surplus glycerol applications in the biodiesel and oleochemical industries. We investigated the ability of 162 acetic acid bacterial strains to produce GA from glycerol and found that the patterns of productivity and enantiomeric GA compositions obtained from several strains differed significantly. The growth parameters of two different strain types, Gluconobacter frateurii NBRC103465 and Acetobacter tropicalis NBRC16470, were optimized using a jar fermentor. G. frateurii accumulated 136.5 g/liter of GA with a 72% d-GA enantiomeric excess (ee) in the culture broth, whereas A. tropicalis produced 101.8 g/liter of d-GA with a 99% ee. The 136.5 g/liter of glycerate in the culture broth was concentrated to 236.5 g/liter by desalting electrodialysis during the 140-min operating time, and then, from 50 ml of the concentrated solution, 9.35 g of GA calcium salt was obtained by crystallization. Gene disruption analysis using G. oxydans IFO12528 revealed that the membrane-bound alcohol dehydrogenase (mADH)-encoding gene (adhA) is required for GA production, and purified mADH from G. oxydans IFO12528 catalyzed the oxidation of glycerol. These results strongly suggest that mADH is involved in GA production by acetic acid bacteria. We propose that GA is potentially mass producible from glycerol feedstock by a biotechnological process.
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. hiroshi.habe@aist.go.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Habe
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shimada
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Yakushi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Hattori
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Ano
authors.forename: Tokuma
authors.initials: T
authors.lastname: Fukuoka
authors.forename: Dai
authors.initials: D
authors.lastname: Kitamoto
authors.forename: Masayuki
authors.initials: M
authors.lastname: Itagaki
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Watanabe
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yanagishita
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Matsushita
authors.forename: Keiji
authors.initials: K
authors.lastname: Sakaki
mesh_terms: D000091:Acetobacter / Q000235:genetics / Q000378:metabolism; D000426:Alcohol Dehydrogenase / Q000235:genetics / Q000378:metabolism; D004098:Dihydroxyacetone / Q000378:metabolism; D041821:Gluconacetobacter / Q000235:genetics / Q000378:metabolism; D020576:Gluconobacter / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D005988:Glyceric Acids / Q000737:chemistry / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism*; D007218:Industrial Microbiology / Q000379:methods*
chemical_list: D005988:Glyceric Acids; C042971:glyceric acid; D000426:Alcohol Dehydrogenase; D004098:Dihydroxyacetone; D005990:Glycerol