title: High-yield production of pure tagatose from fructose by a three-step enzymatic cascade reaction.
abstract: OBJECTIVE
  To produce tagatose from fructose with a high conversion rate and to establish a high-yield purification method of tagatose from the reaction mixture.
  
  
  RESULTS
  Fructose at 1 M (180 g l-1) was converted to 0.8 M (144 g l-1) tagatose by a three-step enzymatic cascade reaction, involving hexokinase, plus ATP, fructose-1,6-biphosphate aldolase, phytase, over 16 h with a productivity of 9 g l-1h-1. No byproducts were detected. Tagatose was recrystallized from ethanol to a purity of 99.9% and a yield of 96.3%. Overall, tagatose at 99.9% purity was obtained from fructose with a yield of 77%.
  
  
  CONCLUSIONS
  This is the first biotechnological production of tagatose from fructose and the first application of solvent recrystallization for the purification of rare sugars.
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea.
authors.forename: Seon-Hwa
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea.
authors.forename: Seung-Hye
authors.initials: SH
authors.lastname: Hong
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea.
authors.forename: Kyoung-Rok
authors.initials: KR
authors.lastname: Kim
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea. deokkun@konkuk.ac.kr.
authors.forename: Deok-Kun
authors.initials: DK
authors.lastname: Oh
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D019149:Bioreactors; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005632:Fructose / Q000378:metabolism*; D005634:Fructose-Bisphosphate Aldolase / Q000235:genetics / Q000378:metabolism; D006601:Hexoses / Q000032:analysis / Q000378:metabolism*; D060847:Metabolic Engineering / Q000379:methods*; D019998:Racemases and Epimerases / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D006601:Hexoses; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D005632:Fructose; D000255:Adenosine Triphosphate; D005634:Fructose-Bisphosphate Aldolase; D019998:Racemases and Epimerases; C030192:tagatose
keywords: Ethanol recrystallization; Fructose; Fructose-1,6-biphosphate aldolase; Tagatose; Three-step enzymatic cascade reaction