Roh H J, Kim P, Park Y C, Choi J H
R&D Center, Tong Yang Confectionery Co., 30-10 Munbai-dong, Yongsan-ku, Seoul 140-715, Korea.
Biotechnol Appl Biochem. 2000 Feb;31(1):1-4. doi: 10.1042/ba19990065.
D-Tagatose is a potential bulking agent in food as a non-calorific sweetener. To produce D-tagatose from cheaper resources, plasmids harbouring the L-arabinose isomerase gene (araA) from Escherichia coli, Bacillus subtilis and Salmonella typhimurium were constructed because L-arabinose isomerase was suggested previously as an enzyme that mediates the bioconversion of galactose into tagatose as well as that of arabinose to ribulose. The constructed plasmids were named pTC101, pTC105 and pTC106, containing araA from E. coli, B. subtilis and S. typhimurium respectively. In the cultures of recombinant E. coli with pTC101, pTC105 and pTC106, tagatose was produced from galactose in 9.9, 7.1 and 6.9% yields respectively. The enzyme extract of E. coli with the plasmid pTC101 also converted galactose into tagatose with a 96.4% yield.
D-塔格糖作为一种无热量甜味剂，是食品中一种潜在的填充剂。为了从更廉价的资源生产D-塔格糖，构建了携带来自大肠杆菌、枯草芽孢杆菌和鼠伤寒沙门氏菌的L-阿拉伯糖异构酶基因（araA）的质粒，因为之前有人提出L-阿拉伯糖异构酶是一种介导半乳糖生物转化为塔格糖以及阿拉伯糖转化为核糖ulose的酶。构建的质粒分别命名为pTC101、pTC105和pTC106，分别含有来自大肠杆菌、枯草芽孢杆菌和鼠伤寒沙门氏菌的araA。在用pTC101、pTC105和pTC106重组大肠杆菌的培养物中，分别以9.9%、7.1%和6.9%的产率从半乳糖生产出塔格糖。带有质粒pTC101的大肠杆菌的酶提取物也以96.4%的产率将半乳糖转化为塔格糖。
