Galactitol dehydrogenase(EC 1.1.1.16)is a key enzyme for D-tagatose production from galactitol.However,only a limited number of galactitol dehydrogenases have been reported,and their inadequate catalytic activity limi...Galactitol dehydrogenase(EC 1.1.1.16)is a key enzyme for D-tagatose production from galactitol.However,only a limited number of galactitol dehydrogenases have been reported,and their inadequate catalytic activity limits industrial-scale applications.To address this bottleneck,a gdh from Rhizobium leguminosarum was engineered to obtain the mutant with high catalytic activity via semi-rational design.The kcat value of the T193G/G98C mutant for galactitol was 24.75-fold higher than that of the wild-type RlGDH.Coupling this mutant with a water-forming NADH oxidase(SpNox)from Streptococcus pyogenes for cofactor regeneration,360.5 g/L D-tagatose was achieved from 364 g/L galactitol within 12 h under oxygen atmosphere,corresponding to a conversion rate of 99%.This is the first report on D-tagatose production exceeding 360 g/L using a galactitol dehydrogenase-based bienzymatic system,thereby demonstrating considerable potential for industrial application in D-tagatose synthesis.展开更多
目的:建立肉苁蓉药材中通便有效成分半乳糖醇的含量测定方法。方法:采用高效液相色谱分离,蒸发光散射检测器(ELSD)检测,色谱柱为 Prevail Carbohydrate ES 聚合凝胶柱(250mm×4.6mm,5μm),流动相为乙腈-水(77:23),流速为0.7mL·...目的:建立肉苁蓉药材中通便有效成分半乳糖醇的含量测定方法。方法:采用高效液相色谱分离,蒸发光散射检测器(ELSD)检测,色谱柱为 Prevail Carbohydrate ES 聚合凝胶柱(250mm×4.6mm,5μm),流动相为乙腈-水(77:23),流速为0.7mL·min^(-1);柱温为25℃,检测器漂移管温度为40℃,气体压力为240kPa。结果:半乳糖醇线性范围为0.25～10.00μg,r=0.9992;平均回收率为99.42%。结论:本法简便、准确,可作为肉苁蓉药材的质控方法。展开更多
基金supported by the Guangxi Regional Inno-vation Capacity Enhancement Program(Grant No.Guike XT2503980005)the Guangxi Key Science and Technology Special Project(Grant No.Guike AA24206048-2)+1 种基金the Guangxi Key Research and Development Program(Grant No.Guike Nong AB2506910016)the GXAS Basic Research Program(Grant No.2024YWF2103).
文摘Galactitol dehydrogenase(EC 1.1.1.16)is a key enzyme for D-tagatose production from galactitol.However,only a limited number of galactitol dehydrogenases have been reported,and their inadequate catalytic activity limits industrial-scale applications.To address this bottleneck,a gdh from Rhizobium leguminosarum was engineered to obtain the mutant with high catalytic activity via semi-rational design.The kcat value of the T193G/G98C mutant for galactitol was 24.75-fold higher than that of the wild-type RlGDH.Coupling this mutant with a water-forming NADH oxidase(SpNox)from Streptococcus pyogenes for cofactor regeneration,360.5 g/L D-tagatose was achieved from 364 g/L galactitol within 12 h under oxygen atmosphere,corresponding to a conversion rate of 99%.This is the first report on D-tagatose production exceeding 360 g/L using a galactitol dehydrogenase-based bienzymatic system,thereby demonstrating considerable potential for industrial application in D-tagatose synthesis.
文摘目的:建立肉苁蓉药材中通便有效成分半乳糖醇的含量测定方法。方法:采用高效液相色谱分离,蒸发光散射检测器(ELSD)检测,色谱柱为 Prevail Carbohydrate ES 聚合凝胶柱(250mm×4.6mm,5μm),流动相为乙腈-水(77:23),流速为0.7mL·min^(-1);柱温为25℃,检测器漂移管温度为40℃,气体压力为240kPa。结果:半乳糖醇线性范围为0.25～10.00μg,r=0.9992;平均回收率为99.42%。结论:本法简便、准确,可作为肉苁蓉药材的质控方法。
