利用大肠杆菌混菌发酵生物合成咖啡醇糖苷。通过在酪氨酸高产大肠杆菌BTAL中表达异源基因酪氨酸解氨酶(tyrosine ammonia-lyase from Rhodotorula glutinis,RgTAL),对羟基肉桂酰辅酶A连接酶(hydroxycinnamate:CoA ligase from Petroseli...利用大肠杆菌混菌发酵生物合成咖啡醇糖苷。通过在酪氨酸高产大肠杆菌BTAL中表达异源基因酪氨酸解氨酶(tyrosine ammonia-lyase from Rhodotorula glutinis,RgTAL),对羟基肉桂酰辅酶A连接酶(hydroxycinnamate:CoA ligase from Petroselinum crispum,Pc4CL)和肉桂酰辅酶A还原酶(cinnamyl-CoA reductase from Arabidopsis thaliana,AtCCR),与大肠杆菌BL21(DE3)中表达对羟基苯乙酸3-羟化酶HpaBC和糖基转移酶(UGT73C5 from A.thaliana,AtUGT73C5)混合培养发酵生产了3种咖啡醇葡萄糖苷,其中2种为非天然化合物。优化共培养比例至3∶1,咖啡醇-4-O-葡萄糖苷的最高产量达到(141.63±3.42)mg/L。这是首次微生物异源合成咖啡醇糖苷的报道,该工作扩大了咖啡醇糖苷的结构多样性,为后续的构效分析提供了新的候选化合物,有望得到具有较好生物活性的咖啡醇糖苷化合物。展开更多
The development of convenient method to obtain graphene-based nanocomposites is a key issue for their application. Herein, we described a facile route for synthesizing graphene-Cu and graphene-Cu2 O nanocomposites usi...The development of convenient method to obtain graphene-based nanocomposites is a key issue for their application. Herein, we described a facile route for synthesizing graphene-Cu and graphene-Cu2 O nanocomposites using graphene oxide-Cu O as a precursor. Remarkably, the different nanocomposites could be formed just by varying the reaction temperature and time. This work provides a feasible route for the preparation of graphene-based nanocomposites with various constituents.展开更多
[背景]乙酸肉桂酯是一种重要的香料化合物,在化妆品和食品工业上具有广泛的应用,传统的生产方法主要依靠植物提取和化学合成。[目的]通过筛选不同植物源的酰基转移酶,利用大肠杆菌从头合成乙酸肉桂酯。[方法]首先,通过在苯丙氨酸高产菌B...[背景]乙酸肉桂酯是一种重要的香料化合物,在化妆品和食品工业上具有广泛的应用,传统的生产方法主要依靠植物提取和化学合成。[目的]通过筛选不同植物源的酰基转移酶,利用大肠杆菌从头合成乙酸肉桂酯。[方法]首先,通过在苯丙氨酸高产菌BPHE中表达异源基因苯丙氨酸解氨酶(Phenylalanine Ammonia-Lyase from Arabidopsis thaliana,AtPAL)、对羟基肉桂酰辅酶A连接酶(Hydroxycinnamate:CoA Ligase from Petroselinum crispum,Pc4CL)和肉桂酰辅酶A还原酶(Cinnamyl-CoA Reductase from Arabidopsis thaliana,AtCCR),并结合大肠杆菌自身的内源性醇脱氢酶(Alcohol Dehydrogenases,ADHs)或醛酮还原酶(Aldo-Keto Reductases,AKRs)的催化作用构建了从苯丙氨酸到肉桂醇的生物合成途径。然后,苯甲醇苯甲酰转移酶(Benzyl Alcohol O-Benzoyltransferase from Nicotiana tabacum,ANN09798;Benzyl Alcohol O-Benzoyltransferase from Clarkia breweri,ANN09796)或苯甲醇乙酰转移酶(Benzyl Alcohol Acetyltransferase from Clarkia breweri,BEAT)被引入到上述重组大肠杆菌中发酵培养生产乙酸肉桂酯。最后,在大肠杆菌中过表达乙酰辅酶A合成酶(Acetyl Coenzyme A Synthetase,ACS)来提高底物乙酰辅酶A的量。[结果]探讨了3个植物源苯甲醇酰基转移酶生物合成乙酸肉桂酯的能力,并应用于合成乙酸肉桂酯的细胞工厂,最终使乙酸肉桂酯最高产量达到166.9±6.6mg/L。[结论]植物源苯甲醇酰基转移酶具有一定的底物宽泛性,能以肉桂醇为底物催化合成乙酸肉桂酯。首次利用植物源的苯甲醇酰基转移酶合成乙酸肉桂酯,为微生物细胞工厂以葡萄糖作为碳源生产乙酸肉桂酯提供参考。展开更多
文摘利用大肠杆菌混菌发酵生物合成咖啡醇糖苷。通过在酪氨酸高产大肠杆菌BTAL中表达异源基因酪氨酸解氨酶(tyrosine ammonia-lyase from Rhodotorula glutinis,RgTAL),对羟基肉桂酰辅酶A连接酶(hydroxycinnamate:CoA ligase from Petroselinum crispum,Pc4CL)和肉桂酰辅酶A还原酶(cinnamyl-CoA reductase from Arabidopsis thaliana,AtCCR),与大肠杆菌BL21(DE3)中表达对羟基苯乙酸3-羟化酶HpaBC和糖基转移酶(UGT73C5 from A.thaliana,AtUGT73C5)混合培养发酵生产了3种咖啡醇葡萄糖苷,其中2种为非天然化合物。优化共培养比例至3∶1,咖啡醇-4-O-葡萄糖苷的最高产量达到(141.63±3.42)mg/L。这是首次微生物异源合成咖啡醇糖苷的报道,该工作扩大了咖啡醇糖苷的结构多样性,为后续的构效分析提供了新的候选化合物,有望得到具有较好生物活性的咖啡醇糖苷化合物。
基金Funded by the Jiangsu Funds for Distinguished Young Scientists(No.BK2012035)Program for New Century Excellent Talents in University(No.NCET-11-0834)the National Natural Science Foundation of China(No.21206075)
文摘The development of convenient method to obtain graphene-based nanocomposites is a key issue for their application. Herein, we described a facile route for synthesizing graphene-Cu and graphene-Cu2 O nanocomposites using graphene oxide-Cu O as a precursor. Remarkably, the different nanocomposites could be formed just by varying the reaction temperature and time. This work provides a feasible route for the preparation of graphene-based nanocomposites with various constituents.
文摘[背景]乙酸肉桂酯是一种重要的香料化合物,在化妆品和食品工业上具有广泛的应用,传统的生产方法主要依靠植物提取和化学合成。[目的]通过筛选不同植物源的酰基转移酶,利用大肠杆菌从头合成乙酸肉桂酯。[方法]首先,通过在苯丙氨酸高产菌BPHE中表达异源基因苯丙氨酸解氨酶(Phenylalanine Ammonia-Lyase from Arabidopsis thaliana,AtPAL)、对羟基肉桂酰辅酶A连接酶(Hydroxycinnamate:CoA Ligase from Petroselinum crispum,Pc4CL)和肉桂酰辅酶A还原酶(Cinnamyl-CoA Reductase from Arabidopsis thaliana,AtCCR),并结合大肠杆菌自身的内源性醇脱氢酶(Alcohol Dehydrogenases,ADHs)或醛酮还原酶(Aldo-Keto Reductases,AKRs)的催化作用构建了从苯丙氨酸到肉桂醇的生物合成途径。然后,苯甲醇苯甲酰转移酶(Benzyl Alcohol O-Benzoyltransferase from Nicotiana tabacum,ANN09798;Benzyl Alcohol O-Benzoyltransferase from Clarkia breweri,ANN09796)或苯甲醇乙酰转移酶(Benzyl Alcohol Acetyltransferase from Clarkia breweri,BEAT)被引入到上述重组大肠杆菌中发酵培养生产乙酸肉桂酯。最后,在大肠杆菌中过表达乙酰辅酶A合成酶(Acetyl Coenzyme A Synthetase,ACS)来提高底物乙酰辅酶A的量。[结果]探讨了3个植物源苯甲醇酰基转移酶生物合成乙酸肉桂酯的能力,并应用于合成乙酸肉桂酯的细胞工厂,最终使乙酸肉桂酯最高产量达到166.9±6.6mg/L。[结论]植物源苯甲醇酰基转移酶具有一定的底物宽泛性,能以肉桂醇为底物催化合成乙酸肉桂酯。首次利用植物源的苯甲醇酰基转移酶合成乙酸肉桂酯,为微生物细胞工厂以葡萄糖作为碳源生产乙酸肉桂酯提供参考。