Betalain has received increased attention because of its high nutritional value and crucial physiological functions.Based on the elucidation of its core biosynthetic pathway,betalain can be produced in additional plan...Betalain has received increased attention because of its high nutritional value and crucial physiological functions.Based on the elucidation of its core biosynthetic pathway,betalain can be produced in additional plants by metabolic engineering.Synthesis of betalain in carrot(Daucus carota L.)can improve its nutritional quality and economic value by extracting betalain from the fleshy root,non-edible part,and processing residue of carrot.In this study,two different constructs,namely,pYB:mCD(AomelOS,BvCYP76AD1S,and BvDODA1S)and p YB:CDD(BvCYP76AD1S,BvDODA1S,and MjcDOPA5GTS),were introduced into carrot for betanin synthesis by Agrobacterium-mediated transformation.Betanin can be synthetized in both transgenic calli,and p YB:m CD-transgenic callus can be used to produce betacyanin by suspension culture.However,pYB:mCD-transgenic seedlings can synthetize betanin only by tyrosine feeding.The p YB:CDD-transgenic lines can synthetize betanin in whole plants.The betanin content in fleshy root of pYB:CDD-transgenic carrot was(63.4±9)μg·g^(-1)fresh weight according to quantitative analysis.These betanin-producing carrot plant materials can be used to synthesize betanin for industrial application or consumption as dietary sources.展开更多
Betanin is a member of natural pigment betacyanins family and has extensive application in the food industry as an important natural red food colorant.Its relatively inefficient production in nature however hampers ac...Betanin is a member of natural pigment betacyanins family and has extensive application in the food industry as an important natural red food colorant.Its relatively inefficient production in nature however hampers access to this phytochemicals through traditional crop-based manufacturing.Microbial bioproduction therefore represents an attractive alternative.Here,we present the construction of a Saccharomyces cerevisiae strain for betanin production.Through minimizing metabolic crosstalk,screening and modifying biosynthetic enzymes,enhancing pathway flux and optimizing fermentation conditions,a final titer of betanin of 28.7 mg/L was achieved from glucose at 25℃ in baffled shake-flask,which is the highest reported titer produced by yeast to our knowledge.This work provides a promising step towards developing synthetic yeast cell factories for de novo biosynthesis of value-added betanin and other betacyanins.展开更多
为研究甜菜苷(Betanin)与乳清分离蛋白(Whey protein isolate,WPI)的相互作用及乳清分离蛋白对甜菜苷热稳定的影响,本文通过自组装法构建了WPI-Betanin复合物,利用紫外可见光谱验证了复合物的形成,并通过荧光光谱和圆二色谱探究了复合...为研究甜菜苷(Betanin)与乳清分离蛋白(Whey protein isolate,WPI)的相互作用及乳清分离蛋白对甜菜苷热稳定的影响,本文通过自组装法构建了WPI-Betanin复合物,利用紫外可见光谱验证了复合物的形成,并通过荧光光谱和圆二色谱探究了复合物形成的作用机制及蛋白质结构的变化,最后采用分子模拟技术将复合物相互作用可视化。结果表明,甜菜苷与乳清分离蛋白主要通过氢键与范德华力形成复合物,结合位点数约为1。复合物的形成导致蛋白的浊度增加,表面疏水性降低,内源荧光猝灭,且猝灭机制为静态猝灭,常温下的猝灭常数为1.78×10^(3)L/mol。相互作用改变了乳清分离蛋白中色氨酸、酪氨酸的微环境和二级结构含量,使甜菜苷在80℃下加热1 h的保留率从6.17%提高到27.26%。本研究为功能性蛋白色素复合物的应用开发和甜菜苷的护色提供了理论基础。展开更多
以甜菜红苷(Bt)为对象,采用-荧光光谱、傅里叶变换红外光谱以及圆二色谱技术分析乳清蛋白(WP)和牛血清白蛋白(BSA)与Bt作用生成的复合物中乳蛋白组分对Bt热稳定性的影响。结果表明:添加WP和BSA能有效抑制甜菜红苷的热降解作用,其中WP对...以甜菜红苷(Bt)为对象,采用-荧光光谱、傅里叶变换红外光谱以及圆二色谱技术分析乳清蛋白(WP)和牛血清白蛋白(BSA)与Bt作用生成的复合物中乳蛋白组分对Bt热稳定性的影响。结果表明:添加WP和BSA能有效抑制甜菜红苷的热降解作用,其中WP对甜菜红苷的保护作用优于BSA。同时,体系环境的pH值变化也明显影响甜菜红苷的热降解,在p H 5.0时甜菜红苷复合物的半衰期最长,其中Bt-WP复合物的半衰期达2.99 h。荧光光谱、傅里叶变换红外光谱以及圆二色谱分析表明,复合物中Bt组分的作用导致WP和BSA发生静态荧光猝灭,WP和BSA色氨酸残基和酪氨酸残基所处微环境的疏水性减弱,极性变强。此外,添加Bt使两种蛋白质的构象结构发生改变,酰胺Ⅰ带和酰胺Ⅱ带的特征峰位置改变,二级结构中各类构象组成发生不同程度的变化。展开更多
基金supported by National Natural Science Foundation of China(Grant No.32072563)Key Research and Development Projects of Ningxia Hui Autonomous Region(Grant No.2022BBF02008)+2 种基金Key Project Fund of the Shanghai Municipal Committee of Agriculture(Grant Nos.2021-02-08-00-12-F00795,Chuangzi 20181e5)Shanghai Academic Technology Research Leader(Grant No.19XD1432300)Priority Academic Program Development of Jiangsu Higher Education Institutions Project(PAPD)。
文摘Betalain has received increased attention because of its high nutritional value and crucial physiological functions.Based on the elucidation of its core biosynthetic pathway,betalain can be produced in additional plants by metabolic engineering.Synthesis of betalain in carrot(Daucus carota L.)can improve its nutritional quality and economic value by extracting betalain from the fleshy root,non-edible part,and processing residue of carrot.In this study,two different constructs,namely,pYB:mCD(AomelOS,BvCYP76AD1S,and BvDODA1S)and p YB:CDD(BvCYP76AD1S,BvDODA1S,and MjcDOPA5GTS),were introduced into carrot for betanin synthesis by Agrobacterium-mediated transformation.Betanin can be synthetized in both transgenic calli,and p YB:m CD-transgenic callus can be used to produce betacyanin by suspension culture.However,pYB:mCD-transgenic seedlings can synthetize betanin only by tyrosine feeding.The p YB:CDD-transgenic lines can synthetize betanin in whole plants.The betanin content in fleshy root of pYB:CDD-transgenic carrot was(63.4±9)μg·g^(-1)fresh weight according to quantitative analysis.These betanin-producing carrot plant materials can be used to synthesize betanin for industrial application or consumption as dietary sources.
基金supported by the Research and Development Program in Key Areas of Guangdong Province,China (2020B0303070002).
文摘Betanin is a member of natural pigment betacyanins family and has extensive application in the food industry as an important natural red food colorant.Its relatively inefficient production in nature however hampers access to this phytochemicals through traditional crop-based manufacturing.Microbial bioproduction therefore represents an attractive alternative.Here,we present the construction of a Saccharomyces cerevisiae strain for betanin production.Through minimizing metabolic crosstalk,screening and modifying biosynthetic enzymes,enhancing pathway flux and optimizing fermentation conditions,a final titer of betanin of 28.7 mg/L was achieved from glucose at 25℃ in baffled shake-flask,which is the highest reported titer produced by yeast to our knowledge.This work provides a promising step towards developing synthetic yeast cell factories for de novo biosynthesis of value-added betanin and other betacyanins.
文摘为研究甜菜苷(Betanin)与乳清分离蛋白(Whey protein isolate,WPI)的相互作用及乳清分离蛋白对甜菜苷热稳定的影响,本文通过自组装法构建了WPI-Betanin复合物,利用紫外可见光谱验证了复合物的形成,并通过荧光光谱和圆二色谱探究了复合物形成的作用机制及蛋白质结构的变化,最后采用分子模拟技术将复合物相互作用可视化。结果表明,甜菜苷与乳清分离蛋白主要通过氢键与范德华力形成复合物,结合位点数约为1。复合物的形成导致蛋白的浊度增加,表面疏水性降低,内源荧光猝灭,且猝灭机制为静态猝灭,常温下的猝灭常数为1.78×10^(3)L/mol。相互作用改变了乳清分离蛋白中色氨酸、酪氨酸的微环境和二级结构含量,使甜菜苷在80℃下加热1 h的保留率从6.17%提高到27.26%。本研究为功能性蛋白色素复合物的应用开发和甜菜苷的护色提供了理论基础。
文摘以甜菜红苷(Bt)为对象,采用-荧光光谱、傅里叶变换红外光谱以及圆二色谱技术分析乳清蛋白(WP)和牛血清白蛋白(BSA)与Bt作用生成的复合物中乳蛋白组分对Bt热稳定性的影响。结果表明:添加WP和BSA能有效抑制甜菜红苷的热降解作用,其中WP对甜菜红苷的保护作用优于BSA。同时,体系环境的pH值变化也明显影响甜菜红苷的热降解,在p H 5.0时甜菜红苷复合物的半衰期最长,其中Bt-WP复合物的半衰期达2.99 h。荧光光谱、傅里叶变换红外光谱以及圆二色谱分析表明,复合物中Bt组分的作用导致WP和BSA发生静态荧光猝灭,WP和BSA色氨酸残基和酪氨酸残基所处微环境的疏水性减弱,极性变强。此外,添加Bt使两种蛋白质的构象结构发生改变,酰胺Ⅰ带和酰胺Ⅱ带的特征峰位置改变,二级结构中各类构象组成发生不同程度的变化。
