The germination process of seeds is influenced by the interplay between two opposing factors,pectin methylesterase(PME)and pectin methylesterase inhibitor(PMEI),which collectively regulate patterns of pectin methylest...The germination process of seeds is influenced by the interplay between two opposing factors,pectin methylesterase(PME)and pectin methylesterase inhibitor(PMEI),which collectively regulate patterns of pectin methylesterification.Despite the recognized importance of pectin methylesterification in seed germination,the specific mechanisms that govern this process remain unclear.In this study,we demonstrated that the overexpression of GhPMEI53is associated with a decrease in PME activity and an increase in pectin methylesterification.This leads to seed cell wall softening,which positively regulates cotton seed germination.AtPMEI19,the homologue in Arabidopsis thaliana,plays a similar role in seed germination to GhPMEI53,indicating a conserved function and mechanism of PMEI in seed germination regulation.Further studies revealed that GhPMEI53 and AtPMEI19 directly contribute to promoting radicle protrusion and seed germination by inducing cell wall softening and reducing mechanical strength.Additionally,the pathways of abscicic acid(ABA)and gibberellin(GA)in the transgenic materials showed significant changes,suggesting that GhPMEI53/AtPMEI19-mediated pectin methylesterification serves as a regulatory signal for the related phytohormones involved in seed germination.In summary,GhPMEI53 and its homologs alter the mechanical properties of cell walls,which influence the mechanical resistance of the endosperm or testa.Moreover,they impact cellular phytohormone pathways(e.g.,ABA and GA)to regulate seed germination.These findings enhance our understanding of pectin methylesterification in cellular morphological dynamics and signaling transduction,and contribute to a more comprehensive understanding of the PME/PMEI gene superfamily in plants.展开更多
The transformation of biomasses from agro-industrial waste can significantly impact the production of green chemicals from sustainable resources.Pectin is a biopolymer present in lignocellulosic biomass as Orange Peel...The transformation of biomasses from agro-industrial waste can significantly impact the production of green chemicals from sustainable resources.Pectin is a biopolymer present in lignocellulosic biomass as Orange Peel Waste(OPW)and has possibilities for making platform compounds such as furfural for sustainable chemistry.In this work,we studied the transformation to furfural of OPW,pectins,and d-galacturonic acid(D-GalA),which is the main component(65 wt%)of pectin.We analyzed pectins with different degrees of esterification(45,60 and 95 DE)in a one-pot hydrolysis reaction system and studied the differences in depolymerization and dehydration of the carbohydrates.The results show that the production of furfural decreases as the DE value increases.Specifically,low DE values favor the formation of furfural since the decarboxylation reaction is favored over deesterification.Interestingly,the furfural concentration is dependent upon the polysaccharide composition of pentoses and uronic acid.The obtained concentrations of furfural(13 and 14 mmol/L),d-xylose(6.2 and 10 mmol/L),and L-arabinose(2.5 and 2.7 mmol/L)remained the same when the galacturonic acid was fed either as a polymer or a monomer under the same reaction conditions(0.01 M SA,90 min and 433 K).OPW is proposed as a feedstock in a biorefinery,in which on a per kg OPW dry basis,90 g of pectin and 15 g of furfural were produced in the most favorable case.We conclude that the co-production of pectin and furfural from OPW is economically feasible.展开更多
Pectin lyase(PMGL)is an industrially important enzyme with widespread applications in the food,paper,and textile industries,owing to its capacity for direct degradation of highly esterified pectin.In this study,PMGL-B...Pectin lyase(PMGL)is an industrially important enzyme with widespread applications in the food,paper,and textile industries,owing to its capacity for direct degradation of highly esterified pectin.In this study,PMGL-Ba derived from Bacillus licheniformis underwent mining and heterologous expression in P.pastoris.Furthermore,diverse strategies,encompassing the optimization of expression cassette components,elevation of gene dosage,and co-expression of chaperone factors,were employed to augment PMGL-Ba production in P.pastoris.The signaling peptide OST1-pre-α-MF-pro and promoter AOX1 were finally selected as expression elements.By overexpressing the transcription factor Hac1p in conjunction with a two-copy PMGL-Ba setup,a strain yielding high PMGL-Ba production was achieved.In shake flask fermentation lasting 144 h,the total protein concentration reached 1.81 g/L,and the enzyme activity reached 1821.36 U/mL.For further scale up production,high-density fermentation transpired in a 5 L fermenter for 72 h.Remarkably,the total protein concentration increased to 12.49 g/L,and the enzyme activity reached an impressive 12668.12 U/mL.The successful heterologous and efficient expression of PMGL-Ba not only furnishes a valuable biological enzyme for industrial applications but also contributes to cost reduction in the utilization of biological enzymes in industrial applications.展开更多
试验旨在增强植物乳植杆菌(Lactiplantibacillum plantarum)的抗逆性,提高其经胃肠道后的存活率。试验以柑橘纤维素和柑橘果胶为原料,对植物乳植杆菌B5 (L. plantarum B5)进行包埋,构建复合乳酸菌微胶囊,通过测定包埋率、结构表征、控...试验旨在增强植物乳植杆菌(Lactiplantibacillum plantarum)的抗逆性,提高其经胃肠道后的存活率。试验以柑橘纤维素和柑橘果胶为原料,对植物乳植杆菌B5 (L. plantarum B5)进行包埋,构建复合乳酸菌微胶囊,通过测定包埋率、结构表征、控释试验、耐胆盐及储藏稳定性试验,对复合微胶囊进行综合评估。结果显示,微胶囊对L. plantarum B5具有良好的包埋效果,当柑橘纤维素和柑橘果胶的配比为1∶3时(CL13微胶囊),包埋率最高达到95.82%。傅里叶红外光谱图表明,纤维素和果胶中的羧基与钙离子通过桥连配位形成微胶囊。扫描电镜图像显示,菌体成功包埋于微胶囊的内部及表面。所有微胶囊均具备良好的控释性能,CL13微胶囊的控释效果显著高于其他配比的微胶囊(P<0.05),在模拟肠液中的释放率达到90.28%。微胶囊能够显著提高L. plantarum B5在胆盐和低温环境下的存活率(P<0.05),微胶囊稳定性良好。研究表明,柑橘纤维-柑橘果胶微胶囊能够有效保护L. plantarum B5顺利到达肠道,在宿主体内最大限度地发挥益生作用。展开更多
优化了乳清分离蛋白-果胶纳米复合物(whey protein isolate-pectin,W-P)的制备工艺,并考察了W-P稳定的百里香精油纳米乳液(thyme essential oil nanoemulsion,TEON)的稳定性及抑菌效果。结果表明:当乳清分离蛋白(whey protein isolate,W...优化了乳清分离蛋白-果胶纳米复合物(whey protein isolate-pectin,W-P)的制备工艺,并考察了W-P稳定的百里香精油纳米乳液(thyme essential oil nanoemulsion,TEON)的稳定性及抑菌效果。结果表明:当乳清分离蛋白(whey protein isolate,WPI)与果胶(pectin,PEC)的质量比为1∶2、pH为5.0、加热温度为80℃、加热时间为15 min、W-P的质量浓度为25 g/L时,制得的W-P的平均粒径为(504.45±1.53)nm,乳化活性和乳化稳定性分别为(28.63±0.34)m^(2)/g和(1034.16±13.64)min,其稳定的TEON在pH 3.0~7.0、温度30~90℃、离子浓度0~200 mmol/L和储藏15 d(4℃)时稳定性良好。同时,TEON对大肠杆菌和金黄色葡萄球菌表现出明显的抑菌效果。W-P展现出优良的乳化性能,显示出其在食品体系中作为乳化剂的应用潜力。展开更多
We studied the effect of two independent variables, the pectin/calcium chloride weight ratio and the overall matrix weight in HPMC/pectin/calcium matrix tablet, on the release of indomethacin. A two-factor 5-level cen...We studied the effect of two independent variables, the pectin/calcium chloride weight ratio and the overall matrix weight in HPMC/pectin/calcium matrix tablet, on the release of indomethacin. A two-factor 5-level central composite experimental design was employed. Responses of the Peppas correlation parameters n and K and the 10% release time （T0.1） were optimized by response surface methodology. Significant effect of the independent variables on the biphasic release parameters, n and K, was observed. N, K and T0.1 were well fitted with the second-order quadratic equations rather than linear equations. Moreover, the mathematic fitting and the response surfaces showed significant cross-interaction between the pectin/calcium chloride ratio and the overall matrix weight. The optimal formulation with larger n, longer T0.1 and smaller K consisted of medium pectin/calcium chloride ratio around 1.0 and medium matrix weight around 200 mg. Validation studies on the optimal formulations showed good predictability of the n, K and T0.1 values with biases within the range of-7.33% and 6.26%. Our results support that central composite design can be used to optimize drug release from HPMC/pectin/calcium matrix tablet with high predictability.展开更多
基金funded by the National Natural Science Foundation of China(32072022)the Nanfan Special Project,CAAS(YBXM07)the Hainan Yazhou Bay Seed Laboratory,China(B23CJ0208)。
文摘The germination process of seeds is influenced by the interplay between two opposing factors,pectin methylesterase(PME)and pectin methylesterase inhibitor(PMEI),which collectively regulate patterns of pectin methylesterification.Despite the recognized importance of pectin methylesterification in seed germination,the specific mechanisms that govern this process remain unclear.In this study,we demonstrated that the overexpression of GhPMEI53is associated with a decrease in PME activity and an increase in pectin methylesterification.This leads to seed cell wall softening,which positively regulates cotton seed germination.AtPMEI19,the homologue in Arabidopsis thaliana,plays a similar role in seed germination to GhPMEI53,indicating a conserved function and mechanism of PMEI in seed germination regulation.Further studies revealed that GhPMEI53 and AtPMEI19 directly contribute to promoting radicle protrusion and seed germination by inducing cell wall softening and reducing mechanical strength.Additionally,the pathways of abscicic acid(ABA)and gibberellin(GA)in the transgenic materials showed significant changes,suggesting that GhPMEI53/AtPMEI19-mediated pectin methylesterification serves as a regulatory signal for the related phytohormones involved in seed germination.In summary,GhPMEI53 and its homologs alter the mechanical properties of cell walls,which influence the mechanical resistance of the endosperm or testa.Moreover,they impact cellular phytohormone pathways(e.g.,ABA and GA)to regulate seed germination.These findings enhance our understanding of pectin methylesterification in cellular morphological dynamics and signaling transduction,and contribute to a more comprehensive understanding of the PME/PMEI gene superfamily in plants.
基金supported by the project:“Obtención de biocombustibles y compuestos químicos de alto valor agregado a partir de biomasas de desecho ricas en pectina”,CONAHCYT agreement:CB 255527-2016the Fellowship with reference number:654271 from the Mexican Council for Science and Technology,CONAHCYT was assigned to Eva Estela Rivera Cedillo as PhD student.
文摘The transformation of biomasses from agro-industrial waste can significantly impact the production of green chemicals from sustainable resources.Pectin is a biopolymer present in lignocellulosic biomass as Orange Peel Waste(OPW)and has possibilities for making platform compounds such as furfural for sustainable chemistry.In this work,we studied the transformation to furfural of OPW,pectins,and d-galacturonic acid(D-GalA),which is the main component(65 wt%)of pectin.We analyzed pectins with different degrees of esterification(45,60 and 95 DE)in a one-pot hydrolysis reaction system and studied the differences in depolymerization and dehydration of the carbohydrates.The results show that the production of furfural decreases as the DE value increases.Specifically,low DE values favor the formation of furfural since the decarboxylation reaction is favored over deesterification.Interestingly,the furfural concentration is dependent upon the polysaccharide composition of pentoses and uronic acid.The obtained concentrations of furfural(13 and 14 mmol/L),d-xylose(6.2 and 10 mmol/L),and L-arabinose(2.5 and 2.7 mmol/L)remained the same when the galacturonic acid was fed either as a polymer or a monomer under the same reaction conditions(0.01 M SA,90 min and 433 K).OPW is proposed as a feedstock in a biorefinery,in which on a per kg OPW dry basis,90 g of pectin and 15 g of furfural were produced in the most favorable case.We conclude that the co-production of pectin and furfural from OPW is economically feasible.
基金supported by the National Key R&D Program of China(NO.2021YFC2100400).
文摘Pectin lyase(PMGL)is an industrially important enzyme with widespread applications in the food,paper,and textile industries,owing to its capacity for direct degradation of highly esterified pectin.In this study,PMGL-Ba derived from Bacillus licheniformis underwent mining and heterologous expression in P.pastoris.Furthermore,diverse strategies,encompassing the optimization of expression cassette components,elevation of gene dosage,and co-expression of chaperone factors,were employed to augment PMGL-Ba production in P.pastoris.The signaling peptide OST1-pre-α-MF-pro and promoter AOX1 were finally selected as expression elements.By overexpressing the transcription factor Hac1p in conjunction with a two-copy PMGL-Ba setup,a strain yielding high PMGL-Ba production was achieved.In shake flask fermentation lasting 144 h,the total protein concentration reached 1.81 g/L,and the enzyme activity reached 1821.36 U/mL.For further scale up production,high-density fermentation transpired in a 5 L fermenter for 72 h.Remarkably,the total protein concentration increased to 12.49 g/L,and the enzyme activity reached an impressive 12668.12 U/mL.The successful heterologous and efficient expression of PMGL-Ba not only furnishes a valuable biological enzyme for industrial applications but also contributes to cost reduction in the utilization of biological enzymes in industrial applications.
文摘试验旨在增强植物乳植杆菌(Lactiplantibacillum plantarum)的抗逆性,提高其经胃肠道后的存活率。试验以柑橘纤维素和柑橘果胶为原料,对植物乳植杆菌B5 (L. plantarum B5)进行包埋,构建复合乳酸菌微胶囊,通过测定包埋率、结构表征、控释试验、耐胆盐及储藏稳定性试验,对复合微胶囊进行综合评估。结果显示,微胶囊对L. plantarum B5具有良好的包埋效果,当柑橘纤维素和柑橘果胶的配比为1∶3时(CL13微胶囊),包埋率最高达到95.82%。傅里叶红外光谱图表明,纤维素和果胶中的羧基与钙离子通过桥连配位形成微胶囊。扫描电镜图像显示,菌体成功包埋于微胶囊的内部及表面。所有微胶囊均具备良好的控释性能,CL13微胶囊的控释效果显著高于其他配比的微胶囊(P<0.05),在模拟肠液中的释放率达到90.28%。微胶囊能够显著提高L. plantarum B5在胆盐和低温环境下的存活率(P<0.05),微胶囊稳定性良好。研究表明,柑橘纤维-柑橘果胶微胶囊能够有效保护L. plantarum B5顺利到达肠道,在宿主体内最大限度地发挥益生作用。
基金Shanghai Municipal Committee of Sciencc and Tcchnology (Grant No.024319114).
文摘We studied the effect of two independent variables, the pectin/calcium chloride weight ratio and the overall matrix weight in HPMC/pectin/calcium matrix tablet, on the release of indomethacin. A two-factor 5-level central composite experimental design was employed. Responses of the Peppas correlation parameters n and K and the 10% release time （T0.1） were optimized by response surface methodology. Significant effect of the independent variables on the biphasic release parameters, n and K, was observed. N, K and T0.1 were well fitted with the second-order quadratic equations rather than linear equations. Moreover, the mathematic fitting and the response surfaces showed significant cross-interaction between the pectin/calcium chloride ratio and the overall matrix weight. The optimal formulation with larger n, longer T0.1 and smaller K consisted of medium pectin/calcium chloride ratio around 1.0 and medium matrix weight around 200 mg. Validation studies on the optimal formulations showed good predictability of the n, K and T0.1 values with biases within the range of-7.33% and 6.26%. Our results support that central composite design can be used to optimize drug release from HPMC/pectin/calcium matrix tablet with high predictability.
