人呼吸道合胞病毒是引起婴幼儿支气管炎和肺炎的主要原因,也可导致免疫缺陷病人及老年人群显著发病和死亡.人呼吸道合胞病毒疫苗已被世界卫生组织(World Health Organization,WHO)列为全球最优先发展的疫苗之一.经过50多年的研究,尤其...人呼吸道合胞病毒是引起婴幼儿支气管炎和肺炎的主要原因,也可导致免疫缺陷病人及老年人群显著发病和死亡.人呼吸道合胞病毒疫苗已被世界卫生组织(World Health Organization,WHO)列为全球最优先发展的疫苗之一.经过50多年的研究,尤其是随着重组技术和反向遗传学的出现,对RSV疫苗的研究取得了重要进展,但尚未有疫苗上市.目前主要集中于亚单位疫苗及活疫苗等,其中活疫苗包括减毒活疫苗和活病毒载体疫苗,因其最有可能用于预防婴幼儿RSV感染,而受到了较大关注.以rA2cp248/404/1030ΔSH为代表的RSV减毒活疫苗临床试验显示,其有较好的安全性及免疫保护作用,不产生疾病增强作用是极有潜力的候选疫苗.因此,本文将重点介绍RSV活疫苗研究的主要进展和发展方向.展开更多
This paper aims to provide better guidance for construction of trehalose-producing recombinant strains to further improve the yield of trehalose. The research progress on trehalose biosynthesis pathways and the applic...This paper aims to provide better guidance for construction of trehalose-producing recombinant strains to further improve the yield of trehalose. The research progress on trehalose biosynthesis pathways and the application of molecular biology technique in trehalose study in recent 30 years, especially the last 10 years are reviewed. Results show that there are 5 pathways of trehalose synthesis. Although enzymes and genes of trehalose synthesis have been isolated and genetic engineering strains have increased gradually, the improvement of trehalose yield is still inadequate because most recombinant strains are limited to study the physicochemical properties of single enzyme. With the development of modern biological technology, especially the rapid development of DNA recombinant technology, metagenomics and synthetic biology, high expression of heterologous trehalose in recombinant strains would become a hot research topic in the future.展开更多
This study investigated the effects of the luxS gene on the biofilm formation of Lactobacillus fermentum and its stress resistance.Deletion of the luxS gene was related to the physiological characteristics of biofilm ...This study investigated the effects of the luxS gene on the biofilm formation of Lactobacillus fermentum and its stress resistance.Deletion of the luxS gene was related to the physiological characteristics of biofilm development,strain resistance,bacterial morphology,biofilm morphology,functional group types,the main components of the biofilm,and the expression of related genes.Therefore,a luxS gene-deficient strain was constructed usingλRed gene recombination technology,and the biofilm production and stress resistance of the WT andΔluxS strains were compared.Deletion of the gene reduced the biofilm formation of L.fermentum and its resistance to acid,bile salt,high temperatures,and a hypertonic environment.Further,this work found that its deletion affects the types of functional groups in biofilms,and at the same time downregulate the expressions of the fabI,cysE,argR,and purD genes,thus reducing the levels of fatty acids,exopolysaccharide,protein,and eDNA in biofilms.A correlation analysis found that protein in biofilms was the most important factor affecting biofilm formation.In conclusion,the luxS gene in L.fermentum is involved in the regulation of biofilm formation and stress resistance.These findings provide a theoretical basis for the study of the mechanism of biofilm formation in beneficial bacteria.展开更多
文摘人呼吸道合胞病毒是引起婴幼儿支气管炎和肺炎的主要原因,也可导致免疫缺陷病人及老年人群显著发病和死亡.人呼吸道合胞病毒疫苗已被世界卫生组织(World Health Organization,WHO)列为全球最优先发展的疫苗之一.经过50多年的研究,尤其是随着重组技术和反向遗传学的出现,对RSV疫苗的研究取得了重要进展,但尚未有疫苗上市.目前主要集中于亚单位疫苗及活疫苗等,其中活疫苗包括减毒活疫苗和活病毒载体疫苗,因其最有可能用于预防婴幼儿RSV感染,而受到了较大关注.以rA2cp248/404/1030ΔSH为代表的RSV减毒活疫苗临床试验显示,其有较好的安全性及免疫保护作用,不产生疾病增强作用是极有潜力的候选疫苗.因此,本文将重点介绍RSV活疫苗研究的主要进展和发展方向.
文摘This paper aims to provide better guidance for construction of trehalose-producing recombinant strains to further improve the yield of trehalose. The research progress on trehalose biosynthesis pathways and the application of molecular biology technique in trehalose study in recent 30 years, especially the last 10 years are reviewed. Results show that there are 5 pathways of trehalose synthesis. Although enzymes and genes of trehalose synthesis have been isolated and genetic engineering strains have increased gradually, the improvement of trehalose yield is still inadequate because most recombinant strains are limited to study the physicochemical properties of single enzyme. With the development of modern biological technology, especially the rapid development of DNA recombinant technology, metagenomics and synthetic biology, high expression of heterologous trehalose in recombinant strains would become a hot research topic in the future.
基金supported by National Natural Science Foundation of China(No.31960467)the Programs of Natural Science Foundation of Inner Mongolia(No.2019BS03002)the Research and Innovation Projects for Postgraduates of Inner Mongolia(B20191147Z).
文摘This study investigated the effects of the luxS gene on the biofilm formation of Lactobacillus fermentum and its stress resistance.Deletion of the luxS gene was related to the physiological characteristics of biofilm development,strain resistance,bacterial morphology,biofilm morphology,functional group types,the main components of the biofilm,and the expression of related genes.Therefore,a luxS gene-deficient strain was constructed usingλRed gene recombination technology,and the biofilm production and stress resistance of the WT andΔluxS strains were compared.Deletion of the gene reduced the biofilm formation of L.fermentum and its resistance to acid,bile salt,high temperatures,and a hypertonic environment.Further,this work found that its deletion affects the types of functional groups in biofilms,and at the same time downregulate the expressions of the fabI,cysE,argR,and purD genes,thus reducing the levels of fatty acids,exopolysaccharide,protein,and eDNA in biofilms.A correlation analysis found that protein in biofilms was the most important factor affecting biofilm formation.In conclusion,the luxS gene in L.fermentum is involved in the regulation of biofilm formation and stress resistance.These findings provide a theoretical basis for the study of the mechanism of biofilm formation in beneficial bacteria.
