The concept of integrated forest biorefineries(IFBRs) has gained significant interest.The prehydrolysis kraft(PHK) dissolving pulp production process is a suitable example of IFBR concept for the production of dissolv...The concept of integrated forest biorefineries(IFBRs) has gained significant interest.The prehydrolysis kraft(PHK) dissolving pulp production process is a suitable example of IFBR concept for the production of dissolving pulp and utilization of dissolved hemicelluloses,acetic acid,and lignin in the prehydrolysis liquor(PHL).This review paper highlights recent progress related to the recovery and utilization of dissolved organics(e.g.,hemicelluloses,acetic acid,and lignin) in the PHL of the PHK dissolving pulp production process.Integrated multi-step recovery and separation processes have been developed for this purpose to accommodate the complex nature of the PHL.Potential products,including xylan-based compounds,acetic acid,and lignin,are also discussed in detail.展开更多
Tyrosol is an important component of pharmaceuticals,nutraceuticals,and cosmetics,and their biosynthetic pathways are currently a hot research topic.D-Erythrose 4-phosphate is a key precursor for the biosynthesis of t...Tyrosol is an important component of pharmaceuticals,nutraceuticals,and cosmetics,and their biosynthetic pathways are currently a hot research topic.D-Erythrose 4-phosphate is a key precursor for the biosynthesis of tyrosol in Saccharomyces cerevisiae.Hence,the flux of D-Erythrose 4-phosphate determined the yield of tyrosol synthesis.In this study,we first obtained an S.cerevisiae strain S19 with a tyrosol yield of 247.66 mg/L by metabolic engineering strategy.To increase the production of D-Erythrose 4-phosphate,highly active phospho-ketolase BA-C was obtained by bioinformatics combined with tyrosol yield assay.The key residue sites 183,217,and 320 were obtained by molecular docking,kinetic simulation,and tyrosol yield verification.After mutation,the highly efficient phosphoketolase BA-C^(His320Met) was obtained,with a 37.32%increase in enzyme activity.The tyrosol production of strain S26 with BA-C^(His320Arg) increased by 43.05%than strain S25 with BA-C and increased by 151.19%compared with the strain S19 without phosphoketolase in a 20 L fermenter.The mining and modification of phosphoketolase will provide strong support for the de novo synthesis of aromatic compounds.展开更多
文摘The concept of integrated forest biorefineries(IFBRs) has gained significant interest.The prehydrolysis kraft(PHK) dissolving pulp production process is a suitable example of IFBR concept for the production of dissolving pulp and utilization of dissolved hemicelluloses,acetic acid,and lignin in the prehydrolysis liquor(PHL).This review paper highlights recent progress related to the recovery and utilization of dissolved organics(e.g.,hemicelluloses,acetic acid,and lignin) in the PHL of the PHK dissolving pulp production process.Integrated multi-step recovery and separation processes have been developed for this purpose to accommodate the complex nature of the PHL.Potential products,including xylan-based compounds,acetic acid,and lignin,are also discussed in detail.
基金supported by the National Natural Science Foundations of China(Grant Nos.31871789 and 41876114)the key project of Hubei Provincial Department of Education(T2022011)the Natural Science Foundation of Hubei Province(No.2024AFB803).
文摘Tyrosol is an important component of pharmaceuticals,nutraceuticals,and cosmetics,and their biosynthetic pathways are currently a hot research topic.D-Erythrose 4-phosphate is a key precursor for the biosynthesis of tyrosol in Saccharomyces cerevisiae.Hence,the flux of D-Erythrose 4-phosphate determined the yield of tyrosol synthesis.In this study,we first obtained an S.cerevisiae strain S19 with a tyrosol yield of 247.66 mg/L by metabolic engineering strategy.To increase the production of D-Erythrose 4-phosphate,highly active phospho-ketolase BA-C was obtained by bioinformatics combined with tyrosol yield assay.The key residue sites 183,217,and 320 were obtained by molecular docking,kinetic simulation,and tyrosol yield verification.After mutation,the highly efficient phosphoketolase BA-C^(His320Met) was obtained,with a 37.32%increase in enzyme activity.The tyrosol production of strain S26 with BA-C^(His320Arg) increased by 43.05%than strain S25 with BA-C and increased by 151.19%compared with the strain S19 without phosphoketolase in a 20 L fermenter.The mining and modification of phosphoketolase will provide strong support for the de novo synthesis of aromatic compounds.
文摘目的评价流行性乙型脑炎(乙脑)纯化灭活疫苗(地鼠肾细胞)[Purified Inactivited Japanese Encephalitis Vaccine(Primary Hamster Kidney Cell),JEV-I(PHK)]接种安全性及血清学效果。方法共选择943名6月龄～10岁儿童进行Ⅰ、Ⅱ、Ⅲ期临床研究,临床研究用疫苗为兰州生物制品研究所研制,批号20010401,剂量为0.5ml/剂,每剂蛋白含量11.5μg。上臂三角肌肌内注射,0、7d各接种1剂。结果接种人体后副反应轻微,无严重全身及局部反应。共接种1848剂次,101剂次出现发热反应,其中98剂次≤37.5℃,24～72h自行恢复。Ⅰ期接种40人,总反应率2.5%;Ⅱ、Ⅲ期接种903人。另设对照疫苗组JEV-I(Vero细胞)接种101人,总反应率分别为6.2%和14.2%。血清学效果测定表明,在试验组与对照组,免疫前抗体阴性组的抗体阳转率分别为96.9%和84.0%,抗体几何平均滴度(Geometric Mean Titer,GMT)分别为1∶32.8和1∶43.9;免疫前抗体阳性组的抗体≥4倍增长率分别为93.1%和100.0%,抗体GMT分别为1∶167.2和1∶181.0。结论JEV-I(PHK)安全性和血清学效果良好。临床试验注册国家食品药品监督管理局《新药临床研究批件》(批件号2003L00429)。
