单克隆抗体(简称单抗)是最重要的生物技术药物,随着产业规模的持续扩大和同行竞争的不断加剧,制备流程的合理性和过程经济性越来越受到重视。本文采用生物过程模拟软件Super Pro Designer分别建立了500、2000、5000和15000 L四个培养规...单克隆抗体(简称单抗)是最重要的生物技术药物,随着产业规模的持续扩大和同行竞争的不断加剧,制备流程的合理性和过程经济性越来越受到重视。本文采用生物过程模拟软件Super Pro Designer分别建立了500、2000、5000和15000 L四个培养规模的单抗制备流程,通过过程分析和成本核算,确定经济热点并提出相应的优化策略。结果表明,单抗制备的规模效应明显,随着规模扩大,生产成本显著降低,经济热点从设备相关成本转移到原材料和消耗品,主要包括无血清培养基和蛋白A亲和层析介质。上游优化的关键是提高细胞的单抗表达量,当表达量达到5 g/L以上时,对成本影响减弱,转为下游过程控制;下游优化的重点在于蛋白A亲和层析介质,包括载量、价格和循环使用次数;整体优化可利用交错模式,采用三个主生物反应器配置一条下游生产线,其中生产规模和设备成本是关键。研究表明,通过合理的过程模拟和经济评价,可以充分了解单抗制备过程的关键热点,提出合适的优化策略,提高生产效率,降低制备成本。展开更多
In general,productions of natural pigment in submerged microorganism culture were much less than that in solid-state fermentation,because the solid-state culture can provide a support carrier for the mycelium. To impr...In general,productions of natural pigment in submerged microorganism culture were much less than that in solid-state fermentation,because the solid-state culture can provide a support carrier for the mycelium. To improve natural pigment production,the cultivation of Monascus purpureus in submerged encapsulated cell was investigated. Monascus purpureus immobilized in polyelectrolyte complex(PEC) microcapsules,which were pre-pared by sodium cellulose sulphate(NaCS) and poly-dimethyl-diallyl-ammonium chloride(PDMDAAC),was a good substitute for submerged cell culture because it mimicked the solid-state environment. The repeated-batch process with encapsulated cells was studied in flasks and a bubble column. The results indicated that the bubble column was more suitable for the encapsulation culture than the shaking flasks because of its good mass transfer performance and minor shear stress on cells. Owing to the protection of the microcapsule's membrane,Monascus purpureus in microcapsules increased approximately three times over that in free cell culture with negligible cell leakage to the medium. The pigment production in the bubble column finally reached 3.82(OD500) ,which was two times higher than in free cell culture. In addition,the duration of each batch was shortened to 15% of that in free cell culture.展开更多
The favorable microbes for the asymmetric reduction of prochiral aromatic ketones was isolated from soil using acetophenone as the sole carbon source,when the asymmetric reduction of acetophenone(ACP)to chiral a-phene...The favorable microbes for the asymmetric reduction of prochiral aromatic ketones was isolated from soil using acetophenone as the sole carbon source,when the asymmetric reduction of acetophenone(ACP)to chiral a-phenethyl alcohol(PEA)was chosen as the model reaction.Two microbe strains with excellent catalytic activity were obtained.They were Geotrichum candidum and Pichia pastoris identified by bacteria identification.The product of the asymmetric reduction of ACP catalyzed by Pichia pastoris was mainly R-PEA and that by Geotrichum candidum was mainly S-PEA.The yield and enantiomeric excesses(e.e.)could respectively reach 75%and 90%for Pichia pastoris,and 80%and 70%for Geotrichum candidum,much higher than those catalyzed by baker’s yeast.展开更多
文摘针对Oligo(d T)亲和层析介质的吸附性能,以poly(A)为模型分子,考察了4种Oligo(d T)亲和层析介质的静态吸附平衡、吸附动力学和动态结合载量(DBC),探讨了载量影响相关机制。结果表明,4种介质的合适吸附条件均为0.6 mol·L-1Na Cl、p H=6~7;Monomix d T20静态吸附容量最大,且poly(A)能扩散至介质微球深层孔内,而Poros Oligo(d T)25、Praesto Jetted (d T)25和Nano Gel d T20等3种介质中poly(A)均主要为表层吸附、静态吸附容量稍低;对于DBC,Nano Gel d T20和Monomix d T20的10%穿透的DBC较高,而Poros Oligo (d T)25和Praesto Jetted (d T)25相对略低。经分析,影响载量的主要因素包含基质种类、微球孔径、配基密度、间隔臂和配基长度等。对于基质种类,聚苯乙烯基质可能孔道结构较为特别。对于微球孔径,应针对不同大小的m RNA分子定制不同孔径的微球,以平衡传质阻力与可及吸附表面积之间的矛盾,从而增大DBC。
文摘单克隆抗体(简称单抗)是最重要的生物技术药物,随着产业规模的持续扩大和同行竞争的不断加剧,制备流程的合理性和过程经济性越来越受到重视。本文采用生物过程模拟软件Super Pro Designer分别建立了500、2000、5000和15000 L四个培养规模的单抗制备流程,通过过程分析和成本核算,确定经济热点并提出相应的优化策略。结果表明,单抗制备的规模效应明显,随着规模扩大,生产成本显著降低,经济热点从设备相关成本转移到原材料和消耗品,主要包括无血清培养基和蛋白A亲和层析介质。上游优化的关键是提高细胞的单抗表达量,当表达量达到5 g/L以上时,对成本影响减弱,转为下游过程控制;下游优化的重点在于蛋白A亲和层析介质,包括载量、价格和循环使用次数;整体优化可利用交错模式,采用三个主生物反应器配置一条下游生产线,其中生产规模和设备成本是关键。研究表明,通过合理的过程模拟和经济评价,可以充分了解单抗制备过程的关键热点,提出合适的优化策略,提高生产效率,降低制备成本。
基金Supported by the National Basic Research Program of China（2007CB707805） the National Natural Science Foundation of China（20876139）
文摘In general,productions of natural pigment in submerged microorganism culture were much less than that in solid-state fermentation,because the solid-state culture can provide a support carrier for the mycelium. To improve natural pigment production,the cultivation of Monascus purpureus in submerged encapsulated cell was investigated. Monascus purpureus immobilized in polyelectrolyte complex(PEC) microcapsules,which were pre-pared by sodium cellulose sulphate(NaCS) and poly-dimethyl-diallyl-ammonium chloride(PDMDAAC),was a good substitute for submerged cell culture because it mimicked the solid-state environment. The repeated-batch process with encapsulated cells was studied in flasks and a bubble column. The results indicated that the bubble column was more suitable for the encapsulation culture than the shaking flasks because of its good mass transfer performance and minor shear stress on cells. Owing to the protection of the microcapsule's membrane,Monascus purpureus in microcapsules increased approximately three times over that in free cell culture with negligible cell leakage to the medium. The pigment production in the bubble column finally reached 3.82(OD500) ,which was two times higher than in free cell culture. In addition,the duration of each batch was shortened to 15% of that in free cell culture.
基金This work was supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20050335131)Wuhan Youth Scientist Dawn Foundation(200750731288)Natural Science Foundation of Wuhan University of Science and Technology(2005XY15).
文摘The favorable microbes for the asymmetric reduction of prochiral aromatic ketones was isolated from soil using acetophenone as the sole carbon source,when the asymmetric reduction of acetophenone(ACP)to chiral a-phenethyl alcohol(PEA)was chosen as the model reaction.Two microbe strains with excellent catalytic activity were obtained.They were Geotrichum candidum and Pichia pastoris identified by bacteria identification.The product of the asymmetric reduction of ACP catalyzed by Pichia pastoris was mainly R-PEA and that by Geotrichum candidum was mainly S-PEA.The yield and enantiomeric excesses(e.e.)could respectively reach 75%and 90%for Pichia pastoris,and 80%and 70%for Geotrichum candidum,much higher than those catalyzed by baker’s yeast.
