In vitro Culture and Temporary Immersion Bioreactor Production of Crescentia cujete

Crescentia cujete L. is a widely distributed medicinal tree with a diverse range of phytochemicals used as medicinal compounds. Seedlings of wild-harvested C. cujete were established in vitro and used as the starting material for the establishment of axenic cultures. Shoots were proliferated from nodal segments and were maintained over a period of more than 2 years by sequential subculture on a medium containing 1.0 μmol l⁻¹ kinetin. De novo regeneration was induced on petiole sections cultured onto a medium containing thidiazuron in combination with 2,4-dichlorophenoxyacetic acid. Axenic cultures were also used to test the efficiency of three different cultivation systems for production of biomass of C. cujete. Growth of plantlets in a temporary immersion bioreactor resulted in significant increases in biomass, leaf number, shoot height and transplant efficiency. Plantlets grown in the bioreactors were acclimatized under greenhouse conditions. Together, these experiments have established optimized parameters for propagation and growth of C. cujete plantlets in a sterile controlled environment for biochemical characterization and production of high-quality medicinal products.     

转新城疫病毒融合蛋白基因水稻植株的获得

以编码新城疫病毒融合蛋白(NDV—F)基因为外源基因,与玉米泛素蛋白(Ubi)启动子和农杆菌胭脂碱合成酶基因(NOS)终止子构建成嵌合基因,构建了适宜于农杆菌介导转化水稻的表达质粒pUNDV;并以潮霉素磷酸转移酶(HPT)基因作选择标记基因、β-半乳糖苷酸酶(GUS)基因作报告基因,借助于农杆菌介导转化水稻,获得了多株转基因植株。PCR分析和GUS活性检测结果证实含有NDV—F基冈的T—DNA已整合到水稻基因组中,为研制廉价的转基因水稻新城疫基因工程疫苗奠定了基础。     

利用纤维床反应器固定化发酵生产丙酸

构建了一种纤维床反应器(FBB), 并将其应用于丙酸的生产。将棉纤维绕成桶状, 固定于反应器中, 即可用于丙酸固定化发酵。以40 g/L的葡萄糖为碳源, 与游离细胞相比, 利用FBB生产丙酸, 丙酸产量由14.58 g/L提高至20.41 g/L, 发酵时间由120 h缩短至60 h。研究了不同糖浓度条件下FBB生产丙酸情况, 并将补料策略应用于丙酸发酵中。结果表明: 补料发酵能够有效改善Propionibacterium freudenreichii CCTCC M207015在高糖条件下丙酸对葡萄糖转化率较低、副产物较多的问题。经补料发酵280 h, 丙酸产量达45.91 g/L, 丙酸质量约占有机酸总质量比例为72.31%。     

大规模动物细胞培养技术研究进展

利用动物细胞大规模培养技术可生产多种生物制品,为提高细胞活力和表达水平及有利于表达产物的纯化,采用有多种添加成分的无血清培养基培养细胞,选择更有利于细胞生长又可提高培养细胞密度的微载体和条件温和、易操作、气体交换速度快的生物反应器,在线监控细胞生存环境和生理活动,减少培养过程培养基中的抑制因素,可创造更适合细胞生存的环境,提高表达水平,向细胞中导入抗凋亡基因,可提高细胞活性和蛋白产量。利用多也微载体以球转球方式大规模培养动物细胞有很好的发展前景。     

有机污染土壤生物修复的生物反应器技术研究进展

人类广泛的工农业生产活动常常导致土壤污染。常见的土壤污染有重金属污染和有机污染。近年来 ,世界各国开始重视污染土壤的治理。处理方式主要包括热处理 (焚烧法 )、物理及物理化学处理(洗涤 )和生物处理 (生物修复技术 )。其中生物修复技术被认为最有生命力[1,7] 。目前 ,国外采用的土壤生物修复技术有原位处理、场上处理和生物反应器。生物反应器技术能够有效地发挥生物法的特长 ,是污染土壤生物修复技术中最有效的处理工艺 ,但该技术尚处于实验室研究阶段 ,未广泛应用于现场处理。本文就国外使用生物反应器治理有机污染土壤的研究进展…     

Comparative characterisation of two Rhodococcus species as potential biocatalysts for ammonium acrylate production

Two Rhodococcal isolates, one possessing a nitrile hydratase and an amidase enzyme, the other an aliphatic nitrilase enzyme have been isolated. The kinetic constants for the enzymes in each isolate have been determined. This data coupled with stability tests indicate that Rhodococcus ruber NCIMB 40757, the nitrilase containing organism, should be an excellent biocatalyst for the commercial production of ammonium acrylate. This is confirmed by a fed-batch bioconversion to produce 5.7 M ammonium acrylate.     

Broth rheology and morphological analysis of Solanum chrysotrichum cultivated in a stirred tank

Solanum chrysotrichum cell cultures were grown in a stirred tank bioreactor and their rheological and morphological behaviour were evaluated. The culture broths exhibited non-Newtonian and shear-thinning characteristics. Pseudoplasticity of the broths was governed by their biomass concentration. The roundness of aggregates measured as the elliptical form factor (EFF) had important changes. At the beginning of the culture the aggregates with an EFF lower than 2 represented 52% of the population, but in stationary phase the proportion increased to 77%. Whereas the size of aggregates did not change 80% of the population had an area lower than 0.1 mm². Overall, these results indicate that the shape of the aggregate therefore needs to be considered when studying plant broth rheology.     

螺旋纤维床固定化反应器两步法生产壳聚糖酶

采用了菌体生长与产酶分步的新工艺利用里氏木霉（Trichoderma reesei） ATCC56764生产壳聚糖酶,酶活力比在相同条件下进行的一步法产酶提高了1.7倍。采用此工艺在螺旋纤维床生物反应器中进行产酶试验,酶活比采用游离细胞培养又提高了39%,达到0.246U/mL。固定化菌丝还能够长期保持活性,在重复分批操作中,经过10批共15天的产酶实验,平均每批的酶活保持在0.235U/mL左右。     

Evaluation of the environmental conditions for the continuous production of lignin peroxidase by Phanerochaete Chrysosporium in fixed-bed bioreactors

A new system to produce lignin peroxidase (LiP) continuously by Phanerochaete chrysosporium is described. A fixed-bed bioreactor with a pulsing device was used as the optimal bioreactor configuration. Addition of veratryl alcohol (1 mM), tryptophan (1 mM), no Mn²⁺ addition, low glucose addition rate (60–70 mg l^–1 h) and an atmosphere of O₂ gave maximum LiP activities of 700 U l^–1, which are higher than those previously reported.     

Performance of hairy root cultures of Cichorium intybus L. In bioreactors of different configurations

Summary A transformed root culture of Cichorium intybus L. cv. Lucknow Local grown in different configurations of bioreactors was examined. The roots grown in an acoustic mist bioreactor showed the best performance in terms of increased specific growth rate (0.072d⁻¹) and esculin content (18.5gl⁻¹), the latter of which was comparable to that of shake flask data. C. intybus hairy root cultures grown in an acoustic mist bioreactor produced nearly twice as much esculin as compared to roots grown in bubble column and nutrient sprinkle bioreactors. Studies relating to on-line estimation of conductivity and osmolarity to predict the growth of hairy root cultures are also discussed. The results demonstrate the efficacy and the advantages of an acoustic mist bioreactor for the cultivation of hairy root cultures, especially with reference to C. intybus hairy roots.