Effects of Nitrogen Sources and Initial NaHCO_3 Concentrations on the Growth and Thymosin α1 Expression of Transgenic Synechococcus sp. PCC7942

研究了氮源和初始NaHCO3浓度对转基因聚球藻 794 2生长与胸腺素α1表达的影响。结果表明 :最适的氮源为NaNO3,NaNO3浓度低于 1g/L时 ,增加NaNO3浓度能提高藻细胞的生长和表达 ,但 1～ 2 .5 g/LNaNO3对转基因聚球藻 794 2生长与表达没有明显的影响。最适的初始NaHCO3浓度为 8.0 g/L。生长在 8.0 g/L初始NaHCO3浓度培养基中藻细胞密度和胸腺素α1最大表达能力分别为BG 11培养基中的 1.94倍和 2 .0 1倍。Effects of nitrogen sources and initial NaHCO 3 concentrations on the growth and thymosin α1 expression of transgenic Synechococcus sp. PCC7942 were studied. The results showed that NaNO 3 was the optimum nitrogen. When NaNO 3 concentration was lower than 1g/L, increasing NaNO 3 concentration could stimulate alga cells growth and improve thymosin α1 expression. While the growth and the thymosin α1 expression were not affected significantly when NaNO 3 concentrations were increased from 1g/L to 2.5g/L. The optimum concentration of NaHCO 3 was 8.0g/L. The cell density and the maximum thymosin α1 expression capability of transgenic Synechococcus sp. PCC7942 growing in the medium containing 8.0g/L NaHCO 3 were 1.94 times and 2.01 times what were obtained in BG-11 medium respectively.863计划 ( 819 Q0 1);; 上海市科技启明星计划;; 上海重点学科资助项

Light Transfer and Its Effect on Cell Growth in the Culture of Transgenic Synechococcus sp. PCC7942

对转人源胸腺素a1基因聚球藻7942光生物反应器分批培养过程中光的分布、平均光强变化及其对藻细胞生长的影响进行了分析. 结果表明,Hyperbolic光衰减模型较之Lambert-Beer光衰减模型能更好地描述转基因聚球藻7942培养液中的光衰减;随着藻细胞密度的增加,光生物反应器内平均光强不断减小,藻细胞的光能比吸收速率也不断降低,反应器中“暗区”体积不断加大;培养时间0~1.5 d,藻细胞能获得充足光能,因而呈指数生长;1.5 d后藻细胞处于光限制,比生长速率不断下降,但体积光能吸收速率达到最大并保持恒定,藻细胞进入线性生长期;5 d后光生物反应器“暗区”体积超过了反应器总体积的50%,藻细胞吸收的光能用于维持的比例不断增加,从而导致生长速率下降;培养8 d,转基因聚球藻7942中人源胸腺素a1表达量为4.53 mg/L.The variation of light distribution and average irradiance in a photobioreactor during batch culture of transgenic Synechococcus sp. PCC7942 carrying thymosin a1 gene was modeled, and their effects on algal cell growth were analyzed. Light attenuation in the suspension culture of the transgenic Synechococcus sp. PCC7942 could be predicted more accurately with a hyperbolic model than with the Lambert-Beer model. With algal cell concentration increasing, the average irradiance in the photobioreactor and the specific light energy absorbance rate decreased continuously, and illumination zone decreased gradually after 1.5 d cultivation, resulting in the reduction of the cell specific growth rate; since light energy absorbed in the volume unit was constant after 1.5 d, the algal cell was in the linear growth phase; with dark zone exceeded 60% of the volume of the photobioreactor after 5 d cultivation, energy used for cell maintenance increased and the cell growth rate decreased. The thymosin a1 expression level of recombinant microalgal cell was 4.53 mg/L for 8 d cultivation.国家海洋863基金资助项目(编号:819-Q01);; 上海市科技启明星计划;; 上海市重点学科部分资

ESTABLISHMENT AND APPLICATION OF INDIRECT ELISA METHOD FOR MEASURING THYMOSINα1CON-TENT IN THE TRANSGENIC Synochococcus sp.PCC7942WITH THYMOSINα1GENE

利用胸腺素α1(Tα1)_小牛血清白蛋白融合蛋白免疫新西兰兔获得的抗体 ,建立了Tα1间接酶联免疫吸附测定法 (ELISA) ,以定量检测转Tα1基因聚球藻7942外源基因表达产物胸腺素α1 ,实验结果表明该方法灵敏度高、专一性强、重复性好 ,可用于转基因微藻Tα1表达量的定量检测 ,同时表明Tα1基因能在聚球藻7942中稳定表达。The indirect ELISA method for measuring thymosinα1content in the transgenic Synochococcus sp.PCC7942with thymosinα1gene has been established by using the anti_thymosinα1-BSA fusion protein serum prepared in rabbits.The experiment reveals that the method is sensitive,specific and reliable.It can be used to measure content of thymosinα1expressed in transgenic Synochococcus sp.PCC7942with thymosinα1gene.It also shows that thymosinα1gene can be expressed steadily in Synochococcus sp.PCC7942.国家863计划(819-Q01)资助项