利用响应面方法优化转小鼠金属硫蛋白-I基因聚球藻7002的培养基成分

Medium Optimization by Response Surface Method for Transgenic Synechococcus sp. PCC 7002 with Mouse Metallothionein-I Gene

摘要:

为实现转小鼠金属硫蛋白基因-I聚球藻7002的高密度培养, 并将其应用于实际的重金属废水处理过程, 首先需要对培养基的成分进行优化。本文利用响应面这一多因素过程优化的有效工具, 通过全因子实验、最陡爬坡实验和中心组合实验, 对转小鼠金属硫蛋白基因-I聚球藻7002培养基的主要成分以及初始pH进行了优化。优化后的培养基组成为: NaHCO3 1.696 g/L, NaNO3 8.57 g/L, 初始pH为8.57, 其他成分同Medium A。优化条件分别在2 L和20 L气升式光生物反应器中得到了验证, 最大细胞浓度分别达到每升4.16 g干重和每升3.12 g干重, 分别比优化前提高了9倍和7倍, 从而为其产业化应用打下基础。

Abstract:

To implement high cell density cultivation of transgenic Synechococcus sp. PCC 7002 with mouse metallothionein-I gene, and its applications in heavy metal wastewater, we optimized the medium components. We used response surface method, a useful tool for multi-factor process optimization, through a three- step experiment design: full factor design, the steepest climbing and central composite design. The selected three factors were NaHCO3, NaNO3, and initial pH. The optimized medium contained 1.696 g/L NaHCO3 and 8.57 g/L NaNO3, at initial pH 8.57. The optimized medium was validated in 2-L and 20-L air lift photo-bioreactor, respectively. The maximum cell concentration reached 4.16 g/L for 2-L bioreactor, and 3.12 g/L for 20-L bioreactor.