利用细菌表面展示技术强化细胞固定化生产吲哚-3-乙酸

    Enhancement of the Cell Immobilization for the Indolyl-3-acetic Acid Production by Using the Bacterial Surface Display Technology

    • 摘要: 目的利用细菌表面展示技术,以冰晶核蛋白INaA、INaK为锚定蛋白,将负电荷的氨基酸(天冬氨酸、谷氨酸)锚定在大肠杆菌表面(Escherichia coli),增加细胞膜表面携带的负电荷,与改性后带正电荷的生物炭吸附以强化生物炭固定化细胞的功能。利用2 mol·L-1的FeCl3改性玉米秸秆生物炭使其呈正电性,将改性生物炭与细胞表面负电荷增加的重组菌株进行静电吸附,重组菌株EPA03与对照菌株相比吸附率提高31.75%。将此策略应用在固定化细胞高效生产IAA的菌株中,在全细胞催化连续循环中,菌株EPA03连续循环中能连续反应6个循环,IAA积累量比对照菌株提高了42.85%。

       

      Abstract: By using the bacterial surface display technology, the ice nucleation proteins including INaA and INaK were used as the anchored protein. The negatively charged amino acids (aspartic acid, glutamic acid) were anchored on the surface of Escherichia coli to increase the negative charge carried on the surface of cell membrane, and the modified positively charged biochar was adsorbed to enhance the function of biochar to immobilize the cells. The corn straw biochar was modified by 2 mol·L-1 FeCl3 to make it positively charged, and then the modified biochar was electrostatically adsorbed to the recombinant strain with the increased negative charge on the cell surface. Compared with the control strain, the adsorption rate of the recombinant strain EPA03 was increased by 31.75%. This strategy was applied to the strain that could produce IAA efficiently by using the immobilized cells. In the continuous cycle of whole-cell catalysis, the strain EPA03 could continuously react for 6 cycles, and the accumulation of IAA increased by 42.85% compared with that of the control strain.

       

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