Immobilizing engineered <i>Escherichia coli</i> cells into zeolitic imidazolate framework 8 for efficient biosynthesis of Ala-Gln.

Yingkang Zhang; Ting Cheng; Feiyang Zhao; Yanqin YI; Qingqing LI; Zhenhua LU; Mianbin WU; Tao Wang; Xiaohuan Liu

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Immobilizing engineered Escherichia coli cells into zeolitic imidazolate framework 8 for efficient biosynthesis of Ala-Gln.

Author: Yingkang ZHANG ¹ ; Ting CHENG ¹ ; Feiyang ZHAO ¹ ; Yanqin YI ¹ ; Qingqing LI ¹ ; Zhenhua LU ² ; Mianbin WU ² ; Tao WANG ¹ ; Xiaohuan LIU ¹
Author Information

1. School of Biological Science, Jining Medical University, Rizhao 276800, Shandong, China.
2. College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310000, Zhejiang, China.
Publication Type:Journal Article
Keywords: immobilization; l-alanyl-l-glutamine; metal-organic frameworks; zeolitic imidazolate framework-8; α-amino acid ester acyl transferase
MeSH: Escherichia coli/genetics*; Glutamine; Zeolites/chemistry*; Amino Acids
From: Chinese Journal of Biotechnology 2023;39(3):1131-1141
CountryChina
Language:Chinese
Abstract: The α-amino acid ester acyltransferase (SAET) from Sphingobacterium siyangensis is one of the enzymes with the highest catalytic ability for the biosynthesis of l-alanyl-l-glutamine (Ala-Gln) with unprotected l-alanine methylester and l-glutamine. To improve the catalytic performance of SAET, a one-step method was used to rapidly prepare the immobilized cells (SAET@ZIF-8) in the aqueous system. The engineered Escherichia coli (E. coli) expressing SAET was encapsulated into the imidazole framework structure of metal organic zeolite (ZIF-8). Subsequently, the obtained SAET@ZIF-8 was characterized, and the catalytic activity, reusability and storage stability were also investigated. Results showed that the morphology of the prepared SAET@ZIF-8 nanoparticles was basically the same as that of the standard ZIF-8 materials reported in literature, and the introduction of cells did not significantly change the morphology of ZIF-8. After repeated use for 7 times, SAET@ZIF-8 could still retain 67% of the initial catalytic activity. Maintained at room temperature for 4 days, 50% of the original catalytic activity of SAET@ZIF-8 could be retained, indicating that SAET@ZIF-8 has good stability for reuse and storage. When used in the biosynthesis of Ala-Gln, the final concentration of Ala-Gln reached 62.83 mmol/L (13.65 g/L) after 30 min, the yield reached 0.455 g/(L·min), and the conversion rate relative to glutamine was 62.83%. All these results suggested that the preparation of SAET@ZIF-8 is an efficient strategy for the biosynthesis of Ala-Gln.