阪崎克罗诺杆菌是婴幼儿配方奶粉（Powdered Infant Formula，PIF）中常见的食源性致病菌，γ-氨基丁酸（γ-Aminobutyric Acid，GABA）是一种广泛存在于各种生物体内的非蛋白氨基酸，而gabT控制的氨基丁酸转氨酶是GABA代谢旁路的关键酶。该研究通过构建阪崎克罗诺杆菌ATCC 29544 gabT基因敲除菌株（ΔgabT），探讨gabT控制的GABA（γ-氨基丁酸）代谢旁路对阪崎克罗诺杆菌抵抗干燥的作用。结果表明，ΔgabT在干燥胁迫下处理一周后存活率可达到28.64%显著高于野生型菌株（WT）的存活率1.57%。此外，GABA在ΔgabT中累积量高于WT，与存活率结果呈正相关，表明GABA累积能帮助阪崎克罗诺杆菌抵御干燥胁迫。扫描电子显微镜检测结果也显示ΔgabT菌株具有较完整的细胞形态，进一步验证了GABA积累有助于阪崎克罗诺杆菌在干燥环境胁迫下的生存。该研究为阪崎克罗诺杆菌中基于GABA旁路的靶向调控奠定了基础，为阪崎克罗诺杆菌防控提供新思路。

Cronobacter sakazakii is a food-borne pathogen commonly found in powdered infant formula (PIF). γ-aminobutyric acid (GABA) is a non-protein amino acid widely present in various organisms. 4-aminobutyrate transaminase, encoded by gabT, is a key enzyme in the GABA shunt. This study constructed a gabT gene knockout strain (ΔgabT) of Cronobacter sakazakii ATCC 29544 to investigate the effect of the GABA shunt controlled by gabT on the resistance of Cronobacter sakazakii to desiccation. The results showed that the survival rate of ΔgabT under one-week desiccation stress was 28.64 %, significantly higher than that of the wild-type strain (WT) which was 1.57%. In addition, GABA accumulation in ΔgabT was higher than that in WT, and was positively correlated with survival rate, suggesting that GABA accumulation can help Cronobacter sakazakii resist desiccation stress. The results of scanning electron microscopy also showed that the ΔgabT strain had relatively intact cell membrane morphology, further confirming that GABA accumulation contributes to Cronobacter sakazakii survival under the stress of dry environments. This study lays a foundation for the targeted inhibition of Cronobacter sakazakii based on its GABA shunt and provides new directions for research into prevention and control of Cronobacter sakazakii.

国家自然科学基金项目（32172320）；广东省自然科学基金（2021A1515011068）