is a foodborne pathogen characterized by its robust stress tolerance and ability to form biofilms, which facilitates its survival in powdered infant formula (PIF) processing environments for prolonged periods. Gamma-aminobutyric acid (GABA) is a kind of non-protein amino acid that acts as an osmoprotectant. This study aimed to elucidate the effects of the gene on the survival of , GABA accumulation, and biofilm formation under desiccation, osmotic stress, and acid exposure. A knockout strain of was developed using gene recombination techniques. The GABA content and survival rates of both the wild-type and knockout strains were compared under various stress conditions. Scanning electron microscopy (SEM) was used to observe cellular damage and biofilm formation. Statistical analysis was performed using a one-way analysis of variance (ANOVA). The deletion of resulted in enhanced GABA accumulation under different stress conditions, improving the bacterium's tolerance to desiccation, osmotic pressure, and acid treatment. SEM images revealed that under identical stress conditions, the knockout strain exhibited less cellular damage compared to the wild-type strain. Both strains were capable of biofilm formation under low osmotic pressure stress, but the knockout strain showed higher GABA content, denser biofilm formation, and increased biofilm quantity. Similar trends were observed under acid stress conditions. The gene plays a key role in modulating GABA accumulation, which enhances the stress tolerance and biofilm formation of . These findings provide new insights into the role of GABA in bacterial survival mechanisms and highlight the potential for targeting GABA pathways to control in food processing environments.