γ-Aminobutyric Acid (GABA) Metabolic Bypass Plays a Crucial Role in Stress Tolerance and Biofilm Formation in <i>C. sakazakii</i> ATCC 29544
<i>Cronobacter sakazakii</i> 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-p...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
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| Series: | Foods |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2304-8158/14/2/171 |
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| Summary: | <i>Cronobacter sakazakii</i> 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 <i>gabT</i> gene on the survival of <i>C. sakazakii</i>, GABA accumulation, and biofilm formation under desiccation, osmotic stress, and acid exposure. A <i>gabT</i> knockout strain of <i>C. sakazakii</i> 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 <i>gabT</i> 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 <i>gabT</i> 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 <i>gabT</i> knockout strain showed higher GABA content, denser biofilm formation, and increased biofilm quantity. Similar trends were observed under acid stress conditions. The <i>gabT</i> gene plays a key role in modulating GABA accumulation, which enhances the stress tolerance and biofilm formation of <i>C. sakazakii</i>. These findings provide new insights into the role of GABA in bacterial survival mechanisms and highlight the potential for targeting GABA pathways to control <i>C. sakazakii</i> in food processing environments. |
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| ISSN: | 2304-8158 |