Effects of galactosyltransferase on EPS biosynthesis and freeze-drying resistance of Lactobacillus acidophilus NCFM.
- 2022-12
- Food chemistry. Molecular sciences 5
- PubMed: 36573108
- DOI: 10.1016/j.fochms.2022.100145
Study Design
- Methods
- overexpressed GalT in Lactobacillus acidophilus NCFM by genetic engineering
Galactosyltransferase (GalT) is an important enzyme in synthesizing exopolysaccharide (EPS), the major polymer of biofilms protecting cells from severe conditions. However, the contribution to, and regulatory mechanism of GalT, in stressor resistance are still unclear. Herein, we successfully overexpressed GalT in Lactobacillus acidophilus NCFM by genetic engineering. The GalT activity and freeze-drying survival rate of the recombinant strain were significantly enhanced. The EPS yield also increased by 17.8%, indicating a positive relationship between freeze-drying resistance and EPS. RNA-Seq revealed that GalT could regulate the flux of the membrane transport system, pivotal sugar-related metabolic pathways, and promote quorum sensing to facilitate EPS biosynthesis, which enhanced freeze-drying resistance. The findings concretely prove that the mechanism of GalT regulating EPS biosynthesis plays an important role in protecting lactic acid bacteria from freeze-drying stress.
Research Insights
| Supplement | Dose | Health Outcome | Effect Type | Effect Size | Source |
|---|---|---|---|---|---|
| Lactobacillus acidophilus NCFM | — | Improved Gut Stress Resistance | Beneficial | Moderate | View sourcethe mechanism of GalT regulating EPS biosynthesis plays an important role in protecting lactic acid bacteria from freeze-drying stress |
| Lactobacillus acidophilus NCFM | — | Improved Survival of Probiotic Bacteria | Beneficial | Moderate | View sourcethe freeze-drying survival rate of the recombinant strain were significantly enhanced |
| Lactobacillus acidophilus NCFM | — | Increased Exopolysaccharide Production | Beneficial | Small | View sourceThe EPS yield also increased by 17.8% |