Lactic acid bacteria fermentation has the potential to enhance the biological activity of bamboo shoot polyphenols. The aim of this study was to investigate the release pattern and biotransformation mechanism of bound phenols from bamboo shoots prepared by fermentation with Lactobacillus acidophilus, Pediococcus pentosaceus, and Lactobacillus plantarum. The results showed that compared with unfermented controls, bound forms of vanillic acid, p-coumaric acid, and ferulic acid significantly decreased, while their free forms increased substantially after 6 d fermentation (p < 0.05). Quantitative analysis revealed particularly dramatic transformations for p-coumaric acid, which showed a 30–3000% increase in free form, and ferulic acid with a 203–359% increase in free form. Pediococcus pentosaceus demonstrated outstanding performance in bound phenol release and conversion, correlating with its higher β-glucosidase (0.67 U/g) and ferulic acid esterase (0.69 U/g) production. FITR, SEM, and IFM also demonstrated that LAB fermentation led to changes between free and bound phenols in bamboo shoots. These results demonstrate Pediococcus pentosaceus fermentation most effectively liberates bound phenolics, significantly improving their bioavailability for functional food applications.
Pseudomonas aeruginosa is a conditional Gram-negative pathogen that produces extracellular virulence factors that can lead to bloodstream invasion, severely harm tissues, and disseminate bacteria, ultimately leading to various diseases. In this study, lactic acid bacteria (LAB) with strong antagonistic ability against P. aeruginosa were screened, and the regulatory mechanism of LAB against P. aeruginosa was evaluated. The results showed that the three selected LAB strains had strong inhibition ability on the growth, biofilm formation, and pyocyanin expression of P. aeruginosa and a promoting effect on the expression of autoinducer-2. Among them, Lactipantibacillus plantarum (Lp. plantarum) LPyang is capable of affecting the metabolic processes of P. aeruginosa by influencing metabolic substances, such as LysoPC, oxidized glutathione, betaine, etc. These results indicate that LPyang reduces the infectivity of P. aeruginosa through inhibition of its growth, biofilm formation, pyocyanin expression, and regulation of its metabolome. This study provides new insights into the antagonistic activity of Lp. plantarum LPyang against P. aeruginosa.
15 September 2022 in International Journal of Food Science and Technology