Potential Probiotic Enterococcus faecium OV3-6 and Its Bioactive Peptide as Alternative Bio-Preservation

Abstract

Probiotic Enterococcus faecium OV3-6 and its secreted active peptide were characterized and investigated. The strain survived in simulated gastric and small intestinal conditions at 88.16% and 94.33%, respectively. The safety assessment revealed that the strain was shown α-hemolysis and susceptible to most clinically relevant antibiotics, but intermediate sensitivity to erythromycin and kanamycin was found. It does not harbor any virulence genes except for the efaAfm gene. Both of its living cells and the cell-free supernatants (CFS) of the strain significantly reduced the adhesion of E. coli and S. Typhi on Caco-2 cells. The strain can regulate the secretion of pro and inflammatory cytokines, IL-6 and IL-12 and induce the secretion of anti-inflammatory IL-10 of the Caco-2 cell. The strain can prevent the growth of Gram-positive strains belonging to the genera Bacillus, Carnobacterium, Listeria, and Staphylococcus. It also presented the entP gene that involves the production of bacteriocin named enterocin P. The antimicrobial peptide was matched 40% with 50S ribosomal proteins L29 (7.325 kDa), as revealed by LC-MS/MS. This active peptide exhibits heat stability, is stable over a wide pH range of 2−10, and maintains its activity at −20 and 4 °C for 12 weeks of storage. Altogether, E. faecium OV3-6 thus has potential for consideration as a probiotic and bio-preservative for applied use as a fermented food starter culture and in functional food or feed industries.

Effect of Gastrointestinal Digestion on the Bioaccessibility of Phenolic Compounds and Antioxidant Activity of Fermented Aloe vera Juices

“…The radical cation decolorization (ABTS) assay was performed according to the method described by Ferreira-Santos et al [ 12 ], with minor modifications. The ABTS •+ cation radical solution was prepared using ABTS solution (7 mM) and potassium persulfate (2.45 mM) in a ratio of 1:1, at 4 °C for 12–16 h, in the dark.…”

“…The DPPH radical scavenging activity was determined using the method described by Ferreira-Santos et al [ 12 ], with minor modifications. The reaction was carried out in a 96-well microplate by mixing 25 µL of the sample and 200 µL of 2,2-diphenyl-1-picrylhydrazyl solution (DPPH, dissolved in 80% methanol to an absorbance of 0.700 ± 0.01 at 515 nm).…”

“…E. faecium has been used in the production of different fermented food products, such as artisanal cheese, sausages, and olives, mainly because it plays an important role in the development of organoleptic characteristics due to proteolytic and lipolytic activity [ 11 ]. Although few studies have demonstrated their probiotic potential, they have been shown to possess several health properties similar to probiotics, such as immune-modulatory activity and anti-inflammatory properties, as well as the ability to produce antimicrobial compounds against pathogens, to lower cholesterol, and to adhere to intestinal cells [ 11 , 12 , 13 ]. On the other hand, L. lactis strains have been recognized as probiotics [ 10 ].…”

Assessment of the safety and probiotic properties of Roseburia intestinalis: A potential “Next Generation Probiotic”

“…FbpA may play a role in the prevention of pathogenic colonization by inhibiting biofilm formation ( Wang et al, 2017 ). EfaA is associated with adhesion of probiotics bacteria to both biotic and abiotic surfaces ( Choeisoongnern et al, 2021 ). GroEL may inhibit colitis by inhibiting pro-inflammatory M1 macrophages and promoting the secretion of anti-inflammatory cytokines ( Dias et al, 2021 ).…”

Genome sequencing of Enterococcus faecium NT04, an oral microbiota revealed the production of enterocin A/B active against oral pathogens

“…Finally, the CFS was filtered with a sterile 0.22-μm pore size filter (Millipore, Merck). The crude CFS was preserved at 4 °C [ 40 ]. The antimicrobial assay was performed by the agar well diffusion test (ADT) against different microorganisms listed in ( Table 1 ), as described by [ 41 ].…”