The influence of growth conditions on enterocin-like production by Enterococcus faecium CWBI-B1430 and Enterococcus mundtii CWBI-B1431 isolates from artisanal Peruvian cheeses

Abstract

Strains of Enterococcus faecium CWBI-B1430and Enterococcus mundtii CWBI-B1431, isolated from artisanal-produced Peruvian cheeses, offer a broad potential application as food biopreservatives for heat-processing treatments. The aim of this work was to optimize the production conditions and medium composition for the production of bacteriocin-like substances (BLIS). The kinetics of the BLIS production for both strains is a growth-associated process, and the maximum inhibitory activity for E. faecium CWBI-B1430 and E. mundtii CWBI-B1431 was achieved after 9 and 8 h of fermentation, respectively. Temperature, initial pH, oxygen level, and their interactions all influence BLIS production for both strains; this influence was specific for each strain. The bacteriocin gene expression in a 20.0-L fermentor confirms previous work carried out by fermentation in the flask; the first reports of expression revealed mundticin KS from E. faecium and enterocin P from E. mundtii. Both strains demonstrated antilisteria activity and were multi-producers of enterocin. Furthermore, the study with whey milk as an inexpensive source of fermentable carbohydrates indicated lower BLIS production than that obtained with M17LG broth. The short chain fatty acid (SCFA) analyses offer a new alternative use for both strains, as strains probiotic, for propionic acid production.

Biological Potential of Semi-Purified Enterocin of Enterococcus Sp. Yt3 Against Selected Food Pathogens

“…along with polypeptide hydrolysis 27,28 . Similar results have been found in the literature where maximum activity has been confirmed by the LAB when initial pH was adjusted to pH 6 25,26,29 .…”

“…On evaluating the influence of incubation temperature on antimicrobial activity, the largest zone of inhibition (27±0.8 mm) was obtained for an incubation temperature of 37°C for 48 h of incubation time (Table 8). Similar reports on different species of Enterococcus, also mention best incubation temperature of 37°C 16,25,26 for bacteriocin production. Enterococcus sp.…”

Exploring Beneficial Properties of the Bacteriocinogenic Enterococcus faecium ST10Bz Strain Isolated from Boza, a Bulgarian Cereal-Based Beverage

“…The production of bacteriocins was observed starting with the early exponential growth phase of the strain. The ability to produce the bacteriocin at the aforementioned time point indicates that the bacteriocin could be considered as a primary metabolite of this strain [ 49 ]. Similar kinetics were previously observed for the bacteriocinogenic enterococci E. faecalis AP45 [ 50 ], E. faecium B3L3 [ 51 ], E. faecium RZS C5 [ 52 ], and E. faecium ST311LD [ 53 ].…”

Relevant physicochemical properties and metabolites with functional properties of two commercial varieties of PeruvianPouteria lucuma

“…Eight hundred microliter of the solution was taken and injected into a Sep‐Pak C18 cartridge (WAT036905, Waters, Ireland), then eluted with 10 ml of 0.2 N H 2 SO 4 . The content of sugars and sugar‐alcohols was determined following the method described by Campos, Aguilar‐Galvez, and Pedreschi (2016); while organic acids according to the protocol described by Aguilar‐Galvez, Guillermo, Dubois‐Dauphin, and Campos (2011). In both cases, a Waters 2695 Separation Module (Waters) equipped with an autoinjector, a 2414 refractive index and detector 996 photodiode array detector, respectively, and the Empower software (Waters) were used.…”