PHYSIOLOGICAL ASPECTS OF ENTEROCOCCUS GALLINARUM CRL 1826, A POTENTIAL PROBIOTIC FOR RANACULTURE

ACEVEDO, M.A.; LORENZO, A.; GRIMALD, N.; PASTERIS, S.E.

Roma

Conferencia; 10TH PROBIOTICS, PREBIOTICS & NEW FOODS, NUTRACEUTICALS AND BOTANICALS FOR NUTRITION & HUMAN AND MICROBIOTA HEALTH. 1ST SCIENCE & BUSINESS SYMPOSIUM; 2019

To evaluate the effect of gastrointestinal conditions on the maintenance of indigenous Enterococcus gallinarum CRL 1826 viability and probiotic properties. The E. gallinarum strain by centrifugation, washed and resuspended in PBS pH 7.4. 109 CFU/mL of fresh cultures (FC), lyophilized (LC) and stored at 4ºC for 1 year (SC), were subjected to simulated sequential gastrointestinal conditions to determine: cell viability (survival factor-SF), bacteriocin activity (Arbitrary Units-AU/mL) and surface properties (% hydrophobicity and auto-aggregation). Cells were added with 0.6% pepsin followed by a gradual descent of pH (7.4 to 2), 90 min. Then, 1% bile (pH 8) was added (10 min) and finally treated with 0.3% bile+0.1% pancreatin, 90 min.Bacterial viability diminished during the treatment with significant differences among FC, LC and SC; LC showing the highest values (SF=0.92). Under gastric conditions there were no variations in cell viability while it diminished during intestinal treatment, independently of the culture. Low bacteriocin activity (AU/mL) was detected in FC. In LC ~1,300 were determined in gastric conditions, while bile treatment increased it up to ~2,000 and then decreased (~800). In SC, it diminished during the gastric treatment, to then increase up to 1,200 AU/mL. The surface properties did not change during treatments.Considering that E. galinarum CRL 1826 kept its probiotic properties during the sequential gastrointestinal digestion, it could prevent the gastrointestinal entrance of pathogens related to red-leg syndrome (a bacterial infectious disease) in bullfrog hatcheries.