ACEVEDO MarÍa AndreÍna
congresos y reuniones científicas
Physiological aspects of Enterococcus gallinarum CRL 1826, a potential probiotic for ranaculture.
M. A. ACEVEDO; A. LORENZO; N. GRIMALD; S.E. PASTERIS
Conferencia; 10TH PROBIOTICS, PREBIOTICS NEW FOODS, NUTRACEUTICALS AND BOTANICALS for NUTRITION & HUMAN and MICROBIOTA HEALTH; 2019
Objective: To evaluate the effect of gastrointestinal conditions on the viability and probiotic properties maintenance of indigenous Enterococcus gallinarum CRL 1826. Methods: E. gallinarum was grown in MRS broth, pH 6.8 at 37°C for 24 h collected by centrifugation, washed and resuspended in PBS pH 7.4. 109 CFU/mL of fresh cultures (FC), lyophilized (LC) and stored at 4ºC, 1 year (SC) (resuspended in PBS) were subjected to a sequential simulated gastrointestinal conditions to determine cell viability (survival factor-SF), bacteriocin activity (AU/mL using L. monocytogenes as indicator strain) and surface properties (% hydrophobicity and auto-aggregation).Cells were added with 0.6% pepsin and allowed to a gradual descent of pH from 7.4 to 2 for 90 min. Then, cells were added with 1% bile (pH 8) for 10 min. Finally, cells were treated with 0.3% bile+0.1% pancreatin for 90 min. Results: The LAB viability diminished during the gastrointestinal treatment with significant values among the FC, LC and SC, with L showing the highest values (SF=0.92). In the gastric conditions there were no variations in cell viability while it diminished during the intestinal conditions, independently of the culture. Low bacteriocin activity was detected in FC; however, in LC ~1,300 AU/mL were detected in gastric conditions. Treatment with bile allowed increasing it up to ~2,000 AU/mL and then decrease (~800 AU/mL). In SC, the bacteriocin activity diminished during the gastric treatment, to then increase up to 1,200 AU/mL. The surface properties did not any change during the treatments. Conclusions: overall, the LAB strain kept its probiotic properties during the gastrointestinal digestion, allowing proposing that it would be able to colonise the intestinal mucosa and to prevent red-leg syndrome outbreaks.