Lactococcus lactis BFE920 activates the innate immune system of olive flounder (Paralichthys olivaceus), resulting in protection against Streptococcus iniae infection and enhancing feed efficiency and weight gain in large-scale field studies
The protective effect of a food-grade lactic acid bacterium Lactococcus lactis BFE920 against disease of olive flounder (Paralichthys olivaceus) cultivated on a large scale was studied. Initially, antimicrobial activity of L. lactis against several fish pathogens was evaluated in vitro; the probioti...
Gespeichert in:
Veröffentlicht in: | Fish & shellfish immunology 2013-11, Vol.35 (5), p.1585-1590 |
---|---|
Hauptverfasser: | , , , , , , , , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | The protective effect of a food-grade lactic acid bacterium Lactococcus lactis BFE920 against disease of olive flounder (Paralichthys olivaceus) cultivated on a large scale was studied. Initially, antimicrobial activity of L. lactis against several fish pathogens was evaluated in vitro; the probiotic showed strong antibacterial activity against Streptococcus iniae, Streptococcus parauberis and Enterococcus viikkiensis, and moderate activity against Lactococcus garviae. When olive flounders were fed for two weeks with experimental diets containing varying concentrations of L. lactis (1 × 106, 5 × 106, 2.5 × 107 and 1.25 × 108 CFU/g feed), all the experimental feed groups showed 68–77% survival upon challenge with S. iniae. A field-scale feeding trial with L. lactis dietary supplement was conducted in a local fish farm (n = 12,000) for three months, and disease resistance, innate immune parameters and growth performance were evaluated. The average weight gain and feed efficiency were increased up to 6.8% and 8.5%, respectively. At the end of the feeding trial, the olive flounders were challenged with S. iniae. The L. lactis-fed group was protected from S. iniae challenge with a 66% survival rate. This disease protection is due to the flounder's innate immunity activated by the L. lactis administration: increased lysosomal activities and production of IL-12 and IFN-γ. These data clearly indicated that L. lactis BFE920 may be developed as a functional feed additive for protection against diseases, and for enhancement of feed efficiency and weight gain in olive flounder farming.
•Lactococcus lactis BFE920 was fed to olive founders (n = 12,000) for three months.•L. lactis administration induced the activation of flounder's innate immune system.•The flounders showed a strong disease resistance against Streptococcus iniae challenges.•Both growth performance and feed efficiencies were also significantly enhanced.•L. lactis BFE920 may be developed as a functional feed additive for fish farming. |
---|---|
ISSN: | 1050-4648 1095-9947 |
DOI: | 10.1016/j.fsi.2013.09.008 |