Author/Authors :
پوركاظمي م. نويسنده , سلطاني م. نويسنده Soltani M. , شناورماسوله الف نويسنده Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran; Center of excellence of aquatic animal health, University of Tehran, Iran Shenavar Masouleh A , احمدي م نويسنده International Sturgeon Research Institute, Rasht, Iran Ahmadi M , طاهري ميرجايد الف نويسنده International Sturgeon Research Institute, Rasht, Iran Taherimirghaed A
Abstract :
Growth behavior of five lactic acid bacteria previously
isolated from Persian sturgeon (Acipenser
persicus), were evaluated at different pH, temperature
and salt concentrations. Also, antibacterial activity
of extracellular products (ECPs) of this LAB
were assessed to Aeromonas hydrophila. Further,
their antibiotic susceptibility was determined with
some commonly used antibiotics in aquaculture.
In an in vivo work the effect of Lactococcus lactis
as the supplementary diet was evaluated on growth
performance of Persian sturgeon for a period of 56
days. Strong growth of all LAB were seen at 20 and
30?C, as well as 40 and 80 g L-1 NaCl. The LAB
ECPs exhibited varied results of antagonism to the
A. hydrophila with maximum activity observed at
temperature between 25 and 30?C. Also, the higher
antagonistic activity was observed for ECPs of W.
cibaria, P. pentosaceus, and L. lactis at pH 9. Both
W. cibaria and E. faecalis were resistance to oxytetracycline,
erythromycin, trimethoprim sulfamethoxazol,
enrofloxacin, florfenicol, and flumequine,
while L. lactis was sensitive to oxytetracycline,
erythromycin, enrofloxacin, florfenicol. These results
showed that use of L. lactis can act as a positive
probiotic in Persian sturgeon feed via improvement
of fish growth performance, feed efficiency
and fish health.
