en Treatment stategies with herbal or others Treatment stategies with herbal or others پژوهشي Original research papers <p dir="ltr" style="text-align: justify;">Growth behavior of five lactic acid bacteria previously isolated from Persian sturgeon (<em>Acipenser persicus</em>), were evaluated at different pH, temperature and salt concentrations. Also, antibacterial activity of extracellular products (ECPs) of this LAB were assessed to <em>Aeromonas hydrophila </em>. Further, their antibiotic susceptibility was determined with some commonly used antibiotics in aquaculture. In an in vivo work the effect of <em>Lactococcus lactis&nbsp; </em>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&nbsp;&nbsp;30⁰ C, as well as 40 and 80 g L-1 NaCl. The LAB ECPs exhibited varied results of antagonism to the <em>A. hydrophila </em>&nbsp;with maximum activity observed at temperature between 25 and &nbsp;30⁰ C Also, the higher antagonistic activity was observed for ECPs of <em>W. cibaria , P. pentosaceus, </em>and <em>L. lactis&nbsp; </em>&nbsp;at pH 9. Both&nbsp; <em>W. cibaria</em> and <em>E. faecalis </em>&nbsp;were resistance to oxytetracycline, erythromycin, trimethoprim sulfamethoxazol, enrofloxacin, florfenicol, and flumequine, while <em>L. lactis </em>&nbsp;was sensitive to oxytetracycline, erythromycin, enrofloxacin, florfenicol. These results showed that use of L. lactis &nbsp;can act as a positive probiotic in Persian sturgeon feed via improvement of fish growth performance, feed efficiency and fish health.</p> sturgeon, health, Lactococcus lactis, probiotic. 54 65 http://ijaah.ir/browse.php?a_code=A-10-35-28&slc_lang=en&sid=1 M Soltani 10031947532846001400 10031947532846001400 Yes Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran; Center of excellence of aquatic animal health, University of Tehran, Iran A Shenavar Masouleh 10031947532846001401 10031947532846001401 No Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran; Center of excellence of aquatic animal health, University of Tehran, Iran M Ahmadi 10031947532846001402 10031947532846001402 No International Sturgeon Research Institute, Rasht, Iran M Pourkazemi 10031947532846001403 10031947532846001403 No Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran; Center of excellence of aquatic animal health, University of Tehran, Iran A Taherimirghaed 10031947532846001404 10031947532846001404 No International Sturgeon Research Institute, Rasht, Iran