Document Type : scientific research article
Authors
1
Department of Fisheries Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
2
Inland Waters Aquatics Resources Research Center, Iranian Fisheries Sciences Research Institute, Agricultural Research, Education and Extension Organization, Gorgan, Iran
3
Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
4
Infectious Diseases Research Center, Golestan University of Medical Sciences, Gorgan, Iran
5
Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, 8 9 Chiang Mai 50200, Thailand
6
Fish Nutrition Research Laboratory, Animal Production Department Faculty of Agriculture Cairo University, Cairo, Egypt
7
Associate Prof
8
Animal Biological Product Research Group, Academic Center for Education, Culture and Research (ACECR), Tehran Organization, Tehran, Iran and Dept. of Aquaculture, Faculty of Fisheries and Environmental Sciences, Gorgan University
Abstract
Lactic acid bacteria are part of the typical intestinal flora of many fish. The aim of this research was to isolate and identify lactic acid bacteria with probiotic potential from adult Caspian white fish. For this purpose, 30 pieces of adult white fish were caught from the Caspian Sea and sterile samples were taken from their intestines. The isolated lactic acid bacteria were isolated and purified by phenotypic (gram staining, biochemical tests) and molecular methods. Then these bacteria were evaluated based on salinity, pH, temperature and antibacterial activity against Aeromonas hydrophila and Yersinia ruckeri. Following specialized tests, including cultivation in a MacConkey, MRS medium, and various pH levels, this number was reduced to 9 confirmed strains. The probiotic potential of the remaining 9 bacteria was assessed at temperatures of 4, 20, and 40 °C, as well as at salinities of 1%, 2%, 3%, and 4%. Additionally, their antibacterial activity against A. hydrophila and Y. ruckeri were evaluated. Ultimately, after performing tests to evaluate probiotic potential, four isolates such as Aerococcus, Pediococcus pentosaceus (two isolates), and Lactococcus plantarum demonstrated the highest probiotic effectiveness compared to the other isolates.
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