Effects of dietary live yeast Debaryomyces hansenii on the immune and antioxidant system in juvenile leopard grouper Mycteroperca rosacea exposed to stress

• Published in: Aquaculture 2008-08, Vol.280 (1-4), p.39-44
• Main Authors: Reyes-Becerril, Martha, Tovar-Ramírez, Dariel, Ascencio-Valle, Felipe, Civera-Cerecedo, Roberto, Gracia-López, Vicente, Barbosa-Solomieu, Valérie
• Format: Article
• Language: English
• Subjects: Amyloodinium ocellatum; Animal aquaculture; Animal productions; antioxidant activity; Antioxidant enzymes; Antioxidants; Aquaculture; Biological and medical sciences; blood proteins; catalase; Debaryomyces hansenii; Dietary supplements; Dinophyceae; disease resistance; ectoparasites; enzyme activity; feed supplements; feeds; Fish; fish culture; fish diseases; fish feeding; Fundamental and applied biological sciences. Psychology; General aspects; grouper; hemoglobin; immune response; Immune system; immunoglobulins; Leopard grouper; Live yeast; Marine; Mycteroperca rosacea; parasitoses; probiotics; Serranidae; superoxide dismutase; Yeast; yeasts
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2008.03.056

This study investigated the effects of the dietary intake of live yeast Debaryomyces hansenii (CBS 8339) on the immune response of juvenile leopard groupers Mycteroperca rosacea and on their resistance to infection by dinoflagellates Amyloodinium ocellatum. During 4 weeks, juvenile groupers were fed either a diet supplemented with D. hansenii at 106 cfu g−1 or a control diet. Both groups were then transferred to a system infected with A. ocellatum and maintained in this stressful environment, for one week. Rearing conditions were favorable to the proliferation of the dinoflagellate and, at 7 days post-infection, the cumulative mortality rate of the control group was 89.5%, suggesting that the yeast-enriched diet conferred protection against the parasite. Only fish with yeast-supplemented diet recovered from the A. ocellatum challenge. The immunological response of both groups of fish was evaluated. Samples were collected at weeks 4 (stressed fish) and 7 (recovering fish) to determine the levels of hemoglobin, plasmatic protein, and immunoglobulin M (IgM) as well as the activity of antioxidant enzymes (SOD and CAT). IgM increased significantly (P≤0.05) in the recovering fish, which had all been fed the yeast diet. A significantly increase was also observed in superoxide dismutase activity in juvenile fish fed the yeast diet; however catalase activity was not affected by the dietary yeast supplement. Overall, fish that received the yeast supplement in their diet have an enhanced immune response as compared with their control counterparts. The present results show that a diet supplemented with D. hansenii stimulates the immune system of juvenile M. rosacea thus enhancing their resistance against A. ocellatum.