Effects of purslane (Portulaca oleracea L.) and Shewanella putrefaciens probiotic enriched diet on gilthead seabream (Sparus aurata L.)

• Autor(a) principal: Ruiz, María Cámara
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/10600
• topic: Portulaca olerácea; Shewanella putrefaciens; Plantas medicinais; Probióticos; Imunoestimulantes; Imunidade; Dourada (Sparus aurata); Aquicultura

The intensification of aquaculture has resulted in a series of detrimental effects to both the environment and human health. A major setback of the intensification of aquaculture systems has been the economic losses caused by the high mortality rates due fish diseases. In order to prevent and/or treat fish diseases, large amounts of veterinary drugs have been administered over the last few decades in fish farms. However, the excessive administration of antibiotics and other chemicals has been shown to cause adverse effects. One of the most promising methods of controlling fish diseases is by enhancing their natural defence mechanisms with the administration of immunostimulants. The aim of the present study was to evaluate to potential effects of dietary supplementation of a medicinal plant (Portulaca oleracea L.) alone or in combination with a probiotic (Shewanella putrefaciens, SpPdp11) on growth performance and the immune status (at both systemic and mucosal level) of gilthead seabream (Sparus aurata L.). Fish were fed a control (CD) or one of the supplemented diets (PD and MIXD) for 30 days. After 15 and 30 days of the feeding trial, growth performance, and cellular and humoral parameters were determined in head-kidney leucocytes, serum, skin mucus and intestine homogenates. Concomitantly, gene expression of several immune-related genes (ef1a, il-1b, igm, hep, bd, tcrb, csfr1, alp) were also evaluated in head kidney, skin and intestine. Our results demonstrated that the dietary administration of purslane (P. oleracea) for 30 days increased phagocytic capacity in head kidney leucocytes, total immunoglobulin Mlevels in skin mucus and the activity of certain enzymes in serum (protease) and intestine homogenates (protease and antiprotease). Moreover, interestingly igm expression was up-regulated in head kidney after 15 days of diet administration. These results suggest that the dietary administration of purslane has the ability to modulate several immune parameters of the systemic and mucosal immunity of gilthead seabream.