Potential application and beneficial effects of a marine microalgal biomass produced in a high-rate algal pond (HRAP) in diets of European sea bass, Dicentrarchus labrax

• Published in: Environmental Science and Pollution Research
• Main Authors: Pascon, Giulia, Messina, Maria, Petit, Lisa, Pinheiro Valente, Luisa Maria, Oliveira, Beatriz, Przybyla, Cyrille, Dutto, Gilbert, Tulli, Francesca
• Other Authors: Laboratoire Service d' Experimentations Aquacoles Palavas les Flots (LSEA MARBEC), MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Instituto de Biologia Experimental e Tecnológica (IBET), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: European sea bass; salmon salmo-salar; nile tilapia; growth-performance; body-composition; fish-meal; Diet digestibility; Gut physiology; Microalgae consortium; Nannochloropsis spp; nutrient digestibility; Oocystis sp; partial substitution; tetraselmis-suecica; tisochrysis-lutea; waste-water; Water treatment; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.MCG]Environmental Sciences/Global Changes; Salmo salar
• Online Access: https://hal.umontpellier.fr/hal-03415633; https://hal.umontpellier.fr/hal-03415633/document; https://hal.umontpellier.fr/hal-03415633/file/11356_2021_Article_14927.pdf; https://doi.org/10.1007/s11356-021-14927-x

WOS:000668058500019 International audience Microalgae have been used as live food in aquatic species. In recent years, the interest in microalgae has considerably increased, thanks to the evolution of production techniques that have identified them as an ecologically attractive aquafeed ingredient. The present study provides the first data about the effects of dietary inclusion of a microalgae consortium grown in a high-rate algal pond system on zootechnical performance, morphometric indices, and dietary nutrient digestibility as well as morphology and functionality of the digestive system of European sea bass, Dicentrarchus labrax. A dietary treatment including a commercial mono-cultured microalgae (Nannochloropsis sp.) biomass was used for comparison. Six hundred and thirty-six European sea bass juveniles (18 +/- 0.28 g) were randomly allotted into 12 experimental groups and fed 4 different diets for 10 weeks: a control diet based on fish meal, fish oil, and plant protein sources; a diet including 10% of Nannochloropsis spp. biomass (100 g/kg diet); and two diets including two levels (10% and 20%) of the microalgal consortium (100 and 200 g/kg diet). Even at the highest dietary inclusion level, the microalgal consortium (200 g/kg diet) did not affect feed palatability and fish growth performance. A significant decrease in the apparent digestibility of dry matter, protein, and energy was observed in diets including 10 and 20% of the microalgal consortium, but all fish exhibited a well-preserved intestinal histomorphology. Moreover, dietary inclusion with the microalgal consortium significantly increased the enzymatic activity of maltase, sucrase-isomaltase, and gamma-glutamil transpeptidase in the distal intestine of the treated European sea bass. Algal consortium grown using fish farm effluents represents an attempt to enhance the utilization of natural biomasses in aquafeeds when used at 10 % as substitute of vegetable ingredients in diet for European sea bass.