Microalgae from Biorefinery as Potential Protein Source for Siberian Sturgeon (A. baerii) Aquafeed

Tiziana Bongiorno,Andrea Pizzera,Domenico Carminati,Aldo Tava,Lorenzo Proietti,Elena Ficara,Francisco Javier Alarcón,Annalaura Lopez,Mauro Vasconi,Katia Parati,Antonio Jesús Vizcaíno,Luciano Foglio

doi:10.3390/su12218779

Abstract

The demand for aquafeed is expected to increase in the coming years and new ingredients will be needed to compensate for the low fish meal and oil availability. Microalgae represent a promising matrix for the future aquafeed formulation, however, the high production cost hinders its application. The use of microalgae from biorefinery would reduce the disposal costs for microalgae production. The present study aimed to (i) verify the growth of microalgae on digestate coming from pig farming and (ii) evaluate their potential valorization as dietary ingredient in aquafeed according to a Circular Bioeconomy approach. For these purposes, a microalgae biomass was produced on an outdoor raceway reactor supplied with digestate and used for partial replacement (10% of the diet) in aquafeed for Siberian sturgeon fingerlings (Acipenser baerii). The results obtained confirm the feasibility for growing microalgae on digestate with satisfactory productivity (6.2 gDM m−2 d−1), nutrient removal efficiency and Chemical Oxygen Demand reduction; moreover, the feeding trial carried out showed similar results between experimental and control groups (p > 0.05), in term of growth performance, somatic indices, fillet nutritional composition and intestinal functionality, to indicate that microalgae from biorefinery could be used as protein source in Siberian sturgeon aquafeed.

Highlights

IntroductionAccording to data reported by FAO [1] aquaculture supplies about half of the fish intended for human consumption and the trend is increasing significantly in the coming decades
According to data reported by FAO [1] aquaculture supplies about half of the fish intended for human consumption and the trend is increasing significantly in the coming decades.These data are in contrast with the significant reduction of fish from fisheries, due to an excessive depletion of wild fish stocks
Few studies have been published on microalgae-derived feed ingredients in Acipenserids diet and no data are available on the use of biomass from biorefineries in aquafeed for this species

Summary

Introduction

According to data reported by FAO [1] aquaculture supplies about half of the fish intended for human consumption and the trend is increasing significantly in the coming decades. These data are in contrast with the significant reduction of fish from fisheries, due to an excessive depletion of wild fish stocks. There are several limits to their future use, since high quality FM and FO derive from wild fish of which there is a growing demand even from emerging economies. The availability and the price of these ingredients is unstable and growing substantially [4]

Methods

Results

Conclusion