Marine microalgae Pavlova viridis and Nannochloropsis sp. as n-3 PUFA source in diets for juvenile European sea bass (Dicentrarchus labrax L.)

Abstract

In the present study, the potential of the microalga Pavlova viridis (=Diacronema viridis) as an n-3 polyunsaturated fatty acid (PUFA) source was evaluated and compared to Nannochloropsis sp. in diets for juvenile European sea bass (Dicentrarchus labrax L.) (initial weight~12.8±1.7 g) in an 8-week feeding trial. Six different isoenergetic and isonitrogenous test diets were used: (1) fish oil diet (FO), major lipid source fish oil (100 %), (2) basal diet, 40 % fish oil and 60 % plant oil (in equal parts rapeseed, sunflower, and linseed oil), (3) Pavlova 50 % (P50), 50 % of the fish oil of the basal diet was substituted by lipid content of P. viridis meal, (4) Pavlova 100 % (P100), 100 % of the fish oil of the basal diet was substituted by lipid content of P. viridis meal, (5) Nannochloropsis 50 % (N50), 50 % of the fish oil of the basal diet was substituted by lipid content of Nannochloropsis sp. meal, and (6) Nannochloropsis 100 % (N100), 100 % of the fish oil of the basal diet was substituted by lipid content of Nannochloropsis sp. meal. The specific growth rate was highest and feed conversion ratio was lowest in the P100 group (SGR 1.77±0.10 % day −1 ; FCR 1.17±0.01), although not significantly different to the results for the FO and the other algae-groups. Furthermore, the sum of PUFA was also highest in the P100 group, followed by the P50, N100, N50, and B group (mainly due to the high content of linoleic and linolenic acids coming from plant oils and microalgal products) with the lowest levels in the FO group. The highest amounts of docosahexaenoic acid (DHA) of total fatty acids were found in the FO and B group, although not significantly higher than in groups P50 and P100. The significantly highest amount of eicosapentaenoic acid (EPA, % of total fatty acids) was in the P100 samples and the lowest amount was in samples of the basal group. The histological analyses of liver and intestine samples did not reveal any negative effects caused by the experimental treatments. Based on the basal diet, a 50 % fish oil replacement by Nannochloropsis sp. meal and a total replacement by P. viridis meal were possible without negative effects on the growth performance and nutrient utilization of juvenile sea bass.

EFFECT OF SPIRULIN (ARTHROSPIRA PLATENSIS) A AND NANNOCHLOROPSIS (NANNOCHLOROPSIS GADITANA) SUPPLEMENTATION ON GROWTH PERFORMANCE, FEED UTILIZATION AND CARCASS COMPOSITION OF NILE TILAPIA (Oreochromis niloticus)

“…These results were in contrary with Sørensen et al (2017) who reported that Neither the whole body, nor fillet proximate composition of Atlantic salmon was affected by the intake of Nannochloropsis gaditana except lipid content. Haas et al (2015) found that there is no significant different in body composition when they fed Atlantic salmon diets contained 50 and 100 % Nannochloropsis gaditana replaced with fish oil. Sarker et al 2018reported that Whole body proximate composition of Nile tilapia fillets did not significantly differ among dietary treatments when they replaced fish meal by 33%, 66% and 100% of Nannochloropsis oculate Shearer (1994) reported that proximate composition varies with life stages of fish and is also influenced by endogenous factors such as genetics, size and sex, as well as exogenous factors such as feed composition, feeding frequency and environment.…”

Marine Microalgae Biomolecules and Their Adhesion Capacity to Salmonella enterica sv. Typhimurium

“…Phylum Haptophyta comprises two classes, Coccolithophyceae and Pavlovophyceae [4], where the latter includes the two marine species under study, Pavlova lutheri and Pavlova gyrans. Since they can be easily grown, quickly ingested and digested, and exhibit a high nutritional value, these species, as well as some other microalgae, are widely used as raw material in the aquaculture of fish, mollusks, and crustaceans [5][6][7]. All these characteristics have also aroused the interest of the biotechnology sector for the potential use of these microorganisms in nutritional and pharmaceutical bioproducts [8].…”

Short‐term supplementation of gilthead seabream (Sparus aurata) diets withNannochloropsis gaditanamodulates intestinal microbiota without affecting intestinal morphology and function

“…However, data available on the effects of Nannochloropsis sp. in carnivorous fish diets are limited (Haas et al, ; Patterson & Gatlin, ; Qiao et al, ; Walker & Berlinsky, ).…”