Effects of plant-based diets on the bacterial counts and bacterial community composition of beluga sturgeon (Huso huso)


1 Department of Microbiology, Urmia Branch, Islamic Azad University, Urmia, Iran

2 Department of Artemia and Aquatic Animals, Urmia Lake Research Institute, Urmia University, Iran

3 3Department of Food industry, Faculty of Agriculture, Urmia University, Iran


BACKGROUND: In recent years, many studies have been conducted on finding a suitable replacement for fish meal to supply the needs of aquaculture feed industry. Objectives: The present study was performed to examine the effect of replacing fish meal and fish oil with plant sources on bacterial counts in intestinal contents and mucus and bacterial composition in Beluga sturgeon. Methods: Beluga sturgeons with a mean initial weight of 133±5 g were distributed into 18 (300 L) tanks (30fish/tank) and were fed experimental diets for 60 days. The control diet contained only fish meal and fish oil as the primary source of protein and lipid, while the experimental diets contained 0, 40, 60, 80 and 100 percent plant protein sources (wheat gluten, corn gluten and soybean meal) and 20% vegetable oil blend (canola, sunflower, cotton and safflower oils) respectively. Results: Results showed that replacement of 80% fish meal and fish oil with plant sources didn’t have significant effect on final weight (235 ± 17 g) compared to control group (256.1 ± 10 g) in a 60 days trial. Replacement of fish meal with 100% plant proteins in combination with 80% vegetable oils resulted in significantly lower final weight (225.7 ± 11 g), compared to other treatments including control group (p<0.05). Replacing 80% fish oil with vegetable oils resulted in a significant reduction of bacterial count in intestinal contents and a significant increase in percentage of Entrobacteriacea sp. However, no significant differences were detected in bacterial counts of mucus in experimental treatments compared to control (p>0.05). Replacement of 60, 80 and 100% fish meal and 80% fish oil with plant sources significantly decreased bacterial counts in intestinal contents and intestinal mucosa compared to control group (p<0.05). Also this replacement cause significant change in bacterial composition of intestine. Conclusions: The results suggested that using plant sources in juvenile Beluga sturgeon diet decreases the bacterial count in the intestinal contents and mucus and changes the composition of intestinal micro flora.


1. Amann, R.I., Ludwig, W., Schleifer, K.H., (1995) Phylogenetic identification and in situ detection of individual microbial cells without cultivation. Microbiol Rev. 59: 143-169.##
Anderson, R.L. Wolf, W.J. (1995) Compositional changes in trypsin inhibitors, phytic acid, and isoflavones related to soybean processing. J Nutr. 125: 581-588.##
Baeverfjord, G., Krogdahl, A. (1996) Development and regression of soybean meal induced enteritis in Atlantic salmon, Salmo salar, distal intestine: A comparison with the intestines of fasted fish. J Fish Dis. 19: 375-387.##
Cahill, M.M. (1990) Bacterial flora of fishes: a review. Microb Ecol. 19: 21-4.##
Cappuccino, N., Mackay, R., Eisner, C. (2002) Spread of the invasive alien vine Vincetoxicum rossicum: trade-offs between seed dispersability and seed quality. Am Mus Novit. 148: 263-270.##
Desai, A.R., Links, M.G., Collins., S.A., Mansfield, G.S., Drew,, M.D., Van Kessel, A.G., Hill, J.E. (2012) Effects of plant-based diets on the distal gut microbiome of rainbow trout (Oncorhynchus mykiss). Aquaculture. 134: 350-353.##
Francis, G., Makkar, H.P.S., Becker, K. (2001) Antinutritional factors present on plant-derived alternate fish feed ingredient and their effects in fish. Aquaculture. 199: 197-222.##
Fuller, R. (1977) The importance of lactobacilli in maintaining normal microbial balance in the crop. Br Poult Sci. 18: 85-94.##
Gatlin, D.M., Barrows, F.T., Brown, P., Dabrowski, K., Gaylord, T.G., Hardy, R.W., Herman, E., Hu, G.S., Krogdahl, Å., Nelson, R., Overturf, K., Rust, M., Sealey, W., Skonberg, D., Souza, E.J., Stone, D., Wilson, R., Wurtele, E. (2007) Expanding theutilization of sustainable plant products in aquafeeds: a review. Aquac Res. 38: 551-579.##
Gong, J., Forster, R.J., Yu, H., Chambers, J.R., Wheatcroft, R., Sabour, P.M., Chen, S. (2002) Molecular analysis of bacterial populations in the ileum of broiler chickens and comparison with bacteria in the caecum. FEMS Microbiol. Ecol. 41: 171-179.##
Hansen, A.C., Rosenlund, G., Karlsen, O., Koppe, W., Hemre, G.I. (2007) Total replacement of fish meal with plant proteins in diets for Atlantic cod (Gadus morhua) I - Effects on growth and protein retention. Aquaculture. 272: 599-611. ##
Jahanbakhshi, A., Imanpuor, M., Taghizadeh, V., Shabani, A. (2012)  Effects of replacing fish meal with plant protein (Sesame oil cake and corn gluten) on growth performance, survival and carcass quality of juvenile beluga (Huso huso). W J Fish Mar Sci.  4: 422-425.##
Khajepour, F., Hosseini, S.A. (2012) Citric acid improves growth performance and phosphorus digestibility in Beluga (Huso huso) fed diets where soybean meal partly replaced fish meal. Anim Feed Sci Technol. 171: 68- 73.##
Krogdahl, A., Bakke-McKellep, A.M., Røed, K.H., Baeverfjord G. (2000) Feeding Atlantic salmon Salmosalar L. soybean products: effects on disease resistance (furunculosis), and lysozyme and IgM levels in the intestinalmucosa. Aquac Nutr. 6: 77-84.##
Krogdahl, A., Penn, M., Thorsen, J., Refstie, S., Bakke, A.M. (2010) Important antinutrients in plant feedstuffs for aquaculture: an update on recent findings regarding responses in salmonids. Aquac. Res. 41: 333-344.##
Mazurkiewicz, J., Przybyl, A., Golski, J. (2009) Usability of some plant protein ingredients in the diets of Siberian sturgeon.  Acipenser baerii.  Arch Pol Fish.17: 45-52.##
Merrifield, D.L., Bradley, G., Baker, R.T.M., Dimitroglou, A., Davies, S.J. (2009) Soybean meal alters autochthonous microbial populations, microvilli morphology and compromises intestinal enterocyte integrity of rainbow trout (Oncorhynchus mykiss). J Fish Dis. 32: 755-766.##
Merrifield, D.L., Dimitroglou, A., Foey, A., Davies, S.J., Baker, R.R., Bøgwald, J., Castex, M., Ringø, E. (2010) The current status and future focus of probiotic and prebiotic applications for salmonids. Aquaculture. 302: 1-18.##
Olsen, R.E., Myklebust, R., Kryvi, H., Mayhew, T.M. Ringo, E. (2001) Damaging effect of dietary inulin on intestinal enterocytes in Arctic charr (Salvelinus alpinus L.). Aquac Res. 32: 931-934.##
Olsen, R.E., Hansen, A.C., Roselund, G., Hemre, G.I., Mayhew Gutierrez-Wing, M.T., Malone, R.F. (2006) Biological filters in aquaculture: Trends and research directions for freshwater and marine applications. Aquac Eng. 34: 163-171.##
Ringo, E., Strom, E., Tabachck, J.A. (1995) Intestinal microflora of Salmonids. A Review Aquac Res. 26: 773-789.##
Ringo, E., Sperstad, S., Myklebust, R., Refstie, S., Krogdahl, Å. (2006) Characterisation of the microbiota associated with intestine of Atlantic cod (Gadus morhua L.): The effect of fish meal, standard soybean meal and a bioprocessed soybean meal. Aquaculture. 261: 829-841.##
Shangong, W., Tianheng, G., Yingzhen, Z., Weiwei, W., Yingyin, C., Guitang, W. (2010) Microbial diversity of intestinal contents and mucus in yellow catfish (Pelteobagrus fulvidraco). Aquaculture. 303: 1-7.##
Sener, E., Yildiz, M., Savas, E. (2005) Effect of dietary lipid source on growth and fatty acid composition in Russian sturgeon (Acipenser Gueldenstadtii) Juveniles. Turk J Vet Anim Sci. 29: 1011-1107.##
Verner-Jeffreys, D.W., Shields, R.J., Bricknell, I.R., Birkbeck, T.H. (2003) Changes in thegut-associated microflora during the development of Atlantic halibut (Hippoglossus hippoglossus L.) larvae in three British hatcheries. Aquaculture. 219: 21-42.##