Food quality of mixed bacteria–algae diets for Daphnia magna
- 832 Downloads
Bacteria can comprise a large fraction of seston in aquatic ecosystems and can therefore significantly contribute to diets of filter-feeding zooplankton. To assess the effect of three heterotrophic bacteria (Flavobacterium sp., Pseudomonas sp. and Escherichia coli) on survival, growth and egg production of juvenile Daphnia magna during six-day growth experiments, five ratios of bacteria–Scenedesmus obliquus mixtures were fed. Potential growth-limiting effects mediated by essential biochemicals were assessed upon supplementation of pure bacterial diets with a sterol (cholesterol) or a polyunsaturated fatty acid (EPA). Pure bacterial diets always had detrimental effects on Daphnia. However, cholesterol supplementation of Flavobacterium sp. enhanced growth rates of Daphnia. Diets containing Pseudomonas impaired Daphnia growth even at low dietary proportions (20%), indicating their toxicity. In contrast, Daphnia grew at relative high dietary proportions of Flavobacterium sp. and E. coli (80–50%). In fact, diets containing small proportions of these heterotrophic bacteria (Flavobacterium ≤50%, E. coli 20%) even significantly increased Daphnia growth rates compared to pure algal diets, indicating a nutritional upgrading by these bacteria. Our results suggest that the relative contribution of bacteria and phytoplankton to total dietary carbon as well as their phylogenetic composition strongly influence Daphnia fitness and potentially other filter-feeding zooplankton under field conditions.
KeywordsFlavobacterium sp. Pseudomonas sp. Escherichia coli Polyunsaturated fatty acids Sterols Scenedesmus
We thank A. Wiese for technical assistance.
- Donderski, W. & B. Nowacka, 1992. Production of B-vitamins by planktonic bacteria isolated from the mesotrophic Lake Jasne. Journal of Islamic Academy of Sciences 5: 32–38.Google Scholar
- Glöckner, F. O., E. Zaichikov, N. Belkova, L. Denissova, J. Pernthaler, A. Pernthaler & R. Amann, 2000. Comparative 16S rRNA analysis of lake bacterioplankton reveals globally distributed phylogenetic clusters including an abundant group of actinobacteria. Applied and Environmental Microbiology 66: 5053–5065.PubMedCrossRefGoogle Scholar
- Greenberg, A. E., R. R. Trussell & L. S. Clesceri, 1985. Standard methods for the examination of water and wastewater. American Public Health Association, Washington, DC.Google Scholar
- Hamelin, K., G. Bruant, A. El Shaarawi, S. Hill, T. A. Edge, J. Fairbrother, J. Harel, C. Maynard, L. Masson & R. Brousseau, 2007. Occurrence of virulence and antimicrobial resistance genes in Escherichia coli isolates from different aquatic ecosystems within the St. Clair River and Detroit River areas, Applied and Environmental Microbiology 73: 477–484.CrossRefGoogle Scholar
- Jürgens, K., 1994. Impact of Daphnia on planktonic microbial food webs—a review. Marine Microbial Food Webs 8: 295–324.Google Scholar
- Mehdipour, N., M. Fallahi, G. Azari Takami, G. Vossoughi & A. Mashinchian, 2011. Freshwater green algae Chlorella sp. and Scenedesmus obliquus enriched with B group of vitamins can enhance fecundity of Daphnia magna. Iranian Journal of Science & Technology A2: 157–163.Google Scholar
- Parveen, B., J. P. Reveilliez, I. Mary, V. Ravet, G. Bronner, J. F. Mangot, I. Domaizon & D. Debroas, 2011. Diversity and dynamics of free-living and particle-associated betaproteobacteria and actinobacteria in relation to phytoplankton and zooplankton communities. FEMS Microbiology Ecology 77: 461–476.PubMedCrossRefGoogle Scholar
- Peters, R. H. & R. de Bernardi, 1987. Daphnia. Memorie dell’Istituto Italiano di Idrobiologia 45: 1–502.Google Scholar
- Taipale, S. J., M. T. Brett, K. Pulkkinen & M. J. Kainz, 2012. The influence of bacteria-dominated diets on Daphnia magna somatic growth, reproduction, and lipid composition, FEMS Microbiology Ecology. doi: 10.1111/j.1574-6941.2012.01406.x.
- Van der Gucht, K., T. Vandekerckhove, N. Vloemans, S. Cousin, K. Muylaert, K. Sabbe, M. Gillis, S. Declerk, L. De Meester & W. Vyverman, 2005. Characterization of bacterial communities in four freshwater lakes differing in nutrient load and food web structure. FEMS Microbiology Ecology 53: 205–220.PubMedCrossRefGoogle Scholar