Elimination of the associated microbial community and bioencapsulation of bacteria in the rotifer Brachionus plicatilis

Centro Interdisciplinario de Ciencias Marinas IPN; Centro de Investigaciones Biológicas del Noroeste; Universidad Autonoma Metropolitana
Aquaculture International (Impact Factor: 1.04). 12/2002; 11(1):95-108. DOI: 10.1023/A:1024117109362

ABSTRACT The bioencapsulation of live bacteria in the rotifer Brachionus plicatilis was determined under monoxenic conditions. The first objective was to evaluate the microbiota of the rotifer during intensive production and to obtain sterile rotifer cultures starting from adult females or amictic eggs using PVP-Iodine, Hydrogen peroxide or antibiotic mixtures. In the rotifers, the proportion of vibrios increased significantly during the mass production, displacing other unidentified marine bacteria. Rotifers, in the absence of culturable bacteria were obtained starting from amictic eggs and using Trimetroprim-sulfametoxasole (Bactrim Roche) at 10 ml l–1. The effect of members of Vibrionaceae on the survival and growth rate of rotifers was determined under monoxenic conditions. The survival of rotifers was not affected in the presence of different isolates, while amictic egg formation occurred and the populations increased when the strains Vibrio proteolyticus C279 and Aeromonas media C226 were tested. All isolates were successfully incorporated in the rotifers, since there was no significant difference between the numbers of bioencapsulated cells of different strains of isolates. The results show that it is possible to replace the microbial community in rotifer cultures, started from disinfected amictic eggs, with selected bacterial strains. This could be used as a tool for future studies to reveal the role of specific bacteria on first larval stages of marine fish species.

1 Bookmark
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Rotifer growth performance and microbial community changes associated with rotifer cultures were monitored while different feed types (Nannochloropsis oculata paste and the commercial yeast based feed CS-3000), different regimes (daily changes, changes per batch and no changes) and mixtures of three probionts (Phenylobacterium sp.; Gluconobacter sp. and Paracoccus denitrificans) were provided. It was shown that the dominant bacterial species in the cultures receiving either N.oculata or CS-3000 were different. However, in cultures receiving both feeds (either switching between feeds on a daily basis or on a batch basis), a high similarity in microbial community fingerprint was found. The presence of probionts was detected by the end of four batch culture cycles in spite of strong shifts of the bacterial community. By group discriminant analysis, it was found that Phenylobacterium sp. and Paracoccus sp. contributed positively to the CS-3000-fed group, while Gluconobacter sp. contributed positively to the N.oculata-fed group, although they did not appear as very dominant species.
    Aquaculture International 04/2009; 17(4):303-315. · 1.04 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the effect of Vibrio harveyi strains on the growth rate of the gnotobiotically cultured rotifer Brachionus plicatilis, and to establish whether quorum sensing is involved in the observed phenomena. Gnotobiotic B. plicatilis sensu strictu, obtained by hatching glutaraldehyde-treated amictic eggs, were used as test organisms. Challenge tests were performed with 11 V. harveyi strains and different quorum sensing mutants derived from the V. harveyi BB120 strain. Brominated furanone [(5Z)-4-bromo-5-(bromomethylene)-3-butyl-2(5H)-furanone] as a quorum sensing inhibitor was tested in Brachionus challenge tests. Some V. harveyi strains, such as strain BB120, had a significantly negative effect on the Brachionus growth rate. In the challenge test with MM77, an isogenic strain of BB120 in which the two autoinducers (HAI-1 and AI-2) are both inactivated, no negative effect was observed. The effect of single mutants was the same as that observed in the BB120 strain. This indicates that both systems are responsible for the growth-retarding (GR) effect of the BB120 strain towards Brachionus. Moreover, the addition of an exogenous source of HAI-1 or AI-2 could restore the GR effect in the HAI-1 and AI-2 nonproducing mutant MM77. The addition of brominated furanone at a concentration of 2.5 mg l(-1) could neutralize the GR effect of some strains such as BB120 and VH-014. Two quorum sensing systems in V. harveyi strain BB120 (namely HAI-1 and AI-2-mediated) are necessary for its GR effect on B. plicatilis. With some other V. harveyi strains, however, growth inhibition towards Brachionus does not seem to be related to quorum sensing. Interference with the quorum sensing system might help to counteract the GR effect of some V. harveyi strains on Brachionus. However, further studies are needed to demonstrate the positive effect of halogenated furanone in nongnotobiotic Brachionus cultures and eventually, in other segments of the aquaculture industry.
    Journal of Applied Microbiology 08/2007; 103(1):194-203. · 2.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this paper was to investigate the nature of the effect of l-carnitine on the cultures of the marine rotifer Brachionus “Cayman” and its microflora. Xenic and gnotobiotic experiments were set up with rotifers, fed axenic wild-type yeast (Saccharomyces cerevisiae) or xenic microalgae (Tetraselmis suecica) and incubated with l-carnitine concentrations of 0.1, 1, 10, 60, 100 and 1000 mg L−1. Axenic neonates were obtained by separating amictic eggs from the rotifers by blending, prior to disinfection with glutaraldehyde and hatching. The gnotobiotic cultures had a significantly lower growth rate and egg ratio (%), compared to both xenic trials. The xenic cultures fed algae performed significantly better than those fed baker's yeast, when comparing population density, growth rate and egg ratio. A significant effect of l-carnitine addition was only found in yeast-fed cultures. Microbial assays, conducted with similar doses of autoclaved l-carnitine, revealed that several bacterial species present in the community of conventional Brachionus “Cayman” cultures, could possibly utilize l-carnitine for growth. These results suggest that the improvement of population density, growth rate and egg ratio in xenic rotifer cultures supplemented with l-carnitine, is most likely due to the stimulation by this compound of certain species of (beneficial) microorganisms, which are in turn valorized by the rotifers, yielding improved culture performance. Because of the absence of a positive effect under gnotobiotic conditions, a direct effect of l-carnitine on fatty acid metabolism, as suggested in literature, is unlikely.
    Journal of Experimental Marine Biology and Ecology 01/2010; 393:114-123. · 2.26 Impact Factor


Available from
May 21, 2014