Microbial control of the culture of Artemia juveniles through preemptive colonization by selected bacterial strains

The use of juvenile Artemia as feed in aquaculture and in the pet shop indu stry has been getting more attention during the last decade. In this study, the use of selected bacterial strains to improve the nutritional value of dry food for Artemia juveniles and to obtain control of the associated micr obial community was examined. Nine bacterial strains were selected based on their positive effects on survival and/or growth of Artemia juveniles unde r monoxenic culture conditions, while other strains caused no significant e ffect, significantly lower rates of survival and/or growth, or even total m ortality of the Artemia, The nine selected strains were used to preemptivel y colonize the culture water of Artemia juveniles. Xenic culture of Artemia under suboptimal conditions yielded better survival and/or growth rates wh en they were grown in the preemptively colonized culture medium than when g rown in autoclaved seawater. The preemptive colonization of the culture wat er had a drastic influence on the microbial communities that developed in t he culture water or that were associated with the Artemia, as determined wi th Biolog GN community-level physiological profiles. Chemotaxonomical chara cterization based on fatty acid methyl ester analysis of bacterial isolates recovered from the culture tanks was performed, and a comparison with the initially introduced strains was made. Finally, several modes of action for the beneficial effect of the bacterial strains are proposed.