Microbial Control of the Culture ofArtemiaJuveniles through Preemptive Colonization by Selected Bacterial Strains

Abstract

The use of juvenile Artemia as feed in aquaculture and in the pet shop industry 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 Artemiajuveniles and to obtain control of the associated microbial community was examined. Nine bacterial strains were selected based on their positive effects on survival and/or growth of Artemiajuveniles under monoxenic culture conditions, while other strains caused no significant effect, significantly lower rates of survival and/or growth, or even total mortality of the Artemia. The nine selected strains were used to preemptively colonize the culture water of Artemia juveniles. Xenic culture ofArtemia under suboptimal conditions yielded better survival and/or growth rates when they were grown in the preemptively colonized culture medium than when grown in autoclaved seawater. The preemptive colonization of the culture water had a drastic influence on the microbial communities that developed in the culture water or that were associated with the Artemia, as determined with Biolog GN community-level physiological profiles. Chemotaxonomical characterization 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.

The impact of mutations in the quorum sensing systems of Aeromonas hydrophila, Vibrio anguillarum and Vibrio harveyi on their virulence towards gnotobiotically cultured Artemia franciscana

“…To this end, sterile Artemia nauplii, obtained via hatching of decapsulated cysts, were cultured in filtered and autoclaved artificial seawater and fed dead LVS3 bacteria. The strain LVS3 was selected as a feed source because it was shown before to be harmless to Artemia (Verschuere et al, 1999). The LVS3 bacteria were killed by autoclavation before addition to the Artemia cultures in order to eliminate any possible interactions between live LVS3 bacteria and the other strains that were added.…”

“…Indeed, the presence of a native bacterial community might cause bias in experiments that try to determine the impact of quorum sensing mutations on virulence of pathogenic bacteria because AI-2-mediated signalling was found to be present in many different species (Xavier and Bassler, 2003). In this view, the brine shrimp Artemia franciscana is an excellent model organism because it can easily be cultured in gnotobiotic conditions (Verschuere et al ., 1999). Therefore, it was used in this study in order to determine the impact of mutations in the quorum sensing systems of Ae.…”

“…LVS3isolate that enhances growth and survival of ArtemiaVerschuere et al (1999) in ahyI (AHL synthase that produces BHL a )Swift et al (1999) AH-1NahyR mutation in ahyR (AHL receptor that detects the AHL produced by AhyI)Swift et al (1999) Vibrio anguillarum strains NB10 wild type from which strains DM21, DM25, DM27, DM64, DM63 and AC11 are derivedMilton et al (1997) DM21 mutation in vanI (AHL synthase that produces ODHL b and to a lesser extend OHL c and OOHL d ) Milton et al (1997) DM25 mutation in vanR (AHL receptor that detects the AHLs produced by VanI) Milton et al (1997) DM27 mutation in vanM (AHL synthase that produces OHHHL e and HHL f ) Milton et al (2001) DM64 mutation in vanN (AHL receptor that detects the AHLs produced by VanM) Croxatto et al (2004) DM63 mutation in vanQ (AI-2 receptor) Croxatto et al (2004) AC11 mutation in vanO (encoding VanO, a protein in the AHL and AI-2 signal transduction chain) Croxatto et al (2004) Vibrio campbellii PN9801 pathogen for Artemia Soto-Rodriguez et al (2003) Vibrio harveyi strains BB120 wild type from which strains BB152, BB170, MM30, BB886, MM77 and JAF548 are derived Bassler et al (1997) BB152 mutation in luxM (AHL synthase that produces OHBHL g ) Bassler et al (1994) BB170 mutation in luxN (AHL receptor that detects the AHL produced by LuxM) Bassler et al (1993) MM30 mutation in luxS (AI-2 synthase) Surette et al (1999) BB886 mutation in luxP (AI-2 receptor) Bassler et al (1994) MM77 mutation in luxM and luxS Mok et al (2003) JAF548 mutation in luxO (encoding LuxO, a protein in the AHL and AI-2 signal transduction chain) Freeman and Bassler (1999) a. N-butanoyl-L-homoserine lactone. b. N-(3-oxodecanoyl)-L-homoserine lactone.…”

Live feeds for early stages of fish rearing

“…In the case of enrichment with Algamac, a commercial spray-dried microalgae, there is even more rapid proliferation of bacteria than after incubation with oil emulsions (Ritar, Dunstan, Nelson, Brown, Nichols, Thomas, Smith, Crear & Kolkovski 2004). Several strategies have been suggested to limit the presence of opportunistic bacteria in Artemia used for feeding of ¢sh larvae, which include the use of probiotic bacteria that limit the growth of opportunistic bacteria or have a positive e¡ect on the growth and survival of Artemia (Verschuere, Rombaut, Huys, Dhont, Sorgeloos & Verstraete 1999;Makridis et al 2000;Gatesoupe 2002;, incubation in microalgae (Olsen et al 2000;Makridis et al 2006), or use of disinfectants, such as formaldehyde (Tovar, Zambonino, Cahu, Gatesoupe, Va Ł zquez-Jua Ł rez & Le¤ sel 2002), short-chain acids (Defoirdt, Crab,Wood, Sorgeloos,Verstraete & Bossier 2006) and quorum-sensing-disrupting furanones (Defoirdt, Halet, Sorgeloos, Bossier & Verstraete 2006;Defoirdt, Boon, Sorgeloos, Verstraete & Bossier 2007).…”

The bacterial storage compound poly‐β‐hydroxybutyrate protects Artemia franciscana from pathogenic Vibrio campbellii

“…Vibrio campbellii LMG21363 (= PN9801; Soto-Rodriguez et al, 2003) and C. testosteroni LMG19554 (= I2; Boon et al, 2000) were obtained from the BCCM/LMG Bacteria Collection (Ghent, Belgium). Vibrio campbellii LMG21363 and Aeromonas hydrophila LVS3 (Verschuere et al, 1999) were grown in Marine Broth (Difco Laboratories, Detroit, USA). Comamonas testosteroni LMG19554 was grown in LB medium.…”