Phylogenetic characterization of the heterotrophic bacterial communities inhabiting a marine recirculating aquaculture system.
OBJECTIVE
The aim of the present work was to characterize the heterotrophic bacterial community of a marine recirculating aquaculture system (RAS).


RESULTS
An experimental RAS was sampled for the rearing water (RW) and inside the biofilter. Samples were analysed for bacterial abundances, community structure and composition by using a combination of culture-dependent and -independent techniques. The most represented species detected among biofilter clones was Pseudomonas stutzeri, while Ruegeria spp. and Roseobacter spp. were more abundant among isolates. In comparison, the genera Roseobacter and Ruegeria were well represented in both the biofilter and the RW samples. A variety of possible bacterial pathogens (e.g. Vibrio spp., Erwinia spp. and Coxiella spp.) were also identified in this study.


CONCLUSIONS
Results revealed that the bacterial community in the RW was quite different to that associated with the biofilter. Moreover, data obtained suggest that the whole bacterial community can be involved in maintaining an effective and a stable rearing environment (shelter effect).


CONCLUSIONS
Improving the reliability and the sustainability of RAS depends on the correct management of the bacterial populations inside it. This study furnishes more accurate information on the bacterial populations and better clarifies the existing relationships between the bacterial flora in the RW and that associated with the biofilter.
Michaud
L
L
Dipartimento di Biologia Animale ed Ecologia Marina, Università di Messina, Messina, Italy. lmichaud@unime.it
Lo Giudice
A
A
Troussellier
M
M
Smedile
F
F
Bruni
V
V
Blancheton
J P
JP
D001419:Bacteria / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D005398:Fisheries; D052836:Heterotrophic Processes; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S