Open AccessImpact of water quality on the bacterial populations and off‐flavours in recirculating aquaculture systems
Author(s) -
Auffret Marc,
Yergeau Étienne,
Pilote Alexandre,
Proulx Émilie,
Proulx Daniel,
Greer Charles W.,
Vandenberg Grant,
Villemur Richard
Publication year - 2013
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/1574-6941.12053
Subject(s) - geosmin , biology , biofilter , water quality , aquaculture , recirculating aquaculture system , turbidity , flesh , population , operational taxonomic unit , bacteria , pyrosequencing , nitrification , food science , 16s ribosomal rna , pulp and paper industry , fish <actinopterygii> , ecology , fishery , gene , odor , sociology , engineering , genetics , biochemistry , quantum mechanics , physics , demography , neuroscience , nitrogen
A variety of factors affecting water quality in recirculating aquaculture systems ( RAS ) are associated with the occurrence of off‐flavours. In this study, we report the impact of water quality on the bacterial diversity and the occurrence of the geosmin‐synthesis gene ( geoA ) in two RAS units operated for 252 days. Unit 2 displayed a higher level of turbidity and phosphate, which affected the fresh water quality compared with unit 1. In the biofilter, nitrification is one of the major processes by which high water quality is maintained. The bacterial population observed in the unit 1 biofilter was more stable throughout the experiment, with a higher level of nitrifying bacteria compared with the unit 2 biofilter. Geosmin appeared in fish flesh after 84 days in unit 2, whereas it appeared in unit 1 after 168 days, but at a much lower level. The geoA gene was detected in both units, 28 days prior to the detection of geosmin in fish flesh. In addition, we detected sequences associated with S orangium and N annocystis ( M yxococcales ): members of these genera are known to produce geosmin. These sequences were observed at an earlier time in unit 2 and at a higher level than in unit 1. This study confirms the advantages of new molecular methods to understand the occurrence of geosmin production in RAS .