TY - JOUR

T1 - Dynamics of geosmin-producing bacteria in a full-scale saltwater recirculated aquaculture system

AU - Lukassen, Mie Bech

AU - Podduturi, Raju

AU - Rohaan, Bram

AU - Jørgensen, Niels O.G.

AU - Nielsen, Jeppe Lund

PY - 2019/2/1

Y1 - 2019/2/1

N2 - Regular monitoring of the microbiome in recirculated aquaculture systems will allow the farmer to link water quality parameters to subsequent fish performance and will function as a tool for early identification of microbial conditions that could lead to impaired fish health. Microbial communities were monitored in different compartments of a commercial full-scale, land-based saltwater RAS for production of Atlantic salmon during 9 months. The microbial communities revealed a unique composition in the production tanks and moving bed biofilters, as compared to the other investigated compartments. The fixed bed compartment had a higher stability in the microbial community over time, relative to the moving bed biofilter compartment. Changes of the operation of the facility (replenishment of brackish water to seawater) caused an immediate shift in the microbial populations. Potential geosmin producers (bacteria harbouring the functional gene for geosmin synthetase geoA) were dominated by Sorangium, Actinomycetales and Myxococcales, but unidentified microorganisms harbouring the geoA gene were also present. The biofilters had the highest numbers of potential geosmin producers, but their presence did not co-vary with the levels of geosmin. This suggest that an observed period with high levels geosmin were due to a change in activity, rather than an increase in cell numbers. Our results provide new insight into the diversity of microbiota in RAS and suggest that monitoring of microbial communities in the aquaculture production may provide a tool for future microbial management to ensure stability in RAS performance.

AB - Regular monitoring of the microbiome in recirculated aquaculture systems will allow the farmer to link water quality parameters to subsequent fish performance and will function as a tool for early identification of microbial conditions that could lead to impaired fish health. Microbial communities were monitored in different compartments of a commercial full-scale, land-based saltwater RAS for production of Atlantic salmon during 9 months. The microbial communities revealed a unique composition in the production tanks and moving bed biofilters, as compared to the other investigated compartments. The fixed bed compartment had a higher stability in the microbial community over time, relative to the moving bed biofilter compartment. Changes of the operation of the facility (replenishment of brackish water to seawater) caused an immediate shift in the microbial populations. Potential geosmin producers (bacteria harbouring the functional gene for geosmin synthetase geoA) were dominated by Sorangium, Actinomycetales and Myxococcales, but unidentified microorganisms harbouring the geoA gene were also present. The biofilters had the highest numbers of potential geosmin producers, but their presence did not co-vary with the levels of geosmin. This suggest that an observed period with high levels geosmin were due to a change in activity, rather than an increase in cell numbers. Our results provide new insight into the diversity of microbiota in RAS and suggest that monitoring of microbial communities in the aquaculture production may provide a tool for future microbial management to ensure stability in RAS performance.

KW - Geosmin-producing microorganisms

KW - Land-based salmon production

KW - Microbial communities

KW - Microbial management

U2 - 10.1016/j.aquaculture.2018.10.008

DO - 10.1016/j.aquaculture.2018.10.008

M3 - Journal article

AN - SCOPUS:85054847454

VL - 500

SP - 170

EP - 177

JO - Aquaculture

JF - Aquaculture

SN - 0044-8486

ER -