We have had great results using our Active Microbiome Management approach to reduce Geosmin in the Kuterra growout salmon facility in British Columbia. Click here to download the full case study.
Currently, standard practice to deal with Geosmin and MIB – the most common off-flavour compounds – is to purge the fish.
We have had encouraging results in removing Geosmin and MIB from RAS systems using our bacteria.
Geosmin and 2-methylisoborneol (MIB) are a common problem encountered in recirculating aquaculture systems (RAS). These two compounds often accumulate in the water, and then are taken up in the lipids (fatty tissues) of the fish.
In fish, with high lipid content (like Atlantic Salmon) these compounds give the fish a distinctly earthy or ‘muddy’ flavour – in fact Geosmin and MIB are often known as ‘off-flavour compounds’ or OFCs because of this. This earthy taste renders the fish worthless for human consumption.
The production of off-flavour compounds in RAS is mainly due to heterotrophic prokaryotes (types of bacteria and archaea), which produce the compounds. Various methods for dealing with OFCs are used, from purging the fish to using ozone.
However, bio-degradation is now being seen as a more effective long-term method. Bacteria remove the off-flavour compounds that accumulate in the water. However, this isn’t the only mode of action. When using an active microbiome management approach, constant additions of ‘good’ bacteria can also out-compete the heterotrophs which produce the OFCs in the first place.
RAS-Boost ensures bacteria are fully functional in 7 to 10 days, and the bioreactor can then be kept running as a continuous source of RAS-Right bacteria, often acclimatized to any salinity.
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