Innovating microbial management in RAS

BioMar contributes to the research project "RASbiome: Microbial management in RAS for sustainable aquaculture production". Through new biological water treatment strategies, this project targets key challenges to overcome in RAS farming.

The research project "RASbiome: Microbial management in RAS for sustainable aquaculture production", funded by ERA-NET BlueBio, aims at improving the sustainability of fish production in recirculating aquaculture systems (RAS) by introducing new and innovative approaches for microbiological water treatment.

Pedro Gómez Requeni, Senior Scientist at the Nutrition Formulation Department of BioMar Global R&D, is leading BioMar’s R&D area working on the development of RAS feeds. Contributing to the RASbiome. Pedro Gómez states:

"It is BioMar’s ambition to contribute to solving important challenges in RAS farming. BioMar welcomes investing R&D efforts in research projects on how to improve RAS production, i.e. by lowering energy consumption and carbon footprint, and on how to alleviate sludge removal."

According to Pedro Gómez, the RASbiome project contributes to developing European aquaculture in a direction characterized by the 3R’s principle in waste management: reduce, reuse, and recycle.

The RASbiome project will focus on implementing two fundamentally distinct biological water treatment strategies, new to RAS, to improve the management of nitrogen compounds.

The first strategy involves anaerobic ammonia-oxidizing (anammox) bacteria, resulting in an almost complete removal of nitrogen from the water. This strategy excludes the need for external organic carbon, it entails reduced energy consumption, and reduced CO2 production.

The second strategy takes advantage of bioflocs formed by heterotrophic bacteria, assimilating nitrogen. This approach allows for harvesting sludge consisting of a nutrient-rich microbial biomass. Therefore, it is compatible with recovery and recycling of nitrogen from RAS water streams.

The project is highly multidisciplinary, involving experts from Belgium, Denmark, and Norway in fields of environmental engineering, biotechnology, microbiology, microbial ecology, and aquaculture. Industry partners, including two large commercial producers of salmon smolt and rainbow trout, play a crucial role in the project.

In the RASbiome project, BioMar participates by providing the feeds for one of the work-packages of the project that includes biological trials with rainbow trout juveniles. The trials are run by DTU Aqua (Department for Aquatic Resources at the Danish Technical University). The different diets in the trials will be varying carbon-to-nitrogen ratios (C/N ratio), an essential parameter for microorganism performance. The role of Pedro Gómez and the BioMar team is to have a close collaboration with DTU Aqua for the formulation and production of these diets and to participate actively in the regular meetings and discussions throughout the project.

In this project of microbial management in RAS, the sustainability benefits for aquaculture production will come by three factors: by improving fish welfare and productivity due to stable and optimized chemical and microbiological water quality, by reducing environmental impact through nitrogen removal from discharged water, and finally, by reducing operational costs.

"BioMar as well as all RASbiome project partners truly expect the proposed project to give innovative outcomes on key challenges. New measures that can be applied in microbial water treatment, and especially in the management of nitrogen compounds, will undoubtedly promote sustainable fish production in freshwater RAS systems", says Pedro Gómez.