Screening for microbial biostimulants in aquaculture - a tool for resilient aquaponic systems

Last changed: 14 October 2021
Cultivation of salad using hydroponics in a greenhouse. Photo.

Aquaponics, integrated systems for production of fish and plants, display an alternative for production of animal protein and health-promoting vegetables. Scaling up aquaponic systems for primary production requires increased knowledge about challenges in the system regarding e.g. nutritional balance with respect to the plants, plant and fish diseases, as well as quality of the product.

The nutrient balance in an aquaponic system is related to fish feed and its consumption, which together with the fish stocking density and age of fish, controls the nutrient content of water in the fish tank and thereby the basis for available plant nutrients. Plant root diseases are common problem in hydroponic systems where only plants are cultivated. However, knowledge about the disease impact in aquaponic systems regarding plant and fish pathogens is still limited.

Biostimulants are defined as substance(s) and/or microorganisms that stimulate natural processes to enhance/benefit nutrient uptake and efficiency, tolerance to stress, and crop quality. Little is known about types of naturally occurring microbial biostimulants in aquaculture systems and their role in aquaponic systems. This project aims at characterising the microbial profiles of biosolids (non-ingested feed and faeces) from fish farmed in recirculating aquaculture systems (RAS). Further, the potential of the biosolids as microbial biostimulants in hydroponic plant production will be evaluated by investigating the effect of the biosolids on plant performance and control of root pathogens.

Partners involved

  • Sammar Khalil from the Department of Biosystems and Technology, LTV-Faculty, SLU.
  • Markus Langeland from the Department of Animal Nutrition and Management, VH-Faculty, SLU.
  • Jean W. H. Yong from the Department of Biosystems and Technology, LTV-Faculty, SLU.


The project started in autumn 2019 and last for one year. The project is funded by SLU Aquaculture, which support cross-faculty collaborations to further strengthen aquaculture research at SLU. Read more about SLU Aquaculture, current research projects and upcoming calls.