Valorization of aquatic waste streams - From waste to worm

Animal feed often relies on the addition of natural resources which are overexploited. E.g., the production of fishmeal and fish oil for fish feed is getting very controversial and unsustainable in this way.


Nutrient recovery is therefore becoming more and more important. As a consequence, clean and sustainable alternatives for natural resources should be found. A promising option is the cultivation of freshwater worms of the species Lumbriculus variegatus. Due to their high content of protein and other functional ingredients, like poly-unsaturated (ω-3 and ω-6) fatty acids, they have a high potential to replace natural resources of protein and lipid, in fish feed

Technological challenge

L. variegatus can be applied for sludge reduction and compaction in municipal wastewater treatment. A reactor concept, with worms immobilized in a carrier material, was developed for this purpose.

However, worm biomass grown on municipal sludge contains low pollutant concentrations which limits it’s controlled re-use. Worm biomass grown on “clean” organic (waste) streams has a much broader application potential. In this way these organic streams are upgraded in value. Schematic overview of the process for producing clean worm biomass

The project will focus on the biosynthesis, production and recovery of functional ingredients from suitable waste streams. To do so a reactor system in which the worms can be easily separated from the liquids will be used and further developed.

Research will focus on:

  • Exploring different waste streams for their potential use in worm production
  • Waste stream and worm composition
  • Methods to harvest the worm biomass and recovery of energy and nutrients from the worm feces
  • Reactor design scale-up