Ichthyophthirius multifiliis (ICH) is a protozoan parasite infecting both aquacultured freshwater fish and ornamental fish worldwide. The parasite is the causative agent of ichthyophthiriasis, also called white spot disease, inducing high morbidity and mortality in fish. It is an economical problem for the ornamental fish industry as well as for the production fish industry and may challenge sustainable fish production.

ParaFishControl partners (KNAW and KU) have found that a bacterial biosurfactant isolated from Pseudomonas (strain H6) has a strong in vitro antiparasitic effect on the fish pathogenic ciliate Ichthyophthirius multifiliis (ICH). Rainbow trout fingerlings exposed to the biosurfactant showed no adverse immediate or late signs following several hours incubation in concentrations effective for killing the parasite.

A new company, Sundew, has been founded to further develop and commercialise the compound. The Copenhagen-based SME will facilitate the development of large-scale production and purification of the product, which it has named BIOKOS.