Surfactants are used as functional ingredients in a wide range of products used in our daily lives e.g. personal- and home care, medicine, paints and inks, cosmetics, foodstuffs, etc. Biosurfactants offer a fully bio-based alternative for fossil-based surfactants. Microbial biosurfactants are a type of biosurfactants produced by microorganisms and some examples are already applied in consumer products (e.g. by Ecover). InBio.be has developed a portfolio of yeast strains producing promising novel types of microbial biosurfactants with promising properties. However, the production of these newly developed S. bombicola strains is not sufficiently high to enable commercialization. Furthermore, the use of first generation feedstocks conflicts with the circular economy envisaged by the European Green Deal. This project will address both problems by designing processes that will enable efficient production of biosurfactants from waste streams. To this end, pretreatment methods will be developed to convert local crude waste streams into sterile growth media and substrates that can be applied towards production of biosurfactants. The delivered proof of concept will bring novel microbial biosurfactants one step closer to the market and therefore contributes to the implementation of the bioeconomy.