In the current environmental context, reducing the share of fossil fuels to produce platform molecules has become a key issue. Among the different technologies, dark fermentation (DF) is a process allowing the production of green Volatile Fatty Acids (VFAs) using complex organic substrates as food wastes, which must be recovered. The so-called VFAs are considered as potential marketable chemicals but can also be used as carbon source and converted into a vast number of valuable bioproducts (Singhania et al., 2013). To help these organic products break into the market and become more widely available, the OLEOFERM project (sustainable OLEOchemicals bioproduction from carboxylates via oleaginous FERMentation) aims to maximize carbon recovery from the waste feedstock in order to produce VFAs suitable for subsequent downstream production of microbial oils by oleaginous yeasts. For this, an innovative submerged membrane bioreactor was used to operate dark fermentation and extract, in the continuous mode, sterile liquid fraction containing VFAs directly usable as a substrate.