Microbial electrolysis cells (MECs) use electroactive bacteria to produce H2 from organic matter [1]. Here we present an innovative integrated H2 producing system converting acetate to collect additional H2 from organic matter. As an initial approach, we fed continuously (10 L/d) a MEC with a synthetic medium containing 20 mM acetate, the predominant end product of glucose or cellulose fermentations [2]. We operated a pilot (6 L total volume) upflow MEC using graphite-felt as anode and stainless steel as cathode separated by an anionic membrane allowing the H2 produced at the cathode to be of high purity (90%). On the anode we successfully developed an electroactive biofilm from saline sediments at constant applied potential (+0.2 V vs. SCE), a novel approach since most MEC studies use biofilms from wastewater [3]. Our MEC showed continuous H2 production of 9.0 m3H2.m-2anode.d-1 (or 1.13 m3H2.m- 3reactor.d-1) at an overall H2 recovery of 85%, both values well in line with current literature [2]. A yield of 2.2 mol H2.mol glc-1 was achieved accompanied of a stable substrate conversion to current (2 A.m-2 or 250 A.m-3). The initial approach has been to feed the MEC with a synthetic medium containing acetate. However, for progressive continuous MEC tests, adaptation to other dark fermentation metabolites (e.g., ethanol, propionate, formate and butyrate) contained in synthetic media and in real effluent has been planned. Nonetheless, from previous tests on dark fermentation reactors with a yield of 0.9 mol H2.mol Glc-1 [4] and considering our current MEC results, we estimated an overall H2 yield increment of 27% compared with fermentation alone. We gratefully acknowledge 6T-MIC and LGC (Toulouse, F) for MEC design.