<P><B>Abstract</B></P><P>Consolidated bioprocessing represents an attractive approach to converting cellulosic materials into bioethanol, yet is practically unavailable. We developed a ventilation-mediated, simultaneous ethanol fermentation and recovery system. Running the system under air-supplied conditions, apparently pure ethanol (28g) was recovered from cellobiose (100g) by growing recombinant <I>Kluyveromyces marxianus</I> expressing β-glucosidase.</P>