Native PAGE and western blot analysis of cellulosomal operons assembled in vivo by the recombinant C. acetobutylicum strains. The culture supernatants of the recombinant strains (thlOIDCel9B, thlOIDCel8A, thlOIDCel9B_CipA3, thlOIDCel8A_CipA3, thlOIDCel9B_Cel8A_CipA3, thlOIDCipA3) were concentrated 70-fold by ultracentrifugation and 10 μl of the concentrated samples loaded onto a native PAGE Tris-acetate gel. The presence of the cellulosomal subunits and the in vivo assembly of the mini-cellulosomes was detected using ANTI-FLAG M2 monoclonal antibody-horseradish peroxidise conjugate (Sigma). The presence of multiple bands in the samples expressing mini-cellulosomes (thlOIDCel9B_CipA3, thlOIDCel8A_CipA3 and thlOIDCel9B_Cel8A_CipA3) likely represents unsaturated complexes with cellulases binding different cohesin domains. These samples were loaded at two different concentrations: 10 and 5 μl (½) of the original samples.