Western blot analysis of cellulosomal operons secreted by the recombinant C. acetobutylicum strains. The wild type (wt, C. acetobutylicum ATCC 824) and the recombinant strains (thlOIDCel9B, thlOIDCel8A, thlOIDCel9B_CipA3, thlOIDCel8A_CipA3, thlOIDCel9B_Cel8A_CipA3, thlOIDCipA3) were grown in buffered 2xYTG (pH 7 using 40 mM MOPS) until early exponential phase (OD600 0.8), concentrated 50-fold and separated by SDS-PAGE. All heterologous proteins were detected using ANTI-FLAG M2 monoclonal antibody-horseradish peroxidise conjugate (Sigma). M, ColorPlus Prestained Protein Ladder (10–230 kDa; New England Biolabs); Flag, N-Flag-Bap control protein (50 kDa, 50 ng/lane; Sigma). Expected molecular masses are indicated by arrows.