tailieunhanh - Báo cáo khoa học: The cellulosomes from Clostridium cellulolyticum Identification of new components and synergies between complexes

Cellulosomes produced byClostridium cellulolyticumgrown on cellulose were purified and separated using anion-exchange chromatography. SDS⁄PAGE analysis of six fractions showed variations in their celluloso-mal protein composition. Hydrolytic activity on carboxymethyl cellulose, xylan, crystalline cellulose and hatched straw differed from one fraction to another. | The cellulosomes from Clostridium cellulolyticum Identification of new components and synergies between complexes Imen Fendri1 Chantal Tardif1 2 Henri-Pierre Fierobe1 Sabrina Lignon3 Odile Valette1 Sandrine Pages1 2 and Stephanie Perret1 2 1 Laboratoire de Chimie Bacterienne CNRS UPR9043 IMM Marseille France 2 Universite Aix Marseille France 3 Centre de microsequencage et d analyse proteomique IMM Marseille France Keywords cellulosome Clostridium cellulolyticum diversity new components synergy Correspondence S. Perret Laboratoire de Chimie Bacterienne CNRS UPR9043 31 chemin Joseph Aiguier 13009 Marseille France Fax 33 4 91 71 33 21 Tel 33 4 91 16 43 40 E-mail perret@ Received 18 January 2009 revised 24 March 2009 accepted 27 March 2009 doi Cellulosomes produced by Clostridium cellulolyticum grown on cellulose were purified and separated using anion-exchange chromatography. SDS PAGE analysis of six fractions showed variations in their celluloso-mal protein composition. Hydrolytic activity on carboxymethyl cellulose xylan crystalline cellulose and hatched straw differed from one fraction to another. Fraction F1 showed a high level of activity on xylan whereas fractions F5 and F6 were most active on crystalline cellulose and carboxymethyl cellulose respectively. Several cellulosomal components specific to fractions F1 F5 and F6 were investigated using MS analysis. Several hemicellulases were identified including three xylanases in F1 and several cellulases belonging to glycoside hydrolase families 9 and 5 and a cystein protease inhibitor were identified in F5 and F6. Synergies were observed when two or three fractions were combined. A mixture containing fractions F1 F3 and F6 showed the most divergent cellulosomal composition the most synergistic effects and the highest level of activity on straw the most heterogeneous substrate tested . These findings show that on complex substrates such as straw synergies occur .