Assembly of xylanases into designer cellulosomes promotes efficient hydrolysis of the xylan component of a natural recalcitrant cellulosic substrate

Sarah Moraïs, Yoav Barak, Yitzhak Hadar, David B. Wilson, Yuval Shoham, Raphael Lamed, Edward A. Bayer

Research output: Contribution to journalArticlepeer-review

52 Scopus citations

Abstract

In nature, the complex composition and structure of the plant cell wall pose a barrier to enzymatic degradation. Nevertheless, some anaerobic bacteria have evolved for this purpose an intriguing, highly efficient multienzyme complex, the cellu-losome, which contains numerous cellulases and hemicellulases. The rod-like cellulose component of the plant cell wall is embedded in a colloidal blend of hemicelluloses, a major component of which is xylan. In order to enhance enzymatic degradation of the xylan component of a natural complex substrate (wheat straw) and to study the synergistic action among different xylanases, we have employed a variation of the designer cellulosome approach by fabricating a tetravalent complex that includes the three endoxylanases of Thermobifida fusca (Xyn10A, Xyn10B, and Xyn11A) and an Xyl43A β-xylosidase from the same bacterium. Here, we describe the conversion of Xyn10A and Xyl43A to the cellulosomal mode. The incorporation of the Xyl43A enzyme together with the three endoxylanases into a common designer cellulosome served to enhance the level of reducing sugars produced during wheat straw degradation. The enhanced synergistic action of the four xylanases reflected their immediate juxtaposition in the complex, and these tetravalent xylanolytic designer cellulosomes succeeded in degrading significant (~25%) levels of the total xylan component of the wheat straw substrate. The results suggest that the incorporation of xylanases into cellulosome complexes is advantageous for efficient decomposition of recalcitrant cellulosic substrates-a distinction previously reserved for cellulose-degrading enzymes.

Original languageEnglish
Article numbere00233-11
JournalmBio
Volume2
Issue number6
DOIs
StatePublished - 1 Jan 2011
Externally publishedYes

Fingerprint

Dive into the research topics of 'Assembly of xylanases into designer cellulosomes promotes efficient hydrolysis of the xylan component of a natural recalcitrant cellulosic substrate'. Together they form a unique fingerprint.

Cite this