Cellulase-Xylanase Synergy in Designer Cellulosomes for Enhanced Degradation of a Complex Cellulosic Substrate
ABSTRACT Designer cellulosomes are precision-engineered multienzyme complexes in which the molecular architecture and enzyme content are exquisitely controlled. This system was used to examine enzyme cooperation for improved synergy among Thermobifida fusca glycoside hydrolases. Two T. fusca cellula...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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American Society for Microbiology
2010-12-01
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| Series: | mBio |
| Online Access: | https://journals.asm.org/doi/10.1128/mBio.00285-10 |
| _version_ | 1828959676661760000 |
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| author | Sarah Moraïs Yoav Barak Jonathan Caspi Yitzhak Hadar Raphael Lamed Yuval Shoham David B. Wilson Edward A. Bayer |
| author_facet | Sarah Moraïs Yoav Barak Jonathan Caspi Yitzhak Hadar Raphael Lamed Yuval Shoham David B. Wilson Edward A. Bayer |
| author_sort | Sarah Moraïs |
| collection | DOAJ |
| description | ABSTRACT Designer cellulosomes are precision-engineered multienzyme complexes in which the molecular architecture and enzyme content are exquisitely controlled. This system was used to examine enzyme cooperation for improved synergy among Thermobifida fusca glycoside hydrolases. Two T. fusca cellulases, Cel48A exoglucanase and Cel5A endoglucanase, and two T. fusca xylanases, endoxylanases Xyn10B and Xyn11A, were selected as enzymatic components of a mixed cellulase/xylanase-containing designer cellulosome. The resultant mixed multienzyme complex was fabricated on a single scaffoldin subunit bearing all four enzymes. Conversion of T. fusca enzymes to the cellulosomal mode followed by their subsequent incorporation into a tetravalent cellulosome led to assemblies with enhanced activity (~2.4-fold) on wheat straw as a complex cellulosic substrate. The enhanced synergy was caused by the proximity of the enzymes on the complex compared to the free-enzyme systems. The hydrolytic properties of the tetravalent designer cellulosome were compared with the combined action of two separate divalent cellulase- and xylanase-containing cellulosomes. Significantly, the tetravalent designer cellulosome system exhibited an ~2-fold enhancement in enzymatic activity compared to the activity of the mixture of two distinct divalent scaffoldin-borne enzymes. These results provide additional evidence that close proximity between cellulases and xylanases is key to the observed concerted degradation of the complex cellulosic substrate in which the integrated enzymes complement each other by promoting access to the relevant polysaccharide components of the substrate. The data demonstrate that cooperation among xylanases and cellulases can be augmented by their integration into a single designer cellulosome. IMPORTANCE Global efforts towards alternative energy programs are highlighted by processes for converting plant-derived carbohydrates to biofuels. The major barrier in such processes is the inherent recalcitrance to enzymatic degradation of cellulose combined with related associated polysaccharides. The multienzyme cellulosome complexes, produced by anaerobic bacteria, are considered to be the most efficient systems for degradation of plant cell wall biomass. In the present work, we have employed a synthetic biology approach by producing artificial designer cellulosomes of predefined enzyme composition and architecture. The engineered tetravalent cellulosome complexes contain two different types of cellulases and two distinct xylanases. Using this approach, enhanced synergistic activity was observed on wheat straw, a natural recalcitrant substrate. The present work strives to gain insight into the combined action of cellulosomal enzyme components towards the development of advanced systems for improved degradation of cellulosic material. |
| first_indexed | 2024-12-14T09:11:29Z |
| format | Article |
| id | doaj.art-634259ed8469436999a8a351dd8be514 |
| institution | Directory Open Access Journal |
| issn | 2150-7511 |
| language | English |
| last_indexed | 2024-12-14T09:11:29Z |
| publishDate | 2010-12-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | mBio |
| spelling | doaj.art-634259ed8469436999a8a351dd8be5142022-12-21T23:08:33ZengAmerican Society for MicrobiologymBio2150-75112010-12-011510.1128/mBio.00285-10Cellulase-Xylanase Synergy in Designer Cellulosomes for Enhanced Degradation of a Complex Cellulosic SubstrateSarah Moraïs0Yoav Barak1Jonathan Caspi2Yitzhak Hadar3Raphael Lamed4Yuval Shoham5David B. Wilson6Edward A. Bayer7Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, IsraelDepartment of Biological Chemistry, The Weizmann Institute of Science, Rehovot, IsraelDepartment of Biological Chemistry, The Weizmann Institute of Science, Rehovot, IsraelFaculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot, IsraelDepartment of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, IsraelDepartment of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, IsraelDepartment of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USADepartment of Biological Chemistry, The Weizmann Institute of Science, Rehovot, IsraelABSTRACT Designer cellulosomes are precision-engineered multienzyme complexes in which the molecular architecture and enzyme content are exquisitely controlled. This system was used to examine enzyme cooperation for improved synergy among Thermobifida fusca glycoside hydrolases. Two T. fusca cellulases, Cel48A exoglucanase and Cel5A endoglucanase, and two T. fusca xylanases, endoxylanases Xyn10B and Xyn11A, were selected as enzymatic components of a mixed cellulase/xylanase-containing designer cellulosome. The resultant mixed multienzyme complex was fabricated on a single scaffoldin subunit bearing all four enzymes. Conversion of T. fusca enzymes to the cellulosomal mode followed by their subsequent incorporation into a tetravalent cellulosome led to assemblies with enhanced activity (~2.4-fold) on wheat straw as a complex cellulosic substrate. The enhanced synergy was caused by the proximity of the enzymes on the complex compared to the free-enzyme systems. The hydrolytic properties of the tetravalent designer cellulosome were compared with the combined action of two separate divalent cellulase- and xylanase-containing cellulosomes. Significantly, the tetravalent designer cellulosome system exhibited an ~2-fold enhancement in enzymatic activity compared to the activity of the mixture of two distinct divalent scaffoldin-borne enzymes. These results provide additional evidence that close proximity between cellulases and xylanases is key to the observed concerted degradation of the complex cellulosic substrate in which the integrated enzymes complement each other by promoting access to the relevant polysaccharide components of the substrate. The data demonstrate that cooperation among xylanases and cellulases can be augmented by their integration into a single designer cellulosome. IMPORTANCE Global efforts towards alternative energy programs are highlighted by processes for converting plant-derived carbohydrates to biofuels. The major barrier in such processes is the inherent recalcitrance to enzymatic degradation of cellulose combined with related associated polysaccharides. The multienzyme cellulosome complexes, produced by anaerobic bacteria, are considered to be the most efficient systems for degradation of plant cell wall biomass. In the present work, we have employed a synthetic biology approach by producing artificial designer cellulosomes of predefined enzyme composition and architecture. The engineered tetravalent cellulosome complexes contain two different types of cellulases and two distinct xylanases. Using this approach, enhanced synergistic activity was observed on wheat straw, a natural recalcitrant substrate. The present work strives to gain insight into the combined action of cellulosomal enzyme components towards the development of advanced systems for improved degradation of cellulosic material.https://journals.asm.org/doi/10.1128/mBio.00285-10 |
| spellingShingle | Sarah Moraïs Yoav Barak Jonathan Caspi Yitzhak Hadar Raphael Lamed Yuval Shoham David B. Wilson Edward A. Bayer Cellulase-Xylanase Synergy in Designer Cellulosomes for Enhanced Degradation of a Complex Cellulosic Substrate mBio |
| title | Cellulase-Xylanase Synergy in Designer Cellulosomes for Enhanced Degradation of a Complex Cellulosic Substrate |
| title_full | Cellulase-Xylanase Synergy in Designer Cellulosomes for Enhanced Degradation of a Complex Cellulosic Substrate |
| title_fullStr | Cellulase-Xylanase Synergy in Designer Cellulosomes for Enhanced Degradation of a Complex Cellulosic Substrate |
| title_full_unstemmed | Cellulase-Xylanase Synergy in Designer Cellulosomes for Enhanced Degradation of a Complex Cellulosic Substrate |
| title_short | Cellulase-Xylanase Synergy in Designer Cellulosomes for Enhanced Degradation of a Complex Cellulosic Substrate |
| title_sort | cellulase xylanase synergy in designer cellulosomes for enhanced degradation of a complex cellulosic substrate |
| url | https://journals.asm.org/doi/10.1128/mBio.00285-10 |
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