The complex physiology of Cellvibrio japonicus xylan degradation relies on a single cytoplasmic β-xylosidase for xylo-oligosaccharide utilization
| Autor: | Jeffrey G. Gardner, Raymond Cheng, Hadassa S. Guttman, Andrew D. Blake, Nina R. Beri |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Cytoplasm 030106 microbiology Context (language use) medicine.disease_cause Microbiology 03 medical and health sciences chemistry.chemical_compound Cellvibrio Bacterial Proteins Arabinoxylan medicine Escherichia coli Computer Simulation Molecular Biology Cellvibrio japonicus chemistry.chemical_classification biology Sequence Analysis RNA Gene Expression Profiling biology.organism_classification Xylan 030104 developmental biology Enzyme Xylosidases chemistry Biochemistry Genes Bacterial Fermentation Xylanase Xylans Heterologous expression Gene Deletion |
| Zdroj: | Molecular microbiology. 107(5) |
| ISSN: | 1365-2958 |
| Popis: | Lignocellulose degradation by microbes plays a central role in global carbon cycling, human gut metabolism and renewable energy technologies. While considerable effort has been put into understanding the biochemical aspects of lignocellulose degradation, much less work has been done to understand how these enzymes work in an in vivo context. Here, we report a systems level study of xylan degradation in the saprophytic bacterium Cellvibrio japonicus. Transcriptome analysis indicated seven genes that encode carbohydrate active enzymes were up-regulated during growth with xylan containing media. In-frame deletion analysis of these genes found that only gly43F is critical for utilization of xylo-oligosaccharides, xylan, and arabinoxylan. Heterologous expression of gly43F was sufficient for the utilization of xylo-oligosaccharides in Escherichia coli. Additional analysis found that the xyn11A, xyn11B, abf43L, abf43K, and abf51A gene products were critical for utilization of arabinoxylan. Furthermore, a predicted transporter (CJA_1315) was required for effective utilization of xylan substrates, and we propose this unannotated gene be called xntA (xylan transporter A). Our major findings are (i) C. japonicus employs both secreted and surface associated enzymes for xylan degradation, which differs from the strategy used for cellulose degradation, and (ii) a single cytoplasmic β-xylosidase is essential for the utilization of xylo-oligosaccharides. |
| Databáze: | OpenAIRE |
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