Profile of Secreted Hydrolases, Associated Proteins, and SlpA in Thermoanaerobacterium saccharolyticum during the Degradation of Hemicellulose
- Dartmouth College
- ORNL
- Mascoma Corporation
- Thayer School of Engineering at Dartmouth
Thermoanaerobacterium saccharolyticum, a Gram-positive thermophilic anaerobic bacterium, grows robustly on insoluble hemicellulose, which requires a specialized suite of secreted and transmembrane proteins. We report here the characterization of proteins secreted by this organism. Cultures were grown on hemicellulose, glucose, xylose, starch, and xylan in pH-controlled bioreactors, and samples were analyzed via spotted microarrays and liquid chromatography-mass spectrometry. Key hydrolases and transporters employed by T. saccharolyticum for growth on hemicellulose were, for the most part, hitherto uncharacterized and existed in two clusters (Tsac_1445 through Tsac_1464 for xylan/xylose and Tsac_1344 through Tsac_1349 for starch). A phosphotransferase system subunit, Tsac_0032, also appeared to be exclusive to growth on glucose. Previously identified hydrolases that showed strong conditional expression changes included XynA (Tsac_1459), XynC (Tsac_0897), and a pullulanase, Apu (Tsac_1342). An omnipresent transcript and protein making up a large percentage of the overall secretome, Tsac_0361, was tentatively identified as the primary S-layer component in T. saccharolyticum, and deletion of the Tsac_0361 gene resulted in gross morphological changes to the cells. The view of hemicellulose degradation revealed here will be enabling for metabolic engineering efforts in biofuel-producing organisms that degrade cellulose well but lack the ability to catabolize C5 sugars
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). BioEnergy Science Center (BESC)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 1149418
- Journal Information:
- Applied and Environmental Microbiology, Vol. 80, Issue 16; ISSN 0099--2240
- Country of Publication:
- United States
- Language:
- English
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