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Proteome-wide systems analysis of a cellulosic biofuel-producing microbe

By Andrew C Tolonen, Wilhelm Haas, Amanda C Chilaka, John Aach, Steven P Gygi and George M Church


We apply mass spectrometry-based ReDi proteomics to quantify the Clostridium phytofermentans proteome during fermentation of cellulosic substrates. ReDi proteomics gives accurate, low-cost quantification of an extra and intracellular microbial proteome. When combined with physiological measurements, these methods form a general systems biology strategy to evaluate the efficiency of cellulosic bioconversion and to identify enzyme targets to engineer for improving this process.C. phytofermentans expressed more than 100 carbohydrate-active enzymes, of which distinct subsets were upregulated on cellulose and hemicellulose. Numerous extracellular enzymes cleave insoluble plant polysaccharides into oligosaccharides, which are transported into the cell to be further degraded by intracellular carbohydratases. Sugars are catabolized by EMP glycolysis incorporating alternative glycolytic enzymes to maximize the ATP yield of anaerobic metabolism.During cellulosic fermentation, cells adhered to the substrate and altered metabolic processes such as upregulation of tryptophan and nicotinamide synthesis proteins and repression of proteins for fatty acid metabolism and cell motility. These diverse metabolic changes highlight how a systems approach can identify novel ways to optimize cellulosic fermentation

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Publisher: Nature Publishing Group
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Provided by: PubMed Central

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  1. (2006). 170: 2891–2897 Somerville C
  2. (2000). A Joint Study by the US Dept of Energy and the US Dept of Agriculture.
  3. (2007). Absolute protein expression profiling estimates the relative contributions of transcriptional and translational regulation.
  4. (1988). Annu Rev Microbiol 37: 311–339 Sleytr UB, Messner P
  5. (2008). The impact of peptide abundance and dynamic range on stable-isotope-based quantitative proteomic analyses.
  6. (2009). Zhang YH (2010a) Glycoside hydrolase family9processiveendoglucanasefromClostridiumphytofermentans: heterologous expression, characterization, and synergy with family 48 cellobiohydrolase. Bioresour Technol 101: 5534–5538 Zhang