Investigating the Central Metabolism of Clostridium thermosuccinogenes
Autor: | Richard van Kranenburg, Jeroen Girwar Koendjbiharie, Kilian Wiersma |
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Jazyk: | angličtina |
Rok vydání: | 2018 |
Předmět: |
0301 basic medicine
Clostridium thermosuccinogenes Succinate Physiology Succinic Acid Industrial fermentation Pentose phosphate pathway Xylose medicine.disease_cause Applied Microbiology and Biotechnology Microbiology Lignin Pentose Phosphate Pathway 03 medical and health sciences chemistry.chemical_compound Microbiologie Malate Dehydrogenase RNA Ribosomal 16S Malate dehydrogenase medicine Escherichia coli Biomass Cloning Molecular VLAG Acetic Acid Clostridium Ecology Temperature Gene Expression Regulation Bacterial Phosphotransferases (Alcohol Group Acceptor) 030104 developmental biology Glucose chemistry Biochemistry Genes Bacterial Xylulokinase Fermentation Heterologous expression Glycolysis Transaldolase Metabolic Networks and Pathways Food Science Biotechnology |
Zdroj: | Applied and Environmental Microbiology Applied and Environmental Microbiology, 84(13) Applied and Environmental Microbiology 84 (2018) 13 |
ISSN: | 0099-2240 |
Popis: | Clostridium thermosuccinogenes is a thermophilic anaerobic bacterium able to convert various carbohydrates to succinate and acetate as main fermentation products. Genomes of the four publicly available strains have been sequenced, and the genome of the type strain has been closed. The annotated genomes were used to reconstruct the central metabolism, and enzyme assays were used to validate annotations and to determine cofactor specificity. The genes were identified for the pathways to all fermentation products, as well as for the Embden-Meyerhof-Parnas pathway and the pentose phosphate pathway. Notably, a candidate transaldolase was lacking, and transcriptomics during growth on glucose versus that on xylose did not provide any leads to potential transaldolase genes or alternative pathways connecting the C 5 with the C 3 /C 6 metabolism. Enzyme assays showed xylulokinase to prefer GTP over ATP, which could be of importance for engineering xylose utilization in related thermophilic species of industrial relevance. Furthermore, the gene responsible for malate dehydrogenase was identified via heterologous expression in Escherichia coli and subsequent assays with the cell extract, which has proven to be a simple and powerful method for the basal characterization of thermophilic enzymes. IMPORTANCE Running industrial fermentation processes at elevated temperatures has several advantages, including reduced cooling requirements, increased reaction rates and solubilities, and a possibility to perform simultaneous saccharification and fermentation of a pretreated biomass. Most studies with thermophiles so far have focused on bioethanol production. Clostridium thermosuccinogenes seems an attractive production organism for organic acids, succinic acid in particular, from lignocellulosic biomass-derived sugars. This study provides valuable insights into its central metabolism and GTP and PP i cofactor utilization. |
Databáze: | OpenAIRE |
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