Carbon roadmap from syngas to polyhydroxyalkanoates in Rhodospirillum rubrum

The gasification of organic waste materials to synthesis gas (syngas), followed by microbial fermentation provides a significant resource for generating bioproducts such as polyhydroxyalkanoates (PHA). The anaerobic photosynthetic bacterium, Rhodospirillum rubrum, is an organism particularly attract...

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Detalles Bibliográficos
Autores: Revelles, Olga, Tarazona, Natalia A., García, José Luis, Prieto, María Auxiliadora
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/123622
Acceso en línea:http://hdl.handle.net/10261/123622
Access Level:acceso abierto
Palabra clave:Rhodospirillum rubrum
Polyhydroxyalkanoates
Syngas
CO metabolism
CO assimilation
Descripción
Sumario:The gasification of organic waste materials to synthesis gas (syngas), followed by microbial fermentation provides a significant resource for generating bioproducts such as polyhydroxyalkanoates (PHA). The anaerobic photosynthetic bacterium, Rhodospirillum rubrum, is an organism particularly attractive for the bioconversion of syngas into PHAs. In this study, a quantitative physiological analysis of R. rubrum was carried out by implementing GC-MS and HPLC techniques to unravel the metabolic pathway operating during syngas fermentation that leads to PHA production. Further, detailed investigations of the central carbon metabolites using 13C-labeled substrate showed significant CO2 assimilation (of 40 %) into cell material and PHA from syngas carbon fraction. By a combination of quantitative gene expression and enzyme activity analyses, the main role of carboxylases from the central carbon metabolism in CO2 assimilation was shown, where the Calvin Benson-Bassham Cycle (CBB) played a minor role. This knowledge sheds light about the biochemical pathways that contribute to synthesis of PHA during syngas fermentation being valuable information to further optimize the fermentation process.