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Carbon roadmap from syngas to polyhydroxyalkanoates in R hodospirillum rubrum
Author(s) -
Revelles O.,
Tarazo.,
García J. L.,
Prieto M. A.
Publication year - 2016
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.13087
Subject(s) - polyhydroxyalkanoates , syngas , rhodospirillum rubrum , fermentation , bioconversion , biology , biochemistry , bioplastic , bioproducts , food science , bacteria , microbiology and biotechnology , enzyme , biofuel , catalysis , ecology , genetics
Summary 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, R hodospirillum 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 13 C ‐labelled substrate showed significant CO 2 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 CO 2 assimilation was shown, where the C alvin– B enson– B assham 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.