Author:
De Meur Quentin,Deutschbauer Adam,Koch Matthias,Bayon-Vicente Guillaume,Cabecas Segura Paloma,Wattiez Ruddy,Leroy Baptiste
Abstract
Abstract
Background
The great metabolic versatility of the purple non-sulfur bacteria is of particular interest in green technology. Rhodospirillum rubrum S1H is an α-proteobacterium that is capable of photoheterotrophic assimilation of volatile fatty acids (VFAs). Butyrate is one of the most abundant VFAs produced during fermentative biodegradation of crude organic wastes in various applications. While there is a growing understanding of the photoassimilation of acetate, another abundantly produced VFA, the mechanisms involved in the photoheterotrophic metabolism of butyrate remain poorly studied.
Results
In this work, we used proteomic and functional genomic analyses to determine potential metabolic pathways involved in the photoassimilation of butyrate. We propose that a fraction of butyrate is converted to acetyl-CoA, a reaction shared with polyhydroxybutyrate metabolism, while the other fraction supplies the ethylmalonyl-CoA (EMC) pathway used as an anaplerotic pathway to replenish the TCA cycle. Surprisingly, we also highlighted a potential assimilation pathway, through isoleucine synthesis and degradation, allowing the conversion of acetyl-CoA to propionyl-CoA. We tentatively named this pathway the methylbutanoyl-CoA pathway (MBC). An increase in isoleucine abundance was observed during the early growth phase under butyrate condition. Nevertheless, while the EMC and MBC pathways appeared to be concomitantly used, a genome-wide mutant fitness assay highlighted the EMC pathway as the only pathway strictly required for the assimilation of butyrate.
Conclusion
Photoheterotrophic growth of Rs. rubrum with butyrate as sole carbon source requires a functional EMC pathway. In addition, a new assimilation pathway involving isoleucine synthesis and degradation, named the methylbutanoyl-CoA (MBC) pathway, could also be involved in the assimilation of this volatile fatty acid by Rs. rubrum.
Funder
Fonds De La Recherche Scientifique - FNRS
European Space Agency
Belgian Scientific policy
European Regional Development Fund
Publisher
Springer Science and Business Media LLC
Subject
Microbiology (medical),Microbiology
Reference46 articles.
1. Lasseur C, Verstraete W, Gros JB, Dubertret G, Rogalla F. MELISSA: a potential experiment for a precursor mission to the moon. Adv Sp Res. 1996;18:111–7. https://doi.org/10.1016/0273-1177(96)00097-X.
2. Lasseur C, Brunet J, De Weever H, Dixon M, Dussap G, Godia F, et al. Melissa: the European project of closed life support system. Gravitational Sp Biol. 2010;23:3–12.
3. Jiang J, Zhang Y, Li K, Wang Q, Gong C, Li M. Volatile fatty acids production from food waste: effects of pH, temperature, and organic loading rate. Bioresour Technol. 2013;143:525–30. https://doi.org/10.1016/j.biortech.2013.06.025..
4. Janssen PH, Schink B. Pathway of butyrate catabolism by Desulfobacterium cetonicum. J Bacteriol. 1995;177:3870–2. https://doi.org/10.1128/JB.177.13.3870-3872.1995.
5. Kornberg HL, Krebs HA. Synthesis of cell constituents from C2-units by a modified Tricarboxylic acid cycle. Nature. 1957;179:988–91. https://doi.org/10.1038/179988a0.
Cited by
16 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献