Ontology highlight
ABSTRACT:
PROVIDER: PRJEB18125 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Clostridium ljungdahlii not only utilizes CO, but also H2 as energy source during autotrophic growth. And C. ljungdahlii also grows in fructose fermentation. In theory, fructose is a more energetically favourable energy source than syngas in the fermentation of C. ljungdahlii. However, C. ljungdahlii grows insufficiently in fructose and produces less acetate and ethanol, compared to syngas fermentation. In this study, C. ljungdahlii wild type and mutants were fermented on fructose. C. ljungdahlii produced less ethanol than the ΔadhE1 mutant and consumed less fructose. The ΔadhE1+2 mutant cannot grow in the syngas fermentation and produced less ethanol among the three strains. The results showed that aldehyde dehydrogenase inactivation led to efficient metabolism in C. ljungdahlii and the bifunctional aldehyde/alcohol dehydrogenases inactivation led to decrease metabolism. Thus, comparative transcriptomes among cells grown on fructose of three strains were performed to investigate gene expression profiles based on three biological replicates.
2023-06-27 | E-MTAB-13020 | biostudies-arrayexpress
Project description:Acetogens are promising cell factories for producing fuels and chemicals from waste feedstocks via gas fermentation, but quantitative characterization of carbon, energy, and redox metabolism is required to guide their rational metabolic engineering. Here, we explore acetogen gas fermentation using physiological, metabolomics, and transcriptomics data for Clostridium autoethanogenum steady-state chemostat cultures grown on syngas at various gas-liquid mass transfer rates. We observe that C. autoethanogenum shifts from acetate to ethanol production to maintain ATP homeostasis at higher biomass concentrations but reaches a limit at a molar acetate/ethanol ratio of ∼1. This regulatory mechanism eventually leads to depletion of the intracellular acetyl-CoA pool and collapse of metabolism. We accurately predict growth phenotypes using a genome-scale metabolic model. Modeling revealed that the methylene-THF reductase reaction was ferredoxin reducing. This work provides a reference dataset to advance the understanding and engineering of arguably the first carbon fixation pathway on Earth.
2017-05-22 | GSE90792 | GEO
Project description:RevR is a putative orphan response regulator with a high degree of similarity to YycF from Bacilus subtilis and PhoB from Clostridium kluyveri. A revR deletion mutant of C. perfringens strain 13 was generated and the transcriptome analysed using microarrays.
2011-01-17 | GSE26508 | GEO
Project description:To identify the mechanism of Microbial Influenced Corrosion (MIC) and the bacterial response toward corrosion, we conducted whole genome microarray expression profile. At log phase, the cell of Clostridium carboxidivorans using iron granule as an electron donor (corroding iron) was collected as a sample, and that of using syngas as an electron donor was collected as a control.
2017-04-04 | GSE97319 | GEO
Project description:The batch fermentation of Clostridium acetobutylicum is characterized by an acetogenic growth phase during exponential growth when mainly acetate and butyrate are fermentation products. Then, at the end of exponential growth and during stationary phase, the organism switches to solventogenic growth and large amounts of acetone, ethanol and butanol are produced. These growth phases can be studied independent from each other in a phosphate-limited continuous culture. In transcription analysis of continuous cultures using DNA microarrays it became evident that, among others, operons involved in sulfur assimilation are strongly up-regulated during solventogenesis. Using the ClosTron technique we constructed two knock-out mutants in the genes CAC0105 and CAC0930 annotated as involved in sulfate reduction and cysteine biosynthesis. Complementation experiments were carried out with sulfite and cysteine to prove the predicted function. The fermentation experiments of wild type and mutants using phosphate-limited and sulfur-limited continuous culture demonstrated that less sulfur source was consumed in solventogenic phase and the efficiency of cysteine uptake became lower. DNA microarrays were performed to study the difference of transcriptional expression when the wild type was challenged with insufficient sulfur source and the mccB (CAC0930) mutant was inactivated in the continuous culture. The result provided insights into understanding the sulfur metabolism regulatory.
2015-04-15 | E-MTAB-2745 | biostudies-arrayexpress
Project description:Gas fermentation is emerging as an economically attractive option for the sustainable production of fuels and chemicals from gaseous waste feedstocks. Clostridium autoethanogenum can use CO and/or CO2 + H2 as its sole carbon and energy sources. Fermentation of C. autoethanogenum is currently being deployed on a commercial scale for ethanol production. Expanding the product spectrum of acetogens will enhance the economics of gas fermentation. To achieve efficient heterologous product synthesis, limitations in redox and energy metabolism must be overcome. Here, we engineered and characterised at a systems-level, a recombinant poly-3-hydroxybutyrate (PHB)-producing strain of C. autoethanogenum. Cells were grown in CO-limited steady-state chemostats on two gas mixtures, one resembling syngas (20% H2) and the other steel mill off-gas (2% H2). Results were characterised using metabolomics and transcriptomics, and then integrated using a genome-scale metabolic model reconstruction. PHB-producing cells had an increased expression of the Rnf complex, suggesting energy limitations for heterologous production. Subsequent optimisation of the bioprocess led to a 12-fold increase in the cellular PHB content. The data suggest that the cellular redox state, rather than the acetyl-CoA pool, was limiting PHB production. Integration of the data into the genome-scale metabolic model showed that ATP availability limits PHB production. Altogether, the data presented here advances the fundamental understanding of heterologous product synthesis in gas-fermenting acetogens.
2019-02-03 | GSE115837 | GEO
Project description:Solventogenic Clostridium species ferment carbohydrates to acetone, butanol and ethanol which are well-known next-generation biofuels. However, repeated subculture of or continuous fermentation by Clostridium often decreases and eventually terminates the solvent production and spore formation, which is a process called strain degeneration. Supplementation of CaCO3 to fermentation medium could partially recover metabolism of degenerated strain by more than 50% increase of cell growth and solvent production. The transcriptome profile of Clostridium beijerinckii NCIMB 8052 (DG-8052) and its response to CaCO3 treatment were analysed by microarray. Since fermentation by C. beijerinckii NCIMB 8052 is a biphasic process, gene expressions of two fermentations were compared at each stage, i.e. 12h and 24h fermentation time representing acidogenic phase and solventogenic phase, respectively. This study examined expression of 5168 genes capturing 98.6% of the C. beijerinckii NCIMB 8052 genome. With the addition of CaCO3, DG-8052 had 565 and 916 genes significantly up-regulated at acidogenic phase and solventogenic phase, respectively. According to the enrichment analysis of pathway and Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, these genes were significantly overrepresented in cellular functions such as Amino acid transport and metabolism, organic acid biosynthetic process, bacteria chemotaxis and defense mechanisms. On the other hand, there were 704 and 1044 genes significantly down-regulated at acidogenic phase and solventogenic phase, respectively. These repressed genes were mainly enriched in functions such as ion transmembrane transport, ATP synthesis, oxidative phosphorylation.
2017-01-02 | GSE81808 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE12358: Clostridium beijerinckii NCIMB 8052 wild-type fermentation time course GSE12359: Clostridium beijerinckii BA101 mutant fermentation time course Refer to individual Series
2009-06-02 | E-GEOD-12365 | biostudies-arrayexpress
Project description:RevR is a putative orphan response regulator with a high degree of similarity to YycF from Bacilus subtilis and PhoB from Clostridium kluyveri. A revR deletion mutant of C. perfringens strain 13 was generated and the transcriptome analysed using microarrays. Total RNA was isolated from exponentially growing cells from the revR mutant and the wild-type control. Gene expression levels were compared between the revR mutant and wild-type strain 13
2011-01-17 | E-GEOD-26508 | biostudies-arrayexpress
Project description:Clostridium acetobutylicum is characterized by its acetone-butanol (AB) fermentation which <br>can be reproducibly established under continuous grow conditions in a chemostat. <br>At pH 5.7 cells show typical acidogenic metabolism and mainly produce the acids <br>acetate and butyrate. After lowering and further control the external pH at 4.5 <br>the exponentially growing cells switch towards stable solvent production with the <br>dominating fermentation products acetone and butanol. <br>Here we present a comprehensive comparison of proteome and transcriptome <br>data of continuously growing cells of C. acetobutylicum in a chemostat culture <br>under phosphate limitation at pH 5.7 (acidogenesis) and pH 4.5 (solventogenesis).
2010-11-10 | E-MEXP-2503 | biostudies-arrayexpress