Project description:Ruminiclostridium thermocellum DSM 1313 strain adhE*(EA) expression was studied along with ∆hydG and ∆hydG∆ech mutants strains deposited under GSE54082. All strains have been described in a study entitled Elimination of hydrogenase post-translational modification blocks H2 production and increases ethanol yield in Clostridium thermocellum. Biswas, et .al. Biotechnology for Biofuels 2015 8:20 Ruminiclostridium (Clostridium) thermocellum is a leading candidate organism for implementing a consolidated bioprocessing (CBP) strategy for biofuel production due to its native ability to rapidly consume cellulose and its existing ethanol production pathway. C. thermocellum converts cellulose and cellobiose to lactate, formate, acetate, H2, ethanol, amino acids, and other products. Elimination of the pathways leading to products such as H2 could redirect carbon flux towards ethanol production. Rather than delete each hydrogenase individually, we targeted a hydrogenase maturase gene (hydG), which is involved in converting the three [FeFe] hydrogenase apoenzymes into holoenzymes by assembling the active site. This functionally inactivated all three Fe-Fe hydrogenases simultaneously, as they were unable to make active enzymes. In the ∆hydG mutant, the [NiFe] hydrogenase-encoding ech was also deleted to obtain a mutant that functionally lacks all hydrogenase. The ethanol yield increased nearly 2-fold in ∆hydG∆ech compared to wild type, and H2 production was below the detection limit. Interestingly, ∆hydG and ∆hydG∆ech exhibited improved growth in the presence of acetate in the medium. Transcriptomic and proteomic analysis reveal that genes related to sulfate transport and metabolism were up-regulated in the presence of added acetate in ∆hydG, resulting in altered sulfur metabolism. Further genomic analysis of this strain revealed a mutation in the bi-functional alcohol/aldehyde dehydrogenase adhE gene, resulting in a strain with both NADH- and NADPH-dependent alcohol dehydrogenase activities, whereas the wild type strain can only utilize NADH. This is the exact same adhE mutation found in ethanol-tolerant C. thermocellum strain E50C, but ∆hydG∆ech is not more ethanol tolerant than the wild type. Targeting protein post-translational modification is a promising new approach to target multiple enzymes simultaneously for metabolic engineering. This GEO study pertains to expression profiles generated for C. thermocellum DSM 1313 strain adhE*(EA)

Project description:Cross species comparison of genomes and transcriptomes is a powerful tool for understanding underlying biological processes, accurate functional classification of genes, and discovery of novel elements. The shift to next-generation sequencing platforms has tremendously accelerated the analysis of genomes and transcriptomes. The use of this technology for transcriptome analysis has many advantages over hybridization based technologies, including higher sensitivity and specificity, and eliminates the need for probe design. Using Illumina sequencing of mRNAs, we have captured the global transcriptional profiles of the developmental cycles of D. discoideum and D. purpureum. The morphology and transcriptional profiles in these two species have been largely conserved even after greater than 300 million years of divergence. We also captured the transcriptional profiles of prespore and prestalk cells from both species. The RNA-seq results correlate well with previously known markers and reveal many new transcripts with unique developmental regulation and cell type enrichment. Our analysis provides the first complete picture of the transcriptional landscape in both D. discoideum and D. purpureum. Transcriptional abundance of over 13,900 genome elements from seven time points of development, and prespore/prestalk cell types will be available through a graphical, highly-interactive, explorative web interface at: http://www.ailab.si/dictyexpress , which currently displays all of our published microarray data. Sequence coverage at a single nucleotide resolution will also be available through an interactive genome browser. These data, from morphology to genome to transcriptome, provide a global picture of the developmental cycles of D. discoideum and D. purpureum and will facilitate the functional classification of genes, as well as discovery of novel genes, splice variants, regulatory elements and non-coding RNAs. Keywords: Transcriptome Analysis Examination of 7 developmental time points in two cell types with 2 biological replicates for each sample.

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Chondrostereum purpureum strain:DSM 4894

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