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:Recent sequencing projects have provided deep insight into fungal lifestyle-associated genomic adaptations. Here we report on the 25 Mb genome of the mutualistic root symbiont Piriformospora indica (Sebacinales, Basidiomycota) and provide a global characterization of fungal transcriptional responses associated with the colonization of living and dead roots. Extensive comparative analysis of the P. indica genome with other Basidiomycota and Ascomycota fungi that have diverse lifestyles strategies identified features typically associated with both, biotrophism and saprotrophism. The tightly controlled expression of the lifestyle-associated gene sets during the onset of the symbiosis, revealed by microarrays analysis, argues for a biphasic root colonization strategy of P. indica. Our finding provides a significant advance in understanding development of biotrophic plant symbionts and suggests a series of incremental shifts along the continuum from saprotrophy towards biotrophy in the evolution of mycorrhizal association from decomposer fungi. P. indica (DSM 11827, DSMZ) was cultivated on complex medium agar plates or liquid medium as described before (Zuccaro et al., 2009). Barley seeds (Hordeum vulgare L. cv. Golden Promise) were surface sterilized with 3 % sodium hypochlorite, rinsed in water and pregerminated for 3 days. To address the experimental design four different treatments were done (P. indica on barley roots on 1/10 PNM medium, P. indica on autoclaved barley roots on 1/10 PNM medium, P. indica on 1/10 PNM medium and P. indica on CM medium), each in three independent biological replications. Root and fungal material was harvested in liquid nitrogen after 24, 36, 48, 72, 120 and 168 hpi. For each time point roots from 15 to 20 living plants or 21 to 36 autoclaved plants were pooled.
Project description:Investigation of whole genome gene expression level changes in Lactococcus lactis KCTC 3769T,L. raffinolactis DSM 20443T, L. plantarum DSM 20686T, L. fujiensis JSM 16395T, L. garvieae KCTC 3772T, L. piscium DSM 6634T and L. chungangensis CAU 28T . This proves that transcriptional profiling can facilitate in elucidating the genetic distance between closely related strains.