Project description:Transcriptional profiling of populations in the clam Ruditapes decussatus determined differentiation in gene-expression along parallel temperature gradients and between races of the Atlantic Ocean and West Mediterranean sea.
Project description:Gene content comparison of control C.j. strain 11168 which colonizes and causes disease in a murine model versus strain NW which colonizes but does not elicit disease symptomology in the mouse model. Keywords: DNA/DNA comparison
Project description:Seawater exposure to the gram negative marine bacterium Vibrio diazotrophicus induces a robust cellular response in sea urchin larvae that includes the migration of pigment cells to the gut epithelium, changes in cell behavior and altered gut morphology (Ho et al., 2016; PMID 27192936). To investigate the transcriptional underpinnings of this response, whole transcriptome sequencing was performed on mRNA isolated from larval samples collected at 0, 6, 12 and 24 hr of exposure to V. diazotrophicus. The morphological simplicity of the sea urchin larva provides a systems-level model for identifying biologically relevant transcriptional state changes in response to dysbiosis in the gut lumen.
Project description:Brown macroalgae holds an enormous potential as a future feedstock because it rapidly forms large biomasses and has high carbohydrate content (35% of its dry weight consists of alginate and mannitol). However, utilization of brown macroalgae by conventional microbial platforms (e.g., Escherichia coli and Saccharomyces cerevisiae) has been limited due to the inability of these platforms to metabolize alginate. Although recent studies engineered them to utilize alginate, their growth rates and metabolic activities are still too low for industrial applications, likely due to the unoptimized expression of multiple xenogeneic genes. Here, we isolated Vibrio sp. dhg, a novel, fast-growing bacterium that has been naturally evolved for efficient alginate assimilation (growth rate = 0.98 h-1). Especially, both the growth rate and sugar uptake rate of V. sp. dhg are substantially higher than the rates of E. coli for most biomass-derivable sugars. Based on our systematic characterization of its metabolism and gene expression architecture, we were able to develop a genetic toolbox for its engineering. By using this microorganism, we successfully demonstrated its ability to produce a broad spectrum of chemicals from alginate-mannitol mixtures with high productivities (1.1 g ethanol/L/h, 1.3 g 2,3-butanediol and acetoin/L/h, and 0.69 mg lycopene/L/h). Collectively, the V. sp. dhg strain is a powerful platform for the conversion of brown macroalgae sugars whose usage will dramatically accelerate the production of value-added biochemicals in the future.
Project description:Physiological and gene expression studies of deep-sea bacteria under pressure conditions similar to those experienced in their natural habitat are critical to understand growth kinetics and metabolic adaptations to in situ conditions. The Epslilonproteobacterium, Nautilia sp. strain PV1, was isolated from hydrothermal fluids released from an active deep-sea hydrothermal vent at 9°N on the East Pacific Rise. Using a high pressure/high temperature continuous culture system we established that strain PV-1 has the shortest generation time of all known piezophilic microorganisms and we investigated its protein expression pattern in response to different hydrostatic pressures. Proteomic analyses of strain PV-1 grown at 200 Bars and 5 Bars showed that pressure adaptation is not restricted only to stress response or homeoviscous adaptation, but that it is more diversified and protein specific, with a fine and variegated regulation of enzymes involved even in the same metabolic pathway. As previously reported, proteins synthesis, motility, transport and energy metabolism are all affected by pressure, although to different extents. In strain PV-1, low pressure condition seems to activate the synthesis of phage-related proteins and an overexpression of enzymes involved in central carbon metabolism.