Project description:We sampled the microbial community at the sea ice edge in McMurdo Sound, Ross Sea at the same location (-77.62S, 165.41E) for four weeks (as described in Wu et al 2019, Nat. Comms.). We had four sampling dates corresponding to weeks 1 to 4: December 28 2014, January 6, 15, and 22 2015. Large volumes of water (150--250 L) were filtered from 1 m depth at the sea ice edge, and passed through three filters sequentially (3.0, 0.8, and 0.1 um, each 293 mm Supor filters). Filters with collected biomass were then placed in tubes with a sucrose-based preservative buffer (20 mM EDTA, 400 mM NaCl, 0.75 M sucrose, 50 mM Tris-HCl, pH 8.0) and stored at -80 C until sample processing. We extracted proteins after buffer exchange into a 3\% SDS solution as previously described Wu et al 2019, Nat. Comms.
Project description:This study aimed to model formamide-based melting for the optimization of the sensitivity and specifcity of oligonucleotide probes in dignostic high-density microarrays. Formamide melting profiles of DNA oligonucleotides were obtained with a high-density microarray targeting 16S rRNA genes of Escherichia coli and Rhodobacter sphaeroides. One or two mismatched versions of perfect match probes were included on the array to systematically analyze the effect of formamide on mismatch stability and mismatch discrimination. A thermodynamics-based mathematical model of formamide denaturation was developed to predict the formamide melting profiles with sufficient accuracy to help with oligonucleotide design in microbial ecology applications.
Project description:Recent studies have unveiled the deep sea as a rich biosphere, populated by species descended from shallow-water ancestors post-mass extinctions. Research on genomic evolution and microbial symbiosis has shed light on how these species thrive in extreme deep-sea conditions. However, early adaptation stages, particularly the roles of conserved genes and symbiotic microbes, remain inadequately understood. This study examined transcriptomic and microbiome changes in shallow-water mussels Mytilus galloprovincialis exposed to deep-sea conditions at the Site-F cold seep in the South China Sea. Results reveal complex gene expression adjustments in stress response, immune defense, homeostasis, and energy metabolism pathways during adaptation. After 10 days of deep-sea exposure, shallow-water mussels and their microbial communities closely resembled those of native deep-sea mussels, demonstrating host and microbiome convergence in response to adaptive shifts. Notably, methanotrophic bacteria, key symbionts in native deep-sea mussels, emerged as a dominant group in the exposed mussels. Host genes involved in immune recognition and endocytosis correlated significantly with the abundance of these bacteria. Overall, our analyses provide insights into adaptive transcriptional regulation and microbiome dynamics of mussels in deep-sea environments, highlighting the roles of conserved genes and microbial community shifts in adapting to extreme environments.
2024-11-24 | GSE263620 | GEO
Project description:Arctic sea ice, cryopeg and massive ice (permafrost) microbial community sequencing
Project description:Proteorhodopsin has been an ongoing hot topic for the past decade. However the complete physiological role of this extremely widely distributed protein remains mysterious. In this study we aim to give an insight to the physiology of a proteorhodopsin-containing sea ice bacteria – Psychroflexus torquis using gel-free label-free proteomic approach for the first time. We also addressed the life strategy that used by this organism to successfully inhabit extreme sea ice environment.
Project description:We investigated the functional gene expression changes associated with temperature stress in two psychrophilic sea ice bacteria, Polaribacter sp. ALD9 and Shewanella sp. ALD11.
Project description:An Autonomous Underwater Vehicle (AUV) and large volume underwater pumps were used to collect microbial biomass from offshore waters of the Sargasso Sea, from surface waters and into the deep ocean. Seawater collection was performed along a transect in the western North Atlantic Ocean beginning near Bermuda and ending off the coast of Massachusetts, capturing metabolic signatures from oligotrophic, continental margin, and productive coastal ecosystems.