Project description:Crude oil is the one of the most important natural assets of humankind, yet it is a major environmental pollutant, in particular, in marine environments. One of the largest crude oil polluted areas in the word is the semi-enclosed Mediterranean Sea, where the metabolic potential of indigenous populations towards the chronic pollution at a large scale is yet to be defined, particularly in anaerobic and micro-anaerobic marine sites. Here, we provided a novel insight into the active microbial metabolism in sediments from three environments along the coastline of Italy. Microbial proteomes exhibited prevalence in anaerobic metabolism, not related to the biodegradation directly, suggesting the strong limitation by oxygen induced by the carbon overload. They also point at previously unrecognized metabolic coupling between methane and methanol utilizers as well as sulfur reducers in marine petroleum polluted sediments.
Project description:Gas hydrates, also known as clathrates, are cages of ice-like water crystals encasing gas molecules such as methane (CH4). Despite the global importance of gas hydrates, their microbiomes remain mysterious. Microbial cells are physically associated with hydrates, and the taxonomy of these hydrate-associated microbiomes is distinct from non-hydrate-bearing sites. Global 16S rRNA gene surveys show that members of sub-clade JS-1 of the uncultivated bacterial candidate phylum Atribacteria are the dominant taxa in gas hydrates. The Atribacteria phylogeny is highly diverse, suggesting the potential for wide functional variation and niche specialization. Here, we examined the distribution, phylogeny, and metabolic potential of uncultivated Atribacteria in cold, salty, and high-pressure sediments beneath Hydrate Ridge, off the coast of Oregon, USA, using a combination of 16S rRNA gene amplicon, metagenomic, and metaproteomic analysis. Methods were developed to extract bacterial cellular protein from these sediments, as outlined below. Sample Description Three sediments samples were collected from beneath Hydrate Ridge, off the coast of Oregon, USA. Sediments were cored at ODP site 1244 (44°35.1784´N; 125°7.1902´W; 895 m water depth) on the eastern flank of Hydrate Ridge ~3 km northeast of the southern summit on ODP Leg 204 in 2002 and stored at -80°C at the IODP Gulf Coast Repository. E10H5 sediment is from 68.5 meters below sediment surface interface C1H2 sediment is from 2 meters below sediment surface interface. C3H4 sediment is from 21 meters below sediment surface interface.
Project description:Marine sediments harbor highly diverse microbial communities that contribute to global biodiversity and play essential roles in the ecosystem functioning. However, the metaproteome of marine sediments remains poorly understood. Extracting proteins from environmental samples can be challenging, especially in marine sediments due to their complex matrix. Few studies have been conducted on improving protein extraction methods from marine sediments. To establish an effective protein extraction workflow for clay-rich sediments, we compared, combined and improved several protein extraction methods. The presented workflow includes blocking of protein binding sites on sediment particles with high concentrations of amino acids, effective cell lysis via ultra-sonication, and the electro-elution and simultaneous fractionation of proteins. Using this workflow, we were able to recover 100% of the previously added Escherichia coli proteins from the sediment.
2025-05-12 | PXD054260 | Pride
Project description:Biogeographical distribution and diversity of microbes in methane hydrate-bearing deep marine sediments on the Pacific Ocean Margin
Project description:Lanthanides (Ln) play essential roles in the metabolism of certain bacteria, catalysing key reactions in methane oxidation. This study investigates the diversity and distribution of Ln-dependent proteins, collectively termed the lanthanome, in aerobic methane-oxidizing bacteria (MOB) using genome, plasmid, and metatranscriptome data from methane-rich lake sediments. A custom database of 180 MOB genomes revealed various methanol dehydrogenase (MDH) isoforms, including XoxF variants, distributed across Proteobacteria and Verrucomicrobia phyla. We conducted an experimental study with Methylosinus trichosporium OB3B exposed to CeCl₃ and an ore containing mixed lanthanides, measuring methane oxidation rates and using proteomics to assess shifts in protein expression. Despite differences in adaptation times, methane oxidation rates were consistent across treatments, indicating similar overall metabolic efficiencies after acclimatisation. The genomic analysis uncovered several Ln-binding proteins, including the TonB-dependent receptors LanA and lutH-like, as well as Lanmodulin and LanPepsy, with unique phylogenetic patterns. Metatranscriptomic data showed active lanthanome expression, particularly in Proteobacteria, with the XoxF5 MDH variant prevalent in MOB genomes. The discovery of Ln-binding proteins in plasmids suggests potential horizontal gene transfer, highlighting adaptive mechanisms of MOB to Ln availability and their ecological role in methane cycling. This work expands our understanding of Ln-utilising bacteria, particularly in the context of lanthanide-driven methane oxidation, and offers potential biotechnological applications for Ln-dependent processes.
Project description:Tris(4-chlorophenyl)methane (TCPM) and tris(4-chlorophenyl)methanol (TCPMOH) are two marine pollutants of emerging concern, found in marine mammals and coastal bird populations. Here, we assess the response to these compounds due to acute exposures in zebrafish embryos (from 96-100 hours post fertilization).
Project description:Tris(4-chlorophenyl)methane (TCPM) and tris(4-chlorophenyl)methanol (TCPMOH) are two marine pollutants of emerging concern, found in marine mammals and coastal bird populations. Here, we assess the response to these compounds due to developmental (24-100 hourrs post fertilization) exposures in zebrafish embryos
Project description:Chemical analysis of the compounds present in sediment, although informative, often is not indicative of the downstream biological effects that these contaminants exert on resident aquatic organisms. More direct molecular methods are needed to determine if marine life is affected by exposure to sediments. In this study, we used an aquatic multispecies microarray and q-PCR to investigate the effects on gene expression in juvenile sea bream (Sparus aurata) of two contaminated sediments defined as sediment 1 and 2 respectively, from marine areas in Northern Italy.
Project description:Marine microbes drive pivotal transformations in planetary-scale elemental cycles and have crucial impacts on global biogeochemical processes. Metaproteomics is a powerful tool for assessing the metabolic diversity and function of marine microbes. However, hundreds of liters of seawater are required for metaproteomic analysis due to the sparsity of microbial populations in seawater, which poses a substantial challenge to the widespread application of marine metaproteomics, particularly for deep seawater. Herein, a sensitive marine metaproteomics workflow, named SMMP, was developed by integrating polycarbonate filter-assisted microbial enrichment, solid-phase alkylation-based anti-interference metaproteome sample preparation and nanoLC-MS/MS for trace peptide separation and characterization. The method provided more than 8500 proteins from 1 L of bathypelagic seawater samples, which covered diverse microorganisms and crucial functions, e.g. the detection of key enzymes associated with the Wood-Ljungdahl pathway. Then, we applied SMMP to investigate vertical variations in the metabolic expression patterns of marine microorganisms from the euphotic zone to the bathypelagic zone. Methane oxidation and carbon monoxide (CO) oxidation were active processes, especially in the bathypelagic zone, as they provided a remarkable energy supply for the growth and proliferation of heterotrophic microorganisms. In addition, marker protein profiles detected related to ammonia transport, ammonia oxidation, and carbon fixation highlighted that Thaumarchaeota played a critical role in primary production based on the coupled carbon-nitrogen process, contributing to the storage of carbon and nitrogen in the bathypelagic regions. SMMP has low microbial input requirements and yields in-depth metaproteome analysis, making it a prospective approach for comprehensive marine metaproteomic investigations.
Project description:Salt marshes provide many key ecosystem services that have tremendous ecological and economic value. One critical service is the removal of fixed nitrogen from coastal waters, which limits the negative effects of eutrophication resulting from increased nutrient supply. Nutrient enrichment of salt marsh sediments results in higher rates of nitrogen cycling and, commonly, a concurrent increase in the flux of nitrous oxide, an important greenhouse gas. Little is known, however, regarding controls on the microbial communities that contribute to nitrous oxide fluxes in marsh sediments. To address this disconnect, we generated microbial community profiles as well as directly assayed nitrogen cycling genes that encode the enzymes responsible for overall nitrous oxide flux from salt marsh sediments. We hypothesized that communities of microbes responsible for nitrogen transformations will be structured by nitrogen availability. Taxa that respond positively to high nitrogen inputs may be responsible for the elevated rates of nitrogen cycling processes measured in fertilized sediments. Our data show that, with the exception of ammonia-oxidizing archaea, the community composition of organisms responsible for production and consumption of nitrous oxide was altered under nutrient enrichment. These results suggest that elevated rates of nitrous oxide production and consumption are the result of changes in community structure, not simply changes in microbial activity.