Ontology highlight
ABSTRACT:
PROVIDER: PRJNA704760 | ENA |
REPOSITORIES: ENA
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Project description:We established simple synthetic microbial communities in a microcosm model system to determine the mechanisms that underlay cross-feeding in microbial methane-consuming communities. Co-occurring strains from Lake Washington sediment were used that are involved in methane consumption, a methanotroph and two non-methanotrophic methylotrophs.
2016-12-26 | GSE85736 | GEO
Project description:Microbial communities of bottom sediments of Lake Baikal before and after thermobaric cultivation Metagenome
| PRJNA292045 | ENA
Project description:In this study, we investigated Mn3+-cycling microbial populations enriched from Lake Matano, Indonesia using metagenomics and metaproteomics. Lake Matano contains an active Mn cycle that links the oxic-anoxic interface with anoxic deep waters that are enriched in iron and manganese, and depleted in sulfate, phosphate, and oxidized nitrogen (Crowe et al., 2008; Jones et al., 2011). Sediments were incubated with sequential transfers for ~1 year with Mn3+ as the sole electron acceptor and methane as organic carbon until achieving sediment-free conditions. Here we investigate this novel species of Dechloromonas (Betaproteobacteria), “Candidatus Dechloromonas occultata,” which was the dominant population in enrichment cultures with active Mn3+ reduction. “Ca. D. occultata” expressed electron conduits related to those involved in Fe2+ oxidation (Mto-like), as well as a novel cytochrome c-rich gene cluster putatively involved in extracellular electron transfer, and an atypical nitrous oxide reductase. According to ribosomal counts, Dechloromonas outnumber Geobacter. In terms of functional genes, Dechloromonas expresses a wider variety and number of genes. Dechloromonas therefore seems to have a (selective?) advantage over Geobacter. Previous experiments revealed that Dechloromonas express nitrogen regulators, reductases and scavenging genes, as well as many carbon central metabolic pathways, and aromatic carbon degradation pathways. Dechloromonas is a beta proteobacteria, and these are "experts" in nitrogen metabolism. Geobacter, on the other hand, is well known for carbon degradation. Our previous experiments lead to our hypothesis that Dechloromonas is more active because they are more successful at acquiring nitrogen, a limiting nutrient for Geobacter. This would further suggest that carbon is not the limiting nutrient. We will test 2 hypotheses with the next suite of experiments 1) pyrophosphate supports the community, by allowing carbon fixation , 2)Dechloromonas has a (selective?) advantage over Geobacter. To test this hypothesis, bioreactors will be used to grow biotriplicate cultures of (1)- CH4 vs. pyrophosphate and (2)-CH4 vs. Mn(III) pyrophosphate. Here we have analyzed whole cell pellets using gas phase fractionations on the Q Exactive. Are Dechloromonas capable of out-competing Geobacter when grown in media with methane as the only carbon source bioreactors because they are capable of acquiring more nitrogen? Source of inoculum. Lake Matano is a metal-rich, ancient ocean analog (Crowe et al. 2011, Jones et al. 2011). Organic carbon in Lake Matano is mostly mineralized via methanogenesis before reaching the iron-rich sediments, limiting organic matter bioavailability for metal-reducers (Kuntz et al. 2015). A 15-cm sediment core from 200 m water depth in Lake Matano, Sulawesi Island, Indonesia (02°26′27.1′′S, 121°15′12.3′′E; in situ sediment temperature ~27°C) was sampled in November 2014 and sub-sampled at 5 cm increments. Sediments were sealed in gas-tight Mylar bags with no headspace (Hansen et al. 2000) and stored at 4°C until incubations began in December 2015.
2020-06-30 | PXD011642 | Pride
Project description:Cell sedimentation in 3D culture environments refers to the vertical migration of cells towards the bottom of the space. This occurs despite the use of hydrogel materials in 3D cell cultures, which would be expected to prevent this behavior. To better understand and explain these experimental observations, we conducted a multiscale experimental and mathematical examination of 3D cancer growth and sedimentation in triple negative breast cancer cells. The migration of cells towards the bottom was examined in the presence and absence of the migrastatic drug Paclitaxel, as well as in a low adhesion environment and the presence of fibroblasts. The observed behaviour was modeled mathematically by hypothesizing self-generated chemotactic gradients. Our results reveal that active migration mechanisms, specifically collective migration regulated by the MAPK and TGF-β pathways, play an important role in sedimentation. The mathematical model was able to describe the experimental data in the absence and presence of Paclitaxel, suggesting the inhibition of random motion and advection mechanism in the latter case. Low adhesion environment and multiple cell type experiments resulted in an inhibition of sedimentation. Overall, our results suggest that cells, initially uniformly distributed in the 3D space, actively migrate towards the bottom due to the presence of signals produced by cells already attached to it, providing mechanistic insights into this unexpected behavior.
2023-02-15 | GSE223350 | GEO
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.
2015-07-24 | PXD001490 | Pride
Project description:The consistent cold temperatures and large amount of precipitation in the Olympic and Cascade ranges of Washington State are thought to increase atmospheric deposition of contaminants in these high elevation locations. Total mercury and 28 organochlorine compounds were measured in composite, whole fish samples collected from 14 remote lakes in the Olympic, Mt. Rainer, and North Cascades National Parks. Mercury was detected in fish from all lakes sampled and ranged in concentration from 17 to 262 ug/kg wet weight. Only two organochlorines, total polychlorinated biphenyls (tPCB) and dichlorodiphenyldichloroethylene (DDE), were detected in fish tissues (concentrations <25 ug/kg wet weight). No organochlorines were detected in sediments (MRL ≈1-5 ug/kg), while median total and methyl mercury in sediments were 30.4 and 0.34 ug/kg (dry weight), respectively. Using a targeted rainbow trout cDNA microarray with known genes, we detected significant differences in liver transcriptional responses, including metabolic, endocrine, and immune-related genes, in fish collected from a contaminated lake compared to a lake with a lower contaminant load. Overall, our results suggest that local urban areas are contributing to the observed contaminant patterns, while the transcriptional changes point to a biological response associated with exposure to these contaminants in fish. Specifically, the gene expression pattern leads us to hypothesize a role for mercury in disrupting the metabolic and reproductive pathways in fish from high elevation lakes in western Washington. Keywords: High altitude lakes, mercury, salmonids, organochlorines
2007-05-01 | GSE6886 | GEO
Project description:Aerobic methanotrophic bacteria use methane as their sole source of carbon and energy and serve as a major sink for the potent greenhouse gas methane in freshwater ecosystems. Despite this important environmental role, little is known about the molecular details of how these organisms interact in the environment. Many bacterial species use quorum sensing systems to regulate gene expression in a density-dependent manner. We have identified a quorum sensing system in the genome of Methylobacter tundripaludum, a dominant methane-oxidizer in methane enrichments of sediment from Lake Washington (Seattle, WA, USA). We determined that M. tundripaludum primarily produces N-3-hydroxydecanoyl-L-homoserine lactone (3-OH-C10-HSL) and that production is governed by a positive feedback loop. We then further characterized this system by determining which genes are regulated by quorum sensing in this methane-oxidizer using RNA-seq, and discovered this system regulates the expression of a novel nonribosomal peptide synthetase biosynthetic gene cluster. These results identify and characterize a mode of cellular communication in an aerobic methane-oxidizing bacterium.
2016-08-16 | GSE85617 | GEO