Gene-centered metagenome analysis of Vulcano Island soil (Aeolian archipelago, Italy) reveals diverse microbial key players in methane, hydrogen and sulfur cycles.

The Aeolian archipelago is known worldwide for its volcanic activity and hydrothermal emissions, of mainly carbon dioxide and hydrogen sulfide. Hydrogen, methane, and carbon monoxide are minor components of these emissions which together can feed large quantities of bacteria and archaea that do contribute to the removal of these notorious greenhouse gases. Here we analyzed the metagenome of samples taken from the Levante bay on Vulcano Island, Italy.

Active coexistence of the novel gammaproteobacterial methanotroph 'Ca. Methylocalor cossyra' CH1 and verrucomicrobial methanotrophs in acidic, hot geothermal soil.

Terrestrial geothermal ecosystems are hostile habitats, characterized by large emissions of environmentally relevant gases such as CO , CH , H S and H . These conditions provide a niche for chemolithoautotrophic microorganisms. Methanotrophs of the phylum Verrucomicrobia, which inhabit these ecosystems, can utilize these gases and grow at pH levels below 1 and temperatures up to 65°C.

" Hydrogenisulfobacillus filiaventi" strain R50 gen. nov. sp. nov., a highly efficient producer of extracellular organic compounds from H and CO.

Production of organic molecules is largely depending on fossil fuels. A sustainable alternative would be the synthesis of these compounds from CO and a cheap energy source, such as H, CH, NH, CO, sulfur compounds or iron(II). Volcanic and geothermal areas are rich in CO and reduced inorganic gasses and therefore habitats where novel chemolithoautotrophic microorganisms for the synthesis of organic compounds could be discovered.

Complete Genome Sequence of 347, Isolated from the Black Sea.

Here, we present the complete genome sequence of Nitrospina watsonii 347, a nitrite-oxidizing bacterium isolated from the Black Sea at a depth of 100 m. The genome has a length of 3,011,914 bp with 2,895 predicted coding sequences. Its predicted metabolism is similar to that of Nitrospina gracilis with differences in defense against reactive oxygen species.

Metascan: METabolic Analysis, SCreening and ANnotation of Metagenomes.

Large scale next generation metagenomic sequencing of complex environmental samples paves the way for detailed analysis of nutrient cycles in ecosystems. For such an analysis, large scale unequivocal annotation is a prerequisite, which however is increasingly hampered by growing databases and analysis time. Hereto, we created a hidden Markov model (HMM) database by clustering proteins according to their KEGG indexing.

Microbial paracetamol degradation involves a high diversity of novel amidase enzyme candidates.

Pharmaceuticals are relatively new to nature and often not completely removed in wastewater treatment plants (WWTPs). Consequently, these micropollutants end up in water bodies all around the world posing a great environmental risk. One exception to this recalcitrant conversion is paracetamol, whose full degradation has been linked to several microorganisms.

Ammonia oxidation at pH 2.5 by a new gammaproteobacterial ammonia-oxidizing bacterium.

Ammonia oxidation was considered impossible under highly acidic conditions, as the protonation of ammonia leads to decreased substrate availability and formation of toxic nitrogenous compounds. Recently, some studies described archaeal and bacterial ammonia oxidizers growing at pH as low as 4, while environmental studies observed nitrification at even lower pH values. In this work, we report on the discovery, cultivation, and physiological, genomic, and transcriptomic characterization of a novel gammaproteobacterial ammonia-oxidizing bacterium enriched via continuous bioreactor cultivation from an acidic air biofilter that was able to grow and oxidize ammonia at pH 2.

Draft Genome Sequence of a Novel Methylobacterium brachiatum Strain Isolated from Human Skin.

MBRA is an aerobic alphaproteobacterium isolated from the human skin on methanol-containing minimal medium. The genome was sequenced using Illumina and Nanopore technology, and the genome was assembled using Unicycler. MBRA possesses two genes, one gene pair, and , and a complete serine pathway.

Geothermal Gases Shape the Microbial Community of the Volcanic Soil of Pantelleria, Italy.

Volcanic and geothermal environments are characterized by low pH, high temperatures, and gas emissions consisting of mainly CO and varied CH, HS, and H contents which allow the formation of chemolithoautotrophic microbial communities. To determine the link between the emitted gases and the microbial community composition, geochemical and metagenomic analysis were performed. Soil samples of the geothermic region Favara Grande (Pantelleria, Italy) were taken at various depths (1 to 50 cm).

Long-term enriched methanogenic communities from thermokarst lake sediments show species-specific responses to warming.

Thermokarst lakes are large potential greenhouse gas (GHG) sources in a changing Arctic. In a warming world, an increase in both organic matter availability and temperature is expected to boost methanogenesis and potentially alter the microbial community that controls GHG fluxes. These community shifts are, however, challenging to detect by resolution-limited 16S rRNA gene-based approaches.

Metagenomic profiling of ammonia- and methane-oxidizing microorganisms in two sequential rapid sand filters.

Elevated concentrations of ammonium and methane in groundwater are often associated with microbiological, chemical and sanitary problems during drinking water production and distribution. To avoid their accumulation, raw water in the Netherlands and many other countries is purified by sand filtration. These drinking water filtration systems select for microbial communities that mediate the biodegradation of organic and inorganic compounds.

Draft Genome Sequences of Two Acidophilic, Mesophilic Verrucomicrobial Methanotrophs Contain Only One Operon.

3B and 4AC are Gram-negative rod-shaped mesophilic methanotrophs isolated from soil samples with low pH at the Solfatara Crater, near Naples, Italy. The genomes of these extremophilic verrucomicrobia were sequenced using Illumina technology, and both species possess one operon and two genes.

Response of the Anaerobic Methanotroph " Methanoperedens nitroreducens" to Oxygen Stress.

" Methanoperedens nitroreducens" is an archaeon that couples the anaerobic oxidation of methane to nitrate reduction. In natural and man-made ecosystems, this archaeon is often found at oxic-anoxic interfaces where nitrate, the product of aerobic nitrification, cooccurs with methane produced by methanogens. As such, populations of " Methanoperedens nitroreducens" could be prone to regular oxygen exposure.

Bioreactor virome metagenomics sequencing using DNA spike-ins.

With the emergence of Next Generation Sequencing, major advances were made with regard to identifying viruses in natural environments. However, bioinformatical research on viruses is still limited because of the low amounts of viral DNA that can be obtained for analysis. To overcome this limitation, DNA is often amplified with multiple displacement amplification (MDA), which may cause an unavoidable bias.

Community Composition and Ultrastructure of a Nitrate-Dependent Anaerobic Methane-Oxidizing Enrichment Culture.

Methane is a very potent greenhouse gas and can be oxidized aerobically or anaerobically through microbe-mediated processes, thus decreasing methane emissions in the atmosphere. Using a complementary array of methods, including phylogenetic analysis, physiological experiments, and light and electron microscopy techniques (including electron tomography), we investigated the community composition and ultrastructure of a continuous bioreactor enrichment culture, in which anaerobic oxidation of methane (AOM) was coupled to nitrate reduction. A membrane bioreactor was seeded with AOM biomass and continuously fed with excess methane.

Enrichment of anaerobic nitrate-dependent methanotrophic 'Candidatus Methanoperedens nitroreducens' archaea from an Italian paddy field soil.

Paddy fields are a significant source of methane and contribute up to 20% of total methane emissions from wetland ecosystems. These inundated, anoxic soils featuring abundant nitrogen compounds and methane are an ideal niche for nitrate-dependent anaerobic methanotrophs. After 2 years of enrichment with a continuous supply of methane and nitrate as the sole electron donor and acceptor, a stable enrichment dominated by 'Candidatus Methanoperedens nitroreducens' archaea and 'Candidatus Methylomirabilis oxyfera' NC10 phylum bacteria was achieved.

Ultrastructure and Viral Metagenome of Bacteriophages from an Anaerobic Methane Oxidizing Bioreactor Enrichment Culture.

With its capacity for anaerobic methane oxidation and denitrification, the bacterium plays an important role in natural ecosystems. Its unique physiology can be exploited for more sustainable wastewater treatment technologies. However, operational stability of full-scale bioreactors can experience setbacks due to, for example, bacteriophage blooms.

New Methyloceanibacter diversity from North Sea sediments includes methanotroph containing solely the soluble methane monooxygenase.

Marine methylotrophs play a key role in the global carbon cycle by metabolizing reduced one-carbon compounds that are found in high concentrations in marine environments. Genome, physiology and diversity studies have been greatly facilitated by the numerous model organisms brought into culture. However, the availability of marine representatives remains poor.

Genome Characteristics of Two Novel Type I Methanotrophs Enriched from North Sea Sediments Containing Exclusively a Lanthanide-Dependent XoxF5-Type Methanol Dehydrogenase.

Microbial methane oxidizers play a crucial role in the oxidation of methane in marine ecosystems, as such preventing the escape of excessive methane to the atmosphere. Despite the important role of methanotrophs in marine ecosystems, only a limited number of isolates are described, with only four genomes available. Here, we report on two genomes of gammaproteobacterial methanotroph cultures, affiliated with the deep-sea cluster 2, obtained from North Sea sediment.

The [FeFe] hydrogenase of Nyctotherus ovalis has a chimeric origin.

Background: The hydrogenosomes of the anaerobic ciliate Nyctotherus ovalis show how mitochondria can evolve into hydrogenosomes because they possess a mitochondrial genome and parts of an electron-transport chain on the one hand, and a hydrogenase on the other hand. The hydrogenase permits direct reoxidation of NADH because it consists of a [FeFe] hydrogenase module that is fused to two modules, which are homologous to the 24 kDa and the 51 kDa subunits of a mitochondrial complex I.

Results: The [FeFe] hydrogenase belongs to a clade of hydrogenases that are different from well-known eukaryotic hydrogenases.