Enigmatic persistence of aerobic methanotrophs in oxygen-limiting freshwater habitats.

Methanotrophic bacteria mitigate emissions of the potent greenhouse gas methane (CH4) from a variety of anthropogenic and natural sources, including freshwater lakes, which are large sources of CH4 on a global scale. Despite a dependence on dioxygen (O2) for CH4 oxidation, abundant populations of putatively aerobic methanotrophs have been detected within microoxic and anoxic waters and sediments of lakes. Experimental work has demonstrated active aerobic methanotrophs under those conditions, but how they are able to persist and oxidize CH4 under O2 deficiency remains enigmatic.

Desulfoferula mesophilus gen. nov. sp. nov., a mesophilic sulfate-reducing bacterium isolated from a brackish lake sediment.

A novel sulfate-reducing bacterium (strain 12FAK) was isolated from sediment sampled from a brackish lake in Japan. Respiratory growth was observed with formate and pyruvate as an electron donor. Sulfate, thiosulfate, elemental sulfur and dimethyl sulfoxide were utilized as an electron acceptor.

Large Fractionation in Iron Isotopes Implicates Metabolic Pathways for Iron Cycling in Boreal Shield Lakes.

Stable Fe isotopes have only recently been measured in freshwater systems, mainly in meromictic lakes. Here we report the δFe of dissolved, particulate, and sediment Fe in two small dimictic boreal shield headwater lakes: manipulated eutrophic Lake 227, with annual cyanobacterial blooms, and unmanipulated oligotrophic Lake 442. Within the lakes, the range in δFe is large (ca.

Freshwater Exhibit Metabolic Specialization among Cosmopolitan and Endemic Populations.

Photosynthetic bacteria from the class (formerly phylum ) sustain carbon fixation in anoxic water columns. They harvest light at extremely low intensities and use various inorganic electron donors to fix carbon dioxide into biomass. Until now, most information on the functional ecology and local adaptations of members came from isolates and merely 26 sequenced genomes that may not adequately represent natural populations.

High functional diversity among Nitrospira populations that dominate rotating biological contactor microbial communities in a municipal wastewater treatment plant.

Nitrification, the oxidation of ammonia to nitrate via nitrite, is an important process in municipal wastewater treatment plants (WWTPs). Members of the Nitrospira genus that contribute to complete ammonia oxidation (comammox) have only recently been discovered and their relevance to engineered water treatment systems is poorly understood. This study investigated distributions of Nitrospira, ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB) in biofilm samples collected from tertiary rotating biological contactors (RBCs) of a municipal WWTP in Guelph, Ontario, Canada.

Interactions between bacterial surface and nanoparticles govern the performance of "chemical nose" biosensors.

Rapid and portable diagnosis of pathogenic bacteria can save lives lost from infectious diseases. Biosensors based on a "chemical nose" approach are attracting interest because they are versatile but the governing interactions between bacteria and the biosensors are poorly understood. Here, we use a "chemical nose" biosensor based on gold nanoparticles to explore the role of extracellular polymeric substances in bacteria-nanoparticle interactions.