Publications by authors named "Anne Grethe Hestnes"

Atmospheric methane oxidizing bacteria (atmMOB) constitute the sole biological sink for atmospheric methane. Still, the physiological basis allowing atmMOB to grow on air is not well understood. Here we assess the ability and strategies of seven methanotrophic species to grow with air as sole energy, carbon, and nitrogen source.

View Article and Find Full Text PDF

Methanotrophs oxidize most of the methane (CH) produced in natural and anthropogenic ecosystems. Often living close to soil surfaces, these microorganisms must frequently adjust to temperature change. While many environmental studies have addressed temperature effects on CH oxidation and methanotrophic communities, there is little knowledge about the physiological adjustments that underlie these effects.

View Article and Find Full Text PDF

Methane (CH) is a sustainable carbon feedstock for value-added chemical production in aerobic CH-oxidizing bacteria (methanotrophs). Under substrate-limited (e.g.

View Article and Find Full Text PDF

The second largest sink for atmospheric methane (CH) is atmospheric methane oxidizing-bacteria (atmMOB). How atmMOB are able to sustain life on the low CH concentrations in air is unknown. Here, we show that during growth, with air as its only source for energy and carbon, the recently isolated atmospheric methane-oxidizer MG08 (USCα) oxidizes three atmospheric energy sources: CH, carbon monoxide (CO), and hydrogen (H) to support growth.

View Article and Find Full Text PDF

The global atmospheric level of methane (CH), the second most important greenhouse gas, is currently increasing by ∼10 million tons per year. Microbial oxidation in unsaturated soils is the only known biological process that removes CH from the atmosphere, but so far, bacteria that can grow on atmospheric CH have eluded all cultivation efforts. In this study, we have isolated a pure culture of a bacterium, strain MG08 that grows on air at atmospheric concentrations of CH [1.

View Article and Find Full Text PDF

The dominant terminal process of carbon mineralization in most freshwater wetlands is methanogenesis. With methane being an important greenhouse gas, the predicted warming of the Arctic may provide a positive feedback. However, the amount of methane released to the atmosphere may be controlled by the activity of methane-oxidizing bacteria (methanotrophs) living in the oxic surface layer of wetlands.

View Article and Find Full Text PDF

Methylobacter tundripaludum SV96(T) (ATCC BAA-1195) is a psychrotolerant aerobic methane-oxidizing gammaproteobacterium (Methylococcales, Methylococcaceae) living in High Arctic wetland soil. The strain was isolated from soil harvested in July 1996 close to the settlement Ny-Ålesund, Svalbard, Norway (78°56'N, 11°53'E), and described as a novel species in 2006. The genome includes pmo and pxm operons encoding copper membrane monooxygenases (Cu-MMOs), genes required for nitrogen fixation, and the nirS gene implicated in dissimilatory nitrite reduction to NO but no identifiable inventory for further processing of nitrogen oxides.

View Article and Find Full Text PDF

With the advent of molecular biological techniques, especially next-generation sequencing and metagenomics, the number of microbial biogeography studies is rapidly increasing. However, these studies involve the synthesis of data generated by different laboratories using different protocols, chemicals, etc., all with inherent biases.

View Article and Find Full Text PDF

A Gram-negative, rod-shaped, non-motile, non-spore-forming, pink-pigmented bacterium, SV97T, was isolated from a wetland soil near Ny-Alesund, Svalbard Islands, Norway (78 degrees N). On the basis of 16S rRNA gene sequence similarity, strain SV97T was shown to belong to the Alphaproteobacteria and was highly related to a number of non-characterized Methylocystis strains with GenBank accession nos AJ458507 and AJ458502 (100 %) and AF177299, AJ458510, AJ458467, AJ458471, AJ431384, AJ458475, AJ458484, AJ458501 and AJ458466 (99 %). The most closely related type strains were Methylocystis parvus OBBP(T) (97.

View Article and Find Full Text PDF

A Gram-negative, rod-shaped, non-motile, non-spore forming bacterium (SV96T) was isolated from wetland soil near Ny-Alesund, Svalbard. On the basis of 16S rRNA gene sequence similarity, strain SV96T was shown to belong to the Gammaproteobacteria, related to Methylobacter psychrophilus Z-0021T (99.1 %), Methylobacter luteus ATCC 49878T (97.

View Article and Find Full Text PDF

The methanotrophic community in arctic soil from the islands of Svalbard, Norway (78 degrees N) was analysed by combining group-specific PCR with PCR of the highly variable V3 region of the 16S rRNA gene and then by denaturing gradient gel electrophoresis (DGGE). Selected bands were sequenced for identification. The analyses were performed with DNA extracted directly from soil and from enrichment cultures at 10 and 20 degrees C.

View Article and Find Full Text PDF

Abstract A new method for isolation of methane oxidising bacteria (methanotrophs) is presented. Soil samples from a wetland area and a landfill were plated on polycarbonate membranes, which were incubated in a methane-air atmosphere using a non-sterile soil suspension as the medium. The membrane acted as a permeable growth support.

View Article and Find Full Text PDF