The rhizosphere microenvironment is crucial to plant–soil physiological processes. differences among microbial communities in the and non-rhizosphere peatland topsoil (0–15 cm) subsoil (15–30 five plant dominated by Carex schmidtii, Chamaedaphne calyculata, Ledum palustre, Betula fruticosa, Vaccinium uliginosum, as well soil discontinuous continuous permafrost regions, were studied. We found th...

Thirty-one nodulating rhizobium strains were collected from root nodules of spring and winter type faba bean cultivars grown in micro ecoarea, i.e. the same field in Chengdu plain, China. The symbiotic efficiency and phylogeny of these strains were studied. Effectively nitrogen fixing strains were isolated from both winter type and spring type cultivars. Based on phylogenetic analysis of 16S rR...

We present software package for classifying protein or nucleotide sequences to user-specified sets of reference sequences. The software trains a model using a multiple sequence alignment and a phylogenetic tree, both supplied by the user. The latter is used to guide model construction and as a decision tree to speed up the classification process. The software was evaluated on all the 16S rRNA g...

The organisms of a bluish-green layer beneath the shards of a gypsum rock were characterized by molecular techniques. The cyanobacterial consortium consisted almost exclusively of Chroococcidiopsis spp. The organisms of the shards expressed nitrogenase activity (C2H2 reduction) aerobically and in light. After a prolonged period of drought at the rock, the cells were inactive, but they resumed n...

Sphagnum mosses represent a main vegetation component in ombrotrophic wetlands. They harbor a specific and diverse microbial community with essential functions for the host. To understand the extend of host specificity and impact of environment, Sphagnum fallax and Sphagnum angustifolium, two phylogenetically closely related species, which show distinct habitat preference with respect to the nu...

Eolian transport of biomass from ephemerally wetted soils, associated with summer glacial meltwater runoffs and lake edges, to low-productivity areas of the Antarctic Dry Valleys (DV) has been postulated to be an important source of organic matter (fixed nitrogen and fixed carbon) to the entire DV ecosystem. However, descriptions and identification of the microbial members responsible for N(2) ...

Red kidney beans (RKBs) are one of the major components in the human diet of Western Indian Himalaya (WIH). Their cultivation in these habitats is strongly influenced by various biotic and abiotic stresses and therefore, there must be a selection of RKB associated microorganisms that are adapted to these harsh conditions. Seven cold adaptive diazotrophs from the same rhizosphere were isolated i...

A well-resolved rhizobial species phylogeny with 51 haplotypes was inferred from a combined atpD + recA data set using Bayesian inference with best-fit, gene-specific substitution models. Relatively dense taxon sampling for the genera Rhizobium and Mesorhizobium was achieved by generating atpD and recA sequences for six type and 24 reference strains not previously available in GenBank. This phy...

Nitrogenous run-off from farmed pastures contributes to the eutrophication of Lake Ellesmere, a large shallow lagoon/lake on the east coast of New Zealand. Tributaries periodically deliver high loads of nitrate to the lake which likely affect microbial communities therein. We hypothesized that a nutrient gradient would form from the potential sources (tributaries) creating a disturbance resulti...

12 Benthic nitrogen (N2) fixation and sulfate reduction (SR) were investigated in the Peruvian 13 oxygen minimum zone (OMZ). Sediment samples, were retrieved by a multiple corer at six 14 stations (70 1025 m water depth) along a depth transect at 12°S, covering anoxic and 15 hypoxic bottom water conditions. Benthic N2 fixation was detected at all sites using the 16 acetylene reduction assay, wi...