We report here the existence of anaerobic nitrogen-fixing consortia (ANFICOs) consisting of N(2)-fixing clostridia and diverse nondiazotrophic bacteria in nonleguminous plants; we found these ANFICOs while attempting to overcome a problem with culturing nitrogen-fixing microbes from various gramineous plants. A major feature of ANFICOs is that N(2) fixation by the anaerobic clostridia is suppor...

Agricultural yields are often limited by nitrogen (N) availability, especially in countries of the developing world, whereas industrialized nations application chemical N fertilizers has reached unsustainable levels that have resulted severe environmental consequences. Finding alternatives to inorganic is critical for sustainable and secure food production. Although gaseous (N2) abundant atmosp...

Simultaneous measurements of photosynthesis (both oxygenic and anoxygenic) and N(inf2) fixation were conducted to discern the relationships between photosynthesis, N(inf2) fixation, and environmental factors potentially regulating these processes in microbial mats in a tropical hypersaline lagoon (Salt Pond, San Salvador Island, Bahamas). Major photoautotrophs included cyanobacteria, purple pho...

N(2) fixation by Chlorobium phaeobacteroides from Lake Kinneret was dependent on ammonia concentration and light intensity. In the thermocline of Lake Kinneret, N(2) fixation and photosynthesis were low. It was concluded that the bacteria do not contribute significantly to the organic nitrogen load of the lake.

microbial calcium carbonate, by bridging sand particles, can play an important role in sand dune stability. a study was carried out on the cementation of sand grains and infilling of pore spaces by caco3. two bacterial species (sporosarcina pasteurii and sporosarcina ureae), three reactant concentrations (0.5, 1 and 1.5m), and six reaction times (12, 24, 48, 96, 192 and 288 hours) were tested i...

The methanogenic Archaea bring a broadened perspective to the field of nitrogen fixation. Biochemical and genetic studies show that nitrogen fixation in Archaea is evolutionarily related to nitrogen fixation in Bacteria and operates by the same fundamental mechanism. At least six nif genes present in Bacteria (nif H, D, K, E, N and X) are also found in the diazotrophic methanogens. Most nitroge...

The microbiome of plants is diverse, and like that of animals, is important for overall health and nutrient acquisition. In legumes and actinorhizal plants, a portion of essential nitrogen (N) is obtained through symbiosis with nodule-inhabiting, N2-fixing microorganisms. However, a variety of non-nodulating plant species can also thrive in natural, low-N settings. Some of these species may rel...

For evaluating N(2) fixation of diazotrophic bacteria, nitrogen-poor liquid media supplemented with at least 0.5% sugar and 0.2% agar are widely used for acetylene reduction assays. In such a soft gel medium, however, many N(2)-fixing soil bacteria generally show only trace acetylene reduction activity. Here, we report that use of a N(2) fixation medium solidified with gellan gum instead of aga...

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...