Pico and nanoplankton communities from the Southwest Atlantic Ocean along the Brazilian Bight are poorly described. The hydrography in this region is dominated by a complex system of layered water masses, which includes the warm and oligotrophic Tropical Water (TW), the cold and nutrient rich South Atlantic Central Water (SACW) and the Coastal Water (CW), which have highly variable properties. ...

Autotrophic denitrification was measured in the southwestern coastal Black Sea, where the Bosporus Plume injects oxidized chemical species (especially O(2) and [Formula: see text]) into the oxic, suboxic, and anoxic layers. Prominent oxygen intrusions caused an overlap of [Formula: see text] and sulfide at the same station where autotrophic denitrification activity was detected with incubation ...

Northern peatlands store globally significant amounts of soil carbon that could be released to the atmosphere under drier conditions induced by climate change. We measured forest floor respiration (RFF) at hummocks and hollows in a treed boreal bog in Alberta, Canada and partitioned the flux into aboveground forest floor autotrophic, belowground forest floor autotrophic, belowground tree respir...

Based on 16S rRNA gene surveys, bacteria of the epsilon subdivision of proteobacteria have been identified to be important members of microbial communities in a variety of environments, and quite a few have been demonstrated to grow autotrophically. However, no information exists on what pathway of autotrophic carbon fixation these bacteria might use. In this study, Thiomicrospira denitrificans...

Euglena gracilis (1224-5/9) contains phosphoenolpyruvate carboxykinase when grown autotrophic with CO(2) in the light. Its yield is higher when an additional carbon source like glucose has been added. The enzyme is lacking in cells provided with CO(2) alone and kept in the dark, whereas highest yields result if both glucose and CO(2) are provided together in the dark. The enzyme was purified by...

in order to study the effect of folic acid on seed reserves partitioning and early vigor of seedlings of kavir wheat cultivar, an experiment was conducted in a completely randomized design with 0, 12.5, 25, 50, 100 and 200 mm of folic acid. results of this study indicated that dry weight of seeds decreased in a same pattern in all treatments and about 6-8% of total seed was structural section. ...

Patterns in primary production and carbon export from the cuphotic zone suggest that the relative contribution of planktonic heterotrophs to community biomass should decline along gradients of phytoplankton biomass and primary production. Here, we use an extensive literature data survey to test the hypothesis that the ratio of total heterotrophic (bacteria + protozoa + mesozooplankton) biomass ...

We investigated the response of the microbial components of the pelagic food web to re-oligotrophication of large, deep Lake Constance where total phosphorus concentrations during mixing decreased from a maximum of 2.81 mmol L 1 in 1979 via 1.87 mmol L 1 in 1987 to 0.26 mmol L 1 in 2007. Measurements of heterotrophic bacteria, autotrophic picoplankton (APP) and heterotrophic nanoflagellates (HN...

The incorporation and distribution of activity from (14)CO(2) was investigated under autotrophic conditions in the facultative photoautotroph, Rhodospirillum rubrum, with cells cultured on hydrogen, carbon dioxide, and ammonium sulfate. In 1 second (14)CO(2) fixation experiments essentially all of the activity was found in 3-phosphoglyceric acid: plotted against time percent incorporation into ...

Proof of concept was obtained that Fe(0) can stoichiometrically reduce nitrate to ammonium and that cathodic hydrogen [produced during anaerobic Fe(0) corrosion by water] can sustain microbial denitrification to reduce nitrate to more innocuous products (i.e., N2O and N2). Autotrophic, denitrifying growth on Fe(0) was proven through the use of a dual-flask apparatus. Cathodic H2 from a flask co...