Glycine, a photorespiratory intermediate, enhanced the in vivo reduction of nitrate in barley (Hordeum vulgare L.) leaf slices, when included in the assay medium. Isonicotinyl hydrazide, an inhibitor of glycine oxidation, partially reduced NO(2) (-) production. The enhancement caused by glycine treatment was reversed by isonicotinyl hydrazide when both were present together in the medium. Simil...

A nitrate uptake system is induced (along with nitrate reductase) when NH(4) (+)-grown Penicillium chrysogenum is incubated with inorganic nitrate in synthetic medium in the absence of NH(4) (+). Nitrate uptake and nitrate reduction are probably in steady state in fully induced mycelium, but the ratios of the two activities are not constant during the induction period. Substrate concentrations ...

The recent elucidation of the enzyme systems involved in nitrate reduction in Neurospora crassa (Evans and Nason, 1952; Nason and Evans, 1953); Bacillus pumilis (Taniguchi et al., 1953); Escherichia coli (Taniguchi et al., 1956; Nicholas and Nason, 1955) and higher plants (Evans and Nason, 1953), has renewed interest in the general problem of nitrate reduction and nitrate assimilation in microo...

The ability of anaerobic prokaryotes to employ different terminal electron acceptors for respiration enables these organisms to flourish in subsurface ecosystems. Desulfurispirillum indicum strain S5 is an obligate anaerobic bacterium that is able to grow by respiring a range of different electron acceptors, including arsenate and nitrate. Here, we examined the growth, electron acceptor utiliza...

Denitrification and nitrification in sediments of Tama Estuary and Odawa Bay, Japan, were investigated by the combined use of a continuous-flow sediment-water system and a N tracer technique. At Odawa Bay, the nitrification rate was comparable to the nitrate reduction rate, and 70% of the N(2) evolved originated from nitrogenous oxides (nitrate and nitrite) which were produced by the action of ...

Coastal zones act as a sink for riverine and atmospheric nitrogen inputs and thereby buffer the open ocean from the effects of anthropogenic activity. Recently, microbial activity in sandy permeable sediments has been identified as a dominant source of N-loss in coastal zones, namely through denitrification. Some of the highest coastal denitrification rates measured so far occur within the inte...

Kinetics of nitrite uptake and reduction by Chlamydomonas reinhardtii cells growing phototrophically has been studied by means of progress curves and the Michaelis-Menten integrated equation. Both uptake and reduction processes exhibited hyperbolic saturation kinetics, the nitrite uptake system lacking a diffusion component. Nitrite uptake and reduction showed significant differences in K(s) fo...

Chromium is often found as a cocontaminant at sites polluted with organic compounds. For nitrate-respiring microbes, Cr(VI) may be not only directly toxic but may also specifically interfere with N reduction. In soil microcosms amended with organic electron donors, Cr(VI), and nitrate, bacteria oxidized added carbon, but relatively low doses of Cr(VI) caused a lag and then lower rates of CO(2) ...

In this paper, lumped-parameter models (LPMs) were developed and utilized to simulate nitrate concentration in the groundwater of Gaza City and Jabalia Camp (GCJC) in the Gaza Coastal Aquifer (GCA) in Palestine. In the GCJC area, nitrate levels exceed the maximum contaminant level (MCL) of 10 mg/L NO3-N (45 mg/L NO3) in many wells. Elevated nitrate concentrations in the groundwater of GCJC area...

Twelve strains of Fusarium moniliforme were examined for their ability to sector spontaneously on toxic chlorate medium. All strains sectored frequently; 91% of over 1200 colonies examined formed chlorate-resistant, mutant sectors. Most of these mutants had lesions in the nitrate reduction pathway and were unable to utilize nitrate (nit mutants). nit mutations occurred in seven loci: a structur...