Fifteen of 23 ATCC strains and 2 of 9 clinical isolates of Xanthomonas maltophilia, all of which grew aerobically on ammonia, but not nitrate, as a sole nitrogen source, reduced nitrate to nitrite. X. maltophilia failed to grow anaerobically on complex medium with or without nitrate, so it is considered an obligate aerobe. Nitrate-reducing strains contained reduced methyl viologen nitrate reduc...

Nitrate addition stimulated sulfide oxidation by increasing the activity of nitrate-reducing sulfide-oxidizing bacteria (NR-SOB), decreasing the concentration of dissolved H2S in the water phase and, consequently, its release to the atmosphere of a pilot-scale anaerobic bioreactor. The effect of four different concentrations of nitrate (0.12, 0.24, 0.50, and 1.00 mM) was investigated for a peri...

The influence of nitrate and nitrite on growth of Corynebacterium glutamicum under aerobic conditions in shake flasks was analysed. When dissolved oxygen became limiting at higher cell densities, nitrate was reduced almost stoichiometrically to nitrite by nitrate reductase (NarGHJI). The nitrite concentration also declined slowly, presumably as a result of several reactions including reduction ...

in this study the effect of nitrogen form and different oxygen levels on growth and development and macronutrients concentrations in lettuce plants was investigated. this investigation showed that sole ammonium application caused fresh and dry weight reduction of shoot and root in lettuce plant. but different oxygen levels had no effect on them. nitrogen concentration of shoot was higher in amm...

In the context of the global nitrogen cycle, the importance of inorganic nitrate for the nutrition and growth of marine and freshwater autotrophic phytoplankton has long been recognized. In contrast, the utilization of nitrate by heterotrophic bacteria has historically received less attention because the primary role of these organisms has classically been considered to be the decomposition and...

Hydrological studies were made for 6 months covering monsoon, summer and transition periods in a reservoir, chiefly to understand the plankton productivity. The physical factors like temperature, light, pH and chemical factors like dissolved O , CO , carbonate, bicarbonate, chloride, nitrate, phosphate, sulphate, calcium, 2 2 magnesium, sodium and potassium were estimated.

Seasonal variations of physico-chemical parameters such as rainfall, temperature, salinity, pH, dissolved oxygen and nutrients like nitrate, nitrite, inorganic phosphate and reactive silicate were studied from two different stations in Uppanar estuary, Cuddalore, southeast coast of India from April 2000 to March 2002. Atmospheric and surface water temperatures (°C) varied from 28 to 40.5 and 26...

The need for prediction is widely recognized in limnology. In this study, data from 25 lakes of the Upper Paraná River floodplain were used to build models to predict chlorophyll-a and dissolved oxygen concentrations. Akaike's information criterion (AIC) was used as a criterion for model selection. Models were validated with independent data obtained in the same lakes in 2001. Predictor variabl...

The biogeochemical composition of 2 spatially separate surface gap layers on a single Antarctic sea ice floe during early austral summer was predominantly controlled by the growth of diatoms and, especially, Phaeocystis. These algal communities in and near the gap layers imposed large geochemical changes in the chemical and isotopic composition of the gap waters, typical of intense autotrophic ...