A modified single sequencing batch reactor (SBR) was developed to remove the nitrogen of the real landfill leachate in this study. To take the full advantage of the SBR, stir phase was added before and after aeration, respectively. The new mechanism in this experiment could improve the removal of nitrogen efficiently by the utilization of carbon source in the raw leachate. This experiment adopt...

Anthropogenic nitrogen contamination has increased in ecosystems around the world (frequently termed the "nitrogen cascade"). Coke production for steel manufacturing is often overlooked as a source of nitrogen to natural ecosystems. We examined sediment cores from a Horseshoe Lake, a floodplain lake located just East of St. Louis Missouri (USA) to test whether a coking plant effluent could be t...

Prevotella spp. are believed to play a central role in ruminal nitrogen metabolism, but little is understood about the genetics and biochemistry of nitrogen assimilation and regulation in these bacteria. The gene encoding a family III glutamine synthetase (GSIII, glnN) in Prevotella bryantii B(1)4 was cloned by Escherichia coli mutant complementation, and enzyme assays as well as Northern blot ...

The level of glutamine synthetase activity in Agmenellum quadruplicatum strain PR-6 was dependent on the nitrogen source used for growth and on the nutritional status of the cells. During exponential growth, glutamine synthetase activity was low in cells grown on ammonia, urea, or nitrate. During the transition from nitrogen replete to nitrogen starved growth, glutamine synthetase activity bega...

The model rumen Firmicutes organism Ruminococcus albus 8 was grown using ammonia, urea, or peptides as the sole nitrogen source; growth was not observed with amino acids as the sole nitrogen source. Growth of R. albus 8 on ammonia and urea showed the same growth rate (0.08 h(-1)) and similar maximum cell densities (for ammonia, the optical density at 600 nm [OD600] was 1.01; and for urea, the O...

this work examined the simultaneous saccharification and fermentation (ssf) process for the biological conversion rice wastewater into ethanol using co-culture of aspergillus niger (a. niger) and saccharomyces cerevisiae (s. cerevisiae) in batch condition. in this study, the a. niger and s. cerevisiae were used for hydrolysis and production of ethanol from rice wastewater, respectively. the effe...

The NADP-specific glutamate dehydrogenase (NADP-GDH) activity of Aspergillus nidulans was rapidly lost from cultures starved for a carbon source. This loss of NADP-GDH was blocked by protein synthesis inhibitors. Glutamate repressed NADP-GDH but did not cause rapid loss of activity. Since NADP-GDH is involved in the participation of ammonium in the regulation of nitrogen metabolism, the loss of...

The effects of various carbon sources and their initial concentrations on mycelia production by Hericium erinaceum were investigated by determining the dry cell weight (DCW) and β-glucan content of mycelia in submerged culture. Glucose and xylose were superior carbon sources for promoting mycelial growth resulting in mycelial concentrations of 3.99 g/L and 4.01 g/L, respectively; glucose was th...

plackett-burman design was used for selection of important media components such as carbon and nitrogen sources and minerals which affect poly(hydroxybutyrate) production and cell growth of methylobacterium extorquens dsmz 1340. among the studied variables, nitrogen and phosphorus sources, mgso4 and most of the trace elements were found to be significant variables for phb production from methan...