Phosphate-limited synthetic culture media were designed to investigate the growth and the pristinamycin production of 'Streptomyces pristinaespiralis' using different nitrogen sources. During balanced growth, either mineral or organic nitrogen sources were readily utilized. However, glutamate and alanine were used as both nitrogen and carbon source, sparing the utilization of the primary carbon...

1. The effects of increasing glucose intake on nitrogen balance, energy expenditure and fuel utilization were measured in 12 malnourished adult patients receiving parenteral nutrition with constant, very high nitrogen intake (500 mg of N/kg), high (105 kJ/kg) or low (30 kJ/kg) glucose intake and constant fat intake (7 kJ/kg). Each patient received each diet for 8-day periods in random order. 2....

The yeast Saccharomyces cerevisiae can use alternative nitrogen sources such as arginine, urea, allantoin, gamma-aminobutyrate, or proline when preferred nitrogen sources like glutamine, asparagine, or ammonium ions are unavailable in the environment. Utilization of alternative nitrogen sources requires the relief of nitrogen repression and induction of specific permeases and enzymes. The produ...

To establish a high-efficiency system of isolated microspore culture for different barley genotypes, we investigated the effects of nitrogen sources and concentrations on callus induction and plant regeneration in different barley genotypes. The results showed that the organic nitrogen sources greatly increased the callus induction, and the great reduction of total nitrogen sources would signif...

The urinary nitrogen excretion of sheep offered a low nitrogen diet was lower than when the sheep were fed a nitrogen-free mixture post-ruminally. This result is discussed in terms of Folin’s (1905) definition of endogenous nitrogen, and the nitrogen recycling and utilization which can occur in the rumen/reticulum of sheep. Reasons are given why post-ruminal feeding should give an endogenous ni...

I M P R O V I N G the utilization of urea nitrogen by ruminants has been the goal of many investigations. One approach, as exemplified by the study of Karr et al. (1965), has involved the addition of certain feedstuffs, which are thought to be sources of "rumen stimulatory" factors, to the diet with the hope of increasing microbial protein synthesis. Two examples of such feedstuffs are corn dis...

Field experiments were conducted in 2006 to investigate the impacts of modified rice cultivation systems on: grain yield, N uptake, ammonia volatilization from rice soil and N use efficiency (ANUE, agronomic N use efficiency; and PFP, partial factor productivity of applied N). The trials compared rice production using modified methods of irrigation, planting, weeding and nutrient management (th...

Uptake of poor nitrogen sources such as branched-chain amino acids is repressed in the presence of high-quality nitrogen sources such as NH4(+) and glutamate (Glu), which is called nitrogen catabolite repression. Amino acid auxotrophic mutants of the fission yeast Schizosaccharomyces pombe were unable to grow on minimal medium containing NH4Cl or Glu even when adequate amounts of required amino...

Twenty-eight (8 ruminally cannulated) lactating, multiparous Holstein cows were blocked by DIM and randomly assigned to 7 replicated 4 x 4 Latin squares (28-d periods) to investigate the effects of different dietary ratios of alfalfa silage (AS) to corn silage (CS) on production, N utilization, apparent digestibility, and ruminal metabolism. The 4 diets contained (dry matter basis): A) 51% AS, ...

in order to evaluate efficiency of nitrogen fertilizers consumption in a sugar beet monogerm hybrid variety of zarghan, a field experiment was conducted in a loamy soil during 2007 in the research farm of sugar beet seed institute located in karaj. five levels of nitrogen fertilizers including 0 (check), 120, 160, 200 and 240 kg/ha of net nitrogen from urea fertilizer (46 percent of pure nitrog...