Pseudomonas aeruginosa uses quorum sensing (QS) to regulate the production of public goods such as the secreted protease elastase. P. aeruginosa requires the LasI-LasR QS circuit to induce elastase and enable growth on casein as the sole carbon and energy source. The LasI-LasR system also induces a second QS circuit, the RhlI-RhlR system. During growth on casein, LasR-mutant social cheaters eme...

the enzyme pgalactosidase from a mutant strain of a. niger uv-5 was partially purified using ammonium sulfate and acetone. the saturation range of 60-80% ammonium sulfate was found to yield 60.5% enzyme recovery with 2.4 fold purification. acetone precipitation at enzyme: acetone ratio of 1 : 1.5 brought about a higher yield i.e. 68% and three-fold purification. the combined procedures of 1.5 v...

abstract regarding to this issue that nitrogen is one of the main essential elements for plant that growth and efficiency of plant is related to it, and on the other hand most of the water and soil resources in iran are alkaline; in order to evaluation of the interactive effect of different concentrations of sodium bicarbonate and nitrogen form on snap bean in hydroponic system, this research w...

Elevated emissions of sulfur dioxide, nitrogen oxides and ammonia in China have resulted in high levels of sulfur and nitrogen deposition, being contributors to soil acidification, especially in and near large cities. However, knowledge gaps still exist in the way that large cities shape spatial patterns of acid deposition. Here, we assessed the patterns of pH, sulfate, nitrate and ammonium in ...

Respiratory ammonification of nitrate is the microbial process that determines the retention of nitrogen in an ecosystem. To date, sulfur-dependent dissimilatory nitrate reduction to ammonium has been demonstrated only with sulfide as an electron donor. We detected a novel pathway that couples the sulfur and nitrogen cycles. Thermophilic anaerobic bacteria Thermosulfurimonas dismutans and Dissu...

Nitrogen is one of the most important factor affecting maize (Zea mays L.) yield and income of smallholders under semiarid climates. Field experiments were conducted to investigate the impact of different N-fertilizer sources [urea, calcium ammonium nitrate (CAN), and ammonium sulfate (AS)] and rates (50, 100, 150, and 200 kg ha-1) on umber of rows ear-1 (NOR ear-1), number of seeds row-1 (NOS ...

Results of experiments on the preparation of high molecular weight constituents from normal and poliomyelitis-infected medullae-cords are presented. Relatively large yields were obtained from glycerolated normal or infected tissues or from tissues that had been stored at -10 degrees C. for a few days. When the frozen tissues were stored for several weeks, the amount of sedimentable nitrogen iso...

The biogeochemical cycling in oxygen-minimum zones (OMZs) is dominated by the interactions of microbial nitrogen transformations and, as recently observed in the Chilean upwelling system, also through the energetically less favorable remineralization of sulfate reduction. The latter process is masked, however, by rapid sulfide oxidation, most likely through nitrate reduction. Thus, the cryptic ...