A resting cell system was used to study the sites of inhibition by NH4+ of protylonolide biosynthesis by a blocked mutant, strain 261, of Streptomyces fradiae. With 14C-labeled succinate or valine as an exogenous substrate, labeled protylonolide formation by high-NH4+ grown mycelia of strain 261 was lower than by low-NH4+ grown mycelia. When 14C-labeled palmitate or acetate + labeled propionate...

Ammonium (NH4(+)) leads to chronological life span (CLS) shortening in Saccharomyces cerevisiae BY4742 cells, particularly evident in cells starved for auxotrophy-complementing amino acids (leucine, lysine, and histidine) simultaneously. Here, we report that the effect of NH4(+) on aging yeast depends on the specific amino acid they are deprived of. Compared with no amino acid starvation, starv...

NH4 + is a major source of inorganic nitrogen for rice (Oryza sativa), and NH4 + is known to stimulate the uptake of phosphorus (P). However, it is unclear whether NH4 + can also stimulate P remobilization when rice is grown under P-deficient conditions. In this study, we use the two rice cultivars ‘Nipponbare’ and ‘Kasalath’ that differ in their cell wall P reutilization, to demonstrate that N...

The effects of ammonium (NH4) and magnesium (Mg) on the precipitation of phosphorus in artificial wastewater by an air-cathode single-chamber microbial fuel cell were investigated. When both NH4 and Mg were added to the wastewater, phosphorus was precipitated as struvite. Almost no precipitation occurred with the addition of only NH4, while phosphorus was precipitated as cattiite with the addit...

Schoenoplectus maritimus (alkali bulrush) has desirable attributes, such as a short growth habit (height of mature stands < 1.5 m) and annual senescence, for a potential alternative to tall (height > 3 m) emergent macrophytes in shallow constructed treatment wetlands treating ammonium-dominated wastewater. The effects of different ammonium nitrogen (NH4-N) levels on alkali bulrush growth and it...

We examined if endogenous endothelins mediate the decreased HCO3 secretion and increased H+ secretion in in vivo-perfused distal tubules of rats fed dietary acid as (NH4)2SO4. Animals given (NH4)2SO4 drinking solution had higher endothelin-1 addition to renal interstitial fluid than those given distilled H2O (480+/-51 vs. 293+/-32 fmol g kidney wt(-1) min(-1), respectively, P < 0.03). (NH4)2SO4...

Cd-tolerant and Cd-sensitive rice cultivars were used to study the role of NH4 + accumulation in Cd-induced toxicity. NH4 + accumulation seems to be involved in regulating the toxicity of rice seedlings caused by CdCl2. This conclusion was based on the observations that (a) on treatment with CdCl2, NH4 + content increased rapidly in the leaves of the Cd-sensitive cultivar (cv. Taichung Native 1...

Futile transmembrane NH3/NH4(+) cycling in plant root cells, characterized by extremely rapid fluxes and high efflux to influx ratios, has been successfully linked to NH3/NH4(+) toxicity. Surprisingly, the fundamental question of which species of the conjugate pair (NH3 or NH4(+)) participates in such fluxes is unresolved. Using flux analyses with the short-lived radioisotope (13)N and electrop...

The Na(+)-K(+)-Cl(-) cotransporters (NKCCs), which belong to the cation-Cl(-) cotransporter (CCC) family, are able to translocate NH4(+) across cell membranes. In this study, we have used the oocyte expression system to determine whether the K(+)-Cl(-) cotransporters (KCCs) can also transport NH4(+) and whether they play a role in pH regulation. Our results demonstrate that all of the CCCs exam...

The gas-permeable membrane process can recover ammonia from manure, reducing pollution whilst converting ammonia into an ammonium salt fertilizer. The process involves manure pH control to increase ammonium (NH4(+)) recovery rate that is normally carried out using an alkali. In this study a new strategy to avoid the use of alkali was tested applying low-rate aeration and nitrification inhibitio...