The first structure of an ammonia channel from the Amt/MEP/Rh protein superfamily, determined to 1.35 angstrom resolution, shows it to be a channel that spans the membrane 11 times. Two structurally similar halves span the membrane with opposite polarity. Structures with and without ammonia or methyl ammonia show a vestibule that recruits NH4+/NH3, a binding site for NH4+, and a 20 angstrom-lon...

1) Comment: General Comments: The manuscript presents an extensive analysis of 13C, NO3 and NH4 -uptake versus irradiance experiments for the Arctic subsurface chlorophyll maxima (SCM). NO3 and NH4 – uptake versus irradiance experiments are rarely conducted alongside traditional “P vs E” curves, so the paper includes some novel information on the rates of NO3 and NH4 uptake compared to carbon f...

signaling, we analyzed [Ca]cyt-associated protein kinase (CAP) genes, which encode signaling components that undergo marked changes in transcription levels in response to various stressors. We demonstrated that CAP1, a tonoplast-localized receptor-like kinase, regulates root hair tip growth by maintaining cytoplasmic Ca2+ gradients. A CAP1 knockout mutant (cap1-1) produced elevated levels of cy...

Pathways of ammonia assimilation into glutamic acid in Bacillus macerans were investigated by measurements of the specific activities of glutamate dehydrogenase (GDH), glutamine synthetase, and glutamate synthase. In ammonia-rich medium, GDH was the predominant pathway of ammonia assimilation. In nitrogen-fixing cells in which the intracellular NH4+ concentration was 1.4 +/- 0.5 mM, the activit...

A two-dimensional porous coordination polymer (NH4)2{HOOC(CH2)4COOH}[Zn2(C2O4)3] (abbreviated as (NH4)2(adp)[Zn2(ox)3] (adp = adipic acid, ox = oxalate)), which accommodates water molecules between the [Zn2(ox)3] layers, is highly remarked as a new type of crystalline proton conductor. In order to investigate its phase behavior and the proton conducting mechanism, we have performed adiabatic ca...

[1] Thermodynamic equilibrium model calculations are used to show thatHNO3 can lower the relative humidity barrier to deliquesce binary ammoniated salts in the upper troposphere, particularly in aerosol solutions with an (NH4)2SO4 composition. Also in the case of (NH4)2SO4 or NH4HSO4 there is no abrupt change in the physical state of the thermodynamic system (instantaneous change of a dry salt ...

Protylonolide is a lactonic precursor of tylosin aglycone, produced by a mutant of Streptomyces fradiae. It originates from n-butyrate, propionate and acetate units. Studies were carried out using a protylonolide-producing mutant on the correlation between protylonolide biosynthesis, regulation by NH4+ and amino acid metabolism. Protylonolide production decreased in a defined medium containing ...

The influence of different N sources on the growth of maté (Ilex paragurariensis St.Hil.) seedlings grown in greenhouse was studied. All seedlings received a base fertilization of 10 mg N.kg soil as NH4NO3, 60 mg P2O5.and 40 mg K2O.kg -1 soil as KH2PO4 15 days before treatments application. Treatments were as follow: Control, with no extra N added; Urea = 100 mg N.kg soil as Urea; NO3 = 100 mg ...

Methane inhibited NH4+ utilization by Nitrosomonas europaea with a Ki of 2mM. O2 consumption was not inhibited. In the absence of NH4+, or with hydrazine as reductant, methane caused nearly a doubling in the rate of O2 uptake. The stimulation was abolished by allylthiourea, a sensitive inhibitor of the oxidation of NH4+. Analysis revealed that methanol was being formed in these experiments, wit...