catena-Poly[[(4-amino­benzoato)aqua­silver(I)]-μ-hexa­methyl­enetetramine]

In the title coordination polymer, [Ag(C7H6NO2)(C6H12N4)(H2O)]n, the AgI ion is five-coordinated by two carboxyl­ate O atoms from one 4-amino­benzoate anion (L), two N atoms from two different hexa­methyl­enetetramine (hmt) ligands, and one water O atom in a distorted square-pyramidal geometry. The metal atom lies on a mirror plane and the L anion, hmt ligand and water mol­ecule all lie across crystallographic mirror planes. Each hmt ligand bridges two neighboring AgI ions, resulting in the formation of a chain structure along the b axis. The chains are linked into a three-dimensional framework by N—H⋯O and O—H⋯O hydrogen bonds

Inhibition of Bacterial Ammonia Oxidation by Organohydrazines in Soil Microcosms

Hydroxylamine oxidation by hydroxylamine oxidoreductase (HAO) is a key step for energy-yielding in support of the growth of ammonia-oxidizing bacteria (AOB). Organohydrazines have been shown to inactivate HAO from Nitrosomonas europaea, and may serve as selective inhibitors to differentiate bacterial from archaeal ammonia oxidation due to the absence of bacterial HAO gene homolog in known ammonia-oxidizing archaea (AOA). In this study, the effects of three organohydrazines on activity, abundance, and composition of AOB and AOA were evaluated in soil microcosms. The results indicate that phenylhydrazine and methylhydrazine at the concentration of 100 μmol g−1 dry weight soil completely suppressed the activity of soil nitrification. Denaturing gradient gel electrophoresis fingerprinting and sequencing analysis of bacterial ammonia monooxygenase subunit A gene (amoA) clearly demonstrated that nitrification activity change is well paralleled with the growth of Nitrosomonas europaea-like AOB in soil microcosms. No significant correlation between AOA community structure and nitrification activity was observed among all treatments during the incubation period, although incomplete inhibition of nitrification activity occurred in 2-hydroxyethylhydrazine-amended soil microcosms. These findings show that the HAO-targeted organohydrazines can effectively inhibit bacterial nitrification in soil, and the mechanism of organohydrazine affecting AOA remains unclear