BACKGROUND Streptomyces griseorubens JSD-1 is a novel actinomycete isolated from soil that can utilize nitrate as its sole nitrogen source for growth and these nitrate assimilation genes active in this biotransformation are expected to be crucial. However, little is known about its genomic or genetic background related to nitrogen metabolism in this isolate. Thus, this study concentrates on ide...

Several aspects of the topography of the membrane-bound respiratory nitrate reductase (EC 1.7.99.4) of Escherichia coli have so far been explored (Kemp et al., 1975; Boxer & Clegg, 1975; Jones &Garland, 1977,1978; MacGregor &Christopher, 1978). Nevertheless, the location of the nitrate-binding site has not yet been positively identified. Garland et al. ( 1 9 7 5 ~ ) noted that the rate of passi...

Currently, researchers turn to natural processes such as using biological microorganisms in order to develop reliable and ecofriendly methods for the synthesis of metallic nanoparticles. In this study, we have investigated extracellular biosynthesis of silver nanoparticles using four Aspergillus species including A. fumigatus, A. clavatus, A. niger, and A. flavus. We have also analyzed nitrate ...

1. The assimilatory nitrite reductase of the N(2)-fixing bacterium Azotobacter chroococcum was prepared in a soluble form from cells grown aerobically with nitrate as the nitrogen source, and some of its properties have been studied. 2. The enzyme is a FAD-dependent metalloprotein (mol.wt. about 67000), which stoicheiometrically catalyses the direct reduction of nitrite to NH(3) with NADH as th...

Intercellular distribution of enzymes involved in amino nitrogen synthesis was studied in leaves of species representing three C(4) groups, i.e. Sorghum bicolor, Zea mays, Digitaria sanguinalis (NADP malic enzyme type); Panicum miliaceum (NAD malic enzyme type); and Panicum maximum (phosphoenolpyruvate carboxykinase type). Nitrate reductase, nitrite reductase, glutamine synthetase, and glutamat...

An active Neurospora-like assimilatory NADPH-nitrate reductase (EC 1.6.6.2), which can be formed in vitro by incubation of extracts of nitrate-induced Neurospora crassa mutant nit-1 with extracts of (a) certain other nonallelic nitrate reductase mutants, (b) uninduced wild type, or (c) xanthine oxidizing and liver aldehyde-oxidase systems was also formed by combination of the nit-1 extract with...

Posttranslational regulation of nitrate assimilation was studied in the cyanobacterium Synechocystis sp. strain PCC 6803. The ABC-type nitrate and nitrite bispecific transporter encoded by the nrtABCD genes was completely inhibited by ammonium as in Synechococcus elongatus strain PCC 7942. Nitrate reductase was insensitive to ammonium, while it is inhibited in the Synechococcus strain. Nitrite ...

In this study it is shown that addition of crude protein extract containing either membrane bound nitrate reductase (Nar) or periplasmic nitrate reductase (Nap) shortens the diauxic lag of denitrifying bacteria switched from aerobic to anoxic conditions. The specific growth rate under anoxic conditions, following resumption of exponential growth, was found to be linearly related to the extract ...

The reduced nicotinamide adenine dinucleotide phosphate (NADPH)-nitrate oxidoreductase (EC 1.6.6.2) from Aspergillus nidulans was purified over 200-fold by use of salt fractionation, gel filtration, and ion-exchange chromatography. The purified enzyme was specific for NADPH and catalyzed reduction of nitrate, cytochrome c from isolated mitochondria of Aspergillus, and mammalian cytochrome c. An...

A comparative study has been carried out of the growth of two lines of Datura innoxia (Mill.) cells, designated DI-6 and NR1, their resistance to chlorate, and their ability to assimilate nitrate in sterile culture. The NR1 cell line was isolated from DI-6 cultures by first growing the latter in a nitrate-based medium for 5 days and then transferring the cells to a medium containing 2 grams lit...