Nitrogen fixation associated with sugarcane was monitored ushg acetylene reducti,on tests and bacteriological techniques. Soil cores and trash from cane fields showed acetylene reducing activity. This activity was usually low in association with sandy soils. Where high activity was detected in soil cores it correlat~d with the wet weight of roots in each core. Nitrogen-fixing bacteria resemblin...

Nitrogen is abundant in the earth's atmosphere but, unlike carbon, cannot be directly assimilated by plants. The limitation this places on plant productivity has been circumvented in contemporary agriculture through the production and application of chemical fertilizers. The chemical reduction of nitrogen for this purpose consumes large amounts of energy and the reactive nitrogen released into ...

OBJECTIVES Polyene antifungal drugs, including amphotericin B or nystatin, target ergosterol in the fungal plasma membrane and are used to treat systemic, vaginal and oral fungal infections. In the oral cavity, the available nitrogen sources are primarily in the form of proteins, which are poor nitrogen sources. This study evaluates the effect of protein as a nitrogen source on drug susceptibil...

The ocean's nitrogen cycle is driven by complex microbial transformations, including nitrogen fixation, assimilation, nitrification, anammox and denitrification. Dinitrogen is the most abundant form of nitrogen in sea water but only accessible by nitrogen-fixing microbes. Denitrification and nitrification are both regulated by oxygen concentrations and potentially produce nitrous oxide (N2O), a...

Studies in which (15)N-labeled precursors of urinary ammonia were infused into the artery of an intact functioning kidney of an acidotic dog have led to the following conclusions: Preformed ammonia and ammonia derived from the amide nitrogen of plasma glutamine are added directly to urine without significant incorporation into amino acid intermediates of renal tissue. Thus, reductive amination ...

N-Nitrosodimethylamine (NDMA) is formed during chlorination of water containing the herbicide diuron (N'-(3,4-dichlorophenyl)-N,N-dimethylurea) but formation is greatly enhanced in the presence of ammonia (chloramination). Groundwater impacted by agricultural runoff may contain diuron and relatively high total nitrogen concentrations; this study examines the impact of the nitrogen form (ammoniu...

This paper presents the effect of soil supplementation with urea and magnesium on nitrogen uptake and its utilization by two different types of hybrid maize cultivars. Based on the results of 3-year fertilization studies, it was shown that for average volume of grain yield of maize, nitrogen content in grain dry matter and nitrogen uptake with its yield was significantly determined by the doses...

There have been numerous studies on the nitrogen metabolism of mycobacteria growing in various culture media, but no work has been reported on the nitrogen assimilation in suspensions of nongrowing cells. For this purpose a number of BCG strains of Mycobacterium tuberculosis were studied for their ability to take up nitrogen in the form of the ammonium ion when shaken aerobically in buffer to w...