There is currently much interest in the interactions between exotic plants and soil organisms. Exotic invasive species can have profound effects on the microbial community of the soil and positive feedback of soil biota to invasive plants may facilitate their successful invasion. To better understand the impacts of Ambrosia artemisiifolia L. invasion on microbial carbon source utilization and r...

abstract improving nitrogen use efficiency (nue) is an important objective of the agroecosystem management. a field experiment was conducted to study the effect of different competition patterns on nitrogen balance in the wheat agroecosystem. experimental design was split–plot based on randomized complete blocks with four replications. the main plots consisted of different nitrogen rates (i.e. ...

The NAC (nitrogen assimilation control) protein from Klebsiella aerogenes is a LysR-like regulator for transcription of several operons involved in nitrogen metabolism, and couples the transcription of these sigma 70-dependent operons to regulation by the sigma 54-dependent NTR system. NAC activates expression of operons (e.g. histidine utilization, hut), allowing use of poor nitrogen sources, ...

The effects of Acinetobacter glutaminase-asparaginase (AGA) on protein and energy requirements were evaluated in mice bearing Ehrlich ascites tumors. In an initial experiment with normal mice, a zero protein diet resulted in a significant decrease in carcass nitrogen, liver nitrogen, and carcass energy relative to the animals on a normal, low, or high protein diet. In a second experiment, mice ...

Amino acid utilization was evaluated in seven children with acute lymphocytic leukemia treated with succinylated Acinetobacter glutaminase-asparaginase. All patients received food p.o. ad libitum and glucose-electrolyte solutions i.V.; four pa tients received an i.v. amino acid supplement (1.5 g/kg/day). Although all patients were in negative energy balance, there was a significant linear regre...