Bacterial denitrification is expressed in response to the concurrent exogenous signals of low-oxygen tension and nitrate or one of its reduction products. The mechanism by which nitrate-dependent gene activation is effected was investigated in the denitrifying bacterium Pseudomonas stutzeri ATCC 14405. We have identified and isolated from this organism the chromosomal region encoding the two-co...

Mycobacterium tuberculosis rapidly reduces nitrate, leading to the accumulation of nitrite. This characteristic served for the past 40 years to differentiate M. tuberculosis from other members of the Mycobacterium tuberculosis complex (MTBC), such as Mycobacterium bovis (non-BCG [referred to here as simply "M. bovis"]), Mycobacterium bovis BCG, Mycobacterium africanum, or Mycobacterium microti....

Escherichia coli synthesizes two biochemically distinct nitrate reductase enzymes, a membrane-bound enzyme encoded by the narGHJI operon and a periplasmic cytochrome c-linked nitrate reductase encoded by the napFDAGHBC operon. To address why the cell makes these two enzymes, continuous cell culture techniques were used to examine napF and narG gene expression in response to different concentrat...

Wetlands represent sources or sinks of the greenhouse gas nitrous oxide (N2O). The acidic fen Schlöppnerbrunnen emits denitrification derived N2O and is also capable of N2O consumption. Global warming is predicted to cause more extreme weather events in future years, including prolonged drought periods as well as heavy rainfall events, which may result in flooding. Thus, the effects of prolonge...

Two experiments were conducted to determine the effects of vitamin E (VE) and Arginine (ARG) on humoral and cellular immunity of broiler chickens, with 2 levels of ARG: normal (NARG, 1.2% in the feed) and high ARG (HARG, additional 0.3% ARG in the drinking water); and 3 levels of VE (40, 80, and 400 IU / kg feed). A cornsoybean meal diet and water were provided ad libitum throughout the study. ...

please cite this article as: shafeian sh, bandehpour m, mirzaahmadi s, tofighi a. identification of anaerobic bacteria in patients with rheumatoid arthritis. . novel biomed 2013;1(2):39-42. background : there is a report about the 2-5% prevalence for septic arthritis by anaerobic bacteria. the relevance between synivitis and intestinal microbial flora has been a hypothesis for ten years. the pc...

Denitrification is an important pathway for nitrogen removal from aquatic systems and this could benefit water quality. However, little is known about the denitrifier community composition and key steps of denitrification in the freshwater environments, and whether different bacteria have a role in multiple processes of denitrification reduction. In this study, quantitative PCR, quantitative RT...

One-day-old broiler chicks (n = 300) were orally vaccinated (Coccivac-B) and divided into 6 groups to evaluate Arg at 3 levels of supplementation, 0, 0.3, or 0.6% [normal level (NARG), medium level (MARG), or high level (HARG), respectively], and 2 levels of vitamin E (VE), 40 or 80 IU/kg of feed (VE40 or VE80, respectively), in a factorial experiment. Birds were reared in floor pens with fresh...

Human activities have greatly increased the availability of bioactive nitrogen and, consequently, altered cycle in riverine systems. Here, we studied denitrification rates and denitrifiers river sediment their relationships with aquatic physicochemical variables along a gradient human-disturbance intensity subtropical stream China. We used high-throughput sequencing to characterize denitrifying...

Wetlands are sources of denitrification-derived nitrous oxide (N2O). Thus, the denitrifier community of an N2O-emitting fen (pH 4.7 to 5.2) was investigated. N2O was produced and consumed to subatmospheric concentrations in unsupplemented anoxic soil microcosms. Total cell counts and most probable numbers of denitrifiers approximated 10(11) cells x g(DW)(-1) (where DW is dry weight) and 10(8) c...