Organic substitutions aggravated microbial nitrogen limitation and decreased nitrogen-cycling gene abundances in a three-year greenhouse vegetable field

2021 ◽  
Vol 288 ◽  
pp. 112379
Author(s):  
Haojie Shen ◽  
Qianqian Zhang ◽  
Shuangge Zhu ◽  
Pengpeng Duan ◽  
Xi Zhang ◽  
...  
Keyword(s):  
Nitrogen Cycling ◽  
Nitrogen Limitation ◽  
Vegetable Field ◽  
Microbial Nitrogen ◽  
Cycling Gene ◽  
Greenhouse Vegetable

scholarly journals Addition of activated switchgrass biochar to an aridic subsoil increases microbial nitrogen cycling gene abundances

2013 ◽  
Vol 65 ◽  
pp. 65-72 ◽  
Author(s):  
Thomas F. Ducey ◽  
James A. Ippolito ◽  
Keri B. Cantrell ◽  
Jeffrey M. Novak ◽  
Rodrick D. Lentz
Keyword(s):  
Nitrogen Cycling ◽  
Microbial Nitrogen ◽  
Cycling Gene

scholarly journals Microbial nitrogen limitation in the mammalian large intestine

2018 ◽  
Vol 3 (12) ◽  
pp. 1441-1450 ◽  
Author(s):  
Aspen T. Reese ◽  
Fátima C. Pereira ◽  
Arno Schintlmeister ◽  
David Berry ◽  
Michael Wagner ◽  
...  
Keyword(s):  
Large Intestine ◽  
Nitrogen Limitation ◽  
Microbial Nitrogen

scholarly journals Changes in the nitrogen biogeochemical cycle in sediments of an urban river under different dissolved oxygen levels

2018 ◽  
Vol 19 (4) ◽  
pp. 1271-1278 ◽  
Author(s):  
Yaping Zhang ◽  
Xiaohong Ruan ◽  
Wenli Shi
Keyword(s):  
Dissolved Oxygen ◽  
Nitrogen Cycling ◽  
Quantitative Polymerase Chain Reaction ◽  
Nitrogen Transformation ◽  
Urban River ◽  
Ammonia Oxidizing Bacteria ◽  
Urban Rivers ◽  
Ammonium Oxidation ◽  
Microbial Nitrogen ◽  
Concentration Changes

Abstract Urban rivers are considered as a hot spot of microbial nitrogen cycling due to extensive N loading. However, microbial nitrogen transformation dynamics in urban rivers with different dissolved oxygen (DO) conditions are still unclear. This study investigated the effects of DO concentration changes (anaerobic to aerobic) in overlying water on nitrogen-cycling gene abundance in incubation conditions using sediment from a typical urban river in the Yangtze River Delta. Quantitative polymerase chain reaction (qPCR) results revealed that the abundances of the nitrification gene amoA, denitrification gene nirS/K, norB, nosZ, and anammox gene hzo increased by one to two orders of magnitude from anaerobic to aerobic conditions. Ammonia-oxidizing archaea (AOA) predominated the ammonium oxidation microbial populations, about tenfold more than the ammonia-oxidizing bacteria (AOB) populations. Significant correlations were found among the abundances of AOA-amoA, AOB-amoA, nirS, nirK, and hzo genes, implying a close coupling of aerobic ammonium oxidation (AAO), denitrification, and anammox processes at the molecular level. Moreover, the nitrogen transformation rates were calculated using a box model linking the measured dissolved inorganic nitrogen species. The contribution of anammox to N2 production was 85% under saturated treatment, and the AAO rate was significantly positive correlated to the anammox rate. Our results suggested that coupled AAO and anammox might be the dominant pathway for reactive nitrogen removal in urban rivers with elevated DO levels.

scholarly journals Biodiversity breakpoints along stress gradients in estuaries and associated shifts in ecosystem interactions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Emily J. Douglas ◽  
Andrew M. Lohrer ◽  
Conrad A. Pilditch
Keyword(s):  
Nitrogen Cycling ◽  
Environmental Gradients ◽  
Interaction Network ◽  
Coastal Sediments ◽  
Ecosystem Functions ◽  
Ecological Interactions ◽  
Fine Sediments ◽  
Microbial Nitrogen ◽  
Ecosystem Interactions ◽  
Biodiversity Effects

AbstractDenitrification in coastal sediments can provide resilience to eutrophication in estuarine ecosystems, but this key ecosystem function is impacted directly and indirectly by increasing stressors. The erosion and loading of fine sediments from land, resulting in sedimentation and elevated sediment muddiness, presents a significant threat to coastal ecosystems worldwide. Impacts on biodiversity with increasing sediment mud content are relatively well understood, but corresponding impacts on denitrification are uncharacterised. Soft sediment ecosystems have a network of interrelated biotic and abiotic ecosystem components that contribute to microbial nitrogen cycling, but these components (especially biodiversity measures) and their relationships with ecosystem functions are sensitive to stress. With a large dataset spanning broad environmental gradients this study uses interaction network analysis to present a mechanistic view of the ecological interactions that contribute to microbial nitrogen cycling, showing significant changes above and below a stressor (mud) threshold. Our models demonstrate that positive biodiversity effects become more critical with a higher level of sedimentation stress, and show that effective ecosystem management for resilience requires different action under different scenarios.

scholarly journals Microbial nitrogen cycling on the Greenland Ice Sheet

2011 ◽  
Vol 8 (5) ◽  
pp. 10423-10457 ◽  
Author(s):  
J. Telling ◽  
M. Stibal ◽  
A. M. Anesio ◽  
M. Tranter ◽  
I. Nias ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogen Cycling ◽  
Microbial Growth ◽  
Inorganic Nitrogen ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Available Nitrogen ◽  
Microbial Nitrogen ◽  
Nitrogen Demand

Abstract. Microbial nitrogen cycling was investigated along a 79 km transect into the Greenland Ice Sheet (GrIS) in early August 2010. The depletion of dissolved nitrate and production of ammonium (relative to icemelt) in cryoconite holes within 7.5 km of the ice sheet margin suggested microbial uptake and ammonification respectively. Nitrogen fixation (<4.2 μmoles C2H4 m−2 day−1 to 16.3 μmoles C2H4 m−2 day−1) was active in some cryoconite holes at sites up to 5.7 km from the ice sheet margin, with nitrogen fixation inversely correlated to concentrations of inorganic nitrogen. There may be the potential for the zone of nitrogen fixation to progressively extend further into the interior of the GrIS as the melt season progresses as reserves of available nitrogen are depleted. Estimated annual inputs of nitrogen from nitrogen fixation along the transect were at least two orders of magnitude lower than inputs from precipitation, with the exception of a 100 m long marginal debris-rich zone where nitrogen fixation could potentially equal or exceed that of precipitation. The average estimated contribution of nitrogen fixation to the nitrogen demand of net microbial growth at sites along the transect ranged from 0% to 17.5%.

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