111 research outputs found
Biological sources and sinks of nitrous oxide and strategies to mitigate emissions
Nitrous oxide (N
2
O) is a powerful atmospheric greenhouse gas and cause of ozone layer depletion. Global emissions continue to rise. More than two-thirds of these emissions arise from bacterial and fungal denitrification and nitrification processes in soils, largely as a result of the application of nitrogenous fertilizers. This article summarizes the outcomes of an interdisciplinary meeting, ‘Nitrous oxide (N
2
O) the forgotten greenhouse gas’, held at the Kavli Royal Society International Centre, from 23 to 24 May 2011. It provides an introduction and background to the nature of the problem, and summarizes the conclusions reached regarding the biological sources and sinks of N
2
O in oceans, soils and wastewaters, and discusses the genetic regulation and molecular details of the enzymes responsible. Techniques for providing global and local N
2
O budgets are discussed. The findings of the meeting are drawn together in a review of strategies for mitigating N
2
O emissions, under three headings, namely: (i) managing soil chemistry and microbiology, (ii) engineering crop plants to fix nitrogen, and (iii) sustainable agricultural intensification.
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Cytochrome P-450-dependent catabolism of triethanolamine in Rhodotorula mucilaginosa
The yeast Rhodotorula mucilaginosa was able to grow in media containing triethanolamine or diethanolamine as the sole nitrogen source. During growth in the presence of triethanolamine, extracts of yeast cells contained increased levels of cytochrome P-450 dependent monooxygenase which catalyzed the oxidative N-dealkylation of aminoalcohols. Formation of diethanolamine, ethanolamine and glyoxylate from triethanolamine was demonstrated, and the identity of the products was verified by thin layer chromatography. These observations suggested the following scheme of triethanolamine catabolism: triethanolamine → diethanolamine + glycolaldehyde, diethanolamine → ethanolamine + glycolaldehyde, ethanolamine → NH3 + glycolaldehyde → glycolate → glyoxylate → glycerate pathway. © 1991 Kluwer Academic Publishers
Design and construction of the MicroBooNE detector
This paper describes the design and construction of the MicroBooNE liquid
argon time projection chamber and associated systems. MicroBooNE is the first
phase of the Short Baseline Neutrino program, located at Fermilab, and will
utilize the capabilities of liquid argon detectors to examine a rich assortment
of physics topics. In this document details of design specifications, assembly
procedures, and acceptance tests are reported
Contribution of Microbe-Mediated Processes in Nitrogen Cycle to Attain Environmental Equilibrium
Nitrogen (N), the most important element, is required by all living organisms for
the synthesis of complex organic molecules like amino acids, proteins, lipids etc.
Nitrogen cycle is considered to be the most complex yet arguably important cycle
next to carbon cycle. Nitrogen cycle includes oxic and anoxic reactions like
organic N mineralization, ammonia assimilation, nitrification denitrification,
anaerobic ammonium oxidation (anammox), dissimilatory nitrate reduction to
ammonium (DNRA), comammox, codenitrification etc. Nitrogen cycling is one
of the most crucial processes required for the recycling of essential chemical
requirements on the planet. Soil microorganisms not only improve N-cycle
balance but also pave the way for sustainable agricultural practices, leading to
improved soil properties and crop productivity as most plants are opportunistic in
the uptake of soluble or available forms of N from soil. Microbial N
transformations are influenced by plants to improve their nutrition and vice
versa. Diverse microorganisms, versatile metabolic activities, and varied biotic and abiotic conditions may result in the shift in the equilibrium state of different
N-cycling processes. This chapter is an overview of the mechanisms and genes
involved in the diverse microorganisms associated in the operation of nitrogen
cycle and the roles of such microorganisms in different agroecosystems
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