title: Simultaneous determinations of nitrification and nitrate reduction in coastal sediments by a 15N dilution technique.
abstract: Nitrification, the oxidation of ammonia to nitrite and nitrate, and nitrate reduction by bacteria in coastal sediments of Mangoku-Ura and Odawa Bay were simultaneously determined by a 15N dilution technique. In muddy sediments of Mangoku-Ura, nitrate reduction proceeded at a rate of 10(-2) to 10 X 10(-2) microgram-atoms of N/g per h. Nitrification was far less intensive. Denitrification, or N2 production from nitrate, accounted for about 30% of the nitrate reduction. A simultaneous occurrence of nitrification and nitrate reduction with a similar rate of 10(-2) microgram-atoms of N/g per h was demonstrated in sandy sediment collected from a Zostera bed of Odawa Bay.
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D009587:Nitrogen Isotopes; D010084:Oxidation-Reduction; D012623:Seawater; D012988:Soil Microbiology; D014871:Water Microbiology
chemical_list: D009566:Nitrates; D009573:Nitrites; D009587:Nitrogen Isotopes; D000641:Ammonia