0000000001069909

AUTHOR

Naohiko Ohkouchi

0000-0002-6355-7469

showing 2 related works from this author

Biological and physical modification of carbonate system parameters along the salinity gradient in shallow hypersaline solar salterns in Trapani, Ita…

2017

Abstract We investigated changes in the chemical characteristics of evaporating seawater under the influence of microbial activity by conducting geochemical analyses of the brines and evaporite sediments collected from solar salterns in Trapani, Italy. The microbial activity had a substantial effect on the carbonate system parameters. Dissolved inorganic carbon (DIC) was substantially removed from the brine during the course of evaporation from the seawater to the point where calcium carbonate precipitates, with an accompanying decrease in its carbon isotopic composition (δ 13 C DIC ) to as low as −10.6‰. Although the removal of DIC was due to calcium carbonate precipitation, photosynthesis…

0301 basic medicine010504 meteorology & atmospheric sciencesEvaporiteMineralogyengineering.materialBiogeochemical cycle01 natural sciences03 medical and health scienceschemistry.chemical_compoundMicrobial matGeochemistry and PetrologyCompound-specific isotope analysishemic and lymphatic diseasesDissolved organic carbonPhotosynthetic pigmentSulfate0105 earth and related environmental sciencesHypersaline environmentSalinity030104 developmental biologyCalcium carbonatechemistryBiogeochemical cycle; Carbonate system; Compound-specific isotope analysis; Hypersaline environment; Microbial mat; Photosynthetic pigments;Photosynthetic pigmentsengineeringHaliteCarbonateSeawaterCarbonate systemCompound-specific isotope analysiGeologycirculatory and respiratory physiology
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Efficient recycling of nutrients in modern and past hypersaline environments

2019

The biogeochemistry of hypersaline environments is strongly influenced by changes in biological processes and physicochemical parameters. Although massive evaporation events have occurred repeatedly throughout Earth history, their biogeochemical cycles and global impact remain poorly understood. Here, we provide the first nitrogen isotopic data for nutrients and chloropigments from modern shallow hypersaline environments (solar salterns, Trapani, Italy) and apply the obtained insights to ¿ 15 N signatures of the Messinian salinity crisis (MSC) in the late Miocene. Concentrations and ¿ 15 N of chlorophyll a, bacteriochlorophyll a, nitrate, and ammonium in benthic microbial mats indicate that…

0301 basic medicineBiogeochemical cycleMultidisciplinaryDenitrificationhypersaline environmentslcsh:Rlcsh:MedicineBiogeochemistryLate MioceneArticleSalinity03 medical and health scienceschemistry.chemical_compound030104 developmental biology0302 clinical medicinechemistryAnammoxEnvironmental chemistryEnvironmental sciencelcsh:QAmmoniumNitrificationlcsh:Science030217 neurology & neurosurgeryScientific Reports
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