Experimental strategies to measure the microbial uptake and mineralization kinetics of dissolved organic carbon in soil

作     者：Baozhen Li Tida Ge Paul W.Hill Davey L.Jones Zhenke Zhu Mostafa Zhran Jinshui Wu Baozhen Li;Tida Ge;Paul W.Hill;Davey L.Jones;Zhenke Zhu;Mostafa Zhran;Jinshui Wu

作者机构：Key Laboratory of Agro-ecological Processes in Subtropical Region&Changsha Research Station for Agricultural and Environmental MonitoringInstitute of Subtropical AgricultureChinese Academy of SciencesChangSha 410125China School of Natural SciencesBangor UniversityBangorGwynedd LL572UWUK Soil and Water Research DepartmentNuclear Research CenterAtomic Energy AuthorityAbou-Zaabl13759Egypt University of Chinese Academy of SciencesBeijing 100049China 

出 版 物：《Soil Ecology Letters》 (土壤生态学快报（英文）)

年 卷 期：2020年第2卷第3期

页      面：180-187页

学科分类：09[农学] 0903[农学-农业资源与环境] 090301[农学-土壤学] 

基　　金：financially supported by grants from the National Key Research and Development Program(2016YFE0101100) the Australia-China Joint Research Centre-Healthy Soils for Sustainable Food Production and Environmental Quality(ACSRF48165) the National Natural Science Foundation of China(41522107,41430860) the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB15020401) Royal Society Newton Advanced Fellowship(NA150182) Talented Young Scientist Program(TYSP)to Mostafa Zhran supported by China Science and Technology Exchange Center(Egypt-19-004) the State Scholarship Fund of China Scholarship Council(CSC)to Baozhen Li 

主　　题：^(14)C tracer Microbial uptake Carbon mineralization Turnover 

摘      要：Soil organic matter turnover rates are typically estimated from mass loss of the material over time or from on rates of carbon dioxide *** the study,we investigated a new way to characterize the concentration-dependent kinetics of amino acids used by measuring microbial uptake and mineralization of ^(14)*** measured the depletion from soil solution after additions ^(14)*** microbial uptake of ^(14)C-alanine from soil solution was concentration-dependent and kinetic analysis indicated the operation of at least three distinct alanine transport systems of differing *** of the ^(14)C-alanine depletion from the soil solution occurred rapidly within the first 10-30 min of the incubation after 10μM to 1 mM substrate *** alanine concentrations less than 250μM,the kinetic parameters for K_(m) and V_(max) of the higher-affinity transporter were 60.0μM and 1.32μmol g^(-1) DW soil h^(-1),*** mineralization of alanine was determined and the half-time values for the rapid mineralization process were 45 min to 1.5 h after the addition at alanine concentrations below 1 *** time delay after its uptake into microbial biomass suggested that alanine uptake and subsequent respiration were uncoupled *** microbial N uptake rate was calculated by microbial mineralization,and an estimated K_(m) value of 1731.7±274.6μM and V_(max )value of 486.0±38.5μmol kg^(-1)DW soil h^(-1).This study provides an alternative approach for measuring the rate of turnover of compounds that turnover very rapidly in soil.