Owing to exploring the biosorption mechanism of Fusarium oxysporum to Cd,the adsorption capacities of live and dead biomass of F.oxysporum strain KF2 were detected.The result showed both the live and dead biomass of s...Owing to exploring the biosorption mechanism of Fusarium oxysporum to Cd,the adsorption capacities of live and dead biomass of F.oxysporum strain KF2 were detected.The result showed both the live and dead biomass of strain KF2 could tolerate the Cd concentration up to 200 mg/L,and had the largest adsorption capacities for Cd,at 2.21 and 1.86 mg/g,respectively,with the inoculation amount of 3 g,the pH at 6,and the initial Cd concentration of 100 mg/L.The pseudo-second-order kinetic model(live biomass r^(2)>0.99,dead biomass r^(2)>0.90)was more suitable for describing the adsorption process of strain KF2.It indicated that the physicochemical adsorption on the cell surface might be the main pattern for Cd removal.Furthermore,the FTIR results showed that the main functional groups for cell wall to bind Cd were carboxyl,hydroxyl,amino,and phosphate.展开更多
The microbial dolomite model has been used to interpret the origin of sedimentary dolomite.In this model,the formation of low-temperature protodolomite,an important precursor to sedimentary dolomite,can be facilitated...The microbial dolomite model has been used to interpret the origin of sedimentary dolomite.In this model,the formation of low-temperature protodolomite,an important precursor to sedimentary dolomite,can be facilitated either by actively metabolizing cells of anaerobic microbes and aerobic halophilic archaea or by their inactive biomass.Aerobic halophilic bacteria are widely distributed in(proto-)dolomite-depositing evaporitic environments and their biomass might serve as a template for the crystallization of protodolomite.To test this hypothesis,carbonation experiments were conducted using dead biomass of an aerobic halophilic bacterium(Exiguobacterium sp.strain JBHLT-3).Our results show that dead biomass of JBHLT-3 can accelerate Mg2+uptake in carbonate mineral precipitates.In addition,the amount of Mg incorporated into Ca-Mg carbonates is proportional to the concentration of biomass.High Mg-calcite is produced with 0.25 or 0.5 g/L biomass,whereas protodolomite forms with 1 g/L biomass.This is confirmed by the main Raman peak of Ca-Mg carbonates,which shifts towards higher wavenumbers with increased Mg substitution.Microbial cells and their imprints are preserved on the surface of high Mg-calcite and protodolomite.Hence,this study furthers our understanding of the dolomitization within buried and dead microbial mats,which provides useful insights into the origin of ancient dolomite.展开更多
基金Sponsored by University-Enterprise Science and Technology Cooperation Project between Hubei Polytechnic University and Huangshi Branch of Hubei West Hubei Geological Survey and Design Institute Co.,Ltd.(KY2022-160)。
文摘Owing to exploring the biosorption mechanism of Fusarium oxysporum to Cd,the adsorption capacities of live and dead biomass of F.oxysporum strain KF2 were detected.The result showed both the live and dead biomass of strain KF2 could tolerate the Cd concentration up to 200 mg/L,and had the largest adsorption capacities for Cd,at 2.21 and 1.86 mg/g,respectively,with the inoculation amount of 3 g,the pH at 6,and the initial Cd concentration of 100 mg/L.The pseudo-second-order kinetic model(live biomass r^(2)>0.99,dead biomass r^(2)>0.90)was more suitable for describing the adsorption process of strain KF2.It indicated that the physicochemical adsorption on the cell surface might be the main pattern for Cd removal.Furthermore,the FTIR results showed that the main functional groups for cell wall to bind Cd were carboxyl,hydroxyl,amino,and phosphate.
基金jointly supported by the National Natural Science Foundation of China(Nos.42272046,42072336 and 41772362)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB26000000)+1 种基金the 111 Project of China(No.BP0820004)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(No.CUGCJ1703)。
文摘The microbial dolomite model has been used to interpret the origin of sedimentary dolomite.In this model,the formation of low-temperature protodolomite,an important precursor to sedimentary dolomite,can be facilitated either by actively metabolizing cells of anaerobic microbes and aerobic halophilic archaea or by their inactive biomass.Aerobic halophilic bacteria are widely distributed in(proto-)dolomite-depositing evaporitic environments and their biomass might serve as a template for the crystallization of protodolomite.To test this hypothesis,carbonation experiments were conducted using dead biomass of an aerobic halophilic bacterium(Exiguobacterium sp.strain JBHLT-3).Our results show that dead biomass of JBHLT-3 can accelerate Mg2+uptake in carbonate mineral precipitates.In addition,the amount of Mg incorporated into Ca-Mg carbonates is proportional to the concentration of biomass.High Mg-calcite is produced with 0.25 or 0.5 g/L biomass,whereas protodolomite forms with 1 g/L biomass.This is confirmed by the main Raman peak of Ca-Mg carbonates,which shifts towards higher wavenumbers with increased Mg substitution.Microbial cells and their imprints are preserved on the surface of high Mg-calcite and protodolomite.Hence,this study furthers our understanding of the dolomitization within buried and dead microbial mats,which provides useful insights into the origin of ancient dolomite.
