Microorganisms are crucial in the bioremediation of organophosphorus pesticides. However, most functional microorganisms (> 99%) are yet to be cultivated. This study applied two cultivation-independent approaches, ...Microorganisms are crucial in the bioremediation of organophosphorus pesticides. However, most functional microorganisms (> 99%) are yet to be cultivated. This study applied two cultivation-independent approaches, DNA-SIP and magnetic-nanoparticle mediated isolation (MMI), to identify the functional microorganisms in degrading dimethoate in agricultural soils. MMI identified five dimethoate degraders: Pseudomonas, Bacillus, Ramlibacter, Arthrobacter, and Rhodococcus, whereas DNA-SIP identified three dimethoate degraders: Ramlibacter, Arthrobacter, and Rhodococcus. Also, MMI showed higher resolution than DNA-SIP in identifying functional microorganisms. Two organic phosphohydrolase (OPH) genes: ophC2 and ophB, were involved in dimethoate metabolism, as revealed by DNA-SIP and MMI. The degradation products of dimethoate include omethoate, O,O,S-trimethyl thiophosphorothioate, N-methyl-2-sulfanylacetamide, O,O-diethyl S-hydrogen phosphorodithioate, O,O,O-trimethyl thiophosphate, O,O,S-trimethyl thiophosphorodithioate, and O,O,O-trimethyl phosphoric. This study emphasizes the feasibility of using SIP and MMI to explore the functional dimethoate degraders, expanding our knowledge of microbial resources with cultivation-independent approaches.展开更多
A novel class of high-entropy rare-earth metal diborodicarbide(Y_(0.2)5 Yb_(0.25)Dy_(0.25)Er_(0.25))B_(2)C_(2)(HE-REB_(2)C_(2))ceramics was successfully fabricated using the in-situ reactive spark plasma sintering(SPS...A novel class of high-entropy rare-earth metal diborodicarbide(Y_(0.2)5 Yb_(0.25)Dy_(0.25)Er_(0.25))B_(2)C_(2)(HE-REB_(2)C_(2))ceramics was successfully fabricated using the in-situ reactive spark plasma sintering(SPS)technology for the first time.Single solid solution with a typical tetragonal structure was formed,having a homogeneous distribution of four rare-earth elements,such as Y,Yb,Dy,and Er.Coefficients of thermal expansion(CTEs)along the a and c directions(aa and ac)were determined to be 4.18 and 16.06μK^(-1),respectively.Thermal expansion anisotropy of the as-obtained HE-REB_(2)C_(2)was attributed to anisotropy of the crystal structure of HE-REB_(2)C_(2).The thermal conductivity(k)of HE-REB_(2)C_(2)was 9.2±0.09 W·m^(-1)·K^(-1),which was lower than that of YB_(2)C_(2)(19.2±0.07 W·m^(-1)·K^(-1)),DyB_(2)C_(2)(11.90.06 W·m^(-1)·K^(-1)),and ErB_(2)C_(2)(12.10.03 W·m^(-1)·K^(-1)),due to high-entropy effect and sluggish diffusion effect of high-entropy ceramics(HECs).Furthermore,Vickers hardness of HE-REB_(2)C_(2)was slightly higher than that of REB_(2)C_(2)owing to the solid solution hardening mechanism of HECs.Typical nano-laminated fracture morphologies,such as kink boundaries,delamination,and slipping were observed at the tip of Vickers indents,suggesting ductile behavior of HE-REB_(2)C_(2).This newly investigated class of ductile HE-REB_(2)C_(2)ceramics expanded the family of HECs to diboridcarbide compounds,which can lead to more research works on high-entropy rare-earth diboridcarbides in the near future.展开更多
Organophosphate flame retardants(OPFRs),as a replacement for polybrominated diphenyl ethers(PBDEs),are of increasing concern due to their high production over the years.Soil is the major environmental reservoir and in...Organophosphate flame retardants(OPFRs),as a replacement for polybrominated diphenyl ethers(PBDEs),are of increasing concern due to their high production over the years.Soil is the major environmental reservoir and interchange for OPFRs.OPFRs in soil could be transferred to the food chain,and pose potential ecological and human health risks.This review focused on the environmental fate and effects of typical OPFRs in the soil-plant system.We concluded that the sorption and transformation behaviors of OPFRs due to their crucial impact on bioavailability.The root uptake and translocation of OPFRs by plants were summarized with analyses of their potential affecting factors.The in planta transformation and potential ecological effects of OPFRs were also briefly discussed.Finally,we highlighted several research gaps and provided suggestions for future research,including the development of simulative/computative methods to evaluate the bioavailability of OPFRs,the effects of root exudates and rhizosphere microorganisms on the bioavailability and plant uptake of OPFRs,and the development of green and sustainable technologies for in situ remediation of OPFRs-contaminated soil.展开更多
基金The authors would like to thank the National Natural Science Foundation of China(Nos.42177359 and 41807119)the Natural Science Foundation of Beijing(No.8212030)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-20-010A3 and FRF-IDRY-22-001)the Open Fund of National Engineering Laboratory for Site Remediation Technologies(No.NEL-SRT201907).
文摘Microorganisms are crucial in the bioremediation of organophosphorus pesticides. However, most functional microorganisms (> 99%) are yet to be cultivated. This study applied two cultivation-independent approaches, DNA-SIP and magnetic-nanoparticle mediated isolation (MMI), to identify the functional microorganisms in degrading dimethoate in agricultural soils. MMI identified five dimethoate degraders: Pseudomonas, Bacillus, Ramlibacter, Arthrobacter, and Rhodococcus, whereas DNA-SIP identified three dimethoate degraders: Ramlibacter, Arthrobacter, and Rhodococcus. Also, MMI showed higher resolution than DNA-SIP in identifying functional microorganisms. Two organic phosphohydrolase (OPH) genes: ophC2 and ophB, were involved in dimethoate metabolism, as revealed by DNA-SIP and MMI. The degradation products of dimethoate include omethoate, O,O,S-trimethyl thiophosphorothioate, N-methyl-2-sulfanylacetamide, O,O-diethyl S-hydrogen phosphorodithioate, O,O,O-trimethyl thiophosphate, O,O,S-trimethyl thiophosphorodithioate, and O,O,O-trimethyl phosphoric. This study emphasizes the feasibility of using SIP and MMI to explore the functional dimethoate degraders, expanding our knowledge of microbial resources with cultivation-independent approaches.
基金supported by the National Natural Science Foundation of China(Grant Nos.12275337 and 11975296)the Natural Science Foundation of Ningbo City(Grant No.2021J199)+1 种基金We would like to recognize the support from the Ningbo 3315 Innovative Teams Program,China(Grant No.2019A-14-C)Thanks for the financial support of Advanced Energy Science and Technology Guangdong Laboratory(Grant No.HND20TDTHGC00).
文摘A novel class of high-entropy rare-earth metal diborodicarbide(Y_(0.2)5 Yb_(0.25)Dy_(0.25)Er_(0.25))B_(2)C_(2)(HE-REB_(2)C_(2))ceramics was successfully fabricated using the in-situ reactive spark plasma sintering(SPS)technology for the first time.Single solid solution with a typical tetragonal structure was formed,having a homogeneous distribution of four rare-earth elements,such as Y,Yb,Dy,and Er.Coefficients of thermal expansion(CTEs)along the a and c directions(aa and ac)were determined to be 4.18 and 16.06μK^(-1),respectively.Thermal expansion anisotropy of the as-obtained HE-REB_(2)C_(2)was attributed to anisotropy of the crystal structure of HE-REB_(2)C_(2).The thermal conductivity(k)of HE-REB_(2)C_(2)was 9.2±0.09 W·m^(-1)·K^(-1),which was lower than that of YB_(2)C_(2)(19.2±0.07 W·m^(-1)·K^(-1)),DyB_(2)C_(2)(11.90.06 W·m^(-1)·K^(-1)),and ErB_(2)C_(2)(12.10.03 W·m^(-1)·K^(-1)),due to high-entropy effect and sluggish diffusion effect of high-entropy ceramics(HECs).Furthermore,Vickers hardness of HE-REB_(2)C_(2)was slightly higher than that of REB_(2)C_(2)owing to the solid solution hardening mechanism of HECs.Typical nano-laminated fracture morphologies,such as kink boundaries,delamination,and slipping were observed at the tip of Vickers indents,suggesting ductile behavior of HE-REB_(2)C_(2).This newly investigated class of ductile HE-REB_(2)C_(2)ceramics expanded the family of HECs to diboridcarbide compounds,which can lead to more research works on high-entropy rare-earth diboridcarbides in the near future.
基金the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01Z134)the National Natural Science Foundation of China(32061133003 and 41603086)+1 种基金the Guangdong Foundation for Program of Science and Technology Research(2019B121205006)Ten Thousand Talent Program of the Organization Department of the Central Committee of the CPC。
文摘Organophosphate flame retardants(OPFRs),as a replacement for polybrominated diphenyl ethers(PBDEs),are of increasing concern due to their high production over the years.Soil is the major environmental reservoir and interchange for OPFRs.OPFRs in soil could be transferred to the food chain,and pose potential ecological and human health risks.This review focused on the environmental fate and effects of typical OPFRs in the soil-plant system.We concluded that the sorption and transformation behaviors of OPFRs due to their crucial impact on bioavailability.The root uptake and translocation of OPFRs by plants were summarized with analyses of their potential affecting factors.The in planta transformation and potential ecological effects of OPFRs were also briefly discussed.Finally,we highlighted several research gaps and provided suggestions for future research,including the development of simulative/computative methods to evaluate the bioavailability of OPFRs,the effects of root exudates and rhizosphere microorganisms on the bioavailability and plant uptake of OPFRs,and the development of green and sustainable technologies for in situ remediation of OPFRs-contaminated soil.
