Microorganisms being used in Cd-contaminated soil remediation have broad prospects in application.In order to obtain more Cd-tolerant microbial resources,paddy soils around lead-zinc tailings were collected to extract...Microorganisms being used in Cd-contaminated soil remediation have broad prospects in application.In order to obtain more Cd-tolerant microbial resources,paddy soils around lead-zinc tailings were collected to extract Cdtolerant bacterial strains by using the methods of enrichment culture,purification and gradient screening.The strains were identified by morphological and biochemical characteristics and 16S rDNA sequence analysis.The Cd-tolerance and Cdadsorption abilities were then analyzed.The results showed that 6 Cd-tolerant bacterial strains were isolated,3 strains could grow in solid medium which had a cadmium concentration of 700 mg/L.These three strains(i.e.KGJ,KDT,and TU)were members of the Pseudomonas genus(Pseudomonas sp.)identified by morphological and biochemical characteristics and 16S rDNA sequence analysis.The growth curve indicated that the growth rates of the strains were obviously inhibited under 250 mg/L cadmium treatment.The three strains were tolerant of cadmium concentrations over 250 mg/L for long periods of time up to the stationary phase,and TU had the strongest Cd-tolerance.The order of metal tolerance of TU to different heavy metals was Cd^2+ >Zn^2+ >Pb^2+respectively.Chemical analysis showed that the adsorption quantity of the 3 bacterial strains of KGJ,KDT,and TU were 7.596 mg/g,12.237 mg/g and 36.926 mg/g respectively by dry-weight,when the concentration of cadmium was 150 mg/L.All 3 strains had good tolerance and ability to adsorb cadmium,and therefore are considered important potential microbial resources for the remediation of Cd pollution in soil.展开更多
In order to simplify the extraction process of tea saponin and improve its extraction rate,tea seed meals was taken as materials to explore effects of ^(60)Coγ-irradiation and H_(2)O_(2) on the extraction rate of tea...In order to simplify the extraction process of tea saponin and improve its extraction rate,tea seed meals was taken as materials to explore effects of ^(60)Coγ-irradiation and H_(2)O_(2) on the extraction rate of tea saponin.The results showed that the optimal crude extract condition of tea saponin was 6%H_(2)O_(2) and an irradiation dose of 5 kGy,the extraction rate was 46.4%.However,when the irradiation dose and the H_(2)O_(2) concentration continued to increase,the extraction rate of tea saponin decreased.After flocculate extraction,the tea saponin content increased from 40.80%to 48.32%.Foaming property test results showed that the higher the tea saponin content in the solution was,the higher the foaming height will be,and the foam had a certain stability.This work provided a new method for the extraction of natural products,usingγ-ray irradiation and H_(2)O_(2) pretreatment to improve the extraction rate,and this was of great significance for industrial extraction.展开更多
Explants,namely the seeds (Cymbidium faberi) and buds (Cymbidium goeringii) of local Hunan orchids were disinfected with 75% ethanol, 0.1% mercuric chloride,and 10% sodium hypochlorite in six different disinfection tr...Explants,namely the seeds (Cymbidium faberi) and buds (Cymbidium goeringii) of local Hunan orchids were disinfected with 75% ethanol, 0.1% mercuric chloride,and 10% sodium hypochlorite in six different disinfection treatments. Results showed that The treatment with 75% ethanol (contact time: 45 s) and 0.1% mercuric chloride (contact time: 8 min) proved to be the most effective one in disinfecting the explants of Cymbidium faberi seeds.The combination of 75% ethanol (contact time: 45 s) and 0.1% mercuric chloride (contact time: 5 min) provided the optimal disinfection effects when disinfecting Cymbidium goeringii buds.In general, the disinfection effect of mercuric chloride was found to be superior to that of sodium hypochlorite,but care should be taken with the disinfection time to avoid damage to the explants.展开更多
Comprehensive Summary Developing new catalysts for highly selectivity and conversion of saturated C(sp^(3))-H bonds is of great significance.In order to obtain catalysts with high catalytic performance,six Eu-based MO...Comprehensive Summary Developing new catalysts for highly selectivity and conversion of saturated C(sp^(3))-H bonds is of great significance.In order to obtain catalysts with high catalytic performance,six Eu-based MOFs with different structural characteristics were obtained by using europium ions and different organic acid ligands,namely Eu-1~Eu-6.Eu-1,Eu-2 and Eu-3 featured three-dimensional structures,while Eu-4 and Eu-5 featured two-dimensional structures.展开更多
基金Supported by Hunan Key Research&Development Project(2016SK2056)~~
文摘Microorganisms being used in Cd-contaminated soil remediation have broad prospects in application.In order to obtain more Cd-tolerant microbial resources,paddy soils around lead-zinc tailings were collected to extract Cdtolerant bacterial strains by using the methods of enrichment culture,purification and gradient screening.The strains were identified by morphological and biochemical characteristics and 16S rDNA sequence analysis.The Cd-tolerance and Cdadsorption abilities were then analyzed.The results showed that 6 Cd-tolerant bacterial strains were isolated,3 strains could grow in solid medium which had a cadmium concentration of 700 mg/L.These three strains(i.e.KGJ,KDT,and TU)were members of the Pseudomonas genus(Pseudomonas sp.)identified by morphological and biochemical characteristics and 16S rDNA sequence analysis.The growth curve indicated that the growth rates of the strains were obviously inhibited under 250 mg/L cadmium treatment.The three strains were tolerant of cadmium concentrations over 250 mg/L for long periods of time up to the stationary phase,and TU had the strongest Cd-tolerance.The order of metal tolerance of TU to different heavy metals was Cd^2+ >Zn^2+ >Pb^2+respectively.Chemical analysis showed that the adsorption quantity of the 3 bacterial strains of KGJ,KDT,and TU were 7.596 mg/g,12.237 mg/g and 36.926 mg/g respectively by dry-weight,when the concentration of cadmium was 150 mg/L.All 3 strains had good tolerance and ability to adsorb cadmium,and therefore are considered important potential microbial resources for the remediation of Cd pollution in soil.
文摘In order to simplify the extraction process of tea saponin and improve its extraction rate,tea seed meals was taken as materials to explore effects of ^(60)Coγ-irradiation and H_(2)O_(2) on the extraction rate of tea saponin.The results showed that the optimal crude extract condition of tea saponin was 6%H_(2)O_(2) and an irradiation dose of 5 kGy,the extraction rate was 46.4%.However,when the irradiation dose and the H_(2)O_(2) concentration continued to increase,the extraction rate of tea saponin decreased.After flocculate extraction,the tea saponin content increased from 40.80%to 48.32%.Foaming property test results showed that the higher the tea saponin content in the solution was,the higher the foaming height will be,and the foam had a certain stability.This work provided a new method for the extraction of natural products,usingγ-ray irradiation and H_(2)O_(2) pretreatment to improve the extraction rate,and this was of great significance for industrial extraction.
文摘Explants,namely the seeds (Cymbidium faberi) and buds (Cymbidium goeringii) of local Hunan orchids were disinfected with 75% ethanol, 0.1% mercuric chloride,and 10% sodium hypochlorite in six different disinfection treatments. Results showed that The treatment with 75% ethanol (contact time: 45 s) and 0.1% mercuric chloride (contact time: 8 min) proved to be the most effective one in disinfecting the explants of Cymbidium faberi seeds.The combination of 75% ethanol (contact time: 45 s) and 0.1% mercuric chloride (contact time: 5 min) provided the optimal disinfection effects when disinfecting Cymbidium goeringii buds.In general, the disinfection effect of mercuric chloride was found to be superior to that of sodium hypochlorite,but care should be taken with the disinfection time to avoid damage to the explants.
基金supported by Changsha Municipal Natural Science Foundation(kq2014164)the Natural Science Foundation of Hunan Province(Grant 2020JJ4684)Science and Technology Innovation Project of Hunan Academy of Agricultural Sciences(2020CX45).
文摘Comprehensive Summary Developing new catalysts for highly selectivity and conversion of saturated C(sp^(3))-H bonds is of great significance.In order to obtain catalysts with high catalytic performance,six Eu-based MOFs with different structural characteristics were obtained by using europium ions and different organic acid ligands,namely Eu-1~Eu-6.Eu-1,Eu-2 and Eu-3 featured three-dimensional structures,while Eu-4 and Eu-5 featured two-dimensional structures.
