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
An investigation of the errors resulted from distribution curve transformations using six different methods was made on the basis of 61 sets of jig performance test data from the coal preparation plants in China. The ...An investigation of the errors resulted from distribution curve transformations using six different methods was made on the basis of 61 sets of jig performance test data from the coal preparation plants in China. The results indicate that minimum error occurred when distribution curves were transformed by keeping imperfection I constant. Generalized distribution curves are developed for jigs and their applications are discussed.展开更多
Targeting Induced Local Lesions IN Genomes （TILLING） is a reverse genetics strategy for the high-throughput screening of induced mutations.γ, radiation, which often induces both insertion/deletion （Indel） and poi...Targeting Induced Local Lesions IN Genomes （TILLING） is a reverse genetics strategy for the high-throughput screening of induced mutations.γ, radiation, which often induces both insertion/deletion （Indel） and point mutations, has been widely used in mutation induction and crop breeding. The present study aimed to develop a simple, high-throughput TILLING system for screening γ ray-induced mutations using high-resolution melting （HRM） analysis. Pooled rice （Oryza sativa） samples mixed at a 1：7 ratio of Indel mutant to wild-type DNA could be distinguished from the wild-type controls by HRM analysis. Thus, an HRM-TILLING system that analyzes pooled samples of four M2 plants is recommended for screening γ, ray-induced mutants in rice. For demonstration, a γ, ray-mutagenized M2 rice population （n=4560） was screened for mutations in two genes, OsLCT1 and SPDT, using this HRM-TILLING system. Mutations including one single nucleotide substitution （G→A） and one single nucleotide insertion （A） were identified in OsLCT1, and one tdnucleotide （TTC） deletion was identified in SPDT. These mutants can be used in rice breeding and genetic studies, and the findings are of importance for the application of γ, ray mutagenesis to the breeding of rice and other seed crops.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An investigation of the errors resulted from distribution curve transformations using six different methods was made on the basis of 61 sets of jig performance test data from the coal preparation plants in China. The results indicate that minimum error occurred when distribution curves were transformed by keeping imperfection I constant. Generalized distribution curves are developed for jigs and their applications are discussed.
基金Project supported by the National Key Research and Development Program of China(No.2016YFD0102103)
文摘Targeting Induced Local Lesions IN Genomes （TILLING） is a reverse genetics strategy for the high-throughput screening of induced mutations.γ, radiation, which often induces both insertion/deletion （Indel） and point mutations, has been widely used in mutation induction and crop breeding. The present study aimed to develop a simple, high-throughput TILLING system for screening γ ray-induced mutations using high-resolution melting （HRM） analysis. Pooled rice （Oryza sativa） samples mixed at a 1：7 ratio of Indel mutant to wild-type DNA could be distinguished from the wild-type controls by HRM analysis. Thus, an HRM-TILLING system that analyzes pooled samples of four M2 plants is recommended for screening γ, ray-induced mutants in rice. For demonstration, a γ, ray-mutagenized M2 rice population （n=4560） was screened for mutations in two genes, OsLCT1 and SPDT, using this HRM-TILLING system. Mutations including one single nucleotide substitution （G→A） and one single nucleotide insertion （A） were identified in OsLCT1, and one tdnucleotide （TTC） deletion was identified in SPDT. These mutants can be used in rice breeding and genetic studies, and the findings are of importance for the application of γ, ray mutagenesis to the breeding of rice and other seed crops.
