The DNA sequence diversities for microbial communities in soils contaminated by heavy metal (HM) Cadmium (Cd) and polycyclic aromatic hydrocarbon (PAH) phenanthrene were evaluated by Random Amplified Polymorphic DNA (...The DNA sequence diversities for microbial communities in soils contaminated by heavy metal (HM) Cadmium (Cd) and polycyclic aromatic hydrocarbon (PAH) phenanthrene were evaluated by Random Amplified Polymorphic DNA (RAPD) analysis in pot and laboratory experiments. Fourteen random primers were used to amplify RAPDs from microbial community DNAs in four soils contaminated by HM or/and PAH. The products of 14 primers were separated in gel and generated 212 reliable fragments, of which 203 were polymorphic. The numbers of microorganisms (fungi, bacteria and actinomycetes) were also analyzed. The results showed that the total number of microorganisms in the soil polluted by Cd was lowest among the soils, about 67.4 % lower than the soil without pollution, especially the number of bacterial, about 73.8 %. In contrast, there was the highest number of microorganisms in the soil polluted by phenanthrene, about 180 % more than those in the control without pollution, especially the number of actinomycete, about 19 times of control. The number of microorganism of soil polluted by Cd + phenanthrene was fallen between Cd and phenanthrene, about 19.5 % lower than control. The number of fungi showed no significant differences among soils. However, increases in DNA sequence diversity were observed in all contaminated soil samples. The effects were stronger in the case of soil contaminated with PAH and HM than those in soils amended with HM or PAH, separately. The soil with Cd and phenanthrene had the highest richness, modified richness and Shannon-Weaver index. These results showed that HM or/and PAH might result in some changes for soil microbe’s DNA itself, such as sequence breakage or insertion and genomic rearrangement. The RAPD marker technique combined with traditional methods appears to be an effective approach for studying the combined effects of HM and PAH on DNA sequence diversity of soil microbial community.展开更多
为治理镉砷污染农田土壤,选取湘南某矿区镉砷复合污染稻田土壤,以水稻盆栽实验研究了复合改良剂HZB（羟基磷灰石＋沸石＋改性秸秆炭）对土壤中镉（Cd）、砷（As）赋存形态以及水稻累积转运Cd和As的影响。结果表明,施用HZB能提高土壤p H ...为治理镉砷污染农田土壤,选取湘南某矿区镉砷复合污染稻田土壤,以水稻盆栽实验研究了复合改良剂HZB（羟基磷灰石＋沸石＋改性秸秆炭）对土壤中镉（Cd）、砷（As）赋存形态以及水稻累积转运Cd和As的影响。结果表明,施用HZB能提高土壤p H 0.19~0.79个单位,阳离子交换量增加22.1%~60.4%;施用HZB使活性较大的酸提取态Cd含量降低了6.5%~22.9%,促进了Cd向难溶态的转变,可使有机结合态Cd增加2.5%~56.5%;施用HZB促进活性As向难溶型的钙型As转化,钙型As含量增加2.8%~53.3%,也可使交换态As含量降低7.0%~39.5%,但当施用量超过4.0 g kg-1时则会增加交换态As含量。水稻根系对Cd的富集系数在0.65~1.21之间,对As的富集系数在0.033~0.049之间,富集Cd的能力大于As;谷壳对Cd的转运能力最大,而根系对As的转运能力最大;施用HZB有降低水稻根系富集Cd和As的能力。施用0.5~2.0 g kg-1的HZB能降低水稻地上各部位中Cd和As含量;在2 g kg-1施用水平,水稻糙米中Cd和As含量均低于0.2 mg kg-1,达到国家食品污染物限量标准。展开更多
基金Item supported by major state basic re-search development program ( 973 ) of China ( No.2004CB18503)national natural science foundation of China(No. 20337010) key program of basic research of Shanghai(No.04JC14051)
文摘The DNA sequence diversities for microbial communities in soils contaminated by heavy metal (HM) Cadmium (Cd) and polycyclic aromatic hydrocarbon (PAH) phenanthrene were evaluated by Random Amplified Polymorphic DNA (RAPD) analysis in pot and laboratory experiments. Fourteen random primers were used to amplify RAPDs from microbial community DNAs in four soils contaminated by HM or/and PAH. The products of 14 primers were separated in gel and generated 212 reliable fragments, of which 203 were polymorphic. The numbers of microorganisms (fungi, bacteria and actinomycetes) were also analyzed. The results showed that the total number of microorganisms in the soil polluted by Cd was lowest among the soils, about 67.4 % lower than the soil without pollution, especially the number of bacterial, about 73.8 %. In contrast, there was the highest number of microorganisms in the soil polluted by phenanthrene, about 180 % more than those in the control without pollution, especially the number of actinomycete, about 19 times of control. The number of microorganism of soil polluted by Cd + phenanthrene was fallen between Cd and phenanthrene, about 19.5 % lower than control. The number of fungi showed no significant differences among soils. However, increases in DNA sequence diversity were observed in all contaminated soil samples. The effects were stronger in the case of soil contaminated with PAH and HM than those in soils amended with HM or PAH, separately. The soil with Cd and phenanthrene had the highest richness, modified richness and Shannon-Weaver index. These results showed that HM or/and PAH might result in some changes for soil microbe’s DNA itself, such as sequence breakage or insertion and genomic rearrangement. The RAPD marker technique combined with traditional methods appears to be an effective approach for studying the combined effects of HM and PAH on DNA sequence diversity of soil microbial community.
文摘为治理镉砷污染农田土壤,选取湘南某矿区镉砷复合污染稻田土壤,以水稻盆栽实验研究了复合改良剂HZB（羟基磷灰石＋沸石＋改性秸秆炭）对土壤中镉（Cd）、砷（As）赋存形态以及水稻累积转运Cd和As的影响。结果表明,施用HZB能提高土壤p H 0.19~0.79个单位,阳离子交换量增加22.1%~60.4%;施用HZB使活性较大的酸提取态Cd含量降低了6.5%~22.9%,促进了Cd向难溶态的转变,可使有机结合态Cd增加2.5%~56.5%;施用HZB促进活性As向难溶型的钙型As转化,钙型As含量增加2.8%~53.3%,也可使交换态As含量降低7.0%~39.5%,但当施用量超过4.0 g kg-1时则会增加交换态As含量。水稻根系对Cd的富集系数在0.65~1.21之间,对As的富集系数在0.033~0.049之间,富集Cd的能力大于As;谷壳对Cd的转运能力最大,而根系对As的转运能力最大;施用HZB有降低水稻根系富集Cd和As的能力。施用0.5~2.0 g kg-1的HZB能降低水稻地上各部位中Cd和As含量;在2 g kg-1施用水平,水稻糙米中Cd和As含量均低于0.2 mg kg-1,达到国家食品污染物限量标准。
