Even though biodissolution of chalcopyrite is considered to be one of the key contributors in the formation of acid mine drainage(AMD),there are few studies to control AMD by inhibiting chalcopyrite biodissolution.The...Even though biodissolution of chalcopyrite is considered to be one of the key contributors in the formation of acid mine drainage(AMD),there are few studies to control AMD by inhibiting chalcopyrite biodissolution.Therefore,a novel method of using hematite to inhibit chalcopyrite biodissolution was proposed and verified.The results indicated that chalcopyrite biodissolution could be significantly inhibited by hematite,which consequently decreased the formation of AMD.In the presence of hematite,the final biodissolution rate of chalcopyrite decreased from 57.9%to 44.4%at 20 day.This in turn suggested that the formation of AMD was effectively suppressed under such condition.According to the biodissolution results,mineral composition and morphology analyses,and electrochemical analysis,it was shown that hematite promoted the formation and accumulation of passivation substances(jarosite and Cu2-xS)on chalcopyrite surface,thus inhibiting the biodissolution of chalcopyrite and limiting the formation of AMD.展开更多
Understanding the role of microbes in the solubility of cadmium(Cd) is of fundamental importance for remediation of Cd toxicity. The present study aimed to identify the microbes that involved in regulating Cd solubili...Understanding the role of microbes in the solubility of cadmium(Cd) is of fundamental importance for remediation of Cd toxicity. The present study aimed to identify the microbes that involved in regulating Cd solubility and to reveal possible mechanisms. Therefore,microbial communities were investigated through high-throughput sequencing approach, the molecular ecological network was constructed and metagenomes were predicted. Our results indicated that redox conditions affected both the solubility of soil Cd and the microbial communities. Anaerobic microbes, such as Anaerolineaceae, did not only play important roles in shaping the microbial community in soils, but might also be involved in regulating the Cd solubility. Two possible mechanisms that how Anaerolineaceae involved in Cd solubility are(1) Anaerolineaceae are important organic matter degraders under anoxic conditions and(2) Anaerolineaceae can co-exist with methane metabolism microbes, while methane metabolism promotes the precipitation of soluble Cd. Thus, application of Anaerolineaceae in bioremediation of soil Cadmium contamination is a potential approach. The study provided a novel insight into the role of microbial community in the regulation of Cd solubility under different redox conditions, and suggested a potential approach for the remediation of soil Cd contamination.展开更多
Extraction of high-quality microbial DNA from contaminated environmental samples is an essential step in microbial ecological study. Based on previously published methods for soil and sediment samples, a modified pret...Extraction of high-quality microbial DNA from contaminated environmental samples is an essential step in microbial ecological study. Based on previously published methods for soil and sediment samples, a modified pretreatrnent method was developed for extracting microbial DNA from heavily contaminated river sediment samples via selection of optimal pretreatment parameters (i.e., reagent solution, reaction duration, and temperature). The pretreatment procedure involves wash ing the river sediment sample for three times with a solution containing 0.1 mol.L-1 ethylene diamine tetra- acetic acid (EDTA), 0.1 mol- L-1 Tris (pH 8.0), 1.5 mol. L1 NaC1, 0.1 mol. L-1 NaH2PO4, and Na2HPO4 at 65~C with 180r.min-1 for 15min to remove humic materials and heavy metals prior to the employment of standard DNA extraction procedures. We compared the results of standard procedure DNA extraction following pretreatrnent, without pretreatment, and with using a commercial PowerSoilTM DNA Isolation Kit. The results indicated that the pretreatment significantly improved the DNA quality based on DNA yield, DNA fragment length, and determination of prokaryotic diversity. Prokaryotic diversity exhibited in the DNA with the pretreatment was also considerably higher than that extracted with the Power- SoilTM DNA Isolation Kit only. The pretreatment method worked well even with a small amount of sediment sample (0.25 g or even lower). The method provides a novel, simple, cost-effective tool for DNA extraction for microbial community analysis in environmental monitoring and remediation processes.展开更多
基金supported by the Natural Science Foundation of Hunan Province(No.2018JJ1041)National Natural Science Foundation of China(Nos.51774332,U1932129,51804350 and51934009)。
文摘Even though biodissolution of chalcopyrite is considered to be one of the key contributors in the formation of acid mine drainage(AMD),there are few studies to control AMD by inhibiting chalcopyrite biodissolution.Therefore,a novel method of using hematite to inhibit chalcopyrite biodissolution was proposed and verified.The results indicated that chalcopyrite biodissolution could be significantly inhibited by hematite,which consequently decreased the formation of AMD.In the presence of hematite,the final biodissolution rate of chalcopyrite decreased from 57.9%to 44.4%at 20 day.This in turn suggested that the formation of AMD was effectively suppressed under such condition.According to the biodissolution results,mineral composition and morphology analyses,and electrochemical analysis,it was shown that hematite promoted the formation and accumulation of passivation substances(jarosite and Cu2-xS)on chalcopyrite surface,thus inhibiting the biodissolution of chalcopyrite and limiting the formation of AMD.
基金supported by the National Natural Science Foundation of China (Nos.31570113 and 41573072)the Scientific Research Fund of Hunan Provincial Education Department in China (No.17 K035)+1 种基金Chinese Postdoctoral Funding Planthe Central South University Postdoctoral Research Funding for D.M.(No.201699)
文摘Understanding the role of microbes in the solubility of cadmium(Cd) is of fundamental importance for remediation of Cd toxicity. The present study aimed to identify the microbes that involved in regulating Cd solubility and to reveal possible mechanisms. Therefore,microbial communities were investigated through high-throughput sequencing approach, the molecular ecological network was constructed and metagenomes were predicted. Our results indicated that redox conditions affected both the solubility of soil Cd and the microbial communities. Anaerobic microbes, such as Anaerolineaceae, did not only play important roles in shaping the microbial community in soils, but might also be involved in regulating the Cd solubility. Two possible mechanisms that how Anaerolineaceae involved in Cd solubility are(1) Anaerolineaceae are important organic matter degraders under anoxic conditions and(2) Anaerolineaceae can co-exist with methane metabolism microbes, while methane metabolism promotes the precipitation of soluble Cd. Thus, application of Anaerolineaceae in bioremediation of soil Cadmium contamination is a potential approach. The study provided a novel insight into the role of microbial community in the regulation of Cd solubility under different redox conditions, and suggested a potential approach for the remediation of soil Cd contamination.
基金The authors thank Yinghua Cen and Xian Fu for their suggestions during manuscript preparation. The authors thank Stephanie Baehas-Daunert for her helps in English language modifications. This research was supported by the National Basic Research Program of China (Grant No. 2012CB22307), the National Natural Science Foundation of China (Grant No. 31170470), Guangdong Provincial Natural Science Foundation of Research Team Program (9351007002000001 ), the International Cooperation Projects of Guangdong Province (2011B050400005) and Guangdong Provincial Programs for Science and Technology Development (2012A061100009). No conflict of interest exits in this manuscript.
文摘Extraction of high-quality microbial DNA from contaminated environmental samples is an essential step in microbial ecological study. Based on previously published methods for soil and sediment samples, a modified pretreatrnent method was developed for extracting microbial DNA from heavily contaminated river sediment samples via selection of optimal pretreatment parameters (i.e., reagent solution, reaction duration, and temperature). The pretreatment procedure involves wash ing the river sediment sample for three times with a solution containing 0.1 mol.L-1 ethylene diamine tetra- acetic acid (EDTA), 0.1 mol- L-1 Tris (pH 8.0), 1.5 mol. L1 NaC1, 0.1 mol. L-1 NaH2PO4, and Na2HPO4 at 65~C with 180r.min-1 for 15min to remove humic materials and heavy metals prior to the employment of standard DNA extraction procedures. We compared the results of standard procedure DNA extraction following pretreatrnent, without pretreatment, and with using a commercial PowerSoilTM DNA Isolation Kit. The results indicated that the pretreatment significantly improved the DNA quality based on DNA yield, DNA fragment length, and determination of prokaryotic diversity. Prokaryotic diversity exhibited in the DNA with the pretreatment was also considerably higher than that extracted with the Power- SoilTM DNA Isolation Kit only. The pretreatment method worked well even with a small amount of sediment sample (0.25 g or even lower). The method provides a novel, simple, cost-effective tool for DNA extraction for microbial community analysis in environmental monitoring and remediation processes.