内蒙古露天矿的大规模开采严重影响了内蒙古草原的生态多样性和生态稳定性。由于矿山开采，金属冶炼，存在于土壤中的重金属被剥离到地表，随着大气、水流进入到土壤及水环境中，矿区及附近的重金属污染非常严重，已经严重危害到附近人类饮食和生活健康，我国面临重金属污染治理的巨大的挑战和难题，为筛选出露天煤矿区高效耐重金属菌株，为草地生态修复提供微生物修复的理论基础和菌种资源，以宝日希勒露天矿区为研究对象，选取矿区内外共5个样地，利用不同类型的重金属胁迫培养基筛选出耐铜离子、铁离子、铬离子、锰离子的细菌进行梯度培育，筛选出每种重金属耐受力最强的菌株。研究结果表明，在不同重金属浓度梯度的胁迫下，菌株XFe-1最高耐铁浓度为500 mg/L，菌株XCu-1最高耐铜浓度为500 mg/L，菌株XCr-1最高耐铬浓度为200 mg/L，菌株XMn-1最高耐锰浓度为50 g/L。随后对4种菌株进行重金属胁迫生长曲线实验，每种菌株均对重金属不同浓度有不同程度的响应。通过16s rDNA基因序列分析比对，对4种优良耐重金属细菌进行分子鉴定，XFe-1为蜡状芽孢杆菌(Bacillus toyonensis)，XCu-1为蜡样芽胞杆菌(Bacillus cereus)，XCr-1属于短杆菌属(Brevibacterium sp.)，XMn-1与Genbank基因库序列比对与芽孢杆菌属最高相似度仅为85.37%，为未知种。并对优良耐重金属菌株进行保藏。

The large-scale open-pit mining in Inner Mongolia seriously affects the ecological diversity and ecological stability of Inner Mongolia grassland. Due to mining,metal smelting,and the exposure of heavy metal in soil,the heavy metals enter into soil and water environment with atmosphere and water flow. Thus,in the mining area and nearby,the heavy metal pollution is very serious,has seriously affected human food chain and human health. There is a huge chal- lenge in heavy metal pollution control in China. In order to provide a theoretical basis for the microbial remediation of grassland ecological restoration,and screen out highly efficient heavy metal-tolerant strains in open pit mines,taking Baorixile open-pit coal mine area as the research area,a total of five sample sites inside and outside the mine area were selected,and the bacteria resistant to copper ion,iron ion,chromium ion and manganese ion were screened out by using different types of heavy metal stress medium for gradient cultivation,and the strains with the strongest tolerance of each heavy metal were screened out. The results showed that the highest iron concentration of strain XFe-1 was 500 mg / L,the highest copper tolerance of strain XCu-1 was 500 mg / L,and the highest chromium tolerance of strain XCr -1 was 200 mg / L,the highest manganese tolerance of strain XMn-1 is 50 g / L,with the stress of different heavy metal concentration gradients. Then,the growth curve of heavy metal stress was tested on four strains. Four excellent heavy metal-tolerant bacteria were identified by 16s rDNA gene sequence analysis. XFe-1 is Bacillus toyonensis,XCu-1 is Bacillus cereus,and XCr-1 is Brevibacterium sp. ,the XMn-1 and Genbank gene bank sequence alignment and the highest similarity of Bacillus are only 85. 37% ,which is unknown species. The strain resistant to heavy metal was pre- served.