强化超积累植物东南景天萃取镉的微生物菌株筛选
MICROORGANISM STRAIN SCREENING OF INTENSIFYING HYPERACCUMULATOR ALFRED STONECROP EXTRACTING CADMIUM
Abstract：The experiments of this thesis are to screen out plant growth-promoting rhizobacteria from plant rhizosphere soil around the cadmium mine lots. By strain screening, we can firstly select supplied experimental rhizobacteria which are tolerant of cadmium, and then measure some promoting properties like production of acid,content of auxin IAA and nitrogen fixation to select supplied experimental rhizobacteria; then to identify the species of the supplied experimental rhizobacteria by 16s rRNA strain identification; cultivating rhizobacteria RA1 and S30 to observe their colonial morphology; selecting rhizobacteria RA1 and S30 to make combination of plant and microorganism with Alfred Stonecrop respectively, to explore the composite effect of efficient rhizobacteria intensify Alfred Stonecrop extracting heavy metal cadmium in soil, and have successfully proved the selected rhizobacteria RA1 does well in all aspects inculuding cadmium resistance, acid production, nitrogen fixation and IAA production, with a further provement of owning certain ability to intensify hyperaccumulator Alfred Stonecrop extracting heavy metal cadmium in soil. However, S30 hasn’t performed as well as RA1.
Key words: Alfred Stonecrop; intensify extracting; cadmium; strain screening；combined remediation of microorganism and plant
目 录
摘要3
关键词3
Abstract 3
Key words 3
引言（或绪论3
1材料与方法4
1.1材料 4
1.1.1菌株 4
1.1.2培养基 4
1.1.3试剂 5
1.1.4土壤 5
1.1.5植物 5
1.2方法 5
1.2.1镉耐性微生物菌株筛选5
1.2.2高产酸菌种筛选5
1.2.3菌株固氮能力测定 5
1.2.4产生长素类物质吲哚乙酸（IAA）试验5
1.2.5菌种鉴定 6
1.2.6菌落形态观察 6
1.2.7探究植物促生菌株对镉污染土壤下东南景天植株的影响6
2结果与分析 7
2.1镉耐性微生物菌株筛选 7
2.2高产酸菌种筛选 7
2.3菌株固氮能力测定 8
2.4产生长素类物质吲哚乙酸（IAA）试验8
2.5菌种鉴定 9
2.6菌落形态观察 9
2.7菌株对植物生物量的影响10
2.8菌株对植物体内镉富集浓度的影响11
3讨论13
3.1植物促生细菌的筛选13
3.2试验菌株对镉污染下东南景天及吸收重金属的影响13
3.3微生物-植物联合修复土壤重金属污染 13
致谢 14参考文献 14
强化超积累植物东南景天萃取镉的微生物菌株筛选
在现代社会，由于开采矿产、滥用农药、排放尾气、处理垃圾等行为的存在，导致数量庞大的重金属离子进入土壤，也导致很多地区的土壤中形成了重金属污染。在重金属污染治理方面，主要采用物理法、化学法和生物法来治理[1][2]。物理法主要采取物理工程措施来治理土壤重金属污染，其特点是见效快，但是工程量大、成本高、易产生二次污染。化学法则通过化学方法改变土壤或生物的性质来改善重金属污染情况，具有效率高、操作性强等特点，但也存在成本和污染问题。生物法主要通过植物和微生物的代谢活动来加强吸收或降解土壤重金属从而修复污染[3]。