耐性细菌的分离鉴定及重金属污染修复初步研究

清远市是中国最大的电子废弃物拆解基地之一，小作坊生产模式已经进行了20多年，大量无法回收的电子废料和处理残渣等被倾倒在田地、沟渠和山谷中，致使周边土壤长期受到重金属Cd、Cu、Pb污染。近年来国内外对拆解区周边的土壤重金属污染现状分析、健康风险评价等相关报道较多，但针对电子废弃物复合重金属污染生物修复技术的研究却并不多见。通过富集、驯化、分离，从清远市电子废弃物拆解区污染土壤中得到4种耐性菌株，经菌落形态、扫描电镜分析以及16S rDNA技术鉴定得出，菌株HS-01、JH-02、YB-03、JY-04分别为海水芽孢八叠球菌（Sporosarcina aquimarina）、佐吕间湖生芽孢八叠球菌（Sporosarcina saromensis）、巨大芽孢杆菌（Bacillus megaterium）、甲基营养型芽孢杆菌（Bacillus methylotrophicus）。由生长特性实验得到，细菌HS-01与JY-04生长周期相同，在0～8 h为调整期，8～12 h为对数期，12～24 h为稳定期，24～32 h为衰亡期。而细菌JH-02与YB-03生长周期相同，在0～4 h为调整期，4～12 h为对数期，12～24 h为稳定期，24～32 h为衰亡期。细菌HS-01、JH-02、JY-04的最适温度与pH分别为30℃和8，而YB-03则为35℃与7.5。生物吸附实验结果显示，随着重金属离子质量浓度的升高，4种耐受细菌对重金属离子的吸附量也逐渐升高，但吸附量增长率以及吸附率却逐渐降低，这4种细菌对Cd2＋、Cu2＋、Pb2＋最大吸附量分别达到了2.25、2.05、2.28、2.25 mg，8.19、4.95、8.53、11.78 mg和10.84、10.59、7.66、9.02 mg。最大吸附率则分别达到了94.4、99.2、100、93.3%，86.1、90.8、88.6、87.3%和88.9、82.2、81.2、86.7%。其中细菌HS-01、YB-03、JY-04吸附Cd2＋能力较强，而细菌JY-04对Cu2＋以及HS-01、JH-02对Pb2＋吸附能力最强。上述结果显示了4种耐性细菌均具有较好的修复复合重金属污染水体的应用潜力，但对

Isolation and Identification of Four Tolerance Bacteria and the Preliminary Study for Pollution Remediation of Heavy Metals

Qing Yuan is one of the biggest electronic wastes dismantling base in China, the production pattern of individual workshop has been going on for more than 20 years. A large number of electronic wastes and treatment residuals were dumped in croplands, ditches and valleys. It made the surrounding soils polluted for a long time by Cd, Cu and Pb. There had lots of researches about the present situation analysis and health risk evaluation for heavy metals contaminated soil surrounding dismantling area. But there still had less reports on the study of bioremediation technologies for the e-waste pollution by combined heavy metals. Four tolerance bacteria was isolated from contaminated soil of e-waste dismantling area of qingyuan by this means of enrichment, domestication and isolation. The tolerance bacteria were identified by analyzed of colony morphology and scanning electron microscope and 16S rDNA technology. Four strains of HS-01, JH-02, YB-03 and JY-04 were respectively Sporosarcina aquimarina, Sporosarcina saromensis, Bacillus megaterium and Bacillus methylotrophicus. The growth characteristic experiments indicated that the bacteria of HS-01 and JY-04 had same growth cycle, the regulatory phase was 0-8 h, 8-12 h was the logarithmic phase, 12-24 h was stable phase and 24-32 h was decline phase;Bacterial JH-02 and YB-03 had same growth cycle, regulatory phase was 0-4 h, 4-12 h was logarithmic phase, 12-24 h was stable phase, and 24-32 h was decline phase. The optimum temperature and pH of HS-01, JH-02 and JY-04 was 30 ℃ and 8, while YB-03 was 35 ℃ and 7.5 respectively. With the increase of mass concentration of heavy metal ions, biosorption experiments showed that the adsorption amounts of four tolerance bacteria to heavy metal ions gradually increased, but the growth ratios of adsorption amounts and adsorption ratios were gradually decreased. The maximum adsorption amounts of four tolerance bacteria to Cd2＋, Cu2＋, Pb2＋were 2.25, 2.05, 2.28, 2.25 mg,8.19, 4.95, 8.53, 11.78 mg and 10.84, 10.59, 7.66, 9.02