Ecological detoxification of methamidophos by earthworms in phaiozem co-contaminated with acetochlor and copper

In view of the ubiquitous co-existence of methamidophos, acetochlor and copper (Cu) in agricultural soils, ecological detoxification of methamidophos in phaiozem by earthworms was examined using the detoxic incubation experiments with illumination. It was validated that the earthworm Eisenia fetida is a useful soil animal in the process of methamidophos detoxification as the assistance of soil microbes and enzymes. Due to the action of earthworms, the half life of methamidophos with concentration of 15 mg/kg in phaiozem could decrease from 5.61 days to 5.08 days. Dynamics of methamidophos detoxification by earthworms could conform to the logistic model. Under the condition of multiple pollution combined with acetochlor (20 mg/kg) and Cu (300 mg/kg), ecological detoxification of methamidophos by earthworms became complicated. Acetochlor played a promoting role in the biodegradation of methamidophos to some extent, while it was basically inhibited by Cu.     

黄土高原地区土壤石油污染状况及生物修复技术研究进展

概述了黄土高原地区土壤石油污染状况及近年来该区油污土壤生物修复的研究进展,分别对微生物、植物及微生物-植物联合修复方法进行综述,强调生物强化技术在生物修复中的突出地位及植物-微生物联合修复方法的应用潜能。由于石油污染物的复杂性,现存技术在实际修复中效果并不明显,提出运用分子生物学技术研究酶功能基因、将代谢组研究融入油污土壤的修复、深入探究植物根际分泌物与微生物作用及菌根真菌生物降解机制的建议,旨在对黄土高原地区石油污染土壤修复探究工作奠定理论基础,对促进黄土高原地区土壤的保护及可持续利用具有重大意义。     

城市河流生物修复技术的研究进展

城市河流的污染严重影响市容和居住环境,已成为人们重点关注的环境问题之一。结合国内外河道治理现状,重点评述了微生物修复技术、植物修复技术、人工浮岛、人工湿地等生物修复技术的研究进展,并展望今后河道治理技术的重点发展方向。     

木霉对多菌灵的生物降解特性研究

从耐药性木霉菌株的诱变选育过程中,得到一株能在含多菌灵2 000 mg L-1培养基上生长的变异菌株T32。该菌株在以多菌灵为唯一碳源的无机盐培养基中,于25℃、200 rm in-1振荡培养5 d,对多菌灵的降解率达到61.4%。在pH6.0、25℃、5%接种量和加入0.5%酵母粉为最适降解条件下,该菌株对多菌灵、速克灵、扑海因、甲基布托津和三唑酮这5种常用化学农药的降解率分别达到91.4%、92.1%、55.3%、40.1%和86.5%。对原土壤、自然风干土壤和高温烘干土壤中的多菌灵进行室内降解实验,在25~28℃、5%接种量、含水量维持15%的条件下处理10 d,对多菌灵的降解率分别达到78.6%、75.3%和70.5%。     

石油污染土壤的生态风险评价和生物修复 Ⅳ.油泥的预制床修复及其微生物群落变化

通过添加有机肥、调理剂、接种烃降解菌以及搭建温室等方式对某油田的含油污泥进行了大规模的预制床生物修复。结果表明,经过230d的修复,不同修复处理油泥中的油和脂含量降低了27.5%～46.3%,其中处理RCPG(有机肥+调理剂+接种烃降解菌+温室)的修复效率最高,而在对照中仅为15.1%。经统计分析,在所有处理措施中添加有机肥、调理剂以及搭建温室对修复效率具有显著影响(p0.05),而投加菌剂效果不显著。生物修复措施在降低油泥中污染物含量的同时也改善了油泥的理化性质,使氮、磷等营养物含量及田间持水率显著升高。同时结果还表明,所有修复处理油泥中的烃降解菌数量、微生物活性与多样性与对照相比均有极显著增加(p0.01)。     

土壤生物修复过程中石油类组分变化规律的研究

[目的]研究土壤生物修复过程中石油类组分的变化规律。[方法]采用微生物修复和植物修复法对油污土壤进行修复,通过分析土壤生物修复过程中石油类含量及组分的变化来评价污染土壤的生物修复效果。[结果]随着修复时间的延长,土壤中矿物油可降到3 000 mg/kg以下;土壤中石油类总烃所占比例大幅下降,而沥青质所占比例明显上升;修复前土壤中石油类以C24为主,微生物修复后（41 d）主碳峰为C29,植物修复后（139 d）主碳峰为C17和C18。[结论]该研究为今后油污土壤生物修复效果的评价提供了科学依据。     

生物修复菌剂的分类·应用及研究进展

由于人类的生产与社会活动,使得我们生存的自然环境遭到了前所未有的破坏。鉴于采用物理或化学方法修复环境,除去有害物质,易造成二次污染,寻找高效的生物修复方法成为了全世界的共同课题。微生物作为生态链中的分解者,由于其具有易繁殖、适应性强、代谢快等特性,是作为生物修复的极佳材料。对生物修复菌剂的分类、生产、应用及研究进展进行了综述。     

果园土壤污染生物修复研究

[目的]弄清土壤污染的生物修复作用机理。[方法]通过果园田间试验和土壤模拟试验,研究施用果树生物有机肥对果园土壤生物修复的作用。[结果]生物有机肥提高了根域土壤多酚氧化酶、脲酶、磷酸酶等酶的活力;促进了根域土壤对Pb2＋等重金属的钝化;增加了有益真菌、放线菌、细菌等活性菌的数量,降低了根腐病菌、疫腐病菌、白／紫纹羽病菌和线虫等有害生物的数量。[结论]该研究为生物有机肥在果树上的推广应用提供了依据,     

浅海养殖环境复合生态净化菌群的筛选及其净化功能

本研究由浅海网箱区富营养沉积物经多步富集和筛选获得高效复合生态净化菌群,对浅海养殖区的有机物、氨氮和亚硝酸氮有明显去除效果.研究了不同条件对复合菌液去除养殖水体中氨氮、亚硝酸氮和有机物能力的影响,并确定了最佳净化条件.结果表明,复合菌添加量、葡萄糖添加量,处理时间、温度、pH和盐度对复合菌的去除效果均有影响,实验条件确定为复合菌的添加量为3%、处理时间为4 d、温度为30±2 ℃、pH值为8.1±0.2、葡萄糖添加量为2 g/L和盐度为(30±10) g/L 时,去除效果达到最佳,此时氨氮、亚硝酸氮和溶解有机物的去除率可分别达到79.1%、85.2%和88.7%.     

Factors affecting transfer of degradative plasmids between bacteria in soils

Horizontal gene transfer is useful for enhancing bioremediation through gene bioaugmentation. However, factors affecting transfer of degradative plasmids have not been systematically addressed. To this end, plasmid transfer experiments were performed using a TOL-like plasmid carrying the gene encoding for catechol 2,3-dioxygenase (C23O) between two soil bacteria under different conditions. Transfer frequency increased with air temperature in the range of 10–35 °C and reached 6 × 10⁻⁴ transconjugants per donor cell at 35 °C. The transfer frequency detected at soil depth 5–10 cm was significantly higher (p < 0.05) compared with other depths. Addition of 5–75% LB in the microbial inoculum promoted plasmid transfer frequencies. Addition of phenol to the experimental system resulted in significantly higher transfer frequency (p < 0.05) compared with no addition. Transfer frequency heat-moisture in loam was significantly higher (p < 0.05) than in other soils. The highest transfer frequency was found in the experiment containing tomato seedlings, with up to about 1.3 × 10⁻³ transconjugants per donor cell. Corn and wheat seedlings also led to significantly higher transfer frequencies (p < 0.05) compared with no plants. Furthermore, C23O activities of transconjugants formed under different conditions were measured, as a surrogate measure of the activity of transconjugant. Transfer temperature, soil and plant types had a minor influence on activities of transconjugants. Topsoil (0–5 cm) transconjugants expressed C23O more efficiently under normal incubation condition, but less efficiently when soils incubated with excessive LB medium concentrations, and in the absence of phenol in soil. These results suggested that transfer temperature, soil depth, dilutions of LB broth, phenol content, and soil and plant types had important effects on transfer of the TOL-like plasmid in soil, and some factors also affected activities of transconjugants.