���ｵ���MZS1�Դ��˼������ж�����Ľ���Ч��

为探明生物降解菌对有机磷类农药残留的降解效果,丰富毒死蜱残留的生物降解菌菌种资源,采用传统方法和分子鉴定方法对实验室分离获得的毒死蜱降解菌株进行鉴定,并采用室内模拟与田间试验相结合的方法研究该菌株对大芥菜及土壤中毒死蜱残留的生物修复作用.结果表明:该菌株为枯草芽孢杆菌MZS1(Bacillus subtilis MZS1).室内,施用菌株MZS1处理15d后其对土壤中浓度为5 mg/kg和10 mg/kg毒死蜱的降解率分别为49.64％和53.02％;田间,随含菌量的增加,菌株MZS1对大芥菜和土壤中毒死蜱的降解率增加,其中,施用量为5 L/hm2时,15d后其对大芥菜和土壤中毒死蜱的降解率分别为33.27％和42.93％.菌株MZS1对大芥菜的生长具有一定的促进作用.     

丛枝菌根对镉污染土壤的修复研究进展

近年来,土壤镉污染愈加严重,因此镉污染的生物修复也成为人们关注的热点之一。丛枝菌根是陆地生态系统分布广泛的植物-真菌共生体。研究证实,AM可促进植物的生长发育,增强植物对重金属毒害的耐性,影响植物对重金属的吸收、转运和积累,在重金属污染土壤的植物修复中显示出巨大的应用潜力。综述了AM对镉污染土壤修复的修复机理(直接作用、间接作用)及其在植物修复中的应用,并对未来的研究方向提出建议。     

锌污染土壤接种丛枝菌根真菌对玉米苗期生长的影响

通过三个土壤锌水平上的盆栽玉米试验,研究了丛枝菌根真菌在锌污染时对玉米苗期生长的影响。研究表明,即使在土壤锌施入量达600mg·kg-1时,菌根真菌对玉米仍有近50%的侵染率,说明菌根真菌对重金属锌具有相当的抗性。锌污染土壤中菌根共生体的建立,明显地改善了植株对磷素的吸收和运输,有助于植株在重金属污染逆境中的生长。更为重要的是,菌根植物在未增加体内锌浓度的前提下,较对照显著提高了叶和根中的锌吸收量,表明菌根植物在重金属锌污染的土壤上具有一定的生物修复作用。     

Investigating the in situ degradation of atrazine in groundwater

This study focused on whether or not atrazine could be degraded by indigenous groundwater bacteria as part of an in situ remediation approach. Groundwater was taken from an unconfined middle upper chalk site where concentrations of atrazine and nitrate were typically in the ranges 0.02-0.2 microg litre-1 and 11.6-25.1 mg NO3-N litre-1 respectively. Sacrificial batch studies were performed using this groundwater spiked with atrazine at a concentration of 10 microg litre-1 in conjunction with a minimal mineral salts liquid (Glu-MMSL) medium which contained glucose as the sole carbon source. Treatments comprised either the Glu-MMSL groundwater cultured bacteria or Pseudomonas sp. strain ADP. Results from sacrificial batches indicated the occurrence of bacterial growth and denitrification as monitored by optical density (absorbance at 600 nm) and NO3-N content. Analysis of atrazine content by solid phase extraction coupled with high-performance liquid chromatography showed no degradation of atrazine over a period of 103 days in either treatment. These results indicated that no acclimatised bacterial community featuring positive degraders to the herbicide atrazine had become established within this chalk aquifer in response to the trace levels encountered.     

海洋沉积物中反硝化细菌的分离及去除硝酸盐氮的模拟试验

本研究从长江口沉积物中筛选分离出了海洋反硝化细菌,模拟了该细菌对不同浓度水平硝酸盐氮的去除效率。研究结果表明,分离出的海洋反硝化细菌能有效去除海水中硝酸盐氮,在硝酸盐氮初始浓度为1mg/L,1d内硝酸盐氮去除率就达到了70%;在100mg/L硝酸盐氮模拟试验中,约在一周内能将90%硝酸盐氮去除。试验证实反硝化细菌的生长与水体中硝酸盐氮浓度有一定的相关关系,一旦生物修复过程完成,反硝化细菌就会大量死亡,水体重新恢复到清澈透明状况。     

双功能木霉突变菌株的筛选和功能分析

研究从木霉菌REMI突变株中筛选到16株对氰化物具有明显降解活性,将其与5种常见病原菌对峙培养,得到7株拮抗性较高的突变株。对这7株转化子进行盆栽试验表明:多数供试转化子对黄瓜幼苗枯萎病具有明显的防效,其中转化子TkA8的防治效果最好,达到了73.5%。同时研究发现TkA8处理黄瓜幼苗可诱导防御反应相关酶系PAL、POD活性明显增加,分别为对照的3.21和4.25倍。因此TkA8是一种具有防病和生物修复氰化物污染的较理想的多功能木霉菌株。     

Phytoremediation of Vineyard Copper-Contaminated Soil and Copper Mining Waste by a High Potential Bioenergy Crop (Helianthus annus L.)

Phytoremediation is a helpful technique to remediate copper-contaminated areas. The aim of this study was to evaluate sunflower phytoremediation capacity in two vineyard copper-contaminated soils (Inceptisol and Mollisol) and a copper mining waste. Nutrient uptake, copper phytoaccumulation, translocation factor (TF), and bioaccumulation factor (BCF) of sunflower were evaluated after 57 days of growth. Plants grown in both the Mollisol and Inceptisol soils showed high plant height. Fresh biomass was high in the Mollisol in the shoots and roots and also demonstrated the highest values on the tolerance index (TI). The BCF after growth in all three of the copper contaminated soils as Inceptisol, Mollisol, and copper mining waste showed reduction of this index value to 0.19, 0.24, and 0.03, respectively against native soil (Mollisol under natural conditions (4.71). Sunflowers have some important characteristics such as high phytomass production, copper phytoaccumulation, and potential use to biofuel. Thus, sunflower is a potential candidate to phytoremediation of vineyard copper-contaminated soils.     

Remediation of polycyclic aromatic hydrocarbon-contaminated soils using microbes and nanoparticles: A review

Polycyclic aromatic hydrocarbon(PAH) pollution is a global concern because of their toxicity to environment and ecosystem, which induces adverse effects on plants, animals, and humans. Hydrocarbons are mainly released from natural and anthropogenic activities, such as incomplete fuel combustion, leakages in oil pipelines, and the extensive use of pesticides; PAH contaminants include petroleum hydrocarbons(PHCs), halogenated hydrocarbons, chlorophenols, and pesticides. Bioremediation using microo...     

AM真菌对重金属污染土壤生物修复的应用与机理

土壤重金属污染威胁人类健康和整个生态系统,而高效、低耗、安全的生物修复技术显示出了极大的应用潜力,特别是利用植物-微生物共生体增强生物修复效应的应用。丛枝菌根(Arbuscular Mycorrhizae,AM)真菌是一类广泛分布于土壤生态系统中的有益微生物,能与90%以上的陆生高等植物形成共生体。研究发现,AM真菌能够增强宿主植物对土壤中重金属胁迫的耐受性。当前,利用AM真菌开展重金属污染土壤的生物修复已经引起环境学家和生态学家的广泛关注。基于此,围绕AM真菌在重金属污染土壤生物修复作用中的最新研究进展,从物理性防御体系的形成、对植物生理代谢的调控、生化拮抗物质的产生、基因表达的调控等角度探究AM真菌在重金属污染土壤生物修复中的作用机理,以期为利用AM真菌开展重金属污染的生物修复提供理论依据,并对本领域未来的发展和应用前景进行了展望。     

原位生物技术对城市重污染河道底泥的治理效果

以扬州市典型城市内河河道为例研究了人工曝气、生态砖覆盖、生物填料覆盖、低位植物浮床(简称低位浮床)等原位生态处理技术对河道底泥污染释放及其对上覆水污染负荷贡献的治理效果.研究结果表明:经不同原位生态处理后,1)底泥中氨氮的释放速率下降50.3％-89.64％,平均为59.27％;底泥污染释放对上覆水氨氮负荷贡献量的去除率为36.59％-82.67％,平均为53.33％;2)底泥中总氮的释放速率下降20.96％-88.94％,平均为42.32％;底泥总氮释放对上覆水污染负荷贡献量的污染去除率为38.00％-67.06％,平均为54.96％;3)底泥中总磷的释放速率下降27.49％-91.00％,平均为55.31％;底泥总磷释放对上覆水总磷污染负荷贡献量的去除率为67.14％-98.46％,平均为84.33％;4)底泥中CODMn的释放速率下降11.84％-79.32％,平均为41.16％;底泥上覆水中CODMn的释放速率下降-1.25％--70.74％,平均为29.83％.研究还发现,原位生态处理技术在运行中对底泥污染治理的效果受该技术对底泥的扰动程度的影响,在进行集成应用的时候,对底泥扰动较大的技术应与对底泥扰动较小的技术相间应用,以减少工程技术运行中对底泥扰动造成的污染爆发式释放,达到更好的整体处理效果.