多环芳烃降解菌的筛选与降解能力测定

从本溪多环芳烃(PAHs)污染土壤中经富集培养筛选出8株PAHs降解菌,研究了8株菌及其等比例混合培养对菲、芘和苯并[a]芘的降解能力。结果表明,在28℃,培养基中菲、芘和苯并[a]芘的浓度分别为50、50和5mg·L-1的复合底物条件下,培养28d后,菌株B3的降解效果最好,对菲、芘和苯并[a]芘的降解率分别为88.4%、54.0%和68.4%,8株菌的混合培养对菲、芘和苯并[a]芘的降解率分别为87.7%、35.3%和42.0%;经生理生化实验和16SrRNA序列比对,初步鉴定B3菌为假单胞菌属(Pseudomonas sp.)。     

细菌降解低分子量多环芳烃的研究进展

具有"三致"效应的多环芳烃污染造成了巨大的环境危害,威胁人类健康和生存。目前能够降解低分子量多环芳烃的细菌已有广泛的研究。细菌通过多层次的调控分析和适应性进化提高它们的降解能力。本文基于国内外文献调研,简要总结了生物修复在低分子量多环芳烃降解领域的研究进展。拟通过多层次的调控分析和适应性进化来产生多种分解代谢途径,为生物降解能力强化的未来降解技术提供支撑。     

微生物降解多环芳烃的研究进展

多环芳烃(PAHs)是具有严重危害的环境污染物质。介绍PAHs的降解菌,降解机理和PAHs的生物修复方面的研究进展。土壤中PAHs的生物修复被认为是解决污染的有效方法,目前,菲的生物降解途径已经比较清楚,但对结构更为复杂的多环芳烃研究较少。文章还对消除环境中多环芳烃的相关生物技术提出展望。     

微生物降解多环芳烃的研究进展

多环芳烃是一类长久存在于环境中,具有毒性、致突变与致癌等特性的环境优先污染物。本文对降解多环芳烃的微生物类群进行了阐述,介绍了在土壤与厌氧条件下细菌降解多环芳烃的研究情况,最后介绍了降解多环芳烃的相关酶类以及分子生物学的研究,并对消除环境中多环芳烃的相关生物技术提出展望。     

多环芳烃微生物降解基因的研究进展

多环芳烃(PAHs)是环境中普遍存在的一类有机污染物,微生物的降解是PAHs去除的主要途径。近年来,有关PAHs微生物降解途径和代谢产物的研究已有很多报道。小分子PAHs一般可以直接被微生物降解,而大分子PAHs则需要微生物以共代谢的方式降解。在过去20年中,微生物降解PAHs的基因相继被发现,各种基因在调控PAHs降解过程中的功能也越来越清晰。本文概述了PAHs微生物降解基因方面的研究进展,详细介绍了微生物对萘、菲的降解基因,最后对PAHs微生物降解基因的应用前景进行了展望。     

污染土壤中多环芳烃的共代谢降解过程

1　前　言多环芳烃是一类普遍存在于环境中的重要有机污染物 ,因其致癌性、致畸性、致突变性而被认为是危险物质。由于其水溶性低 ,辛醇 水分配系数高 ,因此 ,该类化合物易于从水中分配到生物体内、沉积层中。土壤成为多环芳烃的重要载体 ,多环芳烃污染土壤的生物修复也因此倍受关注。多环芳烃在土壤中有较高的稳定性 ,其苯环数与其生物可降解性明显呈负相关关系。很少有能直接降解高环数多环芳烃的微生物。研究表明 ,高分子量的多环芳烃的生物降解一般均以共代谢方式开始[1 3] 。共代谢作用可以提高微生物降解多环芳烃的效率 ,改变微生物碳…     

厌氧微生物降解多环芳烃研究进展

多环芳烃(PAHs)是一类普遍存在于环境介质中的难降解有机污染物,相对于好氧微生物降解PAHs的研究,厌氧微生物降解PAHs的研究则相对较少.本文从厌氧微生物降解PAHs的研究背景,厌氧降解微生物的特点和不同厌氧降解还原反应体系的角度综述了厌氧微生物降解PAHs的概况;结合厌氧微生物降解萘和菲转化途径的介绍,推断了其降解机制的内在原因;同时通过总结影响厌氧微生物降解PAHs的主要因素(包括:PAHs的生物可利用性、外源营养物质的添加、外源电子受体的添加、特定厌氧降解菌的筛选强化和部分环境因素等),指出了制约降解进程的潜在限制因子;并对厌氧微生物降解PAHs研究目前存在的问题和未来的发展方向作了简述与展望.     

多环芳烃降解菌的筛选、鉴定及降解特性

【目的】多环芳烃(PAHs)是一类普遍存在于环境中且具有高毒性的持久性有机污染物,高效降解菌的筛选对利用生物修复技术有效去除环境中的多环芳烃具有重要意义。研究拟从供试菌株中筛选多环芳烃高效降解菌,并分析其降解特性,为多环芳烃污染环境的微生物修复提供资源保障和科学依据。【方法】采用平板法从25株供试菌株中筛选出以菲和芘为唯一碳源和能源的高效降解菌,经16S rRNA基因序列进行初步鉴定,通过单因素实验法分析其在液体培养基中的降解特性。【结果】筛选出的3株多环芳烃高效降解菌SL-1、02173和02830经16S rRNA基因序列分析,02173和02830分别与假单胞菌属中的Pseudomonas alcaliphila和Pseudomonas corrugate同源性最近,SL-1为本课题组发表新类群Rhizobium petrolearium的模式菌株;降解实验表明,菌株SL-1 3 d内对单一多环芳烃菲(100 mg/L)和芘(50 mg/L)的降解率分别达到100%和48%,5 d后能够降解74%的芘;而其3 d内对混合PAHs中菲和芘的降解率分别为75.89%和81.98%。菌株02173和02830 3 d内对混合多环芳烃中萘(200 mg/L)、芴(50 mg/L)、菲(100 mg/L)和芘(50 mg/L)的降解率均分别超过97%。【结论】筛选出的3株PAHs降解菌SL-1、02173和02830不仅可以高效降解低分子量PAHs,还对高分子量PAHs具有很好的降解潜力。研究表明,由于共代谢作用低分子量多环芳烃可促进高分子量多环芳烃的降解,而此时低分子量多环芳烃的降解将受到抑制。     

细菌降解多环芳烃上游途径的遗传学研究进展

多环芳烃是一类毒性较大的环境污染物。微生物降解和转化是消除此类污染物的理想方法,已发现多种细菌具有这种功能。主要针对细菌在多环芳烃降解中上游途径的代谢酶及基因簇的组成进行综述,阐述了酶的遗传学特点,并探讨了PAHs代谢基因的进化。这有助于了解PAHs的细菌降解机制,并为有效实施生物修复提供理论依据。     

红树林湿地多环芳烃的微生物降解

红树林(mangrove)是海陆交汇带重要的湿地生态系统,也是环境污染物蓄积与转化的热区.多环芳烃(polycyclic aromatic hydrocarbons,PAHs)因其环境蓄积特点在红树林生境中广泛分布,威胁生态系统健康,其降解转化是近年的研究重点.本文聚焦红树林湿地多环芳烃的微生物降解研究现状,从红树林生...     

微生物降解多环芳烃(PAHs)的研究进展

从多环芳烃(PAHs)的降解菌株的筛选、降解机制以及PAHs污染的生物修复等方面介绍了微生物降解PAHs的最新研究进展。     

Molecular biology approaches for understanding microbial polycyclic aromatic hydrocarbons (PAHs) degradation

The known or suspected hazards of polycyclic aromatic hydrocarbons (PAHs) have provoked enormous concentration and endeavours to relieve or eliminate these precarious compounds from miscellaneous environments including soil, water and air. Among various interventions, biodegradation is an appealing approach for its comparative high efficiency and preferable safety. Microorganisms played crucial role in biodegradation of PAHs. Traditional access mainly including culture-dependent procedures has discovered and isolated PAHs-degrading microorganisms which could be subsequently applied to specific contaminated locus. Although certain progress has been achieved owing to traditional methods, much details in PAHs bioremedation leave pending because of the complexity nature of this process. As the rapid development of biology, molecular techniques such as PCR, fingerprinting technique (mainly DGGE), DNA hybridization technique and gene reporters technique have been intensively applied to gain further insight into the mechanism of PAHs degradation. These techniques not only proved the existence and role of uncultivable microorganisms in the whole population of PAHs degrading related microbials, but also made it possible to revealed the otherwise undetectable complex relationships between multi-microorganism concerned in PAHs biodegradation. Application of such techniques in the field of PAHs biodegradation were reviewed in this article.     

Molecular biology approaches for understanding microbial polycyclic aromatic hydrocarbons (PAHs) degradation

The known or suspected hazards of polycyclic aromatic hydrocarbons (PAHs) have provoked enormous concentration and endeavours to relieve or eliminate these precarious compounds from miscellaneous environments including soil, water and air. Among various interventions, biodegradation is an appealing approach for its comparative high efficiency and preferable safety. Microorganisms played crucial role in biodegradation of PAHs. Traditional access mainly including culture-dependent procedures has discovered and isolated PAHs-degrading microorganisms which could be subsequently applied to specific contaminated locus. Although certain progress has been achieved owing to traditional methods, much details in PAHs bioremedation leave pending because of the complexity nature of this process. As the rapid development of biology, molecular techniques such as PCR, fingerprinting technique (mainly DGGE), DNA hybridization technique and gene reporters technique have been intensively applied to gain further insight into the mechanism of PAHs degradation. These techniques not only proved the existence and role of uncultivable microorganisms in the whole population of PAHs degrading related microbials, but also made it possible to revealed the otherwise undetectable complex relationships between multi-microorganism concerned in PAHs biodegradation. Application of such techniques in the field of PAHs biodegradation were reviewed in this article.     

土壤中多环芳烃的微生物降解及土壤细菌种群多样性

利用室内模拟方法,研究中、低浓度多环芳烃(PAHs)污染土壤的微生物修复效果,阐明土壤微生物（接种和土著）与PAHs降解的关系.结果表明:投加PAHs高效降解菌可以促进土壤中PAHs的降解,2周内效果显著;典型PAHs降解的难易程度依据为：菲<蒽<芘<苯并(a)芘和屈;细菌种群丰度和多样性均与PAHs降解呈负相关关系,同一处理细菌种群结构随时间变化不大.对于中、低浓度PAHs原位污染土壤,增强土著菌的活性是提高土壤PAHs降解率的有效途径之一.     

Distribution, sources and potential toxicological significance of polycyclic aromatic hydrocarbons (PAHs) in Taihu Lake sediments, China

Taihu Lake is one of the largest freshwater lakes in China. The lake is very shallow with a mean depth of 1.9 m and an area of 2428 km². This is the first time that polycyclic aromatic hydrocarbon concentrations in the surface sediments of Taihu Lake have been analyzed. A distinctive spatial distribution of PAHs was observed. Sediments from Lake Wulihu and Meiliang Bay (sites 1–5) had significantly higher PAH concentrations (858–5260 g kg^–1 dw) than any other area of Taihu Lake. These high PAH levels were associated with the input of untreated and partially treated domestic and industrial sewage from Wuxi, Changzhou, Wujin and other cities. Special PAH ratios, such as phenanthrene/anthracene and fluoranthene/pyrene, were calculated to evaluate the relative importance of different origins. The data confirmed a relatively high level of petrogenic contamination in sites 1–5 (mainly sewage discharge and the river runoff). The other samples were further from the sources of pollution and have relatively low PAH concentrations (410–768 g kg^–1 dw). The sources of PAHs in these sites (6–13) were characterized by combustion-derived PAH contamination associated with atmospheric deposition. In addition, effects range low (ERL) and effects range median (ERM) guidelines (Long et al., 1995) were used to estimate the potential of adverse effects resulting from PAH contamination in Taihu Lake sediments. The results indicated that some sites in the northern part of the lake had levels of PAH that exceeded the ERL value. This was interpreted to mean that acute biological effects may occasionally be expected to occur.     

宁夏东部荒漠草原-灌丛地转变过程土壤氮素响应

选取近30年荒漠草原灌丛引入形成的典型草地-灌丛镶嵌体内部的荒漠草地、草地边缘、灌丛边缘、灌丛地为研究样地,对各样地及其微生境(植丛与空斑)相关土壤指标进行测定,以了解荒漠草地向灌丛地转变过程中土壤氮素的响应特征.结果 表明:随草地灌丛化转变,草本与灌丛生物量均增加,其中一年生草本随灌丛引入增加明显;土壤水分、全碳、全...     

土壤－植物系统中多环芳烃和重金属的行为研究

对土壤中多环芳烃和重金属的行为研究表明,与对照相比,０—２０ｃｍ以上表土层存在多环芳烃和重金属积累,２０ｃｍ以下土层未发现积累;与春、秋两次采样结果相比,土壤中多环芳烃的含量有所下降,表明土壤微生物对多环芳烃有一定降解作用,且其降解程度与土壤－植物系统的生态结构有关．菲在地下水中检出浓度较高,表明这一污染物有向下迁移的可能性．此外,柳树对土壤中重金属Ｃｄ的积累有明显的削减与净化作用．本研究表明,严格限制污水中多环芳烃和重金属的污染负荷以及设计合理的生态结构是避免多环芳烃和重金属在土壤中积累的关键．     

Multispecies and monoculture rhizoremediation of polycyclic aromatic hydrocarbons (PAHs) from the soil

In this study, we investigated the potential of multispecies rhizoremediation and monoculture rhizoremediation in decontaminating polycyclic aromatic hydrocarbon (PAH) contaminated soil Plant-mediated PAH dissipation was evaluated using monoplanted soil microcosms and soil microcosms vegetated with several different grass species (Brachiaria serrata and Eleusine corocana). The dissipation of naphthalene and fluorene was higher in the "multispecies" vegetated soil compared to the monoplanted and nonplanted control soil. The concentration of naphthalene was undetectable in the multispecies vegetated treatment compared to 96% removal efficiencies in the monoplanted treatments and 63% in the nonplanted control after 10 wk of incubation. Similar removal efficiencies were obtained for fluorene. However, there was no significant difference in the dissipation of pyrene in both the mono- and multispecies vegetated treatments. There also was no significant difference between the dissipation of PAHs in the monoplanted treatments with different grass species. Principle component analysis (PCA) and cluster analysis were used to evaluate functional diversity of the different treatments during phytoremediation of PAHs. Both PCA and cluster analysis revealed differences in the metabolic fingerprints of the PAH contaminated and noncontaminated soils. However, the differences in metabolic diversity between the multispecies vegetated and monoplanted treatments were not clearly revealed. The results suggest that multispecies rhizoremediation using tolerant plant species rather than monoculture rhizoremediation have the potential to enhance pollutant removal in moderately contaminated soils.     

氮沉降和降雨变化对荒漠草原凋落物分解的影响

以荒漠草原凋落物为研究对象,通过设置自然降雨(CK)、增雨30%(W)和减雨30%(R) 3种水分处理和0 (N0)、30(N30)、50 (N50)和100 kg hm~(-2) a~(-1)(N100)4种氮素(NH_4NO_3)水平处理,用分解袋法,研究内蒙古短花针茅荒漠草原短花针茅(Stipa breviflora)、冷蒿(Artemisia frigida)、无芒隐子草(Cleistogenes songorica)和木地肤(Kochia prostrata)凋落物分解过程,旨在阐明荒漠草原凋落物分解过程及其对氮沉降和降雨变化的响应特征,为荒漠草原生态系统物质循环过程响应气候变化研究提供基础数据。结果表明:1)经过270 d分解后,短花针茅、冷蒿、木地肤和无芒隐子草干物质残留率分别为69.95%—78.67%、68.89%—79.89%、64.68%—79.23%、66.89%—79.38%,分解速率为木地肤无芒隐子草冷蒿短花针茅。2)氮沉降和降雨对短花针茅和冷蒿凋落物分解速率产生显著影响(P0.05),其交互作用对这两种凋落物分解速率不显著(P0.05)。氮沉降和降雨以及交互作用均对无芒隐子草和木地肤凋落物分解速率产生显著影响(P0.05)。3)单一水分或氮素的添加均提高土壤微生物量碳氮含量,而水氮交互作用下更为显著。4)凋落物分解速率受生物及非生物因子的影响,相关分析表明:冷蒿、无芒隐子草、木地肤与土壤微生物量碳呈极显著正相关(P0.01);冷蒿、木地肤、短花针茅与土壤微生物量氮呈极显著正相关(P0.01);木地肤和短花针茅与土壤含水量呈极显著正相关(P0.01);冷蒿、木地肤、短花针茅与地上生物量呈极显著正相关(P0.01)。     

污灌土壤中多环芳烃（PAHs）的积累与动态变化研究

对污灌土壤中 1 4种多环芳烃的分析表明 ,各灌区土壤中 PAHs的积累一般以渠首最高 ,渠中次之 ,渠尾含量与对照相当 .但在沈抚石油灌区上、中和下游土壤中均有PAHs的积累 .此外 ,水稻生长期污灌可明显增加土壤中 PAHs的总量 ,各单一污染物的增、减趋势有所不同 .