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实际污染土壤中有机污染物通常以复合污染状态存在,有机复合污染物的微生物降解过程及其作用机制显得更为复杂。土壤微生物类群多样,具有丰富的功能多样性。而有机复合污染物的降解通常由微生物组操控,通过微生物群落代谢网络完成污染物的去除。近年来,研究者逐渐关注有机复合污染土壤中微生物群落适应机制-微生物组转化过程-合成微生物组设计-原位微生物组修复等方面的研究,对认知污染土壤治理和修复具有重要的科学意义。本文以具有代谢协同性及功能互补性的微生物组为切入点,系统阐述土壤中有机复合污染物的微生物组转化机制与调控原理等,探讨微生物组在复合污染土壤绿色可持续原位生物修复中的发展前景。 相似文献
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采用现场采样及室内分析方法,对长期施用五氯酚（PCP）作为钉螺杀灭剂的典型血吸虫病流行疫区河滩地的土壤微生物特征进行了初步调查研究。结果表明,长期大量施用PCP对河滩裸地土壤微生物种群造成了一定程度的伤害,降低了微生物的总体活性;而种植杨树有利于恢复土壤微生物生物量碳,对修复PCP污染土壤有一定的促进作用。Biolog结果显示土壤微生物利用单一碳源能力的大小顺序为杨树林地〉对照〉河滩裸地,表明有机污染在一定程度上抑制了土壤微生物的生长。主成分分析显示对照、杨树林与河滩裸地的碳源利用能力差异显著,表明PCP污染对微生物的碳源利用造成了显著影响。土壤微生物对不同种类碳源利用计算结果表明,种植杨树导致林地土壤环境条件发生变化,杨树林地土壤微生物对碳源的利用也发生了明显变化。 相似文献
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有机物料对污染土壤微生物碳和磷的影响 总被引：7，自引：0，他引：7
施用不同的有机物料对污染土壤微生物量及其磷素的固定作用的研究发现 ,有机物料施入污染土壤之后 ,土壤微生物碳 (C)在第 3d即达到高峰 ,土壤微生物磷 (P)在第 10d达到高峰 ,腐熟的牛粪对该土壤磷的活化作用很大 ,而葡萄糖的处理显著地降低了污染土壤磷的有效性 ,并不同程度地增加了对土壤磷的生物固定。 相似文献
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玉垒菌处理猪粪尿技术效果研究 总被引：1，自引：0，他引：1
研究了通过引进玉垒菌等微生物，对养猪场粪尿进行生物处理的效果。结果表明，该方法可使猪粪变成优质有机生物肥料，猪粪尿污水污染指标大大下降，能较好地改善养猪场的环境问题。 相似文献
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土壤有机污染物电化学修复技术研究进展 总被引：2，自引：0，他引：2
综述了有机污染土壤的电动力修复和微生物电化学修复的最新研究进展。分析了电动力修复中电极材料、运行条件等因素对污染物去除效果的影响,总结了添加表面活性剂、引入具有降解能力的基质、与化学或生物联合等方式对土壤修复效果的强化作用,阐述了微生物电化学修复的效果、影响因素和微生物群落演变的规律。电化学技术能够有效去除土壤中的有机污染物,且电动力较微生物电化学具有更好的去除效果。为了实现电化学技术在污染土壤修复中的应用,未来需要从土壤导电性、电极材料以及反应器构型等方面优化以提高修复效果;此外,电化学修复技术的机理、功能微生物的群落特征研究等也是下一步研究的重点。 相似文献
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以江苏省某溶剂化工场地为例，利用英国污染地块水文地质风险评估模型研究了该场地地下水污染物对场地内及周边水环境的影响。比较了稳态和非稳态地下水溶质迁移模型(Ogata Banks、Domenico、Time variant Domenico)对污染物在自然衰减条件下从污染源向场地边界迁移过程模拟。结果表明：该场地的地下水中苯、乙苯、氯苯、1,2-二氯苯、1,4-二氯苯、氯仿超过了地下水质量Ⅲ类标准，但场地内污染物对场地边界地下水的潜在环境风险基本可以忽略。Ogata Banks与Domenico模型对于污染物在含水层的自然衰减下的迁移模拟表明污染物在30 m内的迁移过程中浓度下降较快，在30 m外的迁移过程中污染物的浓度较低且衰减不明显。Domenico模型计算较为简洁，在风险评估中具有较强的适用性；敏感性分析表明合规点至污染源距离x、含水层容重ρ、含水层孔隙度n、有机碳含量foc、有机碳分配系数Koc、水力传导系数K、水力梯度i均影响污染物在含水层的自然衰减迁移过程，通过精细化水文地质调查获取上述参数将有助于提高风险评估结果的精确度。 相似文献
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有机污染物污染土壤环境的植物修复机理 总被引：8，自引：0，他引：8
利用活的生物体对有毒有机物污染土壤环境的修复是一种被人们认为安全可靠的方法。植物修复是生物修复研究的热点。植物修复的机理包括植物对有机污染物的直接吸收、植物根系分泌物、微生物对根际环境中有机污染物降解的促进作用。 相似文献
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苯、甲苯、乙苯和二甲苯统称为苯系物(BTEX)，是化工污染场地检出率最高的芳香族有机污染物。为研究BTEX长期污染对土壤和地下水微生物群落结构和代谢潜能的影响，采集了江苏省某搬迁化工厂的浅层土、地下水和深层土样品，利用16S rRNA基因扩增子测序和宏基因组测序技术对BTEX长期污染场地展开分析。结果表明：相比较未受污染的土壤样品，长期BTEX污染显著改变了微生物群落结构和多样性，其中以变形菌门改变最为显著。共现性网络分析表明，污染场地中随着样品取样深度的增加，微生物网络复杂性和群落稳定性降低。BTEX代谢功能基因注释表明，地下水样品中污染物代谢基因丰度和多样性更高，并且在地下水和浅层土中同时存在完整的好氧降解途径，但在地下水中厌氧降解基因的丰度更高。BTEX降解途径中benABC和bcrCBAD基因簇在浅层土中更完整，但通过构建BTEX开环的关键基因bamA的系统发育树表明，地下水中可能存在新的BTEX开环基因。这些结果证明BTEX长期污染的不同生境中存在高度多样的微生物群落与降解途径，为相关污染场地的微生物修复提供了科学依据。 相似文献
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土壤细菌群落在蔬菜栽培中发挥着重要作用。基于DNA和RNA水平,利用PCR-DGGE技术研究了不同栽培环境下有机与常规蔬菜土壤细菌群落多样性差异,以及土壤理化性质与细菌群落多样性的关系。结果表明：不同栽培方式下土壤细菌多样性存在明显差异,土壤微生物的优势种群和数量受有机、常规栽培和季节影响,有机栽培较之常规栽培能够显著增加土壤细菌群落多样性;聚类分析表明,16S rDNA细菌群落多样性与季节相关,而16S rRNA细菌群落多样性与栽培方式相关;差异条带测序显示,大多细菌与不可培养细菌种属有较高同源性,其余9种推测属于假单胞菌属;CCA分析说明pH是影响土壤细菌群落多样性的主要因素,有机栽培土壤中微生物生物量C、N以及有机质含量显著高于常规栽培土壤。综上,有机栽培能够丰富活性细菌群落多样性,具有土壤优化效应。 相似文献
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《Applied soil ecology》2007,35(2-3):125-139
The toxic effect of chromate on soil microbial communities is not well documented, although microorganisms control biogeochemical cycling, contribute to formation of soil structure, regulate the fate of organic matter applied to soil. In this study the effects of short- and middle-term chromate on the soil microbial community were investigated. The shifts in the size and in the diversity of culturable heterotrophic bacterial community, the resistance to Cr(VI) of heterotrophic bacteria, the presence of cyanobacteria, the activity of 19 enzymes, and the ATP content were monitored over time (120 days) in soil microcosms artificially contaminated with three concentrations of chromate (50, 250 and 1000 mg kg−1 soil). The chromate contamination affected the structure and the diversity of the soil bacterial community. Bacterial strains isolated from the microcosm contaminated with the highest concentration of chromate were identified by 16S rDNA gene sequencing. All isolates belonged to the genus Pseudomonas, were able to reduce Cr(VI), and showed a high resistance to chromate. To our knowledge, this is the first report that shows Pseudomonas strains having the capability to resist up to 40 mM of Cr(VI) on minimal medium. The cyanobacterial group was more sensitive to chromate contamination than culturable heterotrophic bacteria. No cyanobacterial growth was detected in enrichment cultures from the soil polluted with the highest chromate concentration. Some enzymes were inhibited by high concentrations of chromate, whereas others were stimulated. The ATP content in microcosms was strongly affected by chromate. We conclude that the soil microbial community responds to chromate pollution through changes in community structure, in metabolic activity, and in selection for Cr(VI)-resistance. 相似文献
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Mesfin Tesfaye Nicholas S DufaultMelinda R Dornbusch Deborah L AllanCarroll P Vance Deborah A Samac 《Soil biology & biochemistry》2003,35(8):1103-1113
Transgenic alfalfa over-expressing a nodule-enhanced malate dehydrogenase (neMDH) cDNA and untransformed alfalfa plants were grown at the same field site and rhizosphere soils collected after 53 weeks of plant growth. These alfalfa lines differ in the amount and composition of root organic acids produced and exuded into the rhizosphere. Nucleotide sequencing of PCR-based 16S ribosomal DNA (rDNA) clone libraries and Biolog™ GN microtiter plates were employed to assess the activity of naturally occurring rhizobacteria in the two alfalfa rhizospheres. Selected macro- and micro-elements in the two alfalfa rhizosphere soils were also measured. Analysis of 240 16S rDNA clone sequences indicated the existence of about 11 bacterial phyla and their major subdivisions in the two alfalfa rhizosphere samples. There were qualitative changes in the abundance of bacterial phylogenetic groups between rhizosphere soils of transgenic and untransformed alfalfa. Carbon substrate utilization profiles suggested that rhizosphere samples from transgenic alfalfa had significantly greater microbial functional diversity compared with rhizosphere samples from untransformed alfalfa. The concentrations of nitric acid extractable P, K, Mn, Zn and Cu increased significantly in the transgenic alfalfa rhizosphere compared with the untransformed alfalfa rhizosphere. These observations indicate that organic acids produced by plant roots significantly influence rhizosphere microbial diversity and availability of macro- and micro-nutrients and demonstrate the utility of such trangenic plants as tools for studying the potential impact of plant root exudates on soil microbial ecosystems. 相似文献
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Hui Li Dong-sheng Li Hui Xu Guan-xiong Chen Cheng-gang Zhang 《Soil biology & biochemistry》2009,41(5):954-968
The use of molecular approaches based on 16S rDNA-PCR in microbial ecology has revealed a tremendous prokaryotic diversity in environmental samples. However, there is little or no systematic evaluation of the impacts of hypervariable (V) regions of rrs genes choice on microbial community analysis in soil samples, especially the detailed information about the dominant groups preferentially amplified by different primer pairs. In the present study, eight primer pairs were detected to compare the different V regions for fingerprinting microbial communities in a paddy soil irrigated with petroleum-wastewater, using denaturing gradient gel electrophoresis (DGGE) and amplified ribosomal DNA restriction analysis (ARDRA) techniques. Results reveal the obvious PCR bias produced by different V regions. Both ARDRA analysis of 16S rDNA clone library and DGGE suggest that V1-V3 region amplified with primer pair 8f-519r produced the most informative fingerprinting profiles. Additionally, V3-V5 region amplified with 341f-907r was another preferable choice for microbial diversity in petroleum-contaminated soil. The V4-V5 region and single V region (V1, V3, and V8) were not recommended for the future study of microbial diversity in soil samples. Phylogenetic analysis of 123 sequences from libraries constructed by amplicons generated from six different V regions suggests that different dominant groups were amplified with distinct primer sets. In detail, V1-V3 library (amplified with 8f-519r) and V3-V5 library were dominated by Actinobacteria (20.4%) (particularly in genus Arthrobacter), V1-V3 library (amplified with 63f-518r) was dominated by γ-Proteobacteria (25.0%) and α-Proteobacteria (22.0%) (particularly in genus Brevundimonas), V3 library was dominated by β-Proteobacteria (22.3%) (particularly in genus Gallionella) and α-Proteobacteria (20.0%), V6-V8 library was dominated by Chlamydiae (20.4%) and β-Proteobacteria (20.4%), V8 library was dominated by γ-Proteobacteria (27.2%) (particularly in genus Acinetobacter) and β-Proteobacteria (14.0%). The present work strongly recommends that primer pairs should be chosen cautiously in community diversity analysis based on PCR amplification of 16S rDNA, and involving at least two different 16S rDNA universal primer pairs would perform better. 相似文献
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John E Moore Jiru Xu B. Cherie Millar J. Stuart Elborn J.R. Rao 《Compost science & utilization》2013,21(2):192-195
Saccaromonospora viridis is a thermophilic actinomycetes organism which is found in mushroom compost, as well as being a causal agent of mushroom worker's lung (MWL) and other hypersensitivity pneumonitis conditions, including farmer's lung. Phenotypically, it is difficult to distinguish the seven species described for this genus based solely on chemtaxonomic characterization, therefore it was the aim of this study to examine partial 16S rDNA PCR amplification and direct sequencing, as an improved molecular means of identification of Saccharomonospora viridis, associated with MWL. The approach adopted in this study was to identify hypervariable regions within the 16S rRNA gene, which could be employed as signature sequences of the seven individual species within this genus and to employ highly conserved flanking primers to allow initial PCR amplification, prior to direct DNA sequencing of the 16S rDNA amplicon, in a partial 16S rDNA-sequence typing technique. Four universal 16S rDNA primer combinations [P11P/P13P, PSL/PSR, XB1(SV)/PSR and XB1(SV)/P13P] were compared for their ability to identify an unknown thermophilic Saccharomonospora organism from MWL. All PCR primer combinations coupled with direct sequencing allowed for the successful identification of the MWL isolate as S. viridis, demonstrating that universal 16S rDNA PCR primer pairs examined, including the P11P/P13P primer pair, flank regions within the 16S rRNA gene, of sufficient hypervariability to be able to reliably differentiate S. viridis from the other species within this genus. This approach may therefore be useful in the identification of Saccharomonospora spp. associated with composting, as well as with allergic alveolitis or pneumonitis associated occupational exposure in agricultural and horticultural environments, including mushroom production. 相似文献
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采集四川省汉源县富泉乡万顺铅锌矿区5个不同重金属浓度的土壤样品,进行了微生物数量及放线菌多样性的研究。经分离、纯化得到43株不同的放线菌,然后对其进行BOXAIR-PCR和16SrDNAPCR-RFLP分析。结果表明,铅锌矿区重金属复合污染对土壤微生物数量有较大的影响,随着铅锌矿区重金属污染程度的加剧,土壤微生物的总数下降。相关性分析表明,重金属含量与细菌数量呈极显著负相关（P〈0.01）,与放线菌数量、真菌数量呈显著负相关（P〈0.05）。供试菌株的16SrDNA用HaeⅢ、HinfⅠ和TaqⅠ酶切后具有32种遗传图谱类型。BOXAIR-PCR的聚类结果表明在86%的水平上,所有菌株分为10个遗传类型,结果基本与16SrDNAPCR-RFLP聚类差异不大。来源于高重金属的含量样品的菌株基本聚在一起,可能是重金属含量影响了放线菌的分布。同时,16SrDNA序列聚类分析结合系统发育树分析表明链霉菌属是汉源铅锌矿区主要的放线菌属并且具有遗传多样性。 相似文献
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DGGE法与常规培养法对稻田蓝细菌多态性分析结果比较 总被引：1，自引：0，他引：1
研究运用蓝细菌和硅藻16SrDNA特异引物,将晚季水稻生长后期稻田土壤中提取的总DNA进行PCR扩增后,以DGGE技术对PCR产物进行分析结果表明,14条DGGE带经克隆测序,经NCBI基因库比对得晚季水稻生长后期存在10种蓝细菌,包括4种Leptolyngbya、1种Chamaesiphon、1种Nostoc、1种Oscillatoria、2种Syne-chococcus和1种Chroococcidiopsis。同层不同位置土壤中蓝细菌种群亦有所不同,但每个取样点都有一些特有的蓝细菌种类。用常规方法对同一稻田土壤样品进行分离培养,根据蓝细菌鉴定图谱观察到类似Lyngbya、Oscillatori-a、Chroococcidiopsis及Nostoc的蓝细菌,但显微镜下无法准确分类。比较结果表明采用DGGE法比常规培养法能更准确进行蓝细菌多态性鉴定。 相似文献
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Large accumulation of heavy metals in organic layers of forest soils may adversely affect the structure and diversity of microbial communities. The objective of this study was to assess the influence of different soil chemical properties on structure and diversity of microbial communities in soils polluted with different levels of heavy metals. The soil samples were taken at ten sites located in the vicinity of the cities of Legnica and Olkusz, differently polluted with Cu, Zn and Pb. The samples were measured for pH and the contents of organic C (Corg), total N (Nt), total S (St) and total Zn, Cu and Pb. The measured gross microbial properties included microbial biomass (Cmic) and soil respiration (RESP). The structure of soil microbial communities was assessed using phospholipid fatty acid (PLFA) analysis and the structure of soil bacterial communities using pyrosequencing of 16S rRNA genes. To assess diversity of the bacterial communities the Chao1 index was calculated based on the pyrosequencing data. For Cmic and RESP the most important factors were Nt and Corg, respectively. The structure and diversity of soil microbial communities revealed by PLFA profiles and pyrosequencing depended mainly on soil pH. The effect of high heavy metal contents on soil microbial properties was weaker compared with other soil properties. High concentrations of heavy metals negatively affected RESP and the Chao1 diversity index. The heavy metal pollution altered the structure of microbial communities measured with PLFA analysis, but the effect of heavy metal pollution was not observed for the structure of soil bacteria measured by pyrosequencing. The obtained results indicate that the use of soil microbial properties to study heavy metal effects may be difficult due to confounding influences of other environmental factors. In large-scale studies local variability of soil properties may obscure the effect of heavy metals. 相似文献