共查询到19条相似文献,搜索用时 46 毫秒
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厌氧氨氧化菌的研究进展 总被引:1,自引:0,他引:1
厌氧氨氧化技术是一种新型生物脱氮技术,在废水处理中具有广泛的应用前途,对全球海洋的氮循环起着重要作用。由于反应中不需另加有机物、不消耗氧气、不会产生二次污染等优点,厌氧氨氧化技术受到格外关注。通常认为,厌氧氨氧化的机理在于厌氧氨氧化菌使氨和亚硝酸反应生成氮气。通过16SrRNA分子生物学方法已鉴定出该菌群属于分枝很深的浮霉菌,由于至今未能成功分离到纯的菌株,未正式命名,对其微生态环境以及生理生化特征也未能取得一致的意见。本文综述了国内外对厌氧氨氧化微生物的作用、分布、种类、生理生化特征等研究进展,认为厌氧氨氧化菌的分离纯化、生物特性、小生境等是今后的主要研究方向。 相似文献
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厌氧氨氧化污泥中效应菌的分子生物学研究 总被引:10,自引:0,他引:10
对具有厌氧氨氧化作用的细菌进行更深入的分析和了解有助于该新型生物脱氮过程在实践中的应用,采用分子生物学方法从已培养的具有厌氧氨氧化活性的污泥中提取细菌总DNA,经纯化、特异引物PCR扩增、克隆、测序等过程,得到厌氧氨氧化菌部分16S rDNA序列(长度为836bp),少部分克隆具有1~2个碱基的突变。此外,进化分析结果显示培养获得的细菌与已发现的Candidatus Brocadia anammoxidans、Anaerobic ammoniumoxidizing Planctomycete、Uncultured anoxic sludge bacterium KU1细菌在进化上关系较近,但比对分析结果表明所研究的细菌与上述细菌的DNA序列相似度不高,这表明自然环境中还存在一种以前未被发现的可进行厌氧氨氧化的细菌。 相似文献
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单级自养脱氮系统中厌氧氨氧化菌的分子生物学鉴定 总被引:3,自引:0,他引:3
对具有厌氧氨氧化作用的细菌进行更深入的分析有助于了解该菌在生物脱氮过程的应用。对稳定运行、氨氮转化率及总氮去除率分别达到90%及80%左右的单级自养脱氮系统的底部取活性污泥,采用分子生物学方法提取活性污泥细菌总DNA,利用特异引物Pla46rc/Amx820对单级自养脱氮系统中的厌氧氨氧化菌16S rDNA基因进行PCR扩增。扩增产物经克隆、测序及BLAST分析,结果表明该单级自养脱氮系统中存在的厌氧氨氧化菌与Candidatus Kueneniastuttgartiensis和Candidatus Brocadia anammoxidans的16S rDNA序列同源性达99%,进化分析证明与Candidatus Kuenenia stuttgartiensis进化上较为接近。 相似文献
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高效反硝化菌aHD7的筛分、脱氮特性及厌氧氨氧化性 总被引:1,自引:0,他引:1
从活性污泥中筛选出一株高效反硝化菌aHD7,30℃静置培养3d,脱氮率可达91.7%,且反应过程中亚硝酸盐积累量较低,3d后亚硝酸盐氮浓度基本稳定在1.8mg.L-1.显微镜观察显示,菌株为革兰氏阴性杆菌,大小为0.5 μm×(1.5~2.5) μm.通过生理生化特性及16S rDNA同源性分析,初步推断该菌株为门多萨假单胞菌(Pseudomonas mendocina).考察了碳源、C/N、氮初始浓度、pH等因素对菌株反硝化性能的影响.结果表明:对中低浓度硝酸盐(硝酸盐氮浓度≤276.95 mg.L-1),脱氮率接近100%,硝酸盐氮浓度高达553.59 mg·L-1时,脱氮率可达66.8%,且亚硝酸盐积累量甚微;最适碳源为乙醇;C/N为6~8和偏中性条件有利于反硝化反应.aHD7具有较强的厌氧氨氧化性,平均氨利用率达4.56 mg·L-1·d-1. 相似文献
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厌氧氨氧化菌特性及其在生物脱氮中的应用 总被引:9,自引:0,他引:9
在无分子氧环境中,同时存在NH4^+和NO2^-时,NH4^+作为反硝化的无机电子供体,NO2^-作为电子受体,生成氮气,这一过程称为厌氧氨氧化。目前已经发现了3种厌氧氨氧化菌(Brocadia anammoxidans,Kuenenia stuttgartiensis,Scalindua sorokinii);对厌氧氨氧化菌的细胞色素、营养物质、抑制物、结构特征和生化反应机理的研究表明,厌氧氨氧化菌具有多种代谢能力。基于部分硝化至亚硝酸盐,然后与氨一起厌氧氨氧化,以及厌氧氨氧化菌与好氧氨氧化菌或甲烷菌的协同耦合作用,提出了几种生物脱氮的新工艺(ANAMMOX、SHARON—ANAMMOX、CANON和甲烷化与厌氧氨氧化耦合工艺)。 相似文献
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舟山群岛海域沉积物厌氧氨氧化细菌多样性 总被引:2,自引:0,他引:2
通过构建16S rRNA基因文库和克隆测序研究了舟山海域沉积物中厌氧氨氧化细菌(AAOB)的多样性。从5个克隆文库中共获得297条16S rRNA基因序列,包含16个操作分类单元(OTUs)。离岸距离较近的3个站具有相似的群落结构,且与离岸较远的2个站具有明显差异。系统发育结果显示,Scalindua属是该海域AAOB的优势类群,95.3%的序列与Scalindua属AAOB具有较近的亲缘关系;1条序列与Kuenenia属具有较近的亲缘关系;此外还有15条序列与已知的AAOB相似性较低。相关性分析表明沉积物有机碳含量与多样性指数具有显著正相关,可能是该海域AAOB多样性变化的重要影响因子。 相似文献
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Post-anoxic denitrification driven by PHA and glycogen within enhanced biological phosphorus removal
The objective of this research was to interrogate and develop a better understanding for a process to achieve post-anoxic denitrification without exogenous carbon augmentation within enhanced biological phosphorus removal (EBPR). Sequencing batch reactors fed real wastewater and seeded with mixed microbial consortia were operated under variable anaerobic-aerobic-anoxic and organic carbon loading conditions. The process consistently achieved phosphorus and nitrogen removal, while the observed specific denitrification rates were markedly higher than expected for post-anoxic systems operated without exogenous organic carbon addition. Investigations revealed that post-anoxic denitrification was predominantly driven by glycogen, an intracellular carbon storage polymer associated with EBPR; moreover, glycogen reserves can be significantly depleted post-anoxically without compromising EBPR. Success of the proposed process is predicated on providing sufficient organic acids in the influent wastewater, such that residual nitrate carried over from the post-anoxic period is reduced and polyhydroxyalkanoate (PHA) synthesis occurs. 相似文献
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The influence of nitrate concentration upon the end-products of nitrate dissimilation by bacteria in anaerobic salt marsh sediment 总被引:2,自引:0,他引:2
Abstract Experiments were carried out with slurries of saltmarsh sediment to which varying concentrations of nitrate were added. The acetylene blocking technique was used to measure denitrification by accumulation of nitrous oxide, while reduction of nitrate to nitrite and ammonium was also measured. There was good recovery of reduced nitrate and at the smallest concentration of nitrate used (250 μM) there was approximately equal reduction to either ammonium or nitrous oxide (denitrification). Nitrite was only a minor end-product of nitrate reduction. As the nitrate concentration was increased the proportion of the nitrate which was denitrified to nitrous oxide increased, to 83% at the greatest nitrate concentration used (2 mM), while reduction to ammonium correspondingly decreased. This change was attributed either to a greater competitiveness by the denitrifiers for nitrate as the ratio of electron donor to electron acceptor decreased; or to the increased production of nitrite rather than ammonium by fermentative bacteria under high nitrate, the nitrite then being reduced to nitrous oxide by denitrifying bacteria. 相似文献
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生物脱氮具有经济高效、绿色环保的特点,在废水处理中具有广阔前景;目前在废水处理工艺中脱氮效果较好的微生物大部分为嗜温菌,这类菌在低温条件下的脱氮效率会受到强烈抑制,而耐冷脱氮菌可有效抵抗低温环境并进行高效脱氮,逐渐引起了研究者们的重视。其次,纳米颗粒(nanoparticles,NPs)在生物学、农学、医药等领域的应用日渐广泛,但在生产、储存和使用含NPs产品的过程中,不可避免地会向水和土壤环境释放NPs,在水环境中,NPs的大量积累会阻碍微生物的脱氮过程,也对废水处理提出了新的挑战,成为公众日益关注的环境问题和研究热点。当前,有部分研究已关注于耐冷菌的脱氮过程、NPs对耐冷菌脱氮过程的毒害作用及减毒措施。基于此,本篇文章将阐述耐冷菌的耐冷机理与脱氮过程,阐明NPs对耐冷菌脱氮过程的毒害作用与减毒调控措施,为低温环境下采用微生物处理含有NPs的氮污染废水提供理论依据。 相似文献
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A dialysis culture device was used for growth of syntrophic fatty acid-oxidizing and ethanol-oxidizing anaerobic bacteria. A pure culture of the fatty acid oxidizer Clostridium bryantii was grown inside dialysis tubing which was surrounded by a pure culture of Desulfovibrio vulgaris. The same apparatus was used for the syntrophic cultivation of Pelobacter acetylenicus and Acetobacterium woodii with ethanol as substrate. In both cases, substrate degradation and product formation were about half as fast as with the homogeneously mixed control cultures. In the compartment of the hydrogen producer, the concentration of free hydrogen during syntrophic ethanol degradation was about 10 times as high as in that of the hydrogen utilizer, whereas the homogeneously mixed culture exhibited an intermediate hydrogen partial pressure. 相似文献
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对不同林龄杉木人工林(5、8、21、27和40年生)土壤硝化与反硝化过程及功能微生物丰度进行研究。结果表明: 土壤净硝化速率随林龄的增加波动变化,8、27年生杉木人工林土壤净硝化速率显著低于5、21和40年生。27年生杉木人工林土壤氨氧化古菌(AOA) amoA基因丰度显著低于40年生,其他林龄AOA amoA基因丰度之间无显著差异。不同林龄杉木人工林的氨氧化细菌(AOB) amoA基因丰度、反硝化功能基因丰度以及反硝化潜势均无显著差异。逐步回归分析表明,土壤氨氧化微生物AOA amoA基因丰度受土壤理化性质的影响不显著,土壤总碳和土壤pH是影响AOB丰度的重要因子。反硝化功能基因narG、nirK及nosZ随土壤pH的增加而增加,编码亚硝酸盐还原酶(NIR)的功能基因(nirK、nirS)受土壤总碳的影响。林龄可通过影响AOA amoA基因丰度影响土壤净硝化速率。林龄直接作用于反硝化潜势,或间接影响土壤微生物生物量碳、土壤pH及反硝化功能基因丰度(narG和nirK),进而影响反硝化潜势。相较于反硝化过程,土壤硝化作用及AOA amoA基因丰度对杉木林分发育更加敏感,可适当延长轮伐期以降低土壤硝化作用造成的氮流失风险。 相似文献