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1.
【目的】比较不同营养条件及挂膜方式下生物膜法对氨氮污染水体的净化效果及其功能微生物群落结构。【方法】设置空白(Blank)、自然成膜(Raw)、预附脱氮菌强化挂膜(PCC)3组生物膜反应器,利用末端限制性片段长度多态性(T-RFLP)技术和非度量多维标度(NMDS)分析方法对生物膜反应器转化氨氮过程中微生物群落结构及其演替过程进行动态解析。【结果】在C/N=1:1时,除PCC在起始阶段短暂具有较高的氨氮脱除效率外,Blank、Raw和PCC最终均表现出较低的氨氮转化效率(10%-20%)。改变C/N=2:1后,Raw和PCC对人工合成污水中NH4+-N的转化率均提高至95%以上,而且Raw与PCC的群落结构在C/N=2:1时具有较高的相似性,优势菌群主要为γ-变形菌纲(Gammaproteobacteria)、放线菌纲(Actinobacteria)和硝化螺菌纲(Nitrospira)。【结论】C/N是影响生物膜反应器氨氮去除效果及驱动生物膜反应器中细菌群落结构发生改变的重要因子。  相似文献   

2.
《Fungal Biology Reviews》2020,34(3):144-150
It is established that endophytes (bacteria and fungi) affect positively several traits of their host plants including growth, nutrient acquisition, and tolerance to abiotic and biotic stressors. Owing to this, endophytes are envisaged as a route to improve sustainable agricultural production. However, such effects of endophytes on crops although evident under lab conditions, are devoid of consistency under field conditions. The main reason for this could be the lack of our understanding of the functioning of the endophytes as a consortium within the plant (holobiome). It is essential to study the complex web of interactions which operate in the inner tissues of plants harboring endophytes. I highlight here, alluding to the work on foliar fungal endophytes, the importance of studying endophytes as a consortium rather than merely as one species in isolation to better appreciate their role in the plant holobiome. Such an approach should aid in harnessing the technological potential of endophytes.  相似文献   

3.
杨云锋 《微生物学通报》2020,47(9):2683-2684
微生物是地球上生命的主体之一,拥有极为丰富多彩的代谢途径,在很大程度上塑造了使人类宜居的地球。由于绝大部分环境中的微生物无法被分离和培养,微生物被喻为生命物质中的"暗物质"。近年来,迅猛发展的基因组学技术有力地推动了微生物"暗物质"的研究,使我国微生物生态学科发展从"诞生期"和"启蒙期"跨越式发展到"暴发期",乐观预测未来可能进入一个具有鲜明特色的"领航期"。  相似文献   

4.
5.
刘学端 《微生物学通报》2020,47(9):2681-2682
面对物种数量繁多、生态分布广泛、生态功能强大的微生物资源,微生物生态学的任务一方面在于不断发现和认识这类生命"暗物质"及其存在机制,另一方面要充分挖掘和利用这些微生物资源。微生物生态学的应用从最早的混合发酵发展到极端微生物资源利用、微生物生态制剂开发逐渐拓展到合成微生物生态等多个领域。2019年10月在湖南省长沙市举行的"中国生态学学会微生物生态专业委员会学术年会"设立了3个与微生物生态学应用相关的分会场,本期《微生物学通报》也开辟了"人工生态系统微生物"栏目,凸显了我国微生物生态学在资源、能源和环境等应用领域的成果,让我们看到了其成为社会与经济"绿色高效发展"重要驱动力的希望。  相似文献   

6.
氨对脑星状胶质细胞形态结构的影响   总被引:1,自引:0,他引:1  
本文就氨(氯化铵)对体外培养之星状胶质细胞形态结构的影响进行了初步探讨。结果表明,高氨环境下,胶质细胞首先出现空泡变性,之后胞浆内出现细小的嗜碱性颗粒,细胞之间的间隙随着氨浓度的增大及氨作用时间的延长不断增加,细胞的分支状或星状突起显得粗大、清晰。当氨浓度达10mmol/L、氨作用时间延长至72小时时,可见胶质细胞出现核浓缩及崩解坏死现象。观察结果提示:高氨环境下胶质细胞的损伤与修复同时或相继出现,由此其功能代谢也将发生相应变化,这些变化有可能与中枢神经系统在氨中毒时所出现的种种异常有关,其确切作用有待于今后深入研究。  相似文献   

7.
In the tropics, air-breathing fishes can be exposed to environmental ammonia when stranded in puddles of water during the dry season, during a stay inside a burrow, or after agricultural fertilization. At low concentrations of environmental ammonia, NH3 excretion is impeded, as in aerial exposure, leading to the accumulation of endogenous ammonia. At high concentrations of environmental ammonia, which results in a reversed NH3 partial pressure gradient (PNH3), there is retention of endogenous ammonia and uptake of exogenous ammonia. In this review, several tropical air-breathing fishes (giant mudskipper, African catfish, oriental weatherloach, swamp eel, four-eyed sleeper, abehaze and slender African lungfish), which can tolerate high environmental ammonia exposure, are used as examples to demonstrate how eight different adaptations can be involved in defence against ammonia toxicity. Four of these adaptations deal with ammonia toxicity at branchial and/or epithelial surfaces: (1) active excretion of NH4+; (2) lowering of environmental pH; (3) low NH3 permeability of epithelial surfaces; and (4) volatilization of NH3, while another four adaptations ameliorate ammonia toxicity at the cellular and subcellular levels: (5) high tolerance of ammonia at the cellular and subcellular levels; (6) reduction in ammonia production; (7) glutamine synthesis; and (8) urea synthesis. The responses of tropical air-breathing fishes to high environmental ammonia are determined apparently by behavioural adaptations and the nature of their natural environments.Communicated by I.D. Hume  相似文献   

8.
大庆油田微生物采油现场试验进展   总被引:3,自引:0,他引:3       下载免费PDF全文
本文介绍近十几年以来大庆油田利用具有产气、降解原油、产生物表面活性剂及堵调性能的菌剂,通过地下发酵,开展微生物采油现场试验取得的进展.分析了该项技术适用的油藏条件和应用特点.截止到2012年底,应用微生物采油技术增产原油达12×104 t.其中微生物单井吞吐518口,累计增油6.3×104t,实施微生物驱和调驱项目10项(45个井组),累计增油5.7×104 t,为大庆油田稳产发挥了重要作用.  相似文献   

9.
S. Scheu 《Oecologia》1990,84(3):351-358
Summary Microbial biomass, nutrient (N and P) status, and carbon and nutrient limitation of the microflora were investigated in soils from five different sites (field, 5-, 12-, and about 50-year-old fallow, beechwood), which represent different stages of a secondary succession from a wheat field to the climax ecosystem of a beechwood on limestone. In addition, the effect of faeces production by the substrate feeding earthworm species Octolasion lacteum (Örley) on the nutrient status of the soil microflora of these sites was studied. Humus had accumulated in the soil of the third fallow site, with an enhanced biomass of microflora. However, in the beechwood soil, which had the highest humus content, microbial biomass was lower than in the soil of the third fallow site and similar to that of the field and the two younger fallow sites. In general, soil microbial biomass was little affected by the passage of soil through the gut of O. lacteum. The soil microflora of the field, the 5-, 12-, and about 50-year-old fallow was limited by carbon, whereas in the beechwood soil phosphorus limited microbial growth. NItrogen availability to the soil microflora was low in the two younger fallow sites and high in the field and the third fallow. In the beechwood soil nitrogen supply did not affect microbial carbon utilization. Application of phosphorus stimulated glucose mineralization in the soil of the field, the third fallow, and the beechwood, but not in the two younger fallow sites. Therefor, the nutrient status of the soil microflora seems to have changed during secondary succession: presumably, during the first phase the availability of nitrogen decreased, whereas during the second phase microbial phosphorus supply became more important, which resulted in phosphorus limitation of the soil microflora in the climax ecosystem. The passage of soil through the gut of O. lacteum caused an alteration in the microbial nutrient status. Generally, microbial growth in earthworm casts was limited by carbon. The relative effect of the gut passage of the soils on microbial carbon utilization seems to increase during succession. Therefore, the effect of decomposer invertebrates on microbial nutrient supply seems to increase during secondary succession. In general, nitrogen did not limit microbial carbon utilization in earthworm casts. Phosphorus requirements of the soil microflora were lowered by the gut passage of the soil of the third fallow site and the beechwood, which indicates an increased phosphorus supply in earthworm casts. Howerver, this additional supply was not sufficient to enable optimal carbon utilization by the soil microflora. The results indicate that the effect of decomposer invertebrates on the soil microflora depends on the nutrient status of the ecosystem.  相似文献   

10.
Microbial electrochemical systems (MESs) use microorganisms to covert the chemical energy stored in biodegradable materials to direct electric current and chemicals. Compared to traditional treatment-focused, energy-intensive environmental technologies, this emerging technology offers a new and transformative solution for integrated waste treatment and energy and resource recovery, because it offers a flexible platform for both oxidation and reduction reaction oriented processes. All MESs share one common principle in the anode chamber, in which biodegradable substrates, such as waste materials, are oxidized and generate electrical current. In contrast, a great variety of applications have been developed by utilizing this in situ current, such as direct power generation (microbial fuel cells, MFCs), chemical production (microbial electrolysis cells, MECs; microbial electrosynthesis, MES), or water desalination (microbial desalination cells, MDCs). Different from previous reviews that either focus on one function or a specific application aspect, this article provides a comprehensive and quantitative review of all the different functions or system constructions with different acronyms developed so far from the MES platform and summarizes nearly 50 corresponding systems to date. It also provides discussions on the future development of this promising yet early-stage technology.  相似文献   

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