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1.
碳源及碳氮比对异养反硝化微生物异养反硝化作用的影响   总被引:12,自引:0,他引:12  
碳源(甘油和柠檬酸钠)及碳氮比对纯培养的异养反硝化菌HP1(Pseudomonas alcaligenes)异养反硝化能力影响的试验表明,碳源种类对硝酸还原酶活性没有明显影响,对氧化亚氮还原酶活性有影响。批式培养方式下最适C/N为8,菌株HP1可以利用NO3^-f作为唯一氮源进行反硝化作用,证明HP1至少有2种硝酸还原途径。连续培养方式下温度对菌株HP1异养反硝化作用中间产物的积累有影响,不同C/N时均有NH4^ 积累,C/N为3时还有NO2^-的积累。  相似文献   

2.
一株贫营养异养硝化-好氧反硝化菌的筛选及脱氮特性   总被引:5,自引:0,他引:5  
为了探究并优化菌剂应用于微污染水源水体修复的机制和条件,主要针对水库沉积物内筛选出的贫营养好氧反硝化菌进行了菌种鉴定及脱氮特性研究,考察菌株在不同环境条件下的脱氮效果,明确了该菌株的最适宜生长条件,并基于水库水体中贫营养条件对菌株进行水源水库原水的驯化培养试验研究,以期实现该菌株对微污染水源水库原水中氮源污染物的脱除,为原位投菌技术实际工程应用提供理论依据。从微污染水源水库沉积物中驯化筛分出一株高效异养硝化-好氧反硝化菌A14,通过扫描电镜观察、生理生化特征、16S rRNA基因测序和Biolog GenⅢ鉴定,确定该菌株为革兰氏阴性短杆菌,鉴定为皮特不动杆菌(Acinetobacter pittii)。在好氧条件下,菌株细胞内表达反硝化功能基因napA,以NO3-为唯一氮源进行反硝化作用时,36 h时NO3-去除率为78.89%。以NH4+为唯一氮源时,48 h NH4+去除率为95.25%,TN去除率达80.42%,TOC去除率达98.30%,表明该菌株具有异养硝化-好氧反硝化特性。在改变环境条件过程中,该菌株在以乙酸钠为碳源,温度为30℃,C/N为12,pH为7,接种量为10%时,NO3-去除率最高为86.62%,并且在10℃下脱氮率达到40.18%。在水源水库原水脱氮实验中,接种处理TN去除率为50.95%,NO3-去除率为80.25%。结果表明,菌株A14在微污染水源水体菌剂脱氮修复中具有良好的应用潜力。  相似文献   

3.
1株贫营养好氧反硝化菌的分离鉴定及其脱氮特性   总被引:2,自引:0,他引:2  
魏巍  黄廷林  苏俊峰  王春燕  黄卓  李娜 《生态环境》2010,19(9):2166-2171
从水库底泥样品中,以硝酸盐为唯一氮源进行驯化、分离筛选出1株能在贫营养及好氧条件下进行高效反硝化的菌株PY8,经过电镜形态学观察、生理生化和16S rDNA序列分析,并基于16SrDNA序列结果,构建了该菌株的系统发育树,最终确定菌株PY8为根瘤菌Rhizobiumsp.。考察了初始pH值、温度、C/N、初始硝酸钠质量浓度、投菌量对菌株PY8硝酸盐还原活性的影响,以及该菌株的异养硝化性能。结果表明,在pH6.0~10.0,温度25~30℃,C/N1.0~9.0,初始硝酸钠质量浓度0.01~0.50g·L-1,投菌量1%~15%时,菌株PY8培养72h后的硝氮去除率可达到95%以上。另外,该菌株具有同时硝化-反硝化作用,在培养过程中氨氮去除率可达到58%左右。实验结果表明,菌株PY8在微污染水体生物脱氮领域中具有很大的应用潜力。  相似文献   

4.
从实验室定向驯化的活性污泥中分离筛选出一株具有异养硝化-好氧反硝化功能的菌株TS-1.通过生理生化及16S r RNA基因序列鉴定其为脱氮副球菌,通过单因素和正交实验对其去除NH_4~+-N的最佳条件进行优化,并通过对比进一步探究其在不同氮源条件下对各形态无机氮的去除规律.结果表明该菌株最适碳源为丁二酸钠,最佳C/N为15,最佳接种量为5%,最适温度为30℃、p H为8.0.以初始浓度约为100 mg/L的NH_4~+-N、NO_3~--N和NO_2~--N分别为单一氮源时,菌株TS-1对各形态氮的去除率为97.49%、100%和95.94%;维持各形态氮初始浓度不变,将其两两混合时发现混合氮源中若包含NO_2~--N会使菌株OD_(600)值达到最大值所用时间延长,氮源中含有NH_4~+-N会降低菌株对其他形态氮源的去除率,以及NO_3~--N的添加会使菌株对NH_4~+-N的去除能力降低;3种形态氮源同时存在的条件下,该菌对各氮源去除能力由强至弱为NO_2~--NNH_4~+-NNO_3~--N.本研究从活性污泥中分离筛选出一株具有高效异养硝化-好氧反硝化功能的菌株TS-1,通过研究碳源、氮源、温度、p H得到了最佳降解条件,可为废水短程脱氮提供参考.(图9表4参37)  相似文献   

5.
与传统脱氮菌相比,异养硝化-好氧反硝化菌在脱氮方面具有较大优势并受到广泛关注。以乙酰胺为唯一氮源从活性污泥中分离得到1株脱氮性能较高的异养硝化-好氧反硝化细菌,命名为Y1。经形态观察、生理生化特征和16S rRNA分析后鉴定为Acinetobaterjohnsonii(约氏不动杆菌),革兰氏染色结果为阴性。对Y1菌株进行生理生化鉴定试验,结果显示Y1对吲哚、柠檬酸盐、硫化氢和接触酶的反应呈阳性,表明该菌株能良好的利用以上物质;而甲基红、葡萄糖发酵、蔗糖发酵、明胶液化、淀粉水解、氧化酶、尿素酶试验结果呈阴性,表明该菌株不能很好的利用以上物质。为了检测Y1菌株的脱氮性能,将其分别置于异养硝化培养基和好氧反硝化培养基进行培养,在108 h内,接种Y1菌株的异养硝化培养基中的氨氮去除率约为66.9%,去除速率达0.53 mg.L~(-1)·h~(-1),硝氮去除率约为100%,去除速率达0.10 mg·L~(-1)·h~(-1);在84 h内,接种Y1菌株的好氧反硝化培养基中的硝氮去除率约为69.7%,去除速率达0.74 mg·L~(-1)·h~(-1),上述结果表明Y1菌株的脱氮性能较高。为了进一步研究该菌株的生长需求,保持其它条件不变的情况下,将其分别置于不同碳源和氮源下进行培养,结果表明,菌株Y1在琥珀酸钠为唯一碳源时的生长速率、异养硝化和好氧反硝化性能最好,并且利用无机氮源的能力比有机氮源能力强。  相似文献   

6.
好氧同时硝化-反硝化菌的分离鉴定及系统发育分析   总被引:10,自引:0,他引:10  
从土壤中分离到一株好氧同时硝化-反硝化菌,编号为SDN,该菌株革兰氏染色呈阳性,球状或杆状,菌落颜色橙红色.该菌株以硝酸钠为氮源时能进行好氧反硝化作用;以乙酸钠和硫酸铵分别为碳源和氮源能进行异养硝化作用,能以乙酰胺为唯一碳源和氮源进行生长.部分长度的16S rDNA序列分析表明,分离菌株SDN与Rhodococcusruber的16SrDNA序列具有99%相似性.并用PHYLIPS程序将该菌株与报道的相关微生物进行了系统发育分析.图4表1参13  相似文献   

7.
近年来发现了一类具有偶联异养硝化-好氧反硝化功能的细菌.Paracoccus pantotrophus ATCC 35512是其中最早发现的细菌.通过对该菌株16S rRNA序列和细胞色素c的氨基酸序列分析,确立其为一个新种Paracoccuspantotrophus,ATCC 35512被确定为模式株.该菌株的异养硝化-好氧反硝化偶联途径假说被提出,其反应途径中涉及的一系列酶和电子传递体也陆续被纯化研究.本文综述了对该菌株系统分类、形态和生理生化特征、硝化-反硝化偶联假说及氮循环酶系等的研究进展,并提出了进一步揭示异养硝化-好氧反硝化现象的研究方向.  相似文献   

8.
近年来发现了一类具有偶联异养硝化-好氧反硝化功能的细菌.Paracoccus pantotrophus ATCC 35512是其中最早发现的细菌.通过对该菌株16S rRNA序列和细胞色素c的氨基酸序列分析,确立其为一个新种Paracoccus pantotrophus,ATCC 35512被确定为模式株.该菌株的异养硝化一好氧反硝化偶联途径假说被提出,其反应途径中涉及的一系列酶和电子传递体也陆续被纯化研究.本文综述了对该菌株系统分类、形态和生理生化特征、硝化-反硝化偶联假说及氮循环酶系等的研究进展,并提出了进一步揭示异养硝化-好氧反硝化现象的研究方向.表2参50  相似文献   

9.
葛潇霄  田昆  郭雪莲  王胜龙  赖建东 《生态环境》2011,20(12):1846-1852
选取纳帕海常见湿地植物茭草(Zizania caduciflora)和水葱(Scirpus validus)]及其生长土壤为对象,通过培养实验,研究了3个不同氮输入水平[0g-m^2(对照,NO)、20g-m^2(N20)、40g-m^2。(N40)]对茭草和水葱湿地土壤氨挥发和反硝化的影响。结果表明:氮输入促进了茭草和水葱湿地土壤氨挥发化作用,增加了湿地土壤氨挥发的累积量。适量的氮输入对湿地土壤氨挥发促进显著。在培养前期适量氮输入下的氨挥发积累量高于高水平氮输入的,随着培养时间的延长,后期适量氮输入下的积累量明显下降;而高水半氮输入处理下氨挥发积累量的明显增加,适量氮输入下茭草氨挥发积累大于水葱。氮输入增强了菱草和水葱湿地土壤反硝化作用,加快了反硝化N2O的排放。适量的氮输入促进茭草反硝化作用和反硝化损失量增加明显,培养的前期的适量氮输入处理下的反硝化作用和反硝化N2O的排放增强不明显,随着培养时间的延长,高水平氮输入处理下的反硝化损失量越明显,并且水葱较茭草更为明显。后期适量氮输入下的反硝化损失速率和反硝化损失量高于高水平氮输入,适量氮输入较高水平氮输人促进明显,高水平的氮输入限制了反硝化损失,反硝化N2O的排放总量下降,土壤中氮富集增大。  相似文献   

10.
针对传统污水处理工艺中存在的工艺复杂、脱氮效率低等问题,从江苏无锡市桃花山垃圾渗滤液生化反应池活性污泥中富集、分离及筛选出一株异养硝化菌BT1.通过16S rRNA序列分析,对分离菌株进行鉴定,同时对其异养硝化特性、氨氧化功能基因及氨氧化性能影响因素进行研究.结果显示:分离到的异养硝化菌为农杆菌属Agrobacterium sp..该菌经过32 h培养后,NH_4~+-N去除率为99.77%;TN去除率为96.99%.其中,59.62%TN转换为胞内氮,37.37%TN转化为气态氮;检测不到NO_3~--N和NO_2~--N的积累.结合氨单加氧酶基因(amo A)的PCR成功扩增,进一步证明了BT1菌株具有氨氧化能力.单因子试验结果显示,在温度为30℃、C/N为10-15、pH为7.0-9.0、转速为120-160 r/min的条件下,菌株均能去除98.51%以上NH_4~+-N,体现出良好的氨氧化性能.BT1菌株能够适应较宽的氨氮负荷,在高氨氮浓度(500和1 000 mg/L)下生长良好且NH_4~+-N去除率均超过64.69%.本研究表明BT1菌株具有高效的异养硝化性能及优异的氨氮耐受性,具有进一步处理高浓度氨氮废水的应用前景.(图9参39)  相似文献   

11.
Batch experiments were carried out to investigate the promotive effect of pyridine on indole degradation under denitrifying conditions. The seed sludge was obtained from a local coal-coking wastewater treatment facility and was acclimated in the laboratory. Indole and pyridine were supplemented to the synthetic wastewater at different ratios. The optimum ratio of chemical oxygen demand (COD) to nitrate (C/N) was 8.4–8.9 for both denitrification and indole and pyridine degradation. At a temperature of 28°C and pH of 7.0–7.5, the nitrate reductase activity (NRA) was in the best state. The addition of pyridine could promote NRA and the degradation of indole. When the initial concentration of indole was 150 mg/L, the concentration ratio of indole to pyridine was in the range of 1–10. Under optimum C/N conditions, the degradation of indole could be described with pseudo-zero-order kinetics. There was no accumulation of nitrite during the reaction. When the concentration ratio of pyridine to indole was less than 0.25 with an increase in the pyridine proportion, there were more significant augment rates for NRA and the degradation of indole than the situation when the concentration ratio was more than 0.25.  相似文献   

12.
● The availability of PD-anammox was investigated with higher NO3–N concentration. ● NO3–N concentration affects NO3–N accumulation during denitrification. ● COD concentration is determinant for N removal pathways in PD-anammox process. ● The synergy/competition mechanisms between denitrifiers and anammox was explored. Partial denitrification-anammox (PD-anammox) is an innovative process to remove nitrate (NO3–N) and ammonia (NH4+–N) simultaneously from wastewater. Stable operation of the PD-anammox process relies on the synergy and competition between anammox bacteria and denitrifiers. However, the mechanism of metabolic between the functional bacteria in the PD-anammox system remains unclear, especially in the treatment of high-strength wastewater. The kinetics of nitrite (NO2–N) accumulation during denitrification was investigated using the Michaelis-Menten equation, and it was found that low concentrations of NO3–N had a more significant effect on the accumulation of NO2–N during denitrification. Organic matter was a key factor to regulate the synergy of anammox and denitrification, and altered the nitrogen removal pathways. The competition for NO2–N caused by high COD concentration was a crucial factor that affecting the system stability. Illumina sequencing techniques demonstrated that excess organic matter promoted the relative abundance of the Denitratesoma genus and the nitrite reductase gene nirS, causing the denitrifying bacteria Denitratisoma to compete with Cadidatus Kuenenia for NO2–N, thereby affecting the stability of the system. Synergistic carbon and nitrogen removal between partial denitrifiers and anammox bacteria can be effectively achieved by controlling the COD and COD/NO3–N.  相似文献   

13.
The feasibility of pH and oxidation reduction potential (ORP) as on-line control parameters to advance nitrogen removal in pulsed sequencing batch reactors (SBR) was evaluated. The pulsed SBR, a novel operational mode of SBR, was utilized to treat real municipal wastewater accompanied with adding ethanol as external carbon source. It was observed that the bending-point (apex and knee) of pH and ORP profiles can be used to control denitrification process at a low influent C/N ratio while dpH/dt can be used to control the nitrification and denitrification process at a high influent C/N ratio. The experimental results demonstrated that the effluent total nitrogen can be reduced to lower than 2 mg/L, and the average total nitrogen (TN) removal efficiency was higher than 98% by using real-time controll strategy.  相似文献   

14.
从底泥中分离出1株低温贫营养好氧反硝化细菌SY13,经常规生理生化鉴定和16SrDNA测序,鉴定出细菌SY13属于Acinetobactersp.。考察了温度、pH、C/N比及接种量对菌株SY13硝酸盐还原活性的影响,初始硝酸盐浓度为15mg/L左右,温度为15℃时低温贫营养好氧反硝化细菌SY13的硝酸盐去除率为49.26%,在中性环境适应性较强,pH值为7.0时72h的硝氮去除率达到58.08%,随着C/N比不断增加,菌株SY13硝酸盐的去除效果逐渐增强,接种量为10%时,菌株SY13培养72h后的硝氮去除率可达到59.62%。  相似文献   

15.
Isochrysis galbana Parke, Strain CCAP 927/1, was grown in ammonium-limited batch culture under a 12 h light: 12 h dark illumination cycle. Samples were taken every 12 h over the 26 d period from lag phase through exponential into stationary phase (no net carbon fixation), with more frequent sampling at points of interest. Exponential cell-specific growth rate was 0.3 to 0.4d-1. Cell division occurred during the dark phase, while cell volume increase, ammonium uptake, and pigment synthesis occurred during the light. Stationary phase cells were small, and the lag phase was long (5 d) even though the C:N ratio had returned from 18 to 6.5 within 2 d, followed by synthesis of chlorophyll a. Net chlorophyll synthesis ceased within 4 d of exhaustion of the nitrogen source. The chlorophyll c: chlorophyll a ratio remained constant during increasing nitrogen deprivation. Biovolume and carotenoids correlated with carbon biomass. Levels of chlorophyll a correlated poorly with carbon fixation and carbon biomass once the nitrogen source had been exhausted. Except after the addition of ammonium to nitrogen-deprived cells (refeeding), the content of intracellular glutamine and the glutamine: glutamate ratio were low during the dark phase, rising to a plateau within the first 1 h of illumination. Refeeding of cells which had only just exhausted the extracellular nitrogen source resulted in a much smaller increase in glutamine than refeeding of nitrogen-starved (stationary-phase) cells. Nitrogen biomass correlated with the presence of an unidentified intracellular amine.  相似文献   

16.
A membrane-aerated biofilm reactor was employed to investigate the nitrogen removal of one typical municipal reverse osmosis(RO) concentrate with a high total nitrogen (TN) concentration and a low C/ N ratio. The effects of operational conditions, including the aeration pressure, the hydraulic retention time and the C/N ratio, on the systematic performance were evaluated. The nitrogen removal mechanism was evaluated by monitoring the effluent concentrations of nitrogen contents. Furthermore, the microbial tolerance with elevated salinity was identified. The results indicated that the optimal TN removal efficiency of 79.2% was achieved of the aeration pressure of 0.02 MPa, hydraulic retention time of 24 h, and the C/N ratio of 5.8, respectively. It is essential to supplement the carbon source for the targeted RO concentrate to promote the denitrification process. The inhibitory effect of salinity on denitrifying bacteria and nitrite oxidizing bacteria was significant, revealing the limited TN removal capacity of the conditions in this work. The TN removal efficiency remained more than 70% with the addition of salt (NaCl) amount below 20 g/L. This work preliminarily demonstrated the MABR feasibility for the nitrogen removal of municipal RO concentrate with low C/N ratio and provided technical guidance for further scale-up application.
  相似文献   

17.
A composite membrane bioreactor (CMBR) integrating the immobilized cell technique and the membrane separation technology was developed for groundwater denitrification. The CMBR had two well mixed compartments with one filled with the nitrate-containing influent and the other with a dilute ethanol solution; the compartments were separated by the composite membrane consisting of a microporous membrane facing the influent and an immobilized cell membrane facing the ethanol solution. Nitrate and ethanol molecules diffused from the respective compartments into the immobilized cell membrane where nitrate was reduced to gaseous nitrogen by the denitrifying bacteria present there with ethanol as the carbon source. The microporous membrane was attached to one side of the immobilized cell membrane for retention of the disaggregated bacteria. Relative to the single dose of external ethanol, the two-dose supplementation produced better treatment results as evidenced by the lower concentrations of NO 3 ? -N and ethanol (as measured by total organic carbon) of the effluent. The batch treatment in CMBR removed most of the nitrate in the influent and attained a stable denitrification rate of 0.1 g·m?2·h?1 for most of the 96-h cycles during the 30-cycle study. The effluent was essentially free of ethanol and nitrite nitrogen.  相似文献   

18.
Nitrate reductase (NR) activity appeared in ammoniumgrown cultures of 5 species of marine algae, representing 4 classes, after a short period of nitrogen starvation. In nitrogen-limited chemostat cultures of Nannochloropsis oculata and Chlorella stigmatophora there was an inhibition of photosynthetic carbon fixation during nitrate assimilation. In these organisms, nitrate assimilation was light-dependent and inhibited by 3-(3′,4′-dichloro-)-1-1-dimethyl urea (DCMU). In N. oculata, an obligate autotroph, nitrite assimilation was dependent on light absolutely. Physiological changes that occur in these organisms during nitrogen deficiency enable them to assimilate nitrogen rapidly when it becomes available.  相似文献   

19.
The effect of bryozoan colonization on inorganic nitrogen acquisition by Agarum fimbriatum Harv. and Macrocystis integrifolia Bory., collected from the west coast of Vancouver Island, British Columbia, Canada, was examined in laboratory experiments during June and July 1992. Pieces of kelp blades that were completely covered on one side by the bryozoans Lichenopora novae-zelandiae Busk or Membranipora membranacea, L., or uncolonized (clean treatment), were used to estimate the rate at which nitrate and ammonium were removed from the surrounding seawater. In addition, the rate of ammonium excretion by bryozoans isolated from their associated kelp was measured and also estimated from the results of the uptake experiments. Values obtained were used to estimate the contribution of ammonium excreted by bryozoans to the total amount of inorganic nitrogen available to the associated kelp. Both bryozoan species reduced the ability of the associated kelp to remove nitrate and ammonium from seawater but provided a source of ammonium to the kelp through excretion. The nitrogen status of colonized and clean kelp disks was determined from the ratio of total particulate carbon to total particulate nitrogen (C:N ratio). The C:N ratios for A. fimbriatum colonized with either L. novae-zelandiae or M. membranacea were similar (C:N=12 to 14), and differences between colonized and clean treatments were not significant. For A. fimbriatum, therefore, the C:N ratio indicates that this species was not nitrogen limited at the time of the present study. In contrast, both colonized and clean disks of M. integrifolia were nitrogen limited, but colonized disks (C:N=19) were significantly less limited by nitrogen than clean disks (C:N=29). Results are discussed in relation to the different environments inhabited by both kelp species and are consistent with the hypothesis that ammonium excreted by bryozoans was an important source of inorganic nitrogen to M. integrifolia, but not to A. fimbriatum, at the time of the study.  相似文献   

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