2株可培养细菌氮代谢特性的研究

研究旨在分析土壤中可培养细菌菌株的氮代谢特征,并进一步探讨微生物在土壤氮素转化中的可能作用机制。以2株分离自苹果园土壤的细菌菌株SY5-4和SY11-10为试材,采用传统培养方法结合分子检测技术,分别测定菌株生长特性及其氮素转化能力。研究结果表明,异养条件下,菌株SY5-4和SY11-10的世代时间分别为243.5 min和202.7 min。菌株生长过程中,培养液中铵态氮浓度始终维持在较高水平,铵态氮、亚硝态氮和硝态氮浓度均表现出先升后降的趋势。硝化（amoA和hao）和反硝化（nosZ、norB、nirK和nap）基因检测结果表明,菌株SY11-10具有多种氮素转化潜能。综上,供试菌株培养过程中,培养液中氮素发生变化,并在菌体中检测到不同氮转化基因,表明菌株参与多种氮代谢途径。     

Advance in New Technology of Biological Nutrient Removal

General situation studying on new technology of biological nutrient removal is summarized, such as the principle of denitrifying dephosphataion and factors affecting it , such as pH, DO, SRT, MISS etc. The principle of simultaneous nitrification and denitrification and factors affecting it are given, such as carbon source, DO, the property of activated sludge ect. The principle of shortcut nitrification -denitrification and factors affecting it is also given such as temperature, pH, the concentration of ammonia, DO etc. The principle of anaerobic ammonium oxidation and factors affecting if is proposed such as stayer, pH, temperature etc. The technics and its peculiarity of these new technology of biological nutrient removal is commented.     

Acclimation in Partial Nitrification Process of Long MCRT

Nitrite accumulation will drop down when the nitrite oxidation bacteria have acclimated to the nitrifying conditions after stable performance for some times. Accumulation is a gradating course, nitrite disappear will take only a few days. A long MCRT can not maintain a long term stable partial nitrifying process. The refreshment of system sludge and suitable MCRT is key for nitrite accumulation, and bacillar sludge is its typical feature.     

Effects of Free Ammonium and pH on Partial Nitrification Process

Through an activated sludge SBR reactor,the authors study the influence of FA concentration and pH on the partial nitrification of low C/N nitric wastewater.It can be known that low C/N nitric wastewater can realize stable nitrite accumulation to 90%.Maintaining the pH between 6.5~8.5 is suitable for the growth of ammonium oxidation bacteria.While FA rising,the inhibition of ammonium oxidation bacteria is quick,but nitrite oxidation bacteria's is slow.By(adapting) for some time,ammonium oxidation bacteria gain the dominance,and nitrite oxidation bacteria in pessimum,which leads to the nitrite accumulation.Relatively high FA concentration is avail for the competition of ammonium oxidation bacteria.Suitable FA concentration is 7~10 mg/L.Process with long MCRT can not realize stable partial nitrification.The bacillar sludge is its typical feature.     

草地硝化,反硝化微生物功能群研究进展

在全球气候变化的背景下,对于草地土壤中氮素循环的研究更加迫切和重要。温室气体氧化亚氮（N2O）在土壤中主要来自硝化反硝化过程,都由相应地微生物功能群所驱动。为了揭示土壤N2O产生的微生物机制,笔者从近年来草原硝化、反硝化过程相关微生物功能群入手,归纳了全球不同草原生态系统中硝化反硝化微生物功能群的数量,组成及相应的影响机制和地理格局,总结了N2O产生过程的研究进展,分析指出了未来草地土壤微生物研究的热点方向,并对草地N2O产生的微生物机制研究做出了展望。     

脲酶/硝化抑制剂对花生生长和产量的影响

以棕壤为供试土壤,采用田间试验方法,研究了化肥中添加不同种类和不同量的抑制剂对花生生长和产量的影响。结果表明,添加抑制剂的各处理与施肥对照CK1比,开花期的平均植株干重增加了3.2%~23.1%,成熟期的平均株高增加了2.1%~10.0%,而对花生分蘖影响不大。叶绿素总量在开花期增加了2.1%~10.7%,在成熟期,脲酶抑制剂NBPT1和NBPT2处理叶绿素下降幅度小,含量仍在CK1以上,而含硝化抑制剂的DCD1、DMP1、DMP2和DMP3处理下降幅度较大,叶绿素含量在CK1以下。试验同时表明,添加抑制剂可使花生增产2.06%~11.65%,其中DMP3、NBPT1和NBPT2处理增产效果更好。化肥中添加抑制剂后促进花生生长和提高产量。此文主要为提高肥料利用率和保护生态环境,并为抑制剂的研制开发与应用推广提供了科学依据。     

Functional Microbial Diversities in Wastewater Biological Treatment

Molecular biotechnology as one of culture-independent methods has been increasingly used in the studies of wastewater microorganisms, and many uncultured populations have been revealed, which have changed many views of microbial ecology. This paper gives a succinct review of recent studies in wastewater microorganisms. Some novel, in many cases yet not cultured bacteria were identified to be responsible for filamentous bulking and foaming as well as phosphorus and nitrogen removal in wastewater treatment systems ; however, some predominate population recognized previouslY were proved unimportant. The data give some insights about microbial diversity, population dynamics, terns stability and specific microbial population activity, and they will be helpful to optimize plant design and parameter control. ecosysprocess     

应用基因芯片方法检测几种肠道菌

采用基因芯片技术,对几种常见的肠道菌进行检测和鉴定,包括检测靶基因的扩增、基因芯片的制备、杂交反应和杂交结果的检测与分析4个步骤。结果表明:应用基因芯片对涉及4个菌属的23株肠道菌在相同的条件下进行了杂交检测,得到菌属特异性的杂交图谱,从而达到对细菌进行检测鉴定的目的。制备的基因芯片能够同时检测沙门菌属、志贺菌属、葡萄球菌属、耶尔森氏菌属的细菌。     

产几丁质酶细菌CHB101对稻瘟病菌的抑制作用

采用平板对峙及无菌滤液对稻瘟病孢子萌发影响等方法研究了产几丁质酶细菌CHB101对稻瘟病菌的抑制效果,结果表明该菌对稻瘟病菌有明显抑制作用,在PDA平板上25℃培养6d后抑菌带平均宽为11.0mm,并在显微镜下观察到了稻瘟病菌菌丝细胞质浓缩,细胞壁溃解和细胞质外渗等明显的几丁质酶作用现象。该菌培养后的无菌滤液对稻瘟病孢子萌发有强烈的抑制作用,并随滤液的浓度提高抑制作用越强。而且研究结果显示CHB101的抑菌谱宽,抑菌能力强。     

Correlation Studies on Ammonium/Nitrate Concentrations in Soil and Growth and Yield of Wheat

A field experiment was conducted at the Indian Agricultural Research Institute, New Delhi to study the growth and yield of wheat as influenced by the concentrations of ammonium-N and nitrate-N in soil. A series of ammonium and nitrate nitrogen concentrations in soil on a time frame was developed by treating prilled urea with nitrification inhibitors DCD or neem cake as well as by changing the dose and time of N application. The study revealed that number of tillers m^-1 as well as ears m^-1 row length were significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30 and 45 DAS. Number of grains ear^-1 was significantly positively correlated with ammonium-N at 30, 45 and 60 DAS and nitrate-N at 45 and 60 DAS. Ultimately grain yield in wheat was significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30, 45 and 60 DAS. The response between grain yield and concentrations of both ammonium and nitrate forms of N was quadratic. The optimum concentration of ammonium-N in soil for maximum grain yield gradually decreased with the age of the crop from 54.6 to 63.6 μg g^-1 at 15 DAS to 22.7 to 26 μg g^-1 at 30 DAS. In the case of nitrate-N its optimum concentration for maximum grain yield increased with age of the crop from 25.1 to 30 μg g^-1 at 15 DAS to 31.6 to 34 at 45 DAS and it decreased thereafter.     

土壤硝化强度测定方法的改进

为了使土壤硝化强度的测定条件更加统一,结果更加准确,本研究针对土壤硝化强度测定时广泛采用的悬液法,研究了其最佳培养条件：反应体系pH 7.5,底物NH4+-N浓度为100 mg/L,培养温度为30℃,培养时间为5 h,风干土样预培养72 h后才可进行硝化强度的测定。还针对NO₃^--N生成法的不足,探讨了通过NO₂^--N生成法评价硝化强度的途径：通过向反应体系中添加1 mol/L的氯酸钠0.2 mL,有效抑制NO₂^-向NO₃^-的氧化。不同检测方法对硝化强度测定对比的结果发现,NO₂^--N生成法确是评价土壤硝化强度的最佳方法。     

棉花内生细菌及其研究进展

本文从种群及其动态演变规律、研究方法、抗性诱导及机理等方面对棉花内生细菌近年来的进展进行了综合论述,并展望其应用前景。     

Effect of Dissolved Oxygen and the Distribution of Sludge Particles Diameter on the Simultaneous Nitrification and Denitrification

In order to discuss the reaueing theory of simultaneous nitrification and denitrification (SND), with the sequence batch reactor (SBR), the dissolved oxygen (DO) and the floc size distribution were investigated for sewage wastewater.It is found that the SND can be attained in SBR process by nitrogen mass balance calculation with low DO (mean value 0.5 mg/L 0.8 mg/L).Around 23.11% nitrogen in total nitrogen is removed by SND.The ratio of nitrate formation and ammonia decay is at 0.454 with the DO concentration at 0.5 mg/L.Meanwhile, the velocity of nitrification and denitrification is equal.And the SND couldn’t occur when the ratio of nitrate formation and ammonia decay is equal with DO at 4.296 mg/L.The mean floc size distribution of sludge is at the range of 5.02 μm ~6 μm, that is, the SND is not the results of “micro environment action” when SND occurs.     

Study on Factors Affecting the Activated Sludge Bulking and Its Control

In this paper,the concept,types and mechanism of activated sludge bulking were introduced.The factors affecting the sludge bulking were discussed from the aspects of wastewater quality,such as wastewater with high content of carbon hydrate,decayed wastewater,wastewater with toxic substance,wastewater with unbalanced content of N and P and wastewater with low pH value;the environment conditions such as flowing state of the flow,operation manner,variation of water quality and other factors(pH,temperature,nutrition) etc.And also,the emergency controlling,environment controlling and process operating controlling methods are put forward for controlling activated sludge bulking.     

生草栽培对桃园土壤养分特性及细菌群落的影响

为了研究生草栽培方式对土壤养分特性及细菌群落多样性的影响,探讨桃园生草栽培的土壤生态机理,在浙江杨渡桃园培育区设计了套种黑麦草、套种毛苕子和清耕杂草（对照）3个处理,并采集不同样地表层土壤进行分析。结果表明,在套种黑麦草、毛苕子8个月后,桃园土壤(0~20 cm)的有机质、全氮、速效钾和速效磷等指标,没有随着套种带来的土壤养分竞争增加而减少;相反,有机质、全氮等出现增加的趋势。同时,通过变性梯度凝胶电泳(DGGE)技术,对不同生草桃园土壤细菌群落多样性表征得到,与清耕杂草土壤管理方法比较,套种牧草后土壤细菌群落多样性有所提高,优势菌群数量增加幅度明显,尤其是套种毛苕子。研究表明,黑麦草、毛苕子套种对维护桃园土壤肥力、减少土壤中养分元素淋失和提高土壤的细菌生物多样性等方面都具有重要的作用。     

三峡库区澎溪河消落带落干期土壤硝化强度及影响因素

研究了三峡库区澎溪河落干期消落带不同地点、不同高程段、不同土地利用方式下土壤硝化强度及影响因素。结果表明，研究区域消落带硝化强度范围为0.76~9.76 mg/kg·d，平均值为3.76±0.76 mg/kg·d，明显低于国内其他研究区域土壤硝化强度。澎溪河消落带从上游汉丰湖到下游黄石，土壤硝化强度呈现递减的趋势。随着高程的增加，消落带土壤硝化强度逐渐降低，但没有显著差异（P >0.05）。消落带不同土地利用方式中，河滩地土壤硝化强度显著高于耕地土壤硝化强度（P<0.05），是耕地土壤硝化强度的1.82倍。消落带土壤硝化强度与土壤pH值呈显著正相关（P<0.05），与有机质含量及亚硝化菌数量呈极显著正相关（P<0.01），周期性的淹水影响了消落带土壤pH值和有机质含量，从而影响了消落带土壤硝化强度。     

基于紫外吸收光谱法的吡唑类硝化抑制剂在土壤中的水解研究

为了研究不同形态吡唑类硝化抑制剂施入土壤后的转化过程,本研究以3-甲基吡唑（MP）及其衍生物的紫外吸收光谱为基础,分别研究了1-甲氨酰基-3-甲基吡唑（CMP）、1-羟甲基-3-甲基吡唑（HMP）和3-甲基吡唑磷酸盐（MPP）在土壤中的水解反应。结果表明,CMP、HMP和MPP3种吡唑类硝化抑制剂添加到土壤中后,均会水解为MP,通过甲胺酰化、羟甲基化和中和反应处理吡唑类化合物,只能改变其存在形态和物理特征,并不能提高吡唑类化合物的硝化抑制效果。土壤中存在的能催化C-N键水解的微生物或酶可能会使水解反应加速。     

Effects of Livestock Wastewater NH4 +-N Incubation on Landfill CH4 Oxidation by Mineralized Refuse Particle

Ammonia oxidizing bacteria was accumualted for landfill CH4 oxidation in the mineralized refuse throguh livestock wastewater NH4 +-N incubation, which would minimize the total Greenhouse gas emission equivalent from MSW landfill. Mineralized refuse was firstly incubated by livestock wastewater NH4 +-N during the 120d operation. Mineralized refuse possessed the strong nitrification capacity with the removal rate of NH4 +-N content over 60% during the 120 d operation. After 200 mg N kg -1 was inputted, NO3 --N content produced from the 120 d incubated mineralized refuse was 2.0-time and 3.8-time more than those of the original mineralized refuse and clay soil, respectively. CH4 decrease and the net produce of CO2 can be well fitted the one- and zero-order kinetics model during the 120 h incubation (R 2>0.68), respectively. Similar as nitrogen turnover, CH4 oxidation capacity from the 120 d incubated mineralized refuse was 10.6% and 59.3% more than those of the original mineralized refuse and clay soil, respectively. Therefore, the mineralized refuse can be upgraded for the CH4 oxidation throng NH4 +-N content incubation from the livestock wastewater and the influence on CH4 oxidation by other components (including CODCr, SS and phosphate) from wastewater should be further investigated.     

氮沉降对北方森林土壤氮收支的影响研究进展

氮沉降增加是全球气候变化的重要情景之一,已经对全球氮素循环产生了严重的影响,可能会显著改变生态系统的健康和服务。北方森林,作为地球上仅次于热带森林的第二大生物群区,占全球森林面积的30%,其土壤分系统在调节森林生态系统氮循环和应对全球气候变化中起着重要作用。氮沉降对北方森林土壤氮收支的影响已被广泛关注,并成为全球变化科学领域的热点问题。同时,土壤氮收支作为土壤物质交换和能量转换的主要环节,对氮沉降的响应复杂而多变。因此,为深入了解大气氮沉降对北方森林土壤氮收支的影响,笔者综述了国内外近年来的相关研究成果,分别从土壤氮输入(生物固氮和凋落物分解)、氮固存(微生物固存和外生菌根固存)、氮输出(矿化作用、硝化作用、反硝化作用以及淋溶)以及土壤总氮库的变化趋势等方面分析了土壤氮收支对大气氮沉降的响应,可为科学评估氮沉降对北方森林土壤氮收支的影响提供参考数据。