991 resultados para NH4 -N


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OLAND两阶段生物脱氮系统是一项正在开发且极具应用前景的处理高氨氮、低COD废水的新技术。在实验室水平,对OLAND系统限氧亚硝化阶段MBR反应器和厌氧氨氧化阶段SBR反应器的启动和运行进行了系统研究。MBR反应器控制参数在DO0.1-0.3mg/L,pH7.8±0.1,温度30±0.5℃,SRT无穷大的条件下,可实现在较高的容积负荷By=IO00mgN/L,水力停留时间HRT:ld下稳定的亚硝酸型硝化,使NH4+-N和NO2-N的出水比例达到理想的比值(1:1.20±0.20),保证厌氧氨氧化阶段SBR反应器的理想进水;SBR反应器在完全厌氧、pH7.8-8.2,温度30±0.5℃,SRT无穷大的条件下,无需外加任何有机碳源,在较高总氮负荷550mgN/L下,可实现NH4+-N和NO2--N同时稳定的去除,二者的消耗比例为1:(1.21±0.05),总氮去除率高达92%。采用巢式PCR、DGGE、 FISH等分子技术对MBR反应器硝化菌群随溶解氧的动态变化规律和SBR反应器厌氧氨氧化菌群结构、组成进行了研究,并探讨了硝化菌群与氮素组成变化之间的内在联系。结果表明:在限氧亚硝化阶段硝化菌群中氨氧化菌受溶解氧浓度的影响较大,其种群结构从反应器启动初期到稳定后期发生了非常明显的变化。亚硝酸氧化菌NOB的种群组成受溶氧影响并不明显,从启动初期到稳定后期其种群结构无明显变化。硝化菌群中氨氧化菌 AOB与亚硝酸氧化菌NOB的数量比例关系随溶解氧的降低而不断升高,从最初的3.6:1升高到稳定后期的5.5:1。MBR反应器优势硝化菌群主要由A、B、C三类氨氧化菌和硝化杆菌D、硝化螺菌F组成,其中优势菌C为维持MBR反应器稳定出水比例的主要功能菌。硝化菌群组成和结构的变化,带来了不同N素之间组成和比例的规律性变化。厌氧氨氧化阶段基本由厌氧氨氧化菌AnAOB和ANAMMOX两类菌组成,二者空间结构紧密,在反应器中的活菌数量比例分别为55%和42%。厌氧氨氧化菌AnAOB种群多样性相对比较丰富,主要由条带I和H所代表的两种优势菌组成;ANAMMOX菌种群多样性变化较小,其种群主要由优势菌K和J组成。对MBR和SBR反应器中的优势菌进行了克隆、测序和系统发育学分析,结果表明:限氧亚硝化阶段MBR反应器启动初期的优势菌A属于Nitrosomonadaceae科,是否是一个新属,还有待于进一步鉴定。运行中期优势菌B与Nitroso)nonaseurooaea亲缘关系最近,同源性高达99.1%,暂命名为Nilrosomonas sp.BI。稳定后期优势菌C与Nitrosomonas eutroPha亲缘关系最近,同源性为96.3%,暂命名为Nifrosomonas sp.cl。硝化杆菌属优势菌D与Nitrobacter alkalicus、Nitrobacter hambllrgensts和Nitlobac招rwinograsky 亲缘关系较近,同源性分别为95.5-97%、96.5~97%和95.8~96.8%。SBR反应器中AnAOB优势菌I与MBR反应器优势菌B亲缘关系最近,同源性高达98.7%,与Nitlosomonas euroPaea同源性为98.3%。根据序列比较和生理特性分析,优势菌I与优势菌B应为Nitrosomonas属两个不同的种,暂将优势菌I命名为Nitrosomonas sp.II。优势菌H与MBR反应器优势菌C亲缘关系最近,同源性达97.9%,与Nitrosomonas eutropha同源性为96.3%。结合其生理特性分析,二者应为Nitrosomonas属两个不同的种,暂将优势菌H命名为Nitrosomollas sp.Hl。ANAMMox优势菌K与未培养的 Planctomycete和已鉴定的另一种ANAMMoX菌尤uenenia sf况ttgartiensis亲缘关系较近,同源性分别为99.8%和96.6%。优势菌J与Gen bank收录的所有菌的相似性均低于76%,说明该菌是OLAND系统厌氧氨氧化阶段比较独特的菌,是迄今为止在厌氧反应过程中未发现的一个新菌。

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对尿素进行包膜是控制尿素溶出的有效措施,但尿素包膜不能控制尿素溶出后的土壤生物化学转化行为。为了既控制尿素的溶出行为又控制溶出后尿素的水解或水解生成NH4+的硝化过程,本研究利用流化床喷涂技术将脉酶抑制剂氢醒(HQ)和硝化抑制剂双氰胺(DCD)分别加入聚合物包膜尿素内。包膜层的化学组成和通透性抉定性地影响着尿素和抑制剂的溶出特征。尿素从聚合物包膜内溶出过程可分成4个阶段:滞后阶段、溶胀阶段、稳定阶段和衰退阶段。在土壤中,HQ和DCD从包膜内溶出的速度快于尿素。尿素和HQ的同时缓慢溶出使尿素的水解过程比较平缓,有效避免了尿素在土壤中迅速水解所造成的土壤NH4+-N激增和土壤pH剧烈增加现象,使尿素氮的NH3挥发损失大幅度降低。DCD和尿素的同时控制溶出减小了DCD淋失的可能性,延长并增强了DCD对土壤硝化作用的抑制效果,并显著降低了土壤NO3-的淋失。水稻盆栽试验、小麦一白菜复种微区试验和玉米田间小区试验的结果表明,包膜尿素中添加DCD表现出了较高的肥效。施用添加DCD的包膜尿素明显增加了土壤NH4+-N的供应,增加了作物的N累积吸收量,并且使白菜产量显著增加了31.3%(与尿素分施相比)。尽管在包膜尿素中添加HO明显降低了土壤NH3挥发损失的可能性,但施用添加HQ的包膜尿素处理仅获得了与尿素分施处理相当的作物生物性状、N累积吸收量和产量。

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土壤氮素(N)转化是生态系统关键的生态学过程之一;而土壤N有效性是沙地生态系统生产力和稳定性的关键限制性因子。以科尔沁沙地东南缘樟子松(pinus sylvestris var.mongolica)、赤松(P.densiflora)和小叶杨(populus simonii)固沙林以及草地为研究对象,采用野外试验和室内实验相结合的方法,全面系统地开展了凋落物分解、土壤N矿化、淋溶等过程及土壤N有效性的研究,旨在揭示半干旱区固沙林土壤N转化及其有效性的特征和机制,为沙地植被恢复、重建、管理和评价提供科学依据。主要结论如下:(1)采用网袋法进行凋落物的分解试验,结果表明不同类型凋落物乘量衰减、元索释放、质员变化均存在明显差异,分解第1年供N能力表现为小叶杨>草>樟子松>赤松;(2)采用PVC顶盖理管法和离子交换树脂袋法分别研究了林地和草地土壤N矿化过程,结果表明土壤N矿化速率表现为小叶杨川章子松七赤松>草地,N相对有效性表现为赤松>樟子松>草地全小叶杨;(3)草地和小叶杨林地土壤N潜在性淋济较高,而樟子松林地较轻;(4)土壤容重、pH值、养分、温度、水分、土壤微生物、土壤动物、林下植被等环境和生物因子反映区域土壤N转化及共有效性的一般特征,而强烈的人类干扰是引起生态系统问差异的关键因索:造林有利于提高沙地土壤N积累和有效性,但樟子松造林30年后才有明显效果:放牧地土壤N硝化速率及其有效性明显高于禁牧地,但质量下降,即NH4+-N/NO3--N失衡,不利于植物吸收、微生物调控和环境保护;(5)赤松、樟子松和小叶杨均为研究区固沙造林的可选树种,合理和科学管理有利于维护生态系统N平衡,实现.可持续经营。

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土壤氨基糖因其异源性和稳定性可用以指示微生物对土壤碳(C)氮循环的相对贡献。但由于氨基糖是微生物在土壤中长期残留的平衡结果,其数量变化无法准确反映在微生物作用下无机态氮(N)向氨基糖转化的动态过程和机制,从而使氨基糖对土壤氮内循环的指示作用受到限制。如果能够利用新的技术手段研究土壤氨基糖的微生物转化过程,将使土壤氮素内循环研究产生突破。同位素技术是研究土壤C,N转化过程的有效手段。但是研究特定化合物如氨基糖的微生物转化过程还需要新的技术支持,本研究首先建立了稳定同位素培养-气质联机技术测定土壤氨基糖同位素富集比例新方法。对于15N培养样品,由于氨基糖分子中只有一个N原子,15N富集比例可通过m/z(F+1)与F相对丰度的比值计算;对于13C培养样品,由于葡萄糖c整体掺入形成氨基糖c骨架,所以利用m/z(F+n)与F相对丰度的比值计算13c在土壤氨基糖中的富集(n为质谱碎片中骨架C原子数)。同位素富集用原子百分超(APE)表示。EI和cI两种方式测得的APE有很好的同一性,且不受土壤基质的影响,表明方法的可靠性和广泛适用性。利用以上方法,进行了土壤样品的同位素培养与测定,以跟踪土壤氨基糖微生物合成动态,进行氨基糖的微生物转化与更新研究。主要结论如下:1.当以葡萄糖为碳源且每周施入底物时,NH4+和NO3-均可被微生物迅速同化并进行氨基糖的合成。但NO3-必须被还原成NH4+才能被微生物利用,因而NO3.存在短暂的滞后期,之后被微生物快速利用。氨基葡萄糖(GluN)和胞壁酸(MurN)不同的同位素富集特征表明,N源形态对细菌增殖无显著影响,但真菌更倾向于利用NH4+。在NO3-培养中氨基糖的增量及微生物对C的截获均小于NH4+。2.分别利用u一13c一glucose一NH4十和glLlcose一ISNH4+进行样品培养时,同位素富集趋势相同,但APE(13C)大于APE(15N),这种差别反映了了土壤微生物利用C,N的时间特征及土壤有机质含量对C,N循环的影响。3.以gtucose-15NH4+为底物时,施入N素频率的改变也会影响微生物的活性。尤其是细菌的快速生长受到N素不足的限制,转而代之以细菌和真菌的持续的低速生长。微生物活性的降低减少了对有机c的截获。DCD的加入有效抑制了NH4+向NO3一的转化,但对氨基糖的合成无显著影响。4.土壤氨基糖反映的主要是土壤中已经死亡了的微生物的一种长期过程而产生的残留,同土壤微生物量无明显的相关性。但经外加底物培养后,氨基糖同位素富集比例的变化则来源于微生物的转化,因而与微生物量碳有直接的相关性。5.从原理上说,在氨基糖的微生物合成过程中,葡萄糖没有发生C骨架的断裂,而是直接转化成为氨基葡萄糖的骨架。但在复杂的土壤基质中,氨基葡萄糖的合成必然受到葡萄糖其他生物化学过程的影响。使少量葡萄糖经酵解后再次参与己糖胺的合成。以全取代葡萄糖为底物时,葡萄糖碳骨架的断裂与重排不影响13c同位素的富集。但对于单取代葡萄糖培养来说,必须要考虑因葡萄糖碳骨架断裂而产生的同位素的重新分配,Mass(F+1)和Mass(F+2)的丰度变化的总和真正代表了氨基葡萄糖的同位素富集。6.添加有机物料和N素进行土壤样品培养时,对外加氮素的同化远低于相应的葡萄糖培养。碳源尤其是能源不足限制了N的转化。微生物分解高C加的有机物料需吸收外加N源以满足自身生长需要。N素的加入频率影落响微生物对外加N素的利用。当加入的N不能满足微生物分解有机物料的需要,就会降低微生物对有机物料的分解速度,使无机N向氨基糖态N转化速度降低。应用稳定同位素技术,发现施到土壤中的无机氮素可被微生物快速转化成某种形态有机氮,这种有机态氮处于不断转化循环之中,构成土壤有效氮的暂存"过渡库",其中氨基糖是重要成分之一。过渡库现象的发现为氮肥的有效利用提供了新的思路。根据土壤有效氮"过渡库"的模型,氮月巴高效利用调控实际上就是土壤氮素微生物转化过程的调控。提高土壤无机氮素向土壤有机氮的转化速率和转化强度可以有效减少无机氮在土壤中的积累,从而降低肥料和土壤氮素的硝化和反硝化损失,提高氮肥利用率。研究还发现,土壤有效氮"过渡库"容量与循环速率不仅取决于N源自身性质,碳源的可利用性显著影响施入土壤的N素微生物转化特征。只有适当提高可利用碳源即活性碳源的数量,才能提高氮素的微生物同化,土壤有效氮"过渡库"容量,从而减少氮素损失。

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东北黑土区是我国主要粮食基地之一,水资源短缺和水环境污染问题严重;城市生活污水资源化堕待解决。本文根据污水土地处理技术,以黑土和石英砂为介质,采用室内模拟的方法,建立并运行了黑土人工快速渗滤系统。本文首次运用均匀设计原理,建立了以COD、TN、TP最大去除率和最大水力负荷为}!标的优化工艺参数(人工土壤的组成、淹水时间、湿千比)筛选方法;并提出了以倒数方程来确定系统稳定的渗滤速度和稳定的COD、翎、TP去除率。在优化条件下,COD、TN、TP去除率和渗滤速度的理论结果分别为:85.02%、93.75%、92.62%和9.57cm/h;实际运行结果分别为:85.33%、93.01%、93.27%和9.26cm/h。表明此筛选方法是可行的。研究表明,在COD优化条件下可以实现COD(去除率=85.02%)和TP(去除率=91.59%)共同有效地去除。加入草炭影响系统的净化效果。同时本文还研究了在优化条件下黑土人工快速渗滤系统Eh和微生物组成特征。黑土人工快速渗滤系统对LAs具有较强的净化能力,在<100mg/L浓度条件下,LAS去除率在90%以上。LAS主要被吸附于20~40cm土层中;高浓度LAS会在系统中积累;延长干化时间可以提高系统对LAS的去除率。高浓度LAS会造成系统对其它污染物(cOD、TN、NH4+-N、TP,可溶性磷等)去除率的下降,造成Eh降低和微生物数量的减少等。

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在地处下辽河平原的中国科学院沈阳生态实验站潮棕壤上布置施N量分别为180、240和300kg·hm~(-2),施P量分别为70、100和130kg·hm~(-2)的稻田田间试验。应用通气密闭室法和陶土渗滤管法,测定了稻田生态系统三个不同施肥期施用氮肥后的NH3挥发损失和N淋溶,结果表明:1.水稻生长季节施用氮肥后有明显NH3挥发,总挥发量为11.64kgN·hm~(-2)-34.01kgN·hm~(-2),占施N量的4.66%-11.66%,主要发生在施用分孽肥后,每次NH3挥发高峰出现在施氮肥后的2-4d内。2.水分渗漏对NH3挥发损失有重要影响。田面积水条件下,NH3挥发损失量及其占施N量的比率都较大,不同施N处理间差异显著(P<0.05),NH3挥发量随施N量增加而增加;田面不积水条件下,NH3挥发损失挥发量相对较小。3.氮肥用量、田面水NH4斗一浓度和田面水pH是影响NH3挥发重要因素;180kgN·hm~(-2)条件下,积水时不同P处理间NH3挥发差异不显著。4.水稻生长季节各次施用氮肥后,60cm和gocm深处渗漏液中NH4+-N含量都小于2mg·L~(-1),各施氮肥处理与对照间差异不显著。但NO3-淋溶比较显著,多集中在3mgN·ul-15mgN·L~(-1)之间。NO3-的淋溶随施N量增加而增加。水分渗漏状况影响N03一在不同土层深度的累积,渗水越快NO3-淋溶深度越大。渗水快或者施N量高时NO3,淋溶浓度高于国际饮用水卫生标准10mgN·L~(-1),已有污染浅层地下水的可能。5.施用基肥后灌水,NH_4~+、NO_3~-立即出现淋溶高峰,而两次追施氮肥的淋溶高峰出现在施肥后10d或更久;并且基肥时期的淋溶浓度也比较高。

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土壤可溶性有机物质(Dissolved organic matter,DOM)作为土壤有机质的活性组分,在陆地生态系统物质循环中扮演非常重要的角色。土壤DOM的主要成分可溶性有机碳(Dissolved organic carbon,DOC)和氮(Dissolved organic nitrogen,DON)参与C、N循环过程。为深入揭示全球C、N循环过程机制,在未开展DOC和DON的地区进行相关研究是有必要的。森林土壤(包括枯枝落叶层)DOC、DON动态及调控机理的研究是目前国际上森林生态系统C、N循环研究热点之一。本研究立足于暖温带岷江上游茂县地区人工林植被,对土壤DOC和DON的库容量,季节动态及其与其它养分之间的关系进行了系统研究,旨在了解DOC和DON在该区生态系统中的重要作用,并探讨作为DOM主要来源的叶凋落物对DOC和DON的动态影响,研究有助于更加详细地了解该区生态系统C和N循环过程。本论文主要研究结论如下: 1研究了岷江上游地区两大主要土壤类型(棕壤和褐土)不同植物群落下土壤的DOC和DON含量及特征,结果表明:DOC和DON在两种土壤类型中均有库容量存在,DOC在0-10cm和10-20cm土层的含量幅度分别111.96~159.95 mg kg-1和69.02~100.84 mg kg-1。DON在0-10cm和10-20cm土层的含量幅度分别11.88~23.08 mg kg-1和4.70~10.77 mg kg-1。游离氨基酸在0-10cm和10-20cm土层的含量幅度分别0.84~1.66 mg kg-1和0.39~0.73 mg kg-1。DOC、DON与土壤中的一些养分因子表现出了显著的相关关系,共同反映了土壤的状况和质量,在该区开展DOC和DON的系统研究是有必要的。 2 对油松与连香树林地土壤DOC、DON以及其它化学指标的季节动态进行了研究,结果表明:油松与连香树林地土壤DOC和DON的季节动态变化表现了类似的规律,DOC和DON的含量均以秋季最高。DOC和DON的季节动态变化主要受凋落物生物因素的影响,但其微生物活力的生物因素以及降雨、温度等非生物因素也是控制土壤DOC和DON含量的重要因素。土壤DON在土壤中的行为不同于矿质氮,其季节动态不同于NO3--NNH4+-N的季节动态,在研究N循环过程中,应考虑DON的变化情况。 3 对油松与连香树林地分解层和表层土壤(0-10cm)氨基酸周转动态进行了研究,结果表明:油松林地和连香树林地均以分解层的氨基酸含量高于矿质表层土壤的含量。每个取样时期,油松林地内各层次的氨基酸含量高于连香树林地内相应层次的含量。两林地各层次无机氮含量均超过了氨基酸的含量,并且室内培养30天后无机N的含量仍然高于氨基酸的含量,所以可以认为该区立地条件下无论是在有机分解层还是矿质土层植物吸收利用的氮素仍是以无机N为主。 4 松林下松针凋落物易于累积,这与松针凋落物分解缓慢有关,从而导致松林内养分周转缓慢。通过用不同性质凋落物和灌丛地土壤构建微生态系统,比较油松、辐射松、连香树、灌丛虎榛子凋落物分解对C、N循环过程的影响,结果显示油松和辐射松针叶凋落物比连香树、虎榛子凋落物分解更慢,减缓了养分循环过程。然而将针叶凋落物与阔叶凋落物混合后,油松和辐射松针叶凋落物的分解加快,C、N元素的循环过程也加速。此结果表明在松林内维持具有高质量凋落物的灌丛植被或在松林内栽植一些阔叶树种如连香树对维持和增进松树人工林的土壤肥力有重大的作用。室内培养的结果还显示添加凋落物后土壤DOC和DON的含量显著增加,表明凋落物是土壤DOM的直接来源。然而不同物种凋落物处理下土壤DOC和DON的含量有所不同,并随时间发生改变。混合凋落物处理下土壤DOC和DON的含量均高于松针凋落物单独处理下土壤DOC和DON的含量。DON是一个主要的水溶性N库,随时间的变化趋势与无机N的变化趋势不同,在土壤N循环过程中起到了中间N库的作用。 As a labile fraction of soil organic matter, dissolved organic matter (DOM) plays a very important role in material cycling of terrestrial ecosystem. The turnover of DOM is now being considered as main components in nutrient cycling. DOM mainly includes dissolved organic carbon (DOC), -nitrogen (DON), -phosphorous (DOP) and –sulfur (DOS). Among these constituents, DOC and DON directly participate in C and N cycling. It is essential to study DOC and DON dynamics and their controlling factors in the areas where no related study has ever been carried out. Study about them can provide data supports on understanding the mechanism of the global C and N cycling. DOC and DON dynamics and their controlling factors have been focused on in the research of C and N cycling of forest ecosystems. Based on forest plantations of Maoxian, Minjiang River in warm temperate zone, soil DOC and DON pool size, their seasonal dynamics, and the correlation between DOC, DON and other nutrients were studied in order to understand the importance of DOC and DON in the study area. Soil DOC and DON dynamics induced by leaf litter decomposition were also studied. The study contributed to comprehensively understanding C and N cycling processes and providing baseline data for including DOC and DON into the indices system of evaluating nutrient conditions. The results were as follows: 1 Several different plant communities under brown soil and Cinnamon soil were chosen as sampling plots. The contents and features of soil DOC and DON were evaluated. The results showed that DOC and DON were present under the two soil types. DOC contents in the top soil (0-10 cm) and the subsoil (10-20 cm) respectively varied from 111.96 mg kg-1to 159.95 mg kg-1, and 69.02 mg kg-1 to 100.84 mg kg-1. DON contents in the top soil (0-10 cm) and the subsoil (10-20 cm) respectively varied from 11.88 mg kg-1to 23.08 mg kg-1, and 4.70 mg kg-1 to 10.77 mg kg-1. Free amino acid contents in the top soil (0-10 cm) and the subsoil (10-20 cm) respectively varied from 0.84 mg kg-1to 1.66 mg kg-1, and 0.39 mg kg-1 to 0.73 mg kg-1. Significant correlations were found between DOC, DON and some nutrient indices, which together reflected soil condition and quality. It was hence essential to study DOC and DON in the study area. 2 Seasonal dynamics of DOC, DON, inorganic N, microbial biomass C and N were studied under Pinus tabulaeformis and Cercidiphyllum japonicum plantation. The results indicated that seasonal dynamics of soil DOC and DON under the two plantations performed similar change pattern, with the highest values in autumn. The seasonal dynamics of soil DOC and DON were mainly influenced by the litterfall. However, biotic factors such as soil microbial activities and abiotic factors such as precipitation and temperature also controlled the dynamics of soil DOC and DON. The seasonal dynamic of DON was different from that of NO3--N and NH4+-N, which showed that the behavioral differences between DON and inorganic nitrogen. And hence, it was proposed to include DON into soil N cycling in the study area. 3 Amino acid dynamics in Oa and topsoil (0-10 cm) under P. tabulaeformis and C. japonicum plantation were studied. The results showed that amino acid content in Oa was significantly higher than that in mineral soil. At each sampling time, significantly higher amino acid contents were found in P. tabulaeformis plantation than in C. japonicum plantation. The content of inorganic nitrogen was much higher than the content of amino acid in each sampling layer at each sampling time. After a 30-days laboratory incubation the content of amino acid was still lower than the content of inorganic nitrogen. The results implicated that the form of N absorbed by plants in these study sites were mainly inorganic nitrogen. 4 Usually needle litter is more resistant to decomposition, which leads to needle litter accumulation in pure coniferous stands and slows down the rate of nutrient circulation. By constructing microcosms with local shrubland soil and containing the four single-species (P. tabulaeformis, P. radiata, C. japonicum, Ostryopsis davidiana) litters, the decomposition rates and related C and N dynamics of needle litters and broadleaved litters during the early stage were compared. The results showed that the decomposition rates of pine needles were lower than those of broadleaved litters, which descended C and N cycling processes. However, the presence of C. japonicum or O. davidiana litter into pine needles increased the decomposition rates of pine needles and also dramatically promoted C and N cycling processes. It should be appropriate for plantation managers to consider C. japonicum as an ameliorative species or remain O. davidiana in pine plantations to improve soil conditions and help maintain soil fertility. The laboratory incubation still showed that DOC and DON contents in all litter-amended treatments were significantly higher than no litter-amended treatment, which proved that litter could be a direct source of DOM in soils. Different species litters induced different soil DOC and DON contents, which correspondingly changed over time. DOC and DON contents in mixed litter treatments were higher than those in pine needle litter treatments. As a major soluble N pool, DON developed a different changing pattern over time compared with inorganic N and played a role of interim N pool in soil N cycling.

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岷江上游干旱河谷区水土流失强烈,地质灾害频繁,生态环境十分脆弱,而土壤条件恶劣(水分不足和养分缺乏)是阻碍该区植被恢复的关键因子,因此研究水分和乡土灌木生长对土壤的影响对该区的生态恢复具有指导意义。本文通过定点模拟实验,选取三种优势豆科灌木为研究对象,分别是白刺花(Sophora davidii)、小马鞍羊蹄甲(Bauhinia faberi var. microphylla)和小雀花(Campylotropics polyantha),设置5 个水分梯度,分别为100%、80%、60%、40%和20%田间持水量(FC),对栽种植物与不种植物下土壤理化性质和酶活性进行测定分析,系统比较和研究了不同水分条件和不同乡土灌木生长对干旱河谷区土壤结构、养分循环、酶活性以及微生物量的影响。主要结果如下:1. 无论生长植物与否,土壤的毛管持水量和毛管孔隙度都随着水分含量的减少而降低,最大持水量、总孔隙度和容重变化不大,相应地,土壤中的非毛管孔隙随含水量的减少而升高。各水分条件下,种植植物的毛管持水量和毛管孔隙度低于无植物生长的土壤,非毛管孔隙度相应地高于无植物土壤。土壤含水量在100%-40% FC 时,三种豆科灌木的毛管持水量和毛管孔隙度存在差异,而20% FC 条件下,三种豆科灌木土壤的物理性质基本相同。2. 水分胁迫影响土壤中养分的矿化和积累,主要表现在降低了水溶性碳和铵态氮的含量,中等程度胁迫时(60% FC)促进了有机碳和硝态氮的富集,对速效钾和有效磷没有明显作用。种植豆科灌木后各水分梯度上都增加了有机碳、铵态氮、速效钾和有效磷的积累。增加程度上三种豆科灌木间有一定差异,对于土壤有机碳总量,种植白刺花和小马鞍羊蹄甲明显高于小雀花,同样的情况还出现在铵态氮和速效钾上,但是对于有效磷,种植小雀花后的增加程度则明显高于白刺花和小马鞍羊蹄甲。种植豆科灌木不仅增加了土壤养分的相对含量,也改变了其在水分梯度上的变化趋势及其变化幅度,这种作用主要体现在碳元素和氮元素上。3. 无植物生长时脲酶活性随水分含量的减少而升高,水分胁迫对磷酸酶和过氧化氢酶的作用不显著,蔗糖酶也保持在相对较高的水平。种植植物后,蔗糖酶、磷酸酶活性与无植物时相比有较大幅度的提高,种植白刺花的脲酶活性也升高,其升高的程度在不同水分含量时不同。种植植物还降低了酶活性在水分梯度上的变幅,使之在水分梯度间的差异显著性降低。脲酶活性在指示土壤性质改变方面是较敏感的指标,其它三种酶在不同植物间的差异不明显。4. 在无植物生长时,中等程度的水分胁迫(60% FC)提高了土壤微生物量碳含量,过高或过低的土壤水分均不利于微生物碳的积累。种植小马鞍羊蹄甲后微生物量碳在水分梯度上的变化趋势与无植物生长时一致,而种植白刺花和小雀花后微生物量碳随着水分含量的减少而降低。不同种类植物的微生物量碳在水分梯度上的变化特征也不同,100% FC 条件下三种植物间没有差异,80%和60% FC 条件下小马鞍羊蹄甲显著高于白刺花和小雀花,40%和20% FC 条件下白刺花和小马鞍羊蹄甲也显著高于小雀花,说明不同种类植物随着干旱胁迫程度的加深微生物量碳的降低幅度不同,在极度干旱时,白刺花和小马鞍羊蹄甲土壤依然保持了较高的微生物活性,而小雀花土壤微生物量则明显下降。The dry valley of the upper reaches of the Minjiang River is seriously degradedmountain ecosystem. It was endangered by extremely soil lost and frequentlygeological disaster. Previous studies showed that short of water and nutrients in soilwas the principal limiting factors of vegetation restoration in this area. The typical soiland three dominant leguminous shrubs Sophora davidii, Bauhinia faberi var.microphylla and Campylotropics polyantha in upper reaches of arid Minjiang Rivervalley were considered as experimental material. Two-month old seedlings of eachspecies were exposed to five water supplies (100%, 80%, 60%, 40% and 20% waterfield capacity (FC)) in a temperature and light-controlled greenhouse. Afterthree-month water treatment, soil physiochemical variables and soil microbialactivities were determined by conventional methods. The main results showed that:1. Soil capillary capacity and capillary porosity decreased along water supplyregimes in all treatments, while saturated water capacity, total porosity and bulkdensity kept in a relatively stable level, as a result, the non-capillary porosity andcapacity increased with decrease of water supply. Compared to non-planted soil, theplant-soil systems had a higher non-capillary porosity and capacity, suggestingappropriate oxygen was present in soil to maintain the living of microorganism. Soilof three type shrub species shared the same capillary capacity and capillary porosityunder 20% FC.2. Water soluble carbon and NH4+-N decreased in response to water stress, whiletotal organic carbon and NO3--N promoted by moderate water stress and inhibited by 100% and 20% FC. Total organic carbon, NH4+-N, rapidly available K and availableP increased after the planting of leguminous shrubs in five water supply regimescompared to non-planted soil. For TOC, NH4+-N and rapidly available K, thepromotion effect was higher in S. davidii and B. faberi var. microphylla than C.polyantha planted soil, while available P displayed the opposite side. The planting ofshrubs also reduced the variance of observed traits along water supply gradients.3. Drought stress increased urease activity in non-planted soil, while insignificantdifferences were observed in phosphatase and catalase activity among five watersupply regimes. The planting of leguminous shrubs facilitated the β-glucosidase andphosphatase activity compared to the non-planted soil. It also reduced the variance ofenzyme activity along water supply gradients. Urease was more sensitive to waterstress than other three enzymes.4. Soil water content significantly affected microbial biomass carbon andCmic:Corg. S. davidii and B. faberi var. microphylla showed more drought toleranceability than C. polyantha, attributing not only to their relatively smaller variance ofmicrobial biomass carbon along soil water supply gradients, but also to the highlevel of microbial activity under severe water stress. S. davidii and B. faberi var.microphylla benefited reproduction of soil microorganism at 60%-80% FC, whilesevere drought limited it due to the competition of water and nutrients between plantand soil microorganism.

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近年来,随着对作物重茬(连年种植)障碍原因的深入研究,植物的化感作用越来越受到国内外众多学者的重视。而作为重要调料和药用植物的生姜,其连作障碍也备受关注,系统地研究生姜化感作用将有助于理解和最终解决生姜连作障碍问题。本文通过研究生姜不同部位、不同浓度的水浸液对与其间作的两个物种(大豆和四季葱)种子的萌发及幼苗生长的影响,从而证明生姜化感作用的存在;并通过温室盆栽实验研究了生姜的自毒作用(即研究生姜不同部位、不同浓度的水浸液对其幼苗的形态、生理生化、光合作用、土壤酶、土壤微生物多样性及土壤养分的影响),从而揭示生姜退化和衰老的机制,并为生姜筛选出合适的间作物种提供科学依据,对生姜连作障碍提出科学的解决方法。主要研究结果如下: 1. 与对照相比,生姜所有部位(根茎、茎、叶)、所有浓度(10、20、40、 80 g l-1)的水浸液均抑制了大豆种子和葱籽的萌发率、幼苗生长、水分吸收和脂肪酶活性,并且其抑制程度随着水浸液浓度的增加而增强,其生姜各部位水浸液抑制效应的强弱顺序为茎>叶>根茎。这一结果表明生姜根茎、茎、叶含有能够抑制大豆种子和葱籽种子萌发和幼苗生长的水溶性化感物质。根茎是生姜的主要收获部位,而生姜的残株(主要是茎和叶)应该从大田中处理掉以减轻其抑制效应。生姜水浸液中主要化感成分包括:根茎水浸液中主要是丁香酸和伞花内脂;茎水浸液中主要是阿魏酸,且其含量最高为73.4 ug/g;叶水浸液中除了阿魏酸,其他六种物质均检测出来,但含量较高的主要有丁香酸、伞花内脂和香豆酸。 2. 生姜茎和叶不同浓度的水浸液均显著抑制了生姜幼苗的株高、每株叶片数和叶面积,其抑制程度随着水浸液浓度的增加而有所增强,而生姜幼苗每株分枝数差异不显著;同时生姜水浸液也极大程度地影响了生姜幼苗的生物量(包括地下生物量、地上生物量和总生物量,均为鲜重)。在同一浓度下,茎水浸液对生姜幼苗形态指标及生物量指标均显示出最强的抑制作用,叶水浸液次之,根茎水浸液最弱。与对照相比,低浓度的生姜根茎水浸液提高了生姜幼苗叶片内四种抗氧化酶(SOD、POD、CAT、APX)活性,高浓度的根茎水浸液抑制了四种抗氧化酶活性,而茎和叶水浸液均随着浓度的增加而抑制了四种抗氧化酶活性,三种水浸液均随着浓度的增加降低了生姜幼苗叶片内叶绿素的含量,而增加了生姜幼苗叶片的相对电导率和丙二醛含量。同时,三种水浸液均随着浓度的增加降低了生姜幼苗的光合参数(包括胞间CO2浓度、气孔导度、蒸腾速率及净光合速率)。 3. 三种生姜水浸液对所测六种土壤酶活性均产生了不同程度的影响,其中影响最大的是酸性磷酸酶和蔗糖酶,在10 g l-1 时就达到了显著水平,并且所有酶均有随着水浸液浓度增加而增大的趋势;相同部位的水浸液随着浓度的增加,细菌和真菌的数量呈增加趋势,而放线菌的数量呈减少趋势;三种生姜水浸液均随着浓度的增加降低了土壤中有机质的含量,加剧了土壤中硝态氮含量的积累,根茎水浸液对土壤有效磷、速效钾和铵态氮均显示出低浓度提高其含量而高浓度降低其含量的趋势,而茎和叶水浸液则随着浓度的增加均降低了其含量。 4. 与生姜单作相比,所有间作系统均在旺盛生长期和收获期不同程度地提高了土壤酶活性,同时也增加了土壤细菌数量及土壤微生物总数但不显著;所有间作系统在旺盛生长期和收获期均不同程度地影响了土壤真菌及放线菌数量(增加或减少),所有间作系统间的多样性指数差异不显著,除了旺盛生长期四种作物(生姜-大豆-四季葱-大蒜)的间作模式显著降低了多样性指数,其值仅为生姜单作的33.18%;生姜与大豆间作不仅提高了19.6%的生姜产量而且获得了较好的经济效益,并且,所有间作系统均显著抑制了生姜姜瘟病的发生。 5. 不同栽培模式不同程度地影响了收获期生姜的株高、分枝数、根茎产量及内在品质。其中处理2显著地促进了生姜的分枝(10.5%),同时处理2、3和4也促进了生姜的生长(株高分别增加了15.0%、11.4%和14.0%),并且这三个处理提高了生姜的产量;处理2和3能有效提高生姜块茎中维生素C(分别较单作生姜显著提高了3.29%和4.05%)、处理3显著提高了可溶性糖(8.2%)、姜辣素(4.6%)和蛋白质等有益物质的含量,降低硝酸盐有害物质的含量(处理2显著降低了14.0%),改善了姜块的外观和内在品质。并且,生姜与大豆间作具有最高的纯收入和产投比,分别较生姜单作提高了24.80%和8.8%。Recently, allelopathy has been more and more paid attentions by national and foreign scholars with profound research on reasons of crop replanted (continuous planted) obstacle. Ginger rhizome is valuable all over the world either as a spice or herbal medicine and ginger replanted obstacle is also paid attentions. Systematic research on ginger allelopathy will contribute to understanding and ultimate solving problem of ginger replanted obstacle. The effects of ginger aqueous extracts with different parts and concentrations on seed germination and early seedling growth of soybean and chive were studied in this article to testify that ginger existed allelopathy. Furthermore, ginger autotoxicity was also studied by pot experiment in greenhouse (namely research on effects of ginger aqueous extracts with different parts and concentrations on morphological indexes, physiological and biochemical indexes, photosynthesis, soil enzymes, soil microbial diversity and soil nutrients) to reveal mechanism of ginger degeneration and senescence, provide scientific basis for selecting appropriate intercropping species and put forward scientific resolvent for ginger replanted obstacle. The main results were as follows: 1. All aqueous extracts at all concentrations inhibited seed germination, seedling growth, water uptake and lipase activity of soybean and chive compared with the control, and the degree of inhibition increased with the incremental extracts concentration. The degree of toxicity of different ginger plant parts can be classified in order of decreasing inhibition as stem>leaf>rhizome. The results of this study suggested that rhizome, stem and leaf of ginger contained water soluble allelochemicals which could inhibit seed germination and seedling growth of soybean and chive. The rhizome is the main harvested part of ginger. The residue (mainly stems and leaves) of the ginger plant should be removed from the field so as to diminish its inhibitory effect. The main allelopathic components of three kind of aqueous extracts were as follows: Rhizome extract chiefly contained syringic acid and vmbelliferone and stem extract mainly contained frulic acid whose content was the highest (73.4 ug/g). The other six substances were detected except of frulic acid, but only contents of syringic acid, vmbelliferone and p-coumaric acid were higher. 2. Stem and leaf aqueous extracts of ginger with different concentrations significantly inhibited plant height, leaf numbers per plant and leaf area, and the degree of inhibition increased with the incremental extracts concentration. However, tiller number per plant of ginger seedling showed no significant difference. At the same time, ginger aqueous extracts also influenced biomass including under-ground biomass, above-ground biomass and total biomass (fresh weight) to a large extent. Under the same concentration, stem aqueous extract showed the mostly inhibitory effect on morphological indexes and biomass indexes of ginger seedling. Rhizome aqueous extract showed the leastly inhibitory effect and leaf aqueous extract was intervenient. Enhanced concentration of ginger aqueous extracts significantly reduced total chlorophyll content, accompanying with increases in memberane permeability (REL) and lipid peroxidation (MDA). Compared with the control, rhizome ginger aqueous extract of lower concentration (10 g l-1) increased the activities of major antioxidant enzymes (superoxide dismutase, SOD; peroxidase, POD; catalase, CAT; ascorbate peroxidase, APX) of ginger leaf tissue and higher concentration inhibited the activities of four antioxidant enzymes. However, stem and leaf aqueous extract inhibited the activities of four antioxidant enzymes with increase in concentration. Meanwhile, enhanced concentration of ginger aqueous extracts significantly reduced photo-parameters of ginger seedling (including CO2 concentration, stoma conductivity, net photosynthesis rate and transpiration rate). 3. Rhizome, stem and leaf ginger aqueous extract showed different effect on six soil enzyme activities, and acid phosphatase and invertase showed significant effect when aqueous extract concentration got 10 g l-1. Furthermore, six soil enzyme activities increased with increase in aqueous extract concentration. Bcterial and fungi number tended to increase while antinomyces tented to decrease with the increase in aqueous extract concentration of identical part. Ginger aqueous extracts reduced soil organic matter content with increased concentration, accompanying with NO3-—N accumulation in soil. Rhizome aqueous extract showed the same tendency for available P, available K and NH4+—N, namely lower concentration increased their contents in soil and higher concentration reduced their contents. While stem and leaf aqueous extracts reduced their contents with the increamental concentration. 4. All intercropping systems increased soil enzyme activities to different extent both at VGS and at HS compared to solo ginger. All intercropping systems increased the colony numbers of soil bacteria and total of soil microbe but not significantly either at VGS or at HS. All intercropping systems increased the colony numbers of soil fungi and actinomytes to a different extent (increase or decrease) both at VGS and at HS. For DI, difference between all cultivation patterns and S-G was not significant either at VGS or at HS except that G-S-C-G whose value was only 33.18% of S-G at VGS significantly decreased. G-S not only increased ginger yield by 19.6% but also obtained better economic benefit. Furthermore, all intercropping systems significantly inhibited occurrence of bacterial wilt of ginger. 5. Different cultivated pattern influenced plant height, tiller numbers, rhizome yields and intrinsic quality of ginger. Treatment 2 significantly facilitated tiller occurring (10.5%). Treatment 2, 3 and 4 promoted ginger growth (plant height respectively increased 15.0%、11.4% and 14.0%) and enhanced rhizome yields. Treatment 2 and 3 effectively increased vitamin C content (significantly increased 3.29% and 4.05% compared to solo ginger). Treatment 3 significantly increased contents of beneficial substances such as soluble sugar (8.2%), gingerols (4.6%) and protein. Treatment 2 significantly decreased contents of deleterious substance namely nitrate (14.0%) and improved appearance and intrinsic quality of ginger rhizome. Furthermore, treatment 2 (ginger/soybean intercropping) could obtain better economic benefit and showed the highest net income and ratio of benefit and cost whose values respectively increased by 24.80% and 8.8% compared to solo ginger.

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川西北高寒草甸位于青藏高原东部地区,是我国四大牧区之一,也是长江和黄河等江河源区的重要水源涵养功能区。近几十年来,大量牦牛粪便被牧民作为生物能源、肥料或者食用菌产业的原料而利用,为草原生态系统的养分平衡增加了生态风险。鉴于在青藏高原地区针对牦牛粪便的相关研究尚未见报道,本文从粪便和土壤养分相互变化趋势的角度出发,研究了粪便在夏秋两季的分解状况和粪便其下及其周围土壤的养分变化。通过此研究,将有助于了解牦牛粪便在自然状态下的分解速率以及粪便对土壤养分及土壤微生物生物量的影响,为粪便对草地土壤生态系统的贡献提供概念性认识,同时也为高寒草甸草地这种脆弱生态系统的可持续管理提供理论依据。 针对牦牛粪便自身养分释放及其对土壤在时间和空间尺度上的影响,本文通过模拟牛粪堆积,在不同时间和固定区域内对牛粪和土壤进行了夏秋两季的采样测定,分析了牛粪及土壤NO3--NNH4+-N、速效K、无机P、有机C、全N 和全P 含量随时间的变化趋势。得到如下结果: 1. 在研究区域内,牛粪对草地生态系统具有较强的养分(N、P)贡献能力。据初步统计,其估值大致为氮素699~932 kg ha-1,P 素为110~147 kg ha-1。牛粪(湿重、干重)在夏秋季节的分解速率具有较大差异,夏季显著快于秋季。夏季牛粪湿重、干重在2 个月左右之后分别降为初期的14%和24%,而秋季同期分别降为35%和52%。牛粪养分(NO3--NNH4+-N、速效K、无机P、有机C、全N 和全P)的分解速率在夏季也要显著快于秋季。秋季经过2 个月左右的分解之后,牛粪以上含量分别降至初始态的32%、60%、36%、64%、58%、63%和43%,远高于夏季的同期水平。 2. 在不同季节,牛粪周围的土壤养分(NO3--NNH4+-N、速效K 和无机P)含量变化随时间改变呈现相同的趋势。但是,牛粪周围不同远近下土壤养分随时间的动态变化幅度略有不同。粪下土壤养分含量随时间变化波动较大,距粪便越远,随时间变化的变幅越为平缓。总体来说,在夏季由于粪便分解较快,对土壤养分的持续作用时间不及秋季,秋季粪便分解变慢,表现出养分的缓释特征。其次,牛粪对粪下土壤影响的持续时间也长于对周围土壤的作用时间。 3. 粪便对土壤养分(NO3--NNH4+-N、速效K、无机P)影响的范围在不同季节具有差异。夏季要高于秋季,但对周围土壤养分影响的持续时间低于秋季。在夏季短期内,牛粪对土壤NO3--N 和速效K 含量的影响范围能够超过30cm,而对NH4+-N 和无机P 的影响范围则介于10cm 和30cm 之间。在2 个月左右之后,牛粪对周围土壤养分的影响能力基本消失。在秋季,牛粪对周围土壤养分影响范围难以达到30cm 处。粪便在夏季对其下土壤和周围土壤的有机C、全N 和全P 含量并无显著影响,但在秋季能显著增加其下土壤有机C、全N 和全P 含量。 4. 牛粪在秋季对土壤SMB-C、SMB-N 和SMB-P 含量的影响能够持续2 个月以上,由于秋冬季节牛粪分解缓慢,因此推断这种效应持续时间至少能够1 年左右。另一方面,牛粪在秋季对土壤SMB-C、SMB-N 和SMB-P 含量的影响范围主要集中在其下土壤,而周围的影响效应并不明显。 The grassland on the eastern fringe of Qinghai-Tibetan Plateau was one of the four greatest pasture zones in our country and the main water conservation function zones in the hesastream of Yangtse River and Huanghe river. Rencent years, lots of dung in this area was used as biological energy, fertilizer or material of fungoid growing, leading to high risk of nutrient banlance in grassland ecosystem. In view of the researches on the impact of yak dung in this area are relatively rare, the present study focused on the relationship of dung and soil nutrient transformation in sunmer and autumn, which could profoundly illuminate the mechanism of dung decomposition and the effect of dung on soil chemical properties and soil microbe biomass. The present study also contributed to a basic understand and provided scientific management in the high-frigid ecosystem. Decomposition of yak dung and its effect on soil chemical properties in eastern grassland of Qinghai-Tibetan Plateau were determined. The study simulated the real dung pats, took dung and soil samples at different time and fixed-point in summer and autumn. The samples were analysed for NO3--N, NH4+-N, available K, inorganic P, total organic C (TOC), total N (TN), total P (TP). It was concluded that: 1. In study area, the yak dung supplied to ecosystem substantial nutrient. It is estimated that the N contribution of dung was approximately 699~932 kg ha-1, P contribution was approximately 110~147 kg ha-1. The rate of yak decomposition was more rapid in summer than autumn, the wet and dry weight of yak decreased to 14% and 24% respectively after 2 months when dung excreted in summer, with 35% and 52% in autumn. The content of NO3--NNH4+-N、available K、inorganic P、TOC、TN and TP in dung decomposed more rapid in summer too. After 2 months when dung excreted in autumn, the content of above nutrient decreased to 32%、60%、36%、64%、58%、63% and 43% respectively,which were significantly higher than summer. 2. The content of NO3--NNH4+-N、available K and inorganic P in soil around dung had the same transformation trend in each season, whereas it was distinguishing at different gradient of distance from dung, the nutrient in soil below dung had the most significant change while the more far from dung, the less change in soil. It was concluded that the yak dung had prolong impacts on soil in autumn compared with summer, besides, it aslo showed that the yak dung had protract effect on soil below dung compared with soil around dung. 3. The yak dung had expansive impact on soil around dung in summer whereas had relatively short effect compared with autumn. In short-term at summer, there was a significant increase about the content of NO3--N and available K around 30cm radius from dung pat while the content of NH4+-N and inorganic P between 10cm to 30cm. After 2 months, the impact almost disappeared. In autumn, the effect was hard to reach 30cm. The yak dung had no significant effects on the content of TOC、TN and TP in soil below or around dung in summer whereas there was a obvious increase in soil below dung pat in autumn. 4. The duration of effect of yak dung on soil microbial biomass(SMB) C、N and P was at least 2 months, maybe even more than 1 year. On the other hand, the impact of dung on SMB-C、SMB-N and SMB-P mainly acted on soil below dung while no obious effect on soil around dung.

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本文从不同厌氧生境中获得7组(C-2、Y-2、L-2 、NZ、H-3、CZ、L-3)具有纤维素降解能力的复合菌系。经过不断传代、淘汰纤维素降解能力降低的菌系,最后得到一组高效、传代稳定的厌氧纤维素分解复合菌系L-3。该菌系可使滤纸在42 h内溃烂,并能在分解纤维素的同时产氢气。对L-3复合菌系的产酶条件进行了研究,结果表明,在实验范围内该菌系的产酶最适条件为:pH 6.5,温度37 ℃,接种量5 %,最佳碳源为滤纸,最佳氮源为硫酸铵。第10天测得羧甲基纤维素酶(CMCase)、滤纸酶(FPA)、外切葡聚糖酶(C1)、β-葡聚糖苷酶(β-glucodase)的酶活分别为0.216 U/ml、0.101 U/ml、0.132 U/ml、0.002 U/ml,滤纸失重率70.6 %。发酵代谢产物乙醇和丁酸含量分别可达1378 mg/L 、2695 mg/L,发酵产生的气体中氢气含量最高可达70.2 %。DGGE结果表明该菌系主要由14种菌组成,其中有三株菌在发酵前后菌数发生了明显的变化,说明在以滤纸为底物的降解过程中,这三株菌起到了重要作用,对这三株菌进行了分子生物学鉴定,初步定为Clostridium phytofermentans、Clostridium cellulovorans、Desulfovibrio sp。 利用实验室分离得到的纤维素降解菌,最终配制出由10、X-1、X-13、ST-13、L-3组成的好氧-厌氧纤维素降解复合菌剂。以秸秆为发酵底物,菌剂接种量1%,利用复合菌剂预处理后的秸秆,发酵总产气量相对于对照提高了71.62%,甲烷含量最高可达70.08%。 A group of microbial consortia L-3 was isolated from the anaerobic fermentation residue of corn stalk, which could degrade cellulose and produce hydrogen. The CMCase, FPA, C1 and β-glucosidase activity of L-3 could reach to 0.216 U/ml, 0.101 U/ml, 0.132 U/ml and 0.002 U/ml, respectively. In the filter degrading process, the filter paper collapsed in the liquid culture within 42 h and the filter degrading rate could reach to 70.6% in the 13 days, meanwhile, hydrogen was determined and the highest hydrogen content was 70.2%. The optimum cellulase-degrading conditions were filter papaer as the carbon source, (NH4)2SO4 as the nitrogen source, 37 ℃ and pH 6.5 in this experiment. DGGE results showed that the microbial consortia L-3 mainly included 14 strains. The amount of 3 strains were changed during the fermentation. These strains were identified as Clostridium phytofermentans、Clostridium cellulovorans、Desulfovibrio sp by 16S rDNA sequence analysis. The cellulose- degrading microbial agent was composed by 10, X-1, X-13, ST-13, L-3 which were isolated in the laboratory. The straw pretreated by cellulose-degrading microbial agent was used to ferment, the total biogas production increased by 72% comparing to the control. The content of methane could reach to 70.08%。

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本文对不同菌种(酵母菌和运动发酵单胞菌)快速生产燃料乙醇的条件进行了研究,实现了鲜甘薯快速转化为燃料乙醇。全文分为两部分: 第一部分:酵母菌快速生产燃料乙醇的条件研究。通过单因素试验,酵母菌快速生产燃料乙醇的条件为:发酵方式采用边糖化边发酵(SSF),蒸煮温度为85 ℃,料水比2:1(初始糖浓度 210 g/kg),糖化酶用量0.75 AGU/g 鲜甘薯,接种量10%(v/w)。在最优条件下,经过24 h发酵,乙醇浓度可达97.44 g/kg, 发酵效率为92%,发酵强度为4.06 g/kg/h。由于采用了低温蒸煮和SSF,可以大大节约能耗,从而降低乙醇生产的成本。同时,利用摇瓶优化的条件,进行了10 L,100 L,500 L发酵罐的放大试验,由于发酵罐初期可以人为通氧,使菌体能迅速积累,发酵时间缩短2 h,发酵效率在90%以上。 第二部分:运动发酵单胞菌快速生产燃料乙醇条件研究。通过单因素试验和正交试验获得了发酵的最佳参数:初始pH值6.0-7.0,硫酸铵5.0 g/kg,糖化酶量1.6 AUG/kg淀粉,初始糖浓度200 g/kg,接种量12.5%(v/w)。经过21 h发酵,乙醇浓度为95.15 g/kg,发酵效率可达94%。同时对不灭菌发酵也进行了研究,发酵效率可达92%。为鲜甘薯运动发酵单胞菌燃料乙醇的工业化生产打下基础。 对发酵结束后的残糖进行了研究。通过薄层层析和葡萄氧化酶测定证明:无论是酵母菌还是运动发酵单胞菌发酵结束后的发酵液中都不含葡萄糖。经过HPLC进一步分析残糖说明:发酵液中已没有葡萄糖成分;经糖化酶水解后仍没有葡萄糖出现;但经酸水解后又出现了葡萄糖,说明结束后的残糖是一些低聚糖结构。有关残糖的结构需要进一步研究。可以通过开发高效的低聚糖水解酶来降低发酵液的残糖,提高原料的利用率。 A new technology for rapid production fuel ethanol from fresh sweet potato by different microorganisms (Saccharomyces cerevisiae and Zymomonas mobilis) was gained in this research. The paper involved two parts: Part 1: The study on fuel ethanol rapid production from fresh sweet potato by Saccharomyces cerevisiae. The following parameters of Saccharomyces cerevisiae was investigated by a series of experiments: fermentation models, cooking temperature, initial sugar concentration and glucoamylase dosage. The results showed that SSF (simultaneous saccharification and fermentation) not only reduced the fermentation time (from 30 to 24h) but also enhanced the ethanol concentration (from 73.56 to 95.96 g/kg). With low-temperature-cooking (85 ℃) using SSF, the Saccharomyces cerevisiae was able to produce ethanol 97.44 g/kg which the fermentation yield could reach to 92% and ethanol productivity 4.06 g/kg/h from sweet potato enzymatic hydrolysis. Furthermore, the savings in energy by carrying out the cooking (85 ℃) and saccharification (30 ℃) step at low temperature had been realized. The results were also verified in 10 L, 100 L and 500 L fermentor. The fermentation yield was no less than 90%. The fermentation time of fermenter was shorter than Erlenmeyer flask. This may be that the aeration in the early fermentation period is available, which lead to the rapidly commutations of biomass. Part 2: The technology of ethanol rapid production with simultaneous saccharification and fermentation ( SSF ) by Zymomonas mobilis,using fresh sweet potato as raw material was studied. The effects of various factors on the yield of ethanol were investigated by the single factor and the orthogonal experiments. As a result, the optimal technical conditions were obtained from those experiments:initial pH value 6.0-7.0, nitride 5.0 g/kg,(NH4)2SO4, glucoamylase 1.6 AUG/kg starch, inoculums concentration 12.5% (v/w). The Zymomonas mobilis was able to produce ethanol 95.15 g/kg, with 94% of the theoretical yield, from fresh sweet potato after 24 h fermentation. The fermentation efficiency of non-sterilized was also reach to 92%. We also analyzed the final fermentation residual sugars of Saccharomyces cerevisiae and Zymomonas mobilis. When the residual sugars were analyzed by thin-layer chromatogram and glucose oxidase, there was no glucose. The analysis of reducing sugars by HPLC showed that there was no glucose existed in the fermentation liquor. However, the glucose appeared after being hydrolyzed by acid. It is indicated that the residual sugars in the final fermentation liquor were the configuration of oligosaccharide, which was linked by the special glycosidic bonds. It was feasible for reducing residual sugars to develope the enzyme that can degradation the oligosaccharide.

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猪场废水COD浓度高、氨氮浓度高、悬浮物浓度高,已成为农村面源污染的主要来源,并严重威胁到农村饮用水安全。猪场废水氨氮浓度高、处理难度大,如何采用经济高效的方法,去除氨氮使其达到排放标准,一直是猪场废水处理中面临的重要难题。 厌氧氨氧化是近年受到国内外水处理研究者广泛关注的新型生物脱氮技术,具有不需要外加有机碳源、节省供氧量、降低能耗等优点。虽然国内外研究者对厌氧氨氧化过程的脱氮机理、厌氧氨氧化菌的生理生化特性等进行了多方面的研究,但已有的报道大多以模拟废水为研究对象,以猪场废水为研究对象的报道,在国内外文献中极少有报导。 本论文以猪场废水为主要研究对象,考察了猪场废水的亚硝化过程、厌氧氨氧化的启动过程,并对亚硝化和厌氧氨氧化联合用于猪场废水脱氮进行了探索。 1.论文首先研究了猪场废水的亚硝化过程,考察了废水水质和主要运行条件对亚硝化过程的影响。实验表明:(1)亚硝化阶段反应时间为8到10h时,出水中氨氮和亚硝酸盐浓度比可达到1:1~1:1.23,满足厌氧氨氧化反应对二者比例的要求;达到前述要求时,氨氮去除率达到58.3~65.6 %,亚硝化率在整个过程均保持在97 %以上,COD去除率在59.2~68.6 %;(2)曝气量(溶解氧)对亚硝化过程影响显著,随着曝气量增大,达到厌氧氨氧化要求的氨氮与亚硝酸盐氮浓度比例所需水力停留时间τ越短,pH出现明显下降的时间越短;(3)τ对应的pH在7.8~8.1之间,无需进行pH调节即可满足厌氧氨氧化反应对pH的要求;(4)氨氮和COD降解过程遵循一级反应动力学,氨氮和COD降解的速率常数分别为0.0656~0.0724 1/h和0.0491~0.0664 1/h。 2.在进行亚硝化过程研究的同时,以模拟废水为试验对象,进行厌氧氨氧化启动研究。以反硝化污泥和养殖厂储水池厌氧底泥的混合污泥作为接种污泥,历时大约100天,培育出具有厌氧氨氧化活性的污泥,氨氮和亚硝酸盐氮最高进水浓度分别为223.8 mg/L和171.4 mg/L,去除率最高分别达48%和41.5%,此时二者消耗比例为1.33:1。 3.在猪场废水的亚硝化研究完成和厌氧氨氧化过程初步启动成功后,在模拟废水中逐步加入猪场废水的亚硝化处理出水,逐步实现亚硝化和厌氧氨氧化的组合。亚硝化出水添加到厌氧反应器后,厌氧氨氧化反应仍可继续进行,且去除效率逐步提高。研究发现添加的亚硝化出水中携带的亚硝化细菌在厌氧氨氧化菌膜外层生长并累积,增加了厌氧氨氧化反应基质的传质阻力,妨碍了厌氧氨氧化效率的提高。 4.亚硝化-厌氧氨氧化实际工程应用探索中,生物接触氧化池可在有效去除废水中的有机物的同时实现亚硝化,出水中氨氮和亚硝酸盐比例平均为1.10,可满足后续厌氧氨氧化的要求;在适宜的进水浓度和温度下,ABR池出现了厌氧氨氧化启动的迹象;研究同时发现,水质的波动和气温的变化是工程中影响厌氧氨氧化菌活性的重要因素。 论文的主要创新点在于:(1)以猪场废水为研究对象,以实现厌氧氨氧化为目标,对亚硝化过程进行了比较详细的考察,获得了亚硝化出水满足厌氧氨氧化要求的工艺条件,通过对其COD和氨氮降解过程的考察,得出亚硝化阶段COD降解和氨氮去除的动力学模型;(2)对亚硝化-厌氧氨氧化处理猪场废水进行了探索,确立了影响其污染物去除率稳定的重要因素。 论文的上述研究成果,为厌氧氨氧化技术的实用性研究提供理论依据。 Piggery wastewater, which is characterized by high concentration of COD、ammonium and suspend substance, has become a most important source of non-point source pollution and also severely threats drinking water security in rural area. How to discharge piggery wastewater with the ammonium concentration meeting standard by economical and effective method? This is the most urgent problem in piggery wastewater treatment. As a new biological nitrogen removal technology, Anammox process has been paid more and more attention by researchers all over the world. Anammox has advantages of no need of organic carbon addition, low oxygen consumption and energy consumption. Plenty of investigations have been carried out to the mechanism, physiological and biochemical characteristic of bacteria about Anammox. Most of researches focused on synthetic wastewater, there is rare report about its application in piggery wastewater. In this paper,experimental studies were performed to investigate Sharon process in treatment of piggery wastewater,the start up process of Annammox using synthetic wastewater were studied, the feasibility of applying Sharon-Anammox process in the nitrogen removal of piggery wastewater was evaluated. 1. Sharon process of piggery wastewater was firstly investigated to analyze the effects of water quality and main running parameters, which meet the NH4+-N to NO2--N ratio requirement of successive Anammox. Results showed: (1)During Sharon Process,after 8~10 hours’ reaction the NH4+-N to NO2--N ratio in effluent reached 1:1.0~1:1.23, when the removal percentage of NH4+-N was 58.3~65.6 %, a semi-nitration rate of above 97 % was achieved during the process; meanwhile 59.2~68.6 % of the COD was also removed. (2)The aeration rate(oxygen) had obvious effect on the hydraulic retention time(τ) which met the NH4+-N to NO2--N ratio requirement of Anammox. As aeration rate increased, the hydraulic retention time(τ) was shortened. (3) The pH corresponding to τ was between 7.8 and 8.1, thus it needed no artificial adjustment. (4) The reduction of ammonia and COD followed the first-order reaction kinetics. The velocity constants of ammonia and COD were 0.0656~0.0724 1/h and 0.0491~0.0664 1/h, respectively. 2. The startup of Anammox process using the artificial wastewater was performed simultaneously with Sharon. The aim was to investigate the running parameters of Anammox and make foundation for the combination stage. By using the mixture of denitrifying sludge and anaerobic sludge in tank of the breeding factory, sludge of Anammox activity was cultivated in UASB after 100 days. The removal percentage of NH4+-N and NO2-N were up to 48% and 41.5%, respectively, when the NH4+-N and NO2-N influent concentration were 223.8 mg/L and 171.4 mg/L, respectively, the NH4+-N and NO2-N removal rate was 1.33:1. 3. After investigation of Sharon and startup of Anammox, effluent of Sharon process was added into the synthetic wastewater to combine Sharon and Anammox step by step. It took some time after the addition of Sharon effluent that Anammox reaction continued and the removal rate kept increasing. It indicated that nitrifying bacteria were carried by the Sharon effluent cumulated in the outer layer of Anammox. This enhanced transfer resistance of Anammox reaction and the increasing removal rate was restrained. 4. In the bio-contact oxidation pond of practical project, Sharon process were carried out successfully and organic compounds were removed effectively. An average NO2-N/ NH4+-N rate of 1:1.0 was achieved in the effluent, which met the requirement of successive Anammox. Under condition of suitable influent concentration and temperature, there was evidence that Anammox could start up in ABR. The variety of wastewater and temperature had great affects on Anammox activity in practical engineering. Innovation of this paper: (1) The Sharon process for treating piggery wastewater was discussed in details. Technological parameters that met requirement of Anammox were obtained. The dynamic models of COD and ammonium removal in the process were educed. (2) Sharon-Ananmmox for treatment of piggery wastewater was investigated, and the primary influencing factors was studied. This paper could be a theoretical consult for research of Anammox utility.

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本文根据我们实验室建立的发酵产物中辅酶Q10定性定量检测方法,筛选得到一株可以代谢产生较多辅酶Q10的野生菌株放射形土壤杆菌(Agrobacterium radiobacter No.50)。 为了提高放射形土壤杆菌的辅酶Q10的产量,本实验利用液体培养研究了单因素对菌株辅酶Q10产量的影响,并用正交法确定了最佳液态发酵条件。最佳发酵培养基是:葡萄糖20g,蔗糖40g, 硫酸铵10g,玉米浆30g, 酵母膏3g,K2HPO4 3g,MgSO4.7H2O 1g,蒸馏水1000mL,pH 7.0-7.2。最佳发酵条件是:转接斜面菌种到种子培养基, 转速220r/min、温度28。C培养24h后,转入发酵培养基(250mL三角拼装液量为50mL,pH 7.0), 接种量为10%,转速220r/min、温度28。C,培养120h。在此条件下,菌体湿重约为50g/L,辅酶Q10含量约为20mg/L。 本文以放射形土壤杆菌为出发菌株进行诱变育种,以期获得辅酶Q10高产菌。根据微生物育种原理、参照辅酶Q10的代谢调控机制,以野生型放射形土壤杆菌(Agrobacterium radiobacter No.50)为出发菌株,采用紫外线和亚硝基胍复合诱变技术,依次筛选得到菌体提取物M抗性菌ARM-7、烟草提取物T抗性菌株ARMT-26、Vk3抗性菌株ARMTV-25、链霉素抗性菌株ARMTVS-32,菌株ARMTVS-32产量达到了36.8mg/L,与原始出发菌株相比,产量提高了77%。 研究了茄尼醇、对羟基苯甲酸、橘子皮提取物D、胡萝卜提取物E、烟草提取物对ARMTVS-32合成辅酶Q10的影响,结果表明这些物质对菌体合成辅酶Q10有一定促进作用,添加0.2g/L茄尼醇时,辅酶Q10含量提高了17%,达到了40.7mg/L;添加1.2g/L橘子皮提取物D时,辅酶Q10含量提高了13.8%,达到了39.6mg/L;添加0.5g/L胡萝卜提取物E时,辅酶Q10含量提高了25.3% ,达到了43.6mg/L;添加8g/L烟草提取物时,辅酶Q10含量提高了12.6%,达到了39.2mg/L。 Production of Coenzyme- Q10 (CoQ10) by fermentation is considered as a process with broad prospects.Quantitative Analysis of CoQ10 in the culture of microbe by TLC—UV spectrophotometry was developed, by using this method we got the strain Agrobacterium radiobacter,which was isolated from forest soil of southwest of China. The effect of the single factor on CoQ10-production ability of the strain was examined by liquid cultured, and its best optimum cultivation conditions were established by orthogonal method. The results showed that the optimum fermentation conditions were as following: carbon sources glucose 20g/L,sucrose 40g/L; nitrongen sources (NH4)2SO4 10g/L,maize liquid 30g/L;yeast extract 3g; K2HPO4 3g/L,MgSO4.7H2O 1g/L; initial pH was 7 and volume of medium(medium volume vs flask volume) was 50mL/500mL, incubating for 120h on a rotary shaker at 220 rpm and 28℃.Under these conditions, the biomass and CoQ10 concentration reached 50g/L and 20mg/L respectively. According to the biosynthesis mechanism of CoQ10 and breeding theory, CoQ10 over-production strains were screened by UV--NTG. mutation using Agrobacterium radiobacter No.50 as parent strain. A microbe-juice resistant mutant ARMTVS-32, which also could resist tobacco-juice, VK3 and streptomycin, was screened out from an agar plate. The CoQ10 content of ARMTVS-32 reached 36.8mg/L, which was 77% higher than the initial strain. In addition, We discussed the effects of some organic substrates on the synthesis of CoQ10 in ARMTVS-32. The results showed that solanesol, orange juice D, carrot juice E and tobacco juice could promote the CoQ10 accumulation in the cells. The CoQ10 content of ARMTVS-32 reached 40.7mg/L when added 0.2g/L solanesol,it reached 39.6mg/L when added 1.2g/L orange juice D,it reached 43.6mg/L when added 0.5g/L carrot juice E. it reached 39.2mg/L when added 8g/L tobacco juice.

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本文叙述了影响甲烷氧化细菌沼气甲基产孢弧菌81Z菌株生长和甲烷单加氧酶(MMO)活性的若干因素。沼气甲基产孢弧菌81Z菌株细胞生长被高浓度PO43-(>8mM),NH4+([NH4cl]>500mg/l)抑制;[CuSO4·5H2O]在0~4mg/l范围内。生长随[Cu2+]升高而加强,低[Cu2+](0.1mg/l CuSO4·5H2O)培养基中,添加Cocl2·6H2O(0.238mg/l);促进菌体细胞生长。发酵罐分批培养过程中,生长延迟期过后,沼气甲基产孢弧菌81Z菌株细胞MMO比活很快达到最高,并稳定至对数生长中后期,随即急剧下降至初始水平。发现沼气甲基产孢弧菌81Z细胞中存在一种MMO活性,它不同于已报道过的两种MMO,MMOL最适PH6.2~6.4,4℃相对稳定,其产生不受培养基中[Cu2+]调控能与甲醇-甲醇脱氢酶系统相偶联,在无细胞抽提液中其活性被400μM[Cu2+]抑制。在低[Cu2+]发酵罐培养条件下,沼气甲基产孢弧菌81Z菌株产生可溶性MMC,其最适PH7.0,4℃不稳定,可被DE-52分离为三组分:A、B、C。为了获得沼气甲基产孢弧菌81Z细胞MMO的最佳催化活性,①采用高[Cu2+]培养基进行发酵罐培养,收集对数生长中期的细胞;②选择反应缓冲液PH6.3;③反应体系中添加5mM甲醇或甲酸是有效的方法。在本研究所采取过的最佳条件下,测得MMO活性为15.9nmol/min·mg干细胞,是以前报道的该菌株活性0.97nmol/min·mg干细胞的十六倍。Some factors which influence growth and MMO activity of Methylosporovibrio methanica 81Z were described. The growth of Methylosporovibrio methanica 81Z is inhibited by high concentration of PO43-(8mM)or NH4+(500mg/lNH4cl). The growth of Methylosporovibrio methanica 81Z increased with rising of copper concentration up to 4mg/l CuSO4·5H2O. At low copper concentration(0.1mg/lCuSO4·5H2O),adding Cocl2·6H2O(0.238mg/l)could enhance the growth of Methylosporovibrio methanica 81Z.With batch culture of Methylosporovibrio methanica 81Z in a fermentor, after lag phase, the activity of MMO reached the highest level rapidly and steady until later log phase, then falled to initial level.MMOL activity differenct from that of two types of MMO reported before was found from Methylosporovibrio methanica 81Z with optimum PH value from 6.2 to 6.4 and relative stabilty at 4℃. Synthsis of the MMOL was not regulated by copper concentaration in medium. Its activity could couple with methane-l-methanoldehydrogenase system, and in cell-free extract, were inhibited by 400μm copper ion. At low copper concentration(0.1mg/lCuSO4·5H2O) and in a fermentor, Methylosporovibrio methanica 81Z could syntheis soluble MMO similar to solble MMO reported before by Palton and Patel. Its optimum PH value was 7.0. It was unstable at 4℃. It could be resoluted into three components: A, B, and C. It was effentive for obtaining the maxtmum MMO with Methylosporovibrio methanica 81Z that (1) to keep high copper concentration(4mg/lCuSO4·5H2O) in a fermentor and harvest cell at middlel lag phase;(2) to choose 6.3 as the PH value of reaction buffer;(3)and to add 5mM methanol or formate into reaction system. In this dy, the MMO activity of cells of Methylosporovibrio methanica 81Z was reached 15.9 nmol/min.mg, dry weight, sixteen times as high as the value(0.97nmol/min.mg, dry weight) reported with the same strain.