954 resultados para PAHs-degrading microorganisms


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本文以冶炼厂和张士灌区土壤为修复对象,以镉、铅、锌、铜为目标污染物,在室内模拟实验条件下,利用自养菌-嗜酸性氧化亚铁硫杆菌和异养菌-黑曲霉淋滤技术修复重金属污染土壤。在考察自养菌和异养菌对重金属污染土壤修复效果的基础上,重点研究了溶解性有机质和耐酸性异养菌对淋滤修复的影响和机制,同时筛选确定替代蔗糖黑曲霉发酵产酸的廉价碳源。结果发现: 自养菌-氧化亚铁硫杆菌淋滤修复过程中,筛选鉴定嗜酸性氧化亚铁硫杆菌R2对甲酸、乙酸、丙酸、草酸、苹果酸和柠檬酸的耐受浓度分别为0.1、0.4、0.4、2.0、20和40 mmol/L,而高效液相色谱测定沈阳冶炼厂土壤和张士灌区土壤中低分子量有机酸浓度很低,其中草酸含量最高,分别仅为0.04mmol/L和0.149mmol/L,远低于氧化亚铁硫杆菌能耐受的有机酸浓度。同时土壤中溶解性有机质对氧化亚铁硫杆菌R2氧化Fe2+未产生抑制作用,而耐酸性异养微生物H1(红酵母菌)和H2(头孢霉)的加入对氧化亚铁硫杆菌R2淋滤去除重金属效果未产生明显促进作用,本研究中分离筛选的嗜酸性氧化亚铁硫杆菌R2可直接应用于污染土壤的生物淋滤修复。经过5d的生物淋滤,冶炼厂土壤中Cu、Zn和Cd的最高去除率分别为30.6%、58.4%和72%。 在一步黑曲霉生物淋滤过程中,当固液比5%(w/v)、接种量3%(v/v)和淋滤修复7d时,对冶炼厂土壤来说,Cu、Cd、Pb和Zn去除率分别为75.8%,100%,30.6%和26.1%;张士灌区土壤中分别为54%,71.8%,9.5%,18.7%。在二步黑曲霉生物淋滤过程中,当固液比10%(w/v)、接种量为2%(v/v)和黑曲霉发酵时间7d,淋滤2d时,冶炼厂土壤中四种重金属去除率分别为Cu 84%,Cd 75.5%,Pb30.5%和Zn10%;张士灌区土壤中Cu、Cd、Pb和Zn的去除率分别达到57%,94.8%,20.4%和17.5%。 异养菌-黑曲霉淋滤修复重金属污染土壤效果优于有机酸淋滤。与黑曲霉淋滤相比,在直接添加有机酸淋滤修复中,冶炼厂土壤中重金属去除率分别为Cu 46.4%,Cd 61.8%,Pb 30.2%和Zn 43.3%,张士灌区土壤中重金属去除率分别为Cu 44%,Cd 0%,Pb 0%和Zn 26.2%。 淋滤前后土壤中重金属形态分级结果表明,黑曲霉一步和二步淋滤修复能有效去除污染土壤中交换态、碳酸盐结合态部分重金属,并能显著降低氧化物结合态部分重金属,但对有机态和残余态部分重金属离子去除效果并不明显。 以树木落叶和农作物副产品作为廉价碳源实施黑曲霉淋滤实验表明:杨树叶、桃树叶、土豆皮和玉米芯产酸和去除重金属效果较好。杨树叶对冶炼厂土壤中重金属去除率分别为63.5% Cu、100% Cd、16.8% Pb和Zn 27%;桃树叶去除效果分别为Cu61.8%、Cd100%、14.6%Pb和28.5%Zn;土豆皮去除效果分别为61%Cu、100%Cd、10.6%Pb和34%Zn。这些廉价碳源的利用可降低污染土壤生物淋滤修复成本。 研究生物淋滤修复技术为重金属污染土壤处理与处置开辟了新途径。

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仅以污染物浓度定义土壤污染并评价其潜在风险,缺乏对其生态毒性效应的综合考虑,不能反映土壤污染对生物及人体健康的潜在危害。传统的生态毒理研究仅局限于依据宏观生理指标,如半致死剂量,产茧量等,这些指标对环境浓度(亚致死浓度)土壤污染的响应较差甚至不响应,无法应用于环境浓度的污染土壤诊断。土壤生物微观生理、生化指标,作为一种较为敏感的土壤生态毒理效应及毒性诊断手段,近几年来成为研究热点。 本文以赤子爱胜蚓(Eisenia fetida)为供试生物,草甸棕壤为供试土壤,以国际标准组织(International Standard Organization-ISO)方法指南为参考,以蚯蚓微粒体细胞色素P450含量、抗氧化酶系(超氧化物歧化酶-SOD、过氧化氢酶-CAT和过氧化物酶-POD)和谷胱甘肽转移酶(GST)活性为指标,进行了的典型多环芳烃污染物-苯并(a)芘和内泌干扰物-壬基酚在土壤中暴露的动态量效关系研究,试验浓度范围为0.1-2 mg•kg -1。 研究结果如下:1)苯并(a)芘与细胞色素P450含量具有动态响应关系。总体上,诱导效应明显,诱导时间对P450活性影响显著(P<0.05);2)在试验浓度范围(0.1-2 mg•kg-1)内, GST对试验浓度的BaP未产生生态毒性响应;3)CAT 和POD酶活性对低浓度的BaP暴露响应具有延时性(即第7d开始响应)和阶段性(即第7d前无明显响应、第7d后响应消失)特征;4) 在BaP胁迫下,蚯蚓体内SOD产生明显响应,苯并(a)芘暴露1~3d,SOD酶活性整体升高,最大升幅30%,与对照差异显著。苯并(a)芘暴露的第7d和14d, 除0.1 mg•kg -1外,0.5~2 mg•kg-1 BaP处理组中SOD酶活性均显著降低(P<0.05),这表明BaP造成了抗氧化防御酶系的损伤。以上结果表明: 5项指标中, 代谢解毒酶系指标P450和抗氧化酶系指标SOD对BaP暴露响应较为敏感,CAT,POD以及GST的敏感性较差。各指标敏感性总体为:P450>SOD>CAT,POD>GST。综合本试验及其他相关实验结果初步确认,苯并(a)芘生态毒性>芘>菲。 低浓度(0.1~2.0 mg•kg-1)壬基酚(NP)土壤暴露动态关系研究结果表明:1)壬基酚(NP)与细胞色素P450含量具有动态响应关系。1、7、14d时,P450整体表现为低浓度下抑制,而高浓度下诱导的趋势。随着诱导时间的延长P450含量表现出显著的升高趋势;SOD活性在较高浓度3d暴露后降低,而第7、14d时显著升高。NP诱导与P450含量与SOD酶活性两种指标的响应趋势与BaP诱导下的响应趋势大体吻合。CAT的响应较前两者差,随着诱导时间的延长,在第7、14d个别浓度下CAT表现出升高趋势。GST与POD对试验浓度下的NP诱导未产生明显和快速的毒性响应。NP诱导第3dGST出现升高趋势。NP诱导的第14d POD (2 mg•kg-1)有显著降低。总体上,各指标对NP诱导的敏感性顺序依次为:P450,SOD>CAT>GST, POD。 继前期的“蚯蚓P450对土壤菲、芘暴露生态毒理研究”以及“土壤低浓度PAHs胁迫下蚯蚓差异表达基因筛选研究”之后,本论文中所进行的“土壤BaP暴露生态毒性响应研究”作为上述整体研究内容的组成部分,从两个方面获得研究进展:第一,进一步证实P450指标对低剂量多环芳烃污染响应的相对敏感性。第二,从代谢解毒酶系的角度发现苯并(a)芘生态毒性>芘>菲。这一结果与基因水平上论证的细胞色素P450(类似Cyp2R1)对 PAHs胁迫下的研究结果一致。 本论文中进行的土壤NP暴露生态毒性响应研究,首次将内分泌干扰物纳入土壤毒理研究中,丰富了土壤生态毒理学的研究内容。研究进一步证实蚯蚓细胞色素P450指标对多种污染物低剂量暴露诊断的广谱适应性。研究也为内分泌干扰物的生态毒性评价提供了基础依据。

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从沈阳苏家屯地区长期受有机磷污染的土壤中分离到10株以敌敌畏(DDVP)为唯一碳源生长的细菌,其中降解活性最高的菌株经生理生化鉴定和16SrDNA同源性比较,鉴定为甲基杆菌属(Methylobacterium sp.),将其命名为DDV-1(GenBank Accession NO. FJ225120)。该菌株最适生长条件: pH 7.0,温度 30℃。 对菌株DDV-1降解性能的研究表明,该菌株降解敌敌畏的最适条件为:pH 7.0,30℃,在此条件下,500 mg/L敌敌畏经过DDV-1菌株代谢5天后,降解率可达74.9%。装液量对菌株生长及降解率影响不大。DDV-1对敌敌畏有较高的耐受度,在初始量浓度为 1 500 mg/L敌敌畏的高浓度下同样能进行降解。敌敌畏的降解速率与起始接种量呈正比。正交设计实验结果表明6个因素对敌敌畏降解率影响的程度依次为C(pH)、D(温度)>B(N源)>E(接种量)>A(C源)>F(DDVP浓度)。 除了敌敌畏,菌株DDV-1还能以甲基异硫磷、辛硫磷、敌百虫、甲胺磷、对硫磷为唯一碳源,对有机磷类农药有广谱降解性。 酶学方面,酶的定位试验表明,菌株DDV-1的有机磷水解酶为胞内酶。该水解酶最适反应条件为:pH 7.0,温度30℃;粗酶液在20-40℃稳定性良好,在pH6.0-9.0都能保持活力,最适产酶碳、氮源分别为葡萄糖和蛋白胨。 在分子生物学方面,通过功能基因扩增,扩增到有机磷水解酶基因(mpd基因)。该片段为818碱基,其与已知的有机磷水解酶基因不具有同源性。 实验室条件下模拟有机磷污染土壤修复的研究表明,农药的初始浓度和接种量对敌敌畏降解影响较大,最适接种量为1000000个细胞/g土壤。

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沈抚灌区是我国面积最大、污灌历史最长的石油类污水灌溉区,土壤中大分子量多环芳烃污染严重,对当地粮食生产与生态安全造成严重危害。对此类污染土壤进行生物修复,对保证农产品的安全,实现当地人与自然的可持续发展具有重大的意义。 本研究以沈抚灌区污染土壤中大分子多环芳烃芘为主要研究对象,采用稳定同位素比率分析技术(IRMS),以磷脂脂肪酸(PLFA)为生物标记物,分析污染土壤参与芘降解的优势微生物类群;并以此为指导,采用分子生物学手段和传统微生物学分析方法,筛选土壤中的高效降解菌,并追踪其释放到土壤中后的动态变化与调控。 从沈抚灌区土壤富集培养芘的降解菌,经过双层平板法初筛和芘降解菌液体摇瓶复筛,获得5株以芘为唯一碳源生长的具有较高降解活性菌株。 将筛选的降解菌投加到污染土壤中,以13C标记的芘为代谢底物,以土壤微生物的磷脂脂肪酸为生物标记物,采用稳定同位素比率分析方法(GC-C-IRMs),分析投加的降解菌在原位土壤中的降解作用。结果显示,与不加菌的对照土壤相比,富含13C的磷脂脂肪酸指纹图谱相似度较高的为投加了菌株B05和菌株B15的土壤,芘的降解效率也最高,表明这两株菌在原位土壤芘降解中发挥了重要作用。根据形态学观察、16项生理生化鉴定和16S rDNA序列分析结果,将菌株B05鉴定为 Aminobacter ciceronei,将菌株B15鉴定为 Microbacterium arabinogalactanolyticum。菌株B05初步确定为一株新的芘降解菌,并对菌株培养条件进行了优化。 采用PCR-DGGE方法,研究了筛选的5株降解菌在不同的营养条件下释放到土壤中后的数量和代谢活性的变化。PCR-DGGE图谱分析表明:投加初期外加菌在竞争中占据优势,但是随时间推移,营养物质的消耗,优势逐渐消失,PCR-DGGE的条带趋向于一致。菌株B05的稳定期相对较长,在DGGE图谱中的条带相对密度大,而且对芘的降解率最高,是一株具有潜在应用价值的高效降解菌。混合菌比单一菌降解率高,添加碳氮源有利于外加菌群更快更好的适应在污染土壤中生存,而且有助于对多环芳烃的降解。

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本论文以镉超富集植物龙葵(Solanum nigrum L.)为材料,研究化学强化剂对龙葵修复镉-多环芳烃复合污染的作用,并对筛选出的强化剂在不同浓度水平镉-多环芳烃复合污染土壤的适用性进行研究,以期为镉-多环芳烃复合污染土壤的植物修复强化技术提供理论指导。 (1)采用室内盆栽试验的方法,研究外源半胱氨酸、谷氨酸、甘氨酸及其复合处理对超富集植物龙葵修复镉-多环芳烃复合污染土壤的影响。试验表明,各浓度水平的单因素处理对植物株高及地上部干重并没有显著影响(p>0.05),而复合处理则具有显著的促进作用(p<0.05)。各处理能够显著增强龙葵对镉的吸收和富集能力,其中半胱氨酸处理使重金属提取率分别达到1.80%及1.83%,与对照相比提高1.80及1.83倍。研究发现甘氨酸、谷氨酸及半胱氨酸复合处理能够促进镉及多环芳烃在土壤环境中的去除作用,且0.3mmol•kg-1甘氨酸+0.3mmol•kg-1谷氨酸+0.3mmol•kg-1半胱氨酸处理效果最佳,与对照相比龙葵地上部Cd含量增加2.26倍,土壤多环芳烃总量的去除率提高5.46倍。 (2)采用室内盆栽试验的方法,研究EDTA、水杨酸、TW80及其复合处理对超富集植物龙葵修复镉-多环芳烃复合污染土壤的影响。研究发现,单因素EDTA处理对龙葵具有很强的植物毒性作用,显著降低了龙葵地上部干重(p<0.05)。水杨酸及TW80处理促进了土壤中多环芳烃的生物降解作用,其中以0.9mmol•kg-1水杨酸处理效果最佳,芴、苯并(a)蒽、 、苯并(b)荧蒽、苯并(a)芘及苯并(g,h,i) 的降解率分别达到52.3、35.1、60.7、54.5、69.3及68.8%。此外,研究结果显示水杨酸对龙葵地上部提取镉总量具有很好的促进作用,即水杨酸处理能够促进污染物镉和多环芳烃的在土壤环境中的去除作用。 同样,复合处理0.1mmol•kg-1EDTA+0.5mmol•kg-1TW80和0.5mmol•kg-1EDTA+0.3mmol•kg-1水杨酸对以上两种污染物的去除均有很好的促进作用,表明在化学强化剂的协助条件下利用超富集植物修复重金属和有机复合污染土壤是可行的。 (3)采用室外盆栽试验的方法,研究化学强化剂0.1mmol•kg-1EDTA、0.9mmol•kg-1半胱氨酸、0.9mmol•kg-1水杨酸、0.3mmol•kg-1TW80及其复合处理对不同类型的镉和苯并(a)芘土壤修复适用性进行研究。研究发现,高浓度镉和苯并(a)芘对其在土壤环境中的去除产生抑制作用,其抑制强度随浓度的升高而增强。研究结果显示,不同类型的污染土壤对化学强化剂的需求不同,当土壤投加5mg•kg-1Cd时,EDTA+半胱氨酸及EDTA处理对龙葵吸收镉具有显著的促进作用,而土壤镉投加浓度为15mg•kg-1Cd时,仅EDTA+半胱氨酸处理的促进效果最佳;当土壤投加1mg•kg-1Bap时,水杨酸+TW80处理能够显著增强Bap的降解作用,而土壤投加2mg•kg-1Bap时,TW80处理的强化效果最佳;当土壤投加5mg•kg-1Cd和1mg•kg-1Bap时,水杨酸+TW80+EDTA处理对土壤中两种污染物去除均有很好的促进作用,而土壤投加15mg•kg-1Cd和2mg•kg-1Bap时,半胱氨酸+TW80处理效果最佳。

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本论文通过室内土柱淋溶模拟实验和室外冻融土柱淋溶模拟实验,研究阴离子表面活性剂LAS和非离子表面活性剂Tween-80及三种多环芳烃(PAHs)菲、芘、苯并(a)芘在土壤中迁移的状况,研究表面活性剂类型、浓度对PAHs在土壤中迁移的影响及冻融交替产生的优先水流对二者在土壤中产生优先迁移的作用。结果表明,表面活性剂在土壤中虽有较强的迁移能力,但是它们在土壤中可以形成土壤-表面活性剂复合体从而导致其在土壤中吸附量也较大。实验所用三种多环芳烃在土壤中的迁移难度BaP > 芘 > 菲。表面活性剂的施加并不能改变它们的相对迁移能力。实验结果表明:两种表面活性剂LAS和Tween-80的投加均可以促进PAHs在土柱中的迁移,它们可以使土柱中PAHs的淋出锋值提前,而且PAHs的累积淋出量也较对照高。两种表面活性剂对PAHs累积淋出量的贡献LAS > Tween-80。表面活性剂各浓度处理对PAHs在土壤中的迁移影响差异并不显著,即使使用2CMC(纯水浓度)表面活性剂淋洗土柱,其对PAHs在土壤中迁移的也没有显著促进作用,可能是由于土壤中表面活性剂的有效CMC浓度要远大于纯水中CMC 浓度之故。实验验证了冻融交替过程可以产生土壤大孔隙和优先水流,从而可以造成土壤污染物的俦迁移。

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多环芳烃(PAHs)作为一种普遍的环境污染物已开始在一些地区的土壤中高度富集,特别是在与石油、天然气和木材防腐有关的工厂所在地尤为如此。它们作为优先环境污染物而引起人们的关注是因为其中的许多种类已被证明是致癌物、致畸物和诱变剂。多环芳烃在土壤中具有相对稳定性,因此它比一般有机污染物更难降解。生物泥浆反应器已被国外证明是最有效的有机污染土壤清洁方法。本项研究利用自设计的国内第一个生物泥浆反应器对污染土壤中的多环芳烃在生物泥浆反应器中的降解条件进行研究,并优化其运行工艺参数。本研究采用三环的菲和四环的芘作为多环芳烃供试化学品。处理装置为小型的生物泥浆反应器(15L/个)。反应器配备搅拌、通气和温度控制装置,在好氧条件下进行。本项研究设计了七组不同的处理条件:不同的起始浓度(PAHs)、不同的温度(10℃,20℃,30℃)、不同的微生物接种量(5%,10%,15%,20%[W/W])、不同的表面活性剂浓度(Tween-80),研究了生物泥浆反应器在不同处理条件下对多环芳烃污染土壤的净化效果。研究结果表明,温度变化、表面活性剂浓度、接种量均对菲和芘的生物降解有明显影响。菲(3环)在生物泥浆反应器中其浓度很快降低,在360小时内去除率达97%。芘(4环)在实验浓度下下降相对较慢,360小时最高去除率也可达87%以上,平均去除率为50%以上,去除效果明显。在本研究中,多环芳烃在反应器中生物降解的最佳条件是20℃-30℃、水土比为2/1、接种量为5%、添加Tween-80的浓度为10mg/kg。本项研究首次将多环芳烃的生物泥浆反应器降解过程分为两个阶段,第一阶段是多环芳烃的快速降解阶段;第二阶段是降解停滞阶段。指出共代谢底物应在第二阶段投加为宜;研究了影响菲与芘生物半减期的因素;指出了初始浓度对菲与芘生物降解效果的不同影响;对泥浆反应器处理PAHs的运行条件进行了较为全面的研究,为这一技术的广泛应用奠定了基础。

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运用土壤学、微生物学、生态学和统计学方法,系统地开展了石油污染土壤的植物-微生物联合修复研究,对植物-微生物修复的生态影响进行了分析,并从根际微生物区系变化与根分泌物特性两个角度深入探讨了污染土壤植物一微生物联合修复的机理。室内模拟、室外盆栽、田间微区实验的结果表明:(1)植物-微生物联合修复对不同浓度石油烃污染土壤有较好的修复效果,125d的修复周期中对土壤中石油污染物的降解率为7.1%-69.8%,随污染物浓度的升高,联合修复对土壤中污染物的降解作川增强;(2)植物一微生物联合修复作用可能会长期持续,并对难降解物质PAHs存在修复潜力;(3)在本实验条件下,采用经济作物与降解微生物联合修复会降低土壤有机质含量,对土壤生态系统的结构和功能不会产生严重的干扰,对土壤生态环境的影响可以在短时间恢复;(4)植物一微生物联合作用方式在于植物与微生物的相互作用,作用区为植物根际,微生物在植物根际区域的种类数量和生化特征存在差异;植物分泌物对于微生物具有调节作用,促使污染物的生物降解。并以本试验研究为例,进一步探讨石油污染土壤植物一微生物联合修复的机理,利石油污染土壤的植物一微生物联合修复的影响因子进行调控研究,联合修复的主要影响因子是营养因子,其次是污染物浓度。石油污染土壤的植物一微生物联合修复研究,对土壤微生物群落,植物根际效应及潜在自然生物降解获得了进一步的理解,为污染土壤修复技术提供了科学依据和理论支持。

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土壤微生物(Soil microbes)是生态系统的重要组成部分,它参与土壤中复杂有机物质的分解和再合成,也参与C、N、S、P等的循环。土壤酶(Soil enzyme)是土壤中具有生物活性的蛋白质,它与微生物一起推动着土壤的生物化学过程,并在树木营养物质的转化中起着重要的作用。鉴于土壤微生物和土壤酶对环境变化的敏感性,它们在CO2浓度和温度升高时的反应将在很大程度上影响森林生态系统的结构和功能。因此,要全面评价大气CO2浓度和温度升高对整个生态系统的影响,有必要对CO2浓度和温度升高条件下的土壤微生物的反应进行深入的研究与探讨。本文应用自控、封闭、独立的生长室系统,研究了川西亚高山岷江冷杉(Abies faxoniana)根际、非根际土壤微生物数量,红桦(Betula albosinensis)根际微生物数量以及根际、非根际土壤酶活性对大气CO2浓度(环境CO2浓度+350±25μmol·mol-1,EC)和温度(环境温度+2.0±0.5℃,ET)升高及两者同时升高(ECT)的响应。结果表明: 1) EC和ET显著增加岷江冷杉根际微生物数量,但不同微生物种类对EC和ET的反应有所差异。6、8和10月,岷江冷杉根际微生物数量与对照(CK)相比,EC处理的根际细菌数量分别增加了35%、164%和312%,ET处理增加了30%、115%和209%;EC和ET处理对根际放线菌和根际真菌数量影响不显著。ECT处理的根际放线菌数量分别增加了49%、50%和96%,根际真菌数量增加了151%、57%和48%;而ECT对根际细菌数量影响不显著。EC、ET和ECT处理对岷江冷杉土壤微生物总数的根际效应明显,其R/S值分别为1.93、1.37和1.46(CK的R/S值为0.81)。 2) 红桦根际微生物数量对EC、ET和ECT的响应不同。生长季节(5~10月),高密度的红桦根际细菌数量与CK 相比,EC的根际细菌数量分别增加28%、33%、423%、65%、43%和79%,而低密度的红桦根际细菌数量增加不显著。ET能显著增加根际细菌数量(7~10月),其中高密度的根际细菌数量分别增加了377%、107%、35%、22%,而低密度的根际细菌数量分别增加了27%、27%、64%、48%;ECT对两个密度水平下根际细菌数量均未产生有显著的影响。高、低密度的红桦根际放线菌和根际真菌数量与 CK 相比,EC显著增加了低密度的红桦根际放线菌数量,而对高密度的根际放线菌数量无显著影响;ET和ECT对高低密度的红桦根际放线菌数量均未产生显著影响。EC和ET对高低密度的根际真菌数量也无显著影响,而ECT却显著增加了高低密度的根际真菌数量。 3) EC、ET和ECT处理的低密度红桦根际微生物(细菌、放线菌和真菌)数量没有显著高于或低于高密度根际微生物数量,表明短期内密度对红桦根际微生物数量不产生影响。 4) 不同种类的氧化还原酶对EC、ET和ECT的响应不同。5~10月,EC的红桦根际过氧化氢酶活性是CK 的1.44、1.06、1.11、1.10、1.12和1.24倍,差异显著(6月除外);ET和ECT处理根际过氧化氢酶活性无显著增加。EC的红桦根际多酚氧化酶活性比CK显著增加;ET的根际多酚氧化酶活性显著高于CK(8月除外)。ECT的根际多酚氧化酶活性高于CK,差异不显著。EC的根际脱氢酶活性分别增加了46%、40%、133%、48%、17%和26%,差异显著。5~7月,ET和ECT的根际脱氢酶活性高于CK的脱氢酶活性,而8~9月则相反,差异性均不显著。 5) EC、ET和ECT对不同种类的水解酶的影响不同。EC能显著增加红桦根际脲酶活性,5~10月分别增加了29%、42%,、70%、67%、59%和57%。ET和ECT 对根际脲酶活性未产生显著影响。EC显著提高根际转化酶活性,5、6和9月EC的根际转化酶活性分别比CK高51%、42%和40%。5和10月,ET的根际转化酶活性低于CK,而其余月份却高于CK,但均具有显著性差异。ECT的根际转化酶活性与CK的根际转化酶活性有显著性差异(9月除外),5、6和7月的根际转化酶活性分别提高了94%、198%和67%。 6) 与CK相比,EC、ET和ECT的非根际土壤微生物数量以及非根际土壤酶活性均无显著提高。EC、ET和ECT的过氧化氢酶、脲酶的根际效应明显,而多酚氧化酶和脱氢酶根际效应不明显。EC和ECT的转化酶根际效应明显,而ET的转化酶根际效应不明显。 It is well known that atmospheric CO2 concentration and temperature are increasing as a consequence of human activities. In past decades, considerable efforts had been put into investigating the effects of climate change on processes of forest ecological system. In general, studies had been mainly focused on the effects of elevated atmospheric CO2 on plant physiology and development, litter quality, and soil microorganisms. Studies showed that there was variation in the responses of root development and below-ground processes to climate between different plant communities. Since the concentration of CO2 in soil was much higher (10~50 times) than in the atmosphere, increasing levels of atmospheric CO2 may not directly in fluence below ground processes. Betula albosinensis and Abies faxoniana, as the dominated tree species of subalpine dark coniferous forest in the western Sichuan province, which play an important role in the structure and function of this kind of forest ecosystem. In our study, effects of elevated atmospheric CO2 concentration (350±25μmol·mol-1), increased temperature (2.0±0.5℃) and both of the two on the number of rhizospheric microbe and rhizospheric enzyme activity were studied by the independent and enclosed-top chamber’ system under high-frigid conditions. Responses of rhizospheric bacteria, actinomycetes and fungi number of Betula albosinensis and Abies faxoniana under different densities(high density with 84 stems·m-2, low density with 28 stems·m-2 ), and rhizospheric enzyme activity of Betula albo-sinensis to elevated CO2 concentration and increased temperature were analyzed and discussed. The results are as the following, 1) In comparion with the control, the numbers of rhizospheric bacteria of Abies faxoniana were increased by 35%, 164% and 312% significantly in June, August and October respectively of EC, and were increased by 30%, 115% and 209% respectively of ET.However the effect of EC and ET on rhizospheric actinomycetes and fungi was not significant. The number of rhizospheric actinomycetes of ECT were increased significantly by 49%, 50% and 96% respectively, and the increment of rhizospheric fungi were 151%, 57% and 48% respectively .The effect of ECT on rhizospheric bacteria was not significant. Rhizospheric effect of soil microbe for all treatments was significant, with the R/S of 1.93, 1.27 and 1.46 for EC, ET and ECT, respectively. 2) Treatment EC improved the number of rhizospheric bacteria of Betula albosinensis under high density significantly in comparison with the control, over the growing season, the greatest increment of rhizospheric bacteria was from July. However, EC had no effect on the number of rhizospheric bacteria under low density. Except May and June, treatment ET improved the number of rhizospheric signifcantly. The effect of treatment ECT on the number of rhizospheric bacteria under different densities was not significant. Of treatment EC, the number of rhizospheric actinomycetes of Betula albosinensis under low density were increased significantly, however, treatment EC did not stimulate the number of rhizospheric actinomycetes under high density. Simultaneously, treatment ET and ECT did not stimulate the number of rhizospheric actinomycetes. Finally, in treatment ECT, the number of rhizospheric fungi under high density were increased significantly, however treatment EC and ET did not stimulate the number of rhizospheric fungi under different densities. 3) Of treatment EC, ET and ECT, the number of rhizospheric microbe of Betula albosinensis under low density were not more or fewer than that of microbe under hign density along the growing season, which showed that plant density had no effect on the nmber of microbe. 4) From May to October, 2004,rhizospheric catalase activity of Betula albosinensis of treatment EC was 1.44, 1.06, 1.11, 1.10, 1.12 and 1.24 times as treatment CK respectively, and the difference was statistically significant(except June). Treatment ET and ECT did not increase rhizospheric catalase activity significantly. In treatment EC, the rhizospheric pohyphenol oxidase activity was higher than treatment CK significantly. The rhizospheric pohyphenol oxidase activity of treatment ET was higher than CK significantly (except August). The rhizospheric pohyphenol oxidase activity of treatment ECT was higher than CK, but the difference was not statistically significant. Over the growing period, the rhizospheric dehydrogenase activity were increased 46%, 40%, 133%, 48%, 17% and 26% respectively by treatment EC, and the difference was statistically significant. From May to July, the rhizospheric dehydrogenase activity in treatment ET and ECT was higher than CK, but from August to October, the rhizospheric dehydrogenase activity was lower than CK, the difference was not significant. 5) Treatment EC increased rhizospheric urease activity significantly, from May to October, rhizospheric urease activity were increased 29%, 42%, 70%, 67%, 59% and 57% respectively by EC. Treatment ET and ECT had no effect on rhizospheric urease activity. Treatment EC improved rhizospheric invertase activity significantly, in May, June and September, the rhizospheric invertase activity of treatment EC were increased 51%, 42% and 40% in comparison with the control. Except May and October, the rhizospheric invertase activity of treatment ET was markly higher than CK. The rhizospheric invertase activity of treatment ECT was significantly different from CK (except September), in May, June and July treatment ECT increased rhizospheric invertase activity by 94%, 198% and 67% respectively. 6) In comparison with the control, treatment EC, ET, and ECT had no effect on the number of non-rhizospheric microbe and non-rhizospheric enzyme activity. Rhizospheric effect of catalase and urease for all treatments was significant, but rhizospheric effect of pohyphenol oxidase and dehydrogenase was not significant. Rhizospheric effect of invertase of EC and ECT was significant, but rhizospheric effect of invertase of ET was not significant.

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植物生长和生产力受到自然界各种形式的生物和非生物胁迫因子的影响。这些胁迫包括低温、高温、盐碱、干旱、洪水、重金属、虫害、病害和紫外线辐射等等。而人类活动大大加剧了这些胁迫所带来的影响。由于人类污染而导致臭氧层衰减以及由此产生的地球表面紫外辐射增强已经成为全球气候变化的一个主要方面。UV-B胁迫,甚至当前的辐射水平,所带来的影响已经引起科学工作者的广泛关注。 为了生存和繁殖,植物不得不面临环境中各种潜在胁迫所带来的负面影响。然而,植物生活型的不可移动性决定了其逃避胁迫的局限性。因此,绝大多数植物都是通过对胁迫作出反应,通过修复或者更新组织来降低伤害。而植物应对环境变化的能力则是由其生长模式的种属特异性和本身的遗传组成所决定。在自然界,植物常常同时面临多种胁迫,这些胁迫所引发的植物反应可能具有叠加、协同或者拮抗作用。沙棘是一种具刺、具有固氮功能的多年生雌雄异株灌木,广泛分布于亚欧大陆的温带地区和亚洲亚热带的高海拔地区。在中国,沙棘常常被用作植被恢复中的先锋树种而大量栽培。本文采用沙棘作为模式植物,试图探索木本植物对低温,UV-B辐射增强以及其与干旱的复合胁迫的响应以及沙棘对这些胁迫响应是否具有种群差异性。 对来自南北两个种群的沙棘进行短日照和低温处理,检测了其在抗寒锻炼和抗寒性发育过程中存在的性别差异。结果表明,短日照和低温都分别能够诱导抗寒锻炼的发生,而两者同时存在对所有实验植株抗寒性的大小具有叠加效应。然而,短日照和低温所诱导的抗寒性在两个种群中都具有性别差异性,雄性植株比雌雄植株对短日照和低温更为敏感。同时,南北种群间也存在差异性,北方种群的植物比南方种群的植物对短日照和低温敏感,从而在短日照下抗寒锻炼的发生时间更早,低温诱导的抗寒性更大。短日照和低温诱导植物增加抗寒性的同时伴随着脱落酸的变化。脱落酸的变化因处理,种群和性别的不同而不同。这些生理反应表明不同的沙棘种群,不同的植株性别对同一环境胁迫可能存在不同的生存策略。 比较了来自高低两个海拔的沙棘种群对于干旱和UV-B辐射增强以及两者复合胁迫条件下的生理生态反应。干旱使两个种群中植株总的生物量,总叶面积,比叶面积,叶片含碳量,含磷量,木质素含量和碳氮比显著降低,使根冠比,粗根细根比和叶片脱落酸含量显著增加。干旱而非UV-B使得δ13C 值显著增加。但是,比较而言,来自高海拔的种群对干旱反应更为强烈,而来自低海拔的种群对UV-B更敏感。在UV-B辐射增强的处理下,干旱所诱导的脱落酸的积累被显著抑制。而且我们检测到在一些指标上存在显著的干旱×UV-B交互作用,如两个种群中在总生物量上,低海拔种群中在总叶面积,粗根细根比上,高海拔种群中在比叶面积,δ13C值,木质素含量上都存在明显的交互作用。这些结果表明这两个种群对胁迫具有不同的适应性反应,来自高海拔的种群比来自低海拔的种群更能够抵御干旱和UV-B胁迫。 室外实验表明,UV-B 去除/增补对沙棘高低两个海拔种群的影响都不大。对生物量的积累,植株高度以及一些常见的胁迫反应生理指标比如丙二醛、ABA 和游离脯氨酸都没有显著影响。UV-B 的效应比UV-A 大,植物反应在无UV 和仅有UV-A 的处理间没有什么区别。然而,UV-B 去除的两个处理和UV-B 存在的两个处理间存在显著区别。UV-B 使得两个种群都显著降低了比叶面积(SLA),但却使长期用水效率增加。但UV-B对光合色素和光合系统II 的影响不大。总体看来,来自低海拔的种群对UV-B 更为敏感。 Plant is adversely affected by various abiotic and biotic stress factors. These stressors includelow temperature, heat, salt, drought, flooding, heavy metal toxicity, wounding by herbivores,infecting by pathogenic microorganisms, ultraviolet (UV) radiation and so on. Variousanthropogenic activities have accentuated the existing stress factors. One of the mostimportant aspects of global change is that of stratospheric ozone depletion caused by seriousanthropogenic pollution and the resulting increase in UV radiation reaching the surface of theEarth. Scientists have become concerned about the effects that considerable UV-B stress, evenat current levels. In order to survive and reproduce, plants have to be able to cope with lots of potentiallyharmful stress factors that are almost constantly present in their environment. Most plants’responses under stress are to neutralize the stress, repairing the damage or regrowing newtissue rather than to avoid it due to their sessile life style. The plant defense capacity dependson plant-specific modular growth patterns and genetic make-up that allows for flexibleresponses to changing environments. Plants usually encounter several stresses simultaneouslyunder field conditions, and the stresses may cause a variety of plant responses, which can beadditive, synergistic or antagonistic. Sea buckthorn (Hippophae rhamnoides L.), a thorny nitrogen fixing deciduously perennialshrub, which is widely distributed throughout the temperate zones of Asia and Europe and thesubtropical zones of Asia at high altitudes. It has been widely used in forest restoration as thepioneer species in China. In this paper, we used sea buckthorn as a model, tried to get some understand of how plants fight low temperature, enhanced UV-B radiation level and thatcombination of drought. And also, want to know whether does there exist some populationspecific responses to such stressors. Sexual differences in cold acclimation and freezing tolerance development of two contrastingsea buckthorn (Hippophae rhamnoides L.) ecotypes from northern and southern regions inChina were recorded after exposure to short day photoperiod (SD) and low temperature (LT).The results demonstrated that cold acclimation could be triggered by exposing the plants toSD or LT alone, and that a combination of both treatments had an additive effect on freezingtolerance in all plants tested. However, development of freezing tolerance was dependent onthe sex of plants under SD and LT, the males were clearly more responsive to SD and LT thanthe females in both ecotypes studied. On the other hand, development of freezing tolerancewas also ecotype-dependent, the northern ecotype was more responsive to SD and LT than thesouthern ecotype, resulting in earlier cold acclimation under SD and higher freezing toleranceunder LT. Moreover, development of freezing tolerance induced by SD and LT wasaccompanied by changes in ABA levels. These alterations in ABA levels were different indifferent treatments, ecotypes and sexes. Therefore, the differences in SD and LT-inducedphysiological responses showed that the different ecotypes and the different sexes mightemploy different survival strategies under environmental stress. Two contrasting populations from the low and high altitudinal regions were employed toinvestigate the effects of drought, UV-B and their combination on sea buckthorn. Droughtsignificantly decreased total biomass, total leaf area, specific leaf area,leaf carbon (C),phophous (P), lignin content and the ratio of C: N in both populations, and increasedroot/shoot ratio, fine root/coarse root ratio and abscisic acid content (ABA), in bothpopulations. Drought but not UV-B resulted in significantly greater carbon isotopecomposition (δ13C) values in both populations. However, the high altitudinal population wasmore responsive to drought than the low altitudinal population. The drought-inducedenhancement of ABA in the high altitudinal population was significantly suppressed in thecombination of drought and elevated UV-B. Moreover, significant drought × UV-B interactionwas detected on total biomass in both populations, total leaf area and fine root/coarse root inthe low altitudinal population, specific leaf area, δ13C value and leaf lignin content in the high altitudinal population. These results demonstrated that there were different adaptive responsesbetween two contrasting populations, the high altitudinal population exhibited highertolerance to drought and UV-B than the low altitudinal population. A field experiment was conducted to investigate effects of UV-B exclusion/supplementationon two altitudinal populations of sea buckthorn. UV-B exclusion or supplementation had littleeffects on both populations investigated. For instance, the total biomass, plant height andsome physiological index such as Malondialdehyde (MDA), ABA and free proline were notchanged significantly. The UV-B effects are more significant than that of UV-A, nodifferences were found between treatments of excluded UV and excluded UV-B. However,compared with treatments of UV-B exclusion (including absent of UV-B and all UV band),the present of UV-B (including near ambient environment and enhanced UV-B) significantdecreased specific leaf area, and increased long time water use efficiency as evaluated by δ13Cvalue. UV-B had little effects on photosynthetic pigments and Photosystem II (PSII). The lowaltitude population is more sensitive to UV-B than that of the high altitude population.

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穗发芽(PHS,preharvest sprouting)是影响禾本科作物生产的重要的灾害之一。收获时期如遇潮湿天气容易导致穗发芽发生。发生穗发芽的种子内部水解酶(主要是α-淀粉酶)活性急剧升高,胚乳贮藏物质开始降解,造成作物产量和品质严重降低。因此,选育低穗发芽风险的品种是当前作物育种工作中面临的重要任务。 青稞(Hordeum vulgare ssp. vulgare)主要分布于青藏高原,自古以来就是青藏高原人民的主要粮食。近年来,由于青稞丰富的营养成分和特有的保健品质、在燃料工业中的潜力以及在啤酒酿造工业中的利用前景,在发达国家日趋受到重视,掀起综合研究利用的热潮。我国拥有占全世界2/3 以上的青稞资源,具有发展青稞产业的得天独厚的条件。然而,由于青稞收获期间恰逢青藏高原雨季来临,常有穗发芽灾害发生,使青稞生产损失巨大。目前对青稞穗发芽研究很少,适用于育种的穗发芽抗性材料相对缺乏,不能很好的满足青稞穗发芽抗性育种的需要。本研究以青藏高原青稞为材料,对其穗发芽抗性的评价指标和体系进行构建,同时筛选青稞抗穗发芽品种并对其抗性进行评价,还利用分子生物学手段对青稞穗发芽抗性的分子机理进行了初步探讨。主要研究结果如下: 1. 本试验以来自于我国青藏高原地区的青稞为材料,对休眠性测定的温度范围进行探讨,并对各种穗发芽抗性测定方法的对青稞的适用性进行评测。通过探讨温度对13 个不同基因型的青稞籽粒发芽和休眠性表达的影响,对筛选青稞抗穗发芽资源的温度条件进行探索,并初步分析了其休眠性表达的机理。在10,15,20,25,30℃的黑暗条件下,选用新收获的13 个青稞品种为材料进行籽粒发芽实验,以发芽指数(GI)评价其休眠性。结果发现,不同品种对温度敏感性不同,其中温度不敏感品种,在各温度条件下均表现很低的休眠性;而温度敏感品种,其休眠性表达受低温抑制,受高温诱导。15℃至25℃是进行青稞休眠性鉴定的较适宜的温度范围。通过对供试材料发芽后的α-淀粉酶活性,发现温度对青稞种子的休眠性表达的影响至少在一定程度上表现在对α-淀粉酶活性的调控上。随后,对分别在马尔康和成都进行种植的34 份青稞穗发芽指数(SI),穗发芽率(SR),籽粒发芽指数(GI)和α-淀粉酶活性(AA)进行了测定和分析,发现它们均受基因型×栽培地点的极显著影响,且四个参数之间具有一定相关性。GI 参数由于其变异系数较低,在不同栽培地点稳定性好,且操作简便,是较可靠和理想的穗发芽评价参数。SI 参数可作为辅助,区别籽粒休眠性相似的材料(基因型)或全面评价材料(基因型)的穗发芽抗性特征。AA 参数稳定性较差,并且检测方法复杂,因此不建议在育种及大量材料筛选和评价时使用。此外,青稞穗发芽抗性受环境影响较大,评价时应考虑到尽可能多的抗性影响因素及其在不同栽培条件下的变异。 2. 对来自青藏高原的青稞穗发芽抗性特征及其与其它农艺性状间的关系进行研究。通过测定穗发芽指数(SI)、籽粒发芽指数(GI)和α-淀粉酶活性(AA),表明113 份青稞材料的穗发芽抗性具有显著差异。SI、GI 和AA 参数的变幅分别为1.00~8.86、0.01~0.97 和0.00~2.76,其均值分别为4.72、0.63 和1.22。根据SI 参数,六个基因型,包括‘XQ9-5’,‘XQ33-9’,‘XQ37-5’,‘XQ42-9’,‘XQ45-7’和‘JCL’被鉴定为抗性品种。综合SI、GI 和AA 参数,可以发现青稞的穗发芽抗性机制包含颖壳等穗部结构的抗性和种子自身的抗性(即种子休眠性),且供试材料中未发现较强的胚休眠品种,除‘XQ45-7’外,所有品种在发芽第四天均能检测出α-淀粉酶活性。穗部结构和种子休眠的抗性机制因基因型不同而不同,在穗发芽抗性中可单独作用或共同作用。农家品种和西藏群体分别比栽培品种和四川群体的穗发芽抗性强,而在不同籽粒颜色的青稞中未发现明显差异。相关性检验发现,青稞的穗发芽抗性,主要是种子休眠性,与百粒重、开花期、成熟期、穗长、芒长和剑叶长呈显著负相关关系,与株高相关性不显著。农艺性状可以作为穗发芽抗性材料选育中的辅助指标。本试验为青稞穗发芽抗性育种研究提供了必要的理论基础和可供使用的亲本材料。 3. α-淀粉酶是由多基因家族编码的蛋白质,在植物种子萌发时高度表达,与植物种子的萌发能力密切相关。在大麦种子发芽时,高等电点α-淀粉酶的活性远大于低等电点的α-淀粉酶。为了研究不同穗发芽抗性青稞品种中编码高等电点α-淀粉酶Amy1 基因结构与抗性间的关系,我们以筛选得到的抗性品种‘XQ32-5’(TR1)、‘XQ37-5’(TR2)、‘XQ45-7’(TR3),易感品种‘97-15’(TS1)、‘9657’(TS2)以及强休眠大麦品种‘SAMSON’(SAM)为材料,对其Amy1 基因的编码区序列进行克隆和结构分析,并对它们推导的氨基酸序列进行比较。结果显示,青稞Amy1 基因具有三个外显子、两个内含子,编码区中有13 个核苷酸变异位点,均位于2、3 号外显子,2 个变异位点位于2 号外显子。SAM 和TS1 分别在2 号外显子相应位置有5 个相同的碱基(GAACT)的插入片段。相应α-淀粉酶氨基酸序列推导发现,所有核苷酸变异中有8 个导致相应氨基酸残基的改变,其余位点为同义突变。青稞Amy1 基因编码区序列品种间相似度高达99%以上,部分序列变异可能与其穗发芽抗性有关。随后,我们又通过SYBR Green 荧光定量技术对该基因在不同发芽时间(1d~7d)的相对表达水平进行了差异性检测。结果发现,7 天内不能检测到SAM 的Amy1 基因表达,5 个青稞品种间的Amy1 基因的相对表达量均随着发芽时间延长而上升,但上升方式有所不同。弱抗品种该基因表达更早,转录本增加速率更大,且在4~5 天可达到平台期。发芽7 天中,抗性品种总转录水平明显低于易感品种。本研究结果表明,青稞Amy1 基因的转录水平是与其穗发芽抗性高度相关。 我国青藏高原青稞,尤其是农家品种的穗发芽抗性具有丰富的变异,蕴藏着穗发芽抗性育种的宝贵资源。本研究为青稞穗发芽抗性育种建立了合理抗性评价体系,筛选出可供育种使用的特殊材料,阐明了农艺性状可辅助穗发芽抗性育种,同时还对穗发芽抗性与α-淀粉酶基因的结构和表达关系进行分析,为青稞穗发芽抗性资源筛选奠定了基础。 Preharvest sprouting (PHS) is a serious problem in crop production. It often takes place when encountering damp, cold conditions at harvest time and results in the decrease of grain quality and great loss of yield by triggering the synthesis of endosperm degrading enzymes (mostly the α-amylase). Therefore, PHS is regarded as an important criterion for crop breeding. In order to minimize the risk of PHS, resistant genotypes are highly required. Hulless barley (Hordeum vulgare ssp. vulgare) is the staple food crop in Qinghai-Tibetan Plateau from of old, where is one of the origin and genetic diversity centers of hulless barley. Recently, interest in hulless barley has been sparked throughout the world due to the demonstrations of its great potential in health food industry and fuel alcohol production. Indeed, hulless barley can also be utilized to produce good quality malt if the appropriate malting conditions are used. In China, overcast and rainy conditions often occur at maturity of hulless barley and cause an adverse on its production and application. PHS resistant genotypes, therefore, are highly required for the hulless barley breeding programs. However, few investigations have been made so far on this issue. The objectives of this study were: 1) to assessment of methods used in testing preharvest sprouting resistance in hulless barley; 2) to evaluate the variability and characteristics of PHS resistance of hulless barley from Qinghai-Tibet Plateau in China; 3) to select potential parents for PHS resistance breeding; 4) to primarily study on the molecular mechanism of PHS resistance of hulless barley. Our results are as followed: 1. We investigated the temperature effects on seed germination and seed dormancy expression of hulless barley, discussed appropriate temperature range for screening of PHS resistant varieties, and analyzed the mechanism of seed dormancy expression of hulless barley. The dormancy level of 13 hulless barley were evaluated by GI (germination index) values calculating by seed germination tests at temperature of 10,15,20,25,30℃ in darkness. There were great differences in temperature sensitivity among these accessions. The insensitive accessions showed low dormancy at any temperature while the dormancy expression of sensitive accessions could be restrained by low temperature and induced by high temperature. The temperature range of 15℃ to 25℃ was workable for estimating of dormancy level of hulless barley according to our data. Analysis of α-amylase activity showed that the temperature effects on seed germination and the expression of seed dormancy be achieved probable via regulating of α-amylase activity. Furthermore, we evaluated the differences in sprouting index (SI), sprouting rate (SR), germination index (GI) and α-amylase activity (AA) between Maerkang and Chengdu among 34 accessions of hulless barley from Qinghai-Tibetan Plateau in China. These PHS sprouting parameters were significantly affected by accession×location, and they had correlation between each other. GI was the most reliable parameter because of its low CV value, good repeatability and simple operation. SI could assist in differentiating between accessions of similar dormancy or overall evaluation of the resistance. AA was bad in repeatability and had relatively complex testing method, therefore, not appropriate for breeding and evaluation and screening of PHS resistant materials. Besides, since PHS resistance of hulless barley was greatly influenced by its growth environment, possibly much influencing factors and variations between cultivated conditions should be considered. 2. In this study, large variation was found among 113 genotypes of hulless barley (Hordeum vulgare ssp.vulgare) from Qinghai-Tibetan Plateau in China, based on the sprouting index (SI), germination index (GI) and α-amylase activity (AA) which derived from sprouting test of intact spikes, germination test of threshed seeds and determination of α-amylase activity, respectively. The range of SI, GI and AA was 1.00~8.86, 0.01~0.97 and 0.00~2.76,the mean was 4.72, 0.63 and 1.22 espectively. Six resistant genotypes, including ‘XQ9-5’, ‘XQ33-9’, ‘XQ37-5’, ‘XQ42-9’, ‘XQ45-7’ and ‘JCL’, were identified based on SI. Integrating the three parameters, it was clear that both hulls and seeds involved in PHS resistance in intact spikes of hulless barley and there was no long-existent embryo dormancy found among the test genotypes. All the genotypes, except ‘XQ45-7’, had detectable α-amylase activity on the 4th day after germination. There was PHS resistance imposed by the hull and seed per se and the two factors can act together or independent of each other. Besides, landraces or Tibet hulless barley had a wider variation and relatively more PHS resistance when compared with cultivars or Sichuan hulless barley. No significant difference was found among hulless barley of different seed colors. The correlation analysis showed PHS resistance was negatively related to hundred grain weight, days to flowering, days to maturity, spike length, awn length and flag length but not related to plant height. This study provides essential information and several donor parents for breeding of resistance to PHS. 3. Alpha-amylase isozymes are encoded by a family of multigenes. They highly express in germinating seeds and is closely related to seed germination ability. In barley germinating seeds, the activity of high pI α-amylase is much higher than low pI α-amylase. The aim of this study was to determine the relationship between preharvest sprouting resistance of hulless barley and the gene structure of Amy1 gene which encodes high pI α-amylase. The coding region and cDNA of Amy1 gene of three resistant accessions, including ‘XQ32-5’ (TR1), ‘XQ37-5’ (TR2), ‘XQ45-7’ (TR3), two susceptible accessions ‘97-15’ (TS1), ‘9657’ (TS2) and one highly dormant barley accession ‘SAMSON’ (SAM) was cloned. Analysis of their DNA sequences revealed there were three exons and two introns in Amy1 gene. Thirteen variable sites were in exon2 and exon3, 2 variable sites were in intron2. SAM and TS1 had a GAACT insert segment in the same site in intron2. Only 8 variable sites caused the change of amino acid residues. There were 99% of similarity between the tested hulless barley and some of the variable sites might be related with preharvest sprouting resistance. Then, we investigated the expression level of Amy1 gene in the 7-day germination test. Results of quantitative real-time PCR indicated that the relative expression trends of Amy1 gene were the same but had significant differences in the increase fashion between hulless barleys and no detectable expression was found in SAM. Susceptible accessions had earlier expression and faster increase and reached the maximum on day 4 ~ day 5. Besides, total transcripts level was found lower in resistant accessions than susceptible accessions. This study indicated that α-amylase activity was highly related to the transcription level of Amy1 gene which not correlated to missense mutation sites. In conclusion, hulless barley, especially the landraces from Qinghai-Tibetan Plateau in China possesses high degree of variation in PHS performance, which indicates the potential of Tibetan hulless barley as a good source for breeding of resistance to PHS. This study provides several donor parents for breeding of resistance to PHS. Our results also demonstrate that agronomic traits may be used as assistants for PHS resistance selection in hulless barley. Besides, analysis of high pI α-amylase coding gene Amy1 revealed the relative high expression of was Amy1 one of the mainly reason of different PHS resistance level in hulless barley.

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对15株白腐真菌进行了以玉米秸秆为基质的初步筛选,从中获得一株选择性系数较高的菌株Y10,并对其降解玉米秸秆的情况进行了研究。结果表明,在30天的培养过程中菌株Y10对玉米秸秆降解的选择性系数都大于1,第15天选择性系数最高为3.88。对未经降解和降解过的玉米秸秆分别作了紫外光谱和红外光谱分析,结果表明,经该菌降解后玉米秸秆的化学成分发生了很大变化,且木质素的降解程度要大于纤维素的降解程度。对菌株Y10进行了ITS-5.8S rDNA序列鉴定,初步判定其为Cerrena sp.。 为了考查不同的外源添加物对菌株Y10降解玉米秸秆的影响,在以玉米秸秆为基质的固态发酵培养基中分别添加了7种金属离子、8种碳源、6种氮源。结果显示,这7种金属离子均能促进木质素的降解,并且一定浓度的某些离子明显抑制纤维素的降解;其中添加0.036%的MnSO4·H2O和0.36%的MgSO4·7H2O对纤维素降解的抑制作用比较强,降解率分别为0.96%和1.31%,木质素的选择性系数分别达到了34.40和20.17。8种碳源中除麦芽糖外都能促进木质素的降解,除微晶纤维素外都明显促进纤维素的降解。6种氮源中酒石酸铵、硫酸铵、草酸铵和氯化铵的添加都会使该菌生长变慢,而且氮源浓度越高菌丝生长越慢。外加碳源和金属离子对半纤维素降解和选择性系数的影响不大。 同时对菌株Y10在液态培养下产木质素降解酶的条件和培养基做了优化。结果表明,在初始产酶培养基中,菌株Y10的漆酶酶活在第10d达到最高,锰过氧化物酶酶活在第11d达到最高,基本上检测不到木质素过氧化物酶。菌株Y10产漆酶的最适温度为32℃,最适PH为6.0;产锰过氧化物酶的最适温度为32℃,最适PH为6.5。菌株Y10产漆酶的最佳碳源为甘露糖,最佳氮源为酒石酸铵,最适诱导剂VA浓度为3 mmol/L,最适表面活性剂TW-80浓度为1%。 利用响应面法对其产漆酶的培养基进行优化,优化后的培养基配方为葡萄糖10.00 g/L,酒石酸铵0.50 g/L,大量元素296.50 ml/L,微量元素100.00 ml/L,NTA 1.40 g/L,VA 5.00 mmol/L,吐温-80加入量为0.10%。进行了菌株Y10产漆酶的验证实验,实测酶活为5282.56 U/L,与预测酶活5162.73 U/L接近。在优化后培养基中,菌株Y10在第14 d达到生长的最高峰,第20 d时,漆酶酶活最高,为11325.00 U/L;第16 d时,锰过氧化物酶酶活最高,为30.77 U/L。 对菌株Y10的漆酶酶学性质做了初步的研究,结果显示,酶反应的最适温度为40℃-65℃,最适PH为3.0。在40℃,PH=3.0时,漆酶催化ABTS反应的米氏方程为 。 Fifteen white-rot fungi based on corn stalk were screened. One white-rot fungus Y10 with high selectivity value was obtained. The degradation of corn stalk was initially studied. The results indicated that the selectivity value was above 1 during the 30 day-cultivation and the highest was 3.88 after 15 days. The composition of untreated and treated stalk was analyzed through ultraviolet spectroscopy and infrared spectroscopy. It was found that the composition of treated stalk was greatly altered and the degree of the degradation of lignin is greater than the cellulose. Y10 was identified as Cerrena sp. by ITS -5.8S rDNA sequence analysis. The influence of metal ions, carbon sources and nitrogen sources on corn stalk degradation by white-rot fungus was studied. While all seven metal ions could promote lignin degradation, the cellulose degradation was best inhibited at certain ion concentrations. Notably, when 0.036% MnSO4·H2O and 0.36% MgSO4·7H2O were added into the medium, the cellulose degradation was restrained to the extents that the coefficients of lignin selectivity rose to 34.40 and 20.17 respectively. It was also found that all carbon sources except maltose can promote lignin degradation. The addition of carbon sources other than microcrystalline cellulose significantly promoted cellulose degradation. The addition of the nitrogen sources, ammonium tartrate, ammonium sulfate, oxalate, ammonium chloride, resulted in remarkable inhibition to mycelium growth; the larger the concentrations of nitrogen sources are, the slower the mycelium grew. The addition of carbon sources and metal ions had less impact on the degradation of hemicellulose and selectivity value. Meanwhile, we optimized the conditions and culture medium of the lignin-degrading enzyme production of strain Y10. The results showed that in the initial culture medium, the Lac activity was highest at the 10th day, the MnP activity was highest at the 11th day and the LiP could not be detected. The optimum condition of Lac was at temperature 32 and PH =6.0 and the optimum condition of MnP was at temperature 32 and PH =6.5. The optimum carbon source for Lac was seminose, the optimum nitrogen source was ammonium tartrate, the optimum content of VA was 3 mmol/L, the optimum content of TW-80 was 1%. PB and RSM were used to optimize the culture medium of laccase by white-rot fungus Y10. The optimum culture medium was consist of glucose 10.00 g/L, ammonium tartrate 0.50 g/L, macro elements 296.50 ml/L, trace elements 100.00 ml/L, NTA 1.40 g/L, VA 5.00 mmol/L, TW-80 0.10%. Under the optimal conditions, the activity of laccase was 5282.56 U/L and the experimental value agreed with the predicted value 5162.73 U/L. The biomass was highest at the 14th day, the Lac activity was highest at the 20th day, the MnP activity was highest at the 16th day. The results of the studies on the characteristics of Lac showed that the optimum temperature for Lac activity is 40℃-65℃ ; the optimum PH for Lac activity is 3.0 and under 40℃,PH=3.0, the Michaelis-menten equation of Lac catalized ABTS oxidation was .

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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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组特殊自养氨氧化混合种群,表现:无机环境种群生长迅速、生物量高;在一个完全无机的自养生长环境中,不仅保持高氨氧化速率,并出现丰富的异养微生物种群;该种群置于异养、厌氧环境中,迅速表现出产氢特征。对于这样一个特殊的生态体系,研究其共生机理,以及联接这些种群之间的碳源和能源问题,将具有非常重要意义。我们拟从种群特征、细胞表面分泌产物、游离体系产物多糖、蛋白和脂肪酸方面开展研究。 第一部分,自养氨氧化混合种群的基本特征。采用氨氧化培养基,进行种群氨氧化特征研究;采用扫描电镜观察自养混合种群的微观特征;沉降、离心去除微生物种群,分析水相中的总有机碳、糖类等物质;利用LB培养基进行种群的分离、纯化,并采用DGGE手段对微生物种群结构进行分析。结果表明,接入菌种后(2/5000(V/V)),培养液中氨(200mg/L)在3-5天内快速降解;亚硝酸盐与氨氮变化呈负相关趋势,仅有少量硝酸盐含量(< 30mg/L)。氨氧化种群的生物量增长与氨氧化趋势一致,初始生物量7.75 mg/L(蛋白含量),3-5天后生物量快速增长,并达到最高63.06 mg/L(蛋白含量)。电镜图片显示,种群外包裹一层粘液。离心除去菌体后,检测培养液总有机碳和糖的含量,同样表现出与生物量增长相似的特征,分别由初始的3.73、2.35 mg/L,3-5内天迅速增加,并分别达到最大值35.19、27.45 mg/L。经初步分离、纯化并对纯化菌株进行测序,获得了10株异养微生物分别为布鲁氏菌科苍白杆菌属、纤维单孢菌、类芽孢菌属、黄杆菌属、无色杆菌、鞘脂单胞菌、嗜麦芽寡养单胞菌、噬氢菌属、硫红球菌、假单胞菌;DGGE显示,约有20分条离带,我们对其中的两条优势条带进行切割回收测序,鉴定为欧洲亚硝化单胞菌(Nitrosomonas eur)。 第二部分:混合种群自养-异养菌共生的可能机制。在对微生物种群特征初步分析基础上,针对胞外糖类组分可能被微生物代谢分解,我们重点对微生物细胞蛋白质与糖类进行分析。采用超声结合RIPA裂解液裂解,SDS-PAGE电泳分析混合种群总蛋白种类,并通过氨基酸分析仪及红外光谱法分析氨基酸组成及蛋白红外特征。采用超声破碎结合反复冻融对细胞样品进行处理,提取液采用醇沉、Sevage脱氮白,凝胶过滤方法脱盐和分级分离。对提取物的糖分析包括:紫外扫描,红外光谱,核磁共振,单糖组成分析;扫描电镜观察菌群破裂现象。SDS-PAGE分析结果表明:氨氧化种群不同生长阶段都显示出42kD蛋白表达量很高,d4时42kD蛋白表达已经很强,4-7d内一直持续这种过量表达,直到d8后表达开始减弱。说明42kD蛋白可能与氨氧化密切相关。红外光谱分析显示:细胞提取物的特征峰分布在3427.42cm-1、1718.18 cm-1和1681.72 cm-1、1160.07和1086.74 cm-1,分别对应为OH、 C=O、C-O-C基团,表明具有蛋白的典型特征;氨基酸分析显示蛋白中的Gly,Asp,Ala,Glu含量相对较高。 提取物中胞外多糖分离谱图得到不均一组分,共得到6个收集峰;紫外扫描在201-213 nm处有多糖吸收峰,同样表明多糖成分不均一性;多糖红外光谱特征峰主要分别在3400.49 cm-1、2920.28 cm-1、1154.54和1087.52 cm-1,对应OH、-CH2- or CH 、C-O-H or C-O-C等多糖特征基团;多糖提取物核磁共振1H d4.3~5.9之间出现强吸收峰,这是1H中,多糖存在的明显证据,1H NMR中,其中O-乙酰基的甲基上的氢信号为d1.1~1.3之间。糖肟全苯甲酸酯衍生物的HPLC测定中,得到单一的单糖峰,由于时间问题,还未进行更深入的试验;电镜图片显示,种群中的细胞有大量的破裂现象。 实验表明,自养氨氧化混合种群显示出快速的氨氧化速率,氨氧化过程生物量和有机质的增加明显。微生物种群包裹粘液层,并分离纯化出大量的异养菌;去除菌体后的游离培养液中存在有机质(包括多糖)说明无机自养生长体系中存在异养菌生长、繁殖的二次碳源;细胞提取物中蛋白条带数目多、种类丰富;细胞多糖提取物具有明显的多糖特征,以及单糖的存在。结合种群的显微特征和游离体系中的有机质的检测结果,我们认为,无机自养生长体系中,种群细胞生长过程中发生的破裂现象可能是导致大量的蛋白、多糖释放到游离胞外,并成为其他异养菌生长的碳源和氮源。这可能是自养体系中,大量异养菌共生的可能机制,至于是什么原因引起种群生长过程中产生的破裂现象,还有待下一步深入研究。 A group of mixed autotrophic ammonia oxidizing populations, having much biological characteristic tested by concerned personnel for pilot test: Performed rapid population growth and obtained high biomass in inorganic environment; Not only maintained a high rate of ammoxidation, promoted a wealth of heterotrophic microbial populations growth in a totally inorganic and autotrophic growth environment; Placed in heterotrophic and anaerobic environment,had the performance characteristics that could rapidly produce hydrogen.For such a special ecological system, Study its symbiotic mechanism and the connection between these populations of carbon and energy issues, will have a very important significance. We intended from the characteristics of the population, the secretion product of cell surface, free substance in the liquid medium like polysaccharide, protein and fatty acids carrying out research. Part I: The basic features of mixed autotrophic ammonia oxidizing populations . Use inorganic liquid medium, processed study for ammonia oxidation characteristics of the population; we used scanning electron microscopy to get micro-features of autotrophic ammonia oxidizing populations .The medium was carried out settlement and centrifugal then removed the microbial populations, after all of that we analysis the water phase for total organic carbon(TOC), carbohydrate and other substances; Solid ammonia oxidizing medium was adopted to separation and purification of population, DGGE means was for structure analysis of microbial population. The results showed that after the inoculum of bacteria (2 / 5000 (V / V)), ammonia in the culture medium (200 mg / L) was rapid degradation in 3-5 days; ammonia and nitrite have the negative correlation between changes in the trend, then only a small amount of nitrate content (<30mg / L). The biomass growth of ammoxidation population in line with the trend of ammonia oxidation, the initial volume of it was 7.75 mg / L (protein content), in 3-5 days upto 63.06 mg / L (protein content). Electron microscope image showed, the populations were wrapped in a layer of mucus, including the a large number ruptted micorbe , Centrifuge to remove bacteria, then detected the medium for total organic carbon and sugar content, result took on the same characteristics with biomass growth, that were from the initial 3.73、2.35 mg / L respectively, in 3-6 days achieved rapid increase in the maximum to 35.19、27.45 mg / L respectively. After initial separation、 purification ,then processed sequencing to strains purified and got the result that there were 10 heterotrophic microorganisms : Brucella Branch pale bacillus, Cellu lomonas, Bacillus species category, a Flavobacterium, colorless Bacteria, Aeromonas sheath fat, little support maltophilia Aeromonas, macrophages species hydrogen, sulphur-MI, Pseudomonas bacteria spores; DGGE display, there were 20 separation bands approximately. Part II: Mixed populations that autotrophic - heterotrophic bacteria symbiotic mechanism. On the basis of preliminary analysis of microbial population characteristics, aiming at extracellular carbohydrate components might be decomposition by microbial, we focused on microbial cell protein and carbohydrate analysis. Using ultrasound combined with RIPA lysis cracking the cells, SDS-PAGE electrophoresis analysis the total protein species of the population, and through the amino acid analyzer studied the compositions of amino acid and infrared spectroscopy analysis of a protein infrared characteristics. Using ultrasound combined with repeatedly freezing and thawing to treated the cell sample, then took the means that alcohol precipitation, deproteinization by Sevage, gel filtration aimed at desalination and grade separation to deal with the lysates . The extraction of sugar analysis included: UV scanning, IR, NMR, single-sugar composition analysis. SDS-PAGE analysis showed that: 42 kD protein expression was very high at different growth stages of mixed autotrophic ammonia oxidizing populations , on the fourth day, 42 kD protein expression had been very strong, 4-7d, it had continued this excessive expression, then started to weaken after 7 days. 42 kD protein that might be closely associated with ammonia oxidation. Infrared spectral analysis showed that: cell extracts with the characteristic that the peak distribution in 3427.42 cm-1、1718.18 cm-1 and 1681.72 cm-1、1160.07 cm-1 and 1086.74 cm-1 corresponding to OH、C = O、C-O-C Groups which had the typical characteristics of protein; and analysis showed that amino acids including Gly, Asp, Ala, Glu ,the content in the protein is relatively high. Exopolysaccharide in the extracts had the separation map that it was uneven, received a total of six collection peaks by the detection mode of phenol-sulphruic acid method ; ultraviolet scan in the 201-213 nm department had polysaccharide absorbing peak, the same ingredients that polysaccharide heterogeneity; infrared polysaccharide spectral characteristics of the main peak at 3400.49 cm-1, 2920.28 cm-1, 1154.54 and 1087.52 cm-1, corresponding OH,-CH2-or CH, C-O-H or C-O-C;and other characteristics of polysaccharide group; 1H NMR of polysaccharide extract appeared absorption peak between d4.3 ~5.9, which is the apparent evidence of polysaccharide, In 1H NMR, the hydrogen signal of one of O-acetyl was between 1.1 to 1.3. The determination of Sugar oxime whole benzoate derivatives by HPLC, there was a single-sugar peak, as a matter of time, yet more in-depth test. Summary: Mixed autotrophic ammonia oxidizing populations show us that it had the ability in ammonia oxidizing and it was great, organic matter and biomass increased significantly in the process of ammonia oxidation. Microbial populations was wrapped up slime layer, the phenomenon of cell breakdown obviously, and there were a lot of separation and purification of the heterotrophic bacteria; a lot of organic matter (including polysaccharides)remined in the medium that removal of cell indicated the inorganic system existed secondary carbon sources that could be used by the heterotrophic bacteria ; there were a large number proteins bands of cell extract, rich variety; cell extracts of polysaccharide had obvious characteristics of polysaccharide, and the existence evidence of single-sugar. Combined population of microscopic characteristics and free of organic matter in the test results, we believe that the health of inorganic system, population growth occurred in the course of the breakdown of the phenomenon is likely to lead to a lot of protein and polysaccharide released into the extracellular free, And other heterotrophic bacteria use them to the growth as carbon and nitrogen. This may be autotrophic system, the large number of heterotrophic bacteria symbiotic mechanism.

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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.