230 resultados para 37, 60
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于2010-11-23批量导入
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本文收集白河林业局的林火历史纪录、二类清查数据、遥感影像以及数字高程模型等数据,利用空间信息技术与多种统计方法对森林火险预报和林火蔓延模拟进行了研究。该研究对于林火的预防及扑救可以提供理论指导和技术支持,对于实现林业的可持续发展具有重要意义。主要结论如下。 (1)白河林业局自1974到2001年28年中共发生火灾153次,高发年代为70年代末80年代初;主要火源为烧荒,约占全部火灾次数的37.25%;高发区为两江林场,占总次数的37%;高发月份为3-5月和9-11月。(2)利用二类清查数据、1987年及2000年的遥感影像、数字高程模型等数据,采用地理信息系统和遥感技术及主成分分析法得出白河林业局的可燃物、地形、人为活动以及综合所有因素的森林火险区划,得到了相应的高火险等级小班的分布。并利用相关分析方法进行检验,结果证明这种方法与实际林火发生数据相关系数达到92.46%,说明具有很高的可信度。(3)利用非参数的最近邻法和有参数的最近邻法分别对森林火险气象预报进行了分析,非参数的最近邻法的森林火险气象总体预报准确率为78.57%,无林火发生的预报准确率为80%,而林火发生的预报准确率为77.78%。应用有参数的最近邻法进行森林火险气象预报时,利用相关分析确定的权重进行预报的总体准确率为78.57%,无林火发生的预报准确率为60%,林火发生的预报准确率为88.89%。利用逻辑斯蒂回归确定权重的最近邻法进行预报得到的结果最好,尽管这种方法预报的未发生林火的预报准确率仅为60%,但总体预报正确率达到了85.71%,特别是林火发生预报的准确率达到了100%。(4)通过对林火在不同情况下蔓延模拟发现,无风、地形条件相同时的林火蔓延呈现圆形;无风、地形条件不同时的林火蔓延呈现出不规则的多边形;有风、地形条件不同时的林火蔓延呈现出不规则的多边形,但有一个主蔓延方向。
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石油开采炼制中产生的含油固体废物已经被列入《国家危险废物名录》,其来源和物理化学性质复杂,油、水、泥比例差异显著。目前尚无高效资源回收技术。本文以大庆油田两种典型含油固体废物(罐底含油污泥与老化油)为研究对象,针对其性质提出了以热馏、三相分离为核心的处理工艺,并分析处理后衍生品性质,在此基础上进行系统的含油固体废物资源化技术研究。 试验结果表明:大庆油田罐底含油污泥含油量高于25%,适合于热馏处理,油总收率在20%-35%之间,其中所含的油回收率40%-60%;剩余残渣热值比原油泥提高近30%,可以焚烧回收热值;馏出产品中含汽油馏分8.35%、柴油馏分53.95%、润滑油馏分37.7%;柴油符合优等0#柴油的质量标准;热馏技术主要同反应温度与反应器内残压相关,高温低残压易于油回收。 通过三相分离法处理老化油,加热、破乳、离心后,无机盐、金属离子、无机相硫化物等随水相分离出;氧化胶质、破碎菌胶团、机械杂质及有机药剂随固相分离出;处理后样品含水率减少99.7%,氮含量(聚合物)减少10.24%,机械杂质减少60%,胶质、沥青质减少35.38%,硫含量减少1.67%,盐含量减少60%,铁含量减少34.78%。处理后老化油耐受电场强度为3000 V/cm。
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由于采样条件和培养条件的限制,深海微生物研究的较少,因此目前海洋微生物资源的研究主要集中在近海和浅海。而深海独特的生态环境,使微生物形成了独特的代谢体系,成为新颖化合物的重要来源,具有很好的开发应用前景。本文首次较为系统的研究了深度为1758-3600m南海海底沉积物中深海微生物资源的分离和活性菌株的筛选情况,旨在为探索我国南海深海微生物资源提供一定的科学依据。 采用多种分离培养基从6个不同深度(1758、2620、3200、3500、3587和3600m)的南海深海沉积物样品中,分离到225株深海微生物,包括40株放线菌和185株细菌。以分离得到的225株深海微生物为研究对象,从产蛋白酶、抗真菌、杀虫三个方面进行活性菌株的筛选,研究南海深海沉积物中的微生物资源状况: (1).将分离到的225株深海微生物,同时在10℃、28℃、45℃三个温度下进行产低温蛋白酶、中温蛋白酶、高温蛋白酶的筛选。初筛结果表明:这225株深海微生物大都有大小不同的产蛋白酶能力。10℃有产蛋白酶的有109株,28 ℃产蛋白酶的有160株,45℃产蛋白酶的有117株。筛选到一株在45℃下有较强产蛋白酶能力的菌株B1394,其酶活可达873U/ml,有一定的应用前景。通过形态观察、生理生化测定、16SrDNA序列测定,将B1394定名为枯草芽孢杆菌(Bacillus subtilis)。其粗酶液性质研究发现:最适酶活温度60℃,最适pH 8.0, 40℃、50℃和60℃热稳定性较好, Mn2+ 、Mg2+ 、Ca2+对该蛋白酶有激活作用,Hg2+ 、Fe3+ 、Cu2+ 、Zn2+ 、 Fe2+对其有抑制作用,苯甲基磺酰氟(PMSF)几乎完全抑制其活性,推断为丝氨酸蛋白酶。 (2).对其中100株深海细菌和40株深海放线菌,以立枯丝核菌( Rhizoctonia solani)和白色念珠菌(Candida albicans)为靶菌进行了抗真菌活性的筛选。初筛结果表明:分别有37株和35株深海细菌对立枯丝核菌和白色念珠菌有抑菌活性,分别占被检测细菌数目的37%和35%;有18株深海放线菌对立枯丝核菌有抑制作用,占被检测放线菌总数的45%。筛选到一株有较强抗真菌活性的深海放线菌SHA6,其发酵液对包括尖孢镰刀菌(Fusarium oxysporum)在内的10种植物病原菌有明显的抑制作用。对其发酵液的理化性质进行初步研究发现SHA6发酵液具有良好的热稳定性和酸碱稳定性, 对SHA6进行分子生物学鉴定后将其初步定名为为橙色单胞菌(Aurantimonas altamirensis)。 (3).以卤虫为初步筛选模型,对其中的20株深海放线菌进行了杀虫方面的筛选,结果发现有5个深海放线菌菌株表现有较强的杀虫活性。其中深海放线菌SHA4发酵液的乙酸乙脂提取物杀卤虫的活性最强,在浓度为100μg/ml时杀卤虫活性为83%,而在浓度400ppm时,48h可以杀死38%的甜菜夜娥。对SHA4进行分子生物学鉴定后将其初步定为拟诺卡氏菌属(Nocardiopsis sp)。 总之,本论文阐明了我国南海深海沉积物中微生物资源状况的初步研究结果,为进一步开发利用我国南海深海微生物资源奠定了基础。
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土壤类型、温度等条件是影响硝化抑制剂效果的重要因素,为了探讨几种国外报道的高效硝化抑制剂在我国棕壤和红壤上的适应情况,以及温度等条件对于施肥土壤中NO3--N的积累和硝化抑制剂效果的影响,进行了本研究。采用室内培养的方式,研究了ATC、DMPP和CMP(每种抑制剂在两种土壤上分别设两个浓度处理)在我国棕壤和红壤上的效果,与目前应用较多的DCD(0.5%、1.0%两个浓度处理)进行效果对比;研究了温度条件、添加C源及培养条件对土壤中NO3--N积累及CMP硝化抑制效果的影响。结果表明,土壤条件是影响NO3--N积累和所用四种硝化抑制剂(DMPP、CMP、ATC、DCD)抑制效果的一个显著因素,棕壤中氮素转化较快,硝化抑制剂表现出效果较早,在红壤中起效时间较晚,在两种土壤条件下,所用抑制剂都表现出了良好的效果,在60天内ATC、CMP和DMPP的效果与10倍用量的DCD效果类似,甚至好于DCD,在棕壤中同种抑制剂的两个浓度处理之间存在显著差异,但是在红壤几个处理之间没有表现出显著差异;温度条件也是影响NO3--N积累的一个显著因素,从计算硝化抑制率看出,在25℃和30℃下CMP表现出了高效,37℃下抑制率下降,效果变差;添加两个浓度的葡萄糖对于对照中NO3--N的积累以及硝化抑制剂的硝化抑制效果没有表现出显著作用;增加的一步预培养恢复了土壤中微生物的活性在短期内体现了出来,但是长期看对于NO3--N积累量、变化趋势以及硝化抑制率都没有表现出显著作用。
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生态系统评价是为了向决策者提供生态系统管理信,息而对生态系统结构、功能进行分析,并根据其变化趋势及驱动力提出相应措施的综合研究过程。生态功能分区是依据生态系统胁迫过程与效应、生态环境质量、敏感性和生态系统服务功能重要性等特征空间分异规律而进行的地理空间分区,目的是辨析区域生态环境问题与生态环境脆弱区和良好区,明确优先保护的生态系统和地区,为生态保护与建设、产业结构调整与优化及区域生态系统分区管理提供科学依据。本研究以辽宁省域生态系统为对象,在生态环境调查的基础上,分析了生态环境状况及变化趋势,进行了生态环境质量、敏感性和生态系统服务功能重要性评价,辨析了存在的生态环境问题及驱动力,明确了生态环境质量、敏感性和生态系统服务功能重要性空间分布格局,然后对辽宁省进行了生态功能区划分,并指出了各功能区生态保护与建设的重点和措施以及产业结构调整与优化的对策和方向研究结果表明,在经济和人口增长的长期胁迫作用下,辽宁省生态环境问题依然严峻,主要表现为:土地退化,地表水污染严重,森林质量下降和功能减弱,草地减少与退化并存,天然湿地萎缩,滩涂和海岸带生境恶化,生物多样性面临威胁,农业面源污染凸显,生态系统抗干扰能力下降,生态灾害加剧。全省生态环境质量超过2/3属于一般以下水平,其中优级面积仅占12.56%,良好级面积占18.71%,主要分布在东部及东南部;一般级面积占34.25%,主要分布在中部、北部和南部;较差级面积占34.48%,主要分布在西部及西北部。全省县级市及县有44个,其中生态环境质量为优的仅有4个市县,占总县数的9.09%;生态环境质量为良的有7个市县,占总县数的15.91%;生态环境质量一般的有19个市县,占总县数的43.18%,生态环境质量较差的有14个市县,占总县数的31.82%。全省处于轻度至高度敏感区域。高度敏感区占34.00%,主要分布在辽东山地丘陵、辽东半岛、辽西低山丘陵、辽西北、柳绕地区和大洼县。辽东山地丘陵、辽东半岛和辽西低山丘陵主要是土壤侵蚀高度敏感。辽西北和柳绕地区主要是土地沙漠化高度敏感。大洼县是土壤盐渍化高度敏感。中度敏感区占能.66%,与高度敏感区相间分布。轻度敏感区占3.34%,零星分布在辽东,在辽西和辽河平原也有少量分布。全省生态服务功能均处于比较重要以上。极重要地区占60.66%,基本分布在辽东、辽西和辽河平原的北部与盘锦滨海地区,辽东主要为水源涵养、生物多样性保护、土壤保持、营养物质保持,辽西主要为土壤保持、生物多样性保护、水源涵养、营养物质保持,辽北主要为土壤保持,盘锦滨海地区主要为生物多样性保护。中等重要地区占37.01%,基本分布在辽河平原,在辽东、辽西也有分布,辽河平原主要为土壤保持、水源涵养,沙漠化控制,辽东和辽西主要为土壤保持,辽西北为沙漠化控制。其它地区为比较重要地区,仅占2.33%,主要分布在辽东和辽河平原,在辽西也有少量分布,主要为土壤保持。在生态系统评价的基础上,首先根据地貌和气候划分出4个生态区,即辽东山地丘陵温带湿润半湿润生态区、辽河平原温带半湿润生态区、辽西低山丘陵温带半湿润生态区、辽南环黄渤海海岸带生态区。在明确生态区的基础上,依据生态系统类型与过程的完整性,以及生态服务功能类型的一致性,划分出21个生态亚区。依据生态环境质量、敏感性及生态服务功能重要性等的一致性,进一步划分出52个生态功能区。
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全球气候变化已经成为不争的事实,其中全球变暖是近年来国内外的研究热点之一。土壤碳库作为陆地生态系统最大的碳库,气温升高必然会导致一系列的土壤碳储量和碳通量的变化,这些微小的变化又可能导致大气CO2浓度的变化并强化这种变暖的趋势。目前,土壤碳循环对温度升高的响应仍然是陆地碳循环研究最缺乏的部分,对土壤有机碳动态变化的研究仍存在着很大的不确定性与争议。四川西部的亚高山人工针叶林是青藏高原东部高寒林区的重要组成部分,是研究全球变化对森林生态系统影响的关键地区和重要森林类型。本研究通过采用原位人工模拟增温装置(Open-top chambers,OTCs)对川西米亚罗60年人工云杉林土壤实施增温,研究高海拔地区森林,尤其是人工森林系统下的土壤有机碳 含量、土壤呼吸及土壤酶活性对温度升高的响应。结果表明: 1. 增温处理的660天(2005年11月至2007年9月)期间,增温条件下的平均气温和土壤平均温度分别比对照提高0.43 ℃和0.27 ℃;0~10 cm土壤含水量在增温的不同时期均有不同程度的降低。 2. 土壤蔗糖酶、蛋白酶和脲酶活性在温度升高的不同阶段均有不同程度的提高。在增温处理300天(2006.09)、540天(2007.05)、600天(2007.07)和660天(2007.05)后,0~10 cm层的蔗糖酶活性分别比对照提高了36.36%(P<0.05)、24.31%、14.54%(P<0.05)和7.22%,脲酶活性分别提高了12.90%、24.19%(P<0.01)、34.48%(P<0.05)和14.64%(P<0.05),蛋白酶活性分别提高了31.37%、1.99%、3.70%和17.80%。10~20 cm层的土壤酶活性也均有不同程度的提高,但均没有显著差异。蔗糖酶、脲酶和蛋白酶活性均呈现出随土层加深而减弱的趋势。 3. 土壤过氧化氢酶和多酚氧化酶活性在增温的第1年内均有不同程度的提高,但在增温的第2年内比对照有所降低。增温300天后(2006.09),过氧化氢酶和多酚氧化酶在0~10 cm层分别比对照增加3.76%和49.25%(P<0.05),10~20 cm层分别增加了5.54%和29.67%。在增温的第2年内,增温540天(2007.05)、600天(2007.07)和660天(2007.09)后,0~10 cm层的过氧化氢酶活性分别比对照降低了27.70%(P<0.05)、4.34%和1.47%,多酚氧化酶活性分别降低了5.86%、11.76%(P<0.05)和7.47%。增温的第2年内,10~20 cm层的过氧化氢酶和多酚氧化酶活性也均有不同程度的降低,但差异均未达到显著水平。不同土层之间相比较,过氧化氢酶活性随土层加深而降低,多酚氧化酶活性随土层加深而增加。 4. 土壤有机碳和有机质在增温的不同阶段,含量比对照均有所降低;且随增温时间的延长,降低的幅度下降。0~10 cm层的土壤有机碳和土壤有机质在增温300天(2006.09)、540天(2007.05)、600天(2007.07)和660天(2007.09)后分别降低了8.69%、4.35%、3.80%和2.44%,差异均未达到显著水平。土壤全氮含量在增温后与对照相比无明显的增加或者降低趋势。增温条件下的土壤C/N比与对照相比有所降低,但在增温各阶段的差异均不显著。10~20 cm层的有机碳、有机质和C/N比也有不同程度的降低趋势,但差异均不显著。不同土层之间相比,0~10 cm层的有机碳、有机质、全氮含量和C/N比均高于10~20 cm层,呈现出随土层加深而降低的趋势。 5. 土壤呼吸速率在增温第1年内,与对照相比明显提高,但在增温处理2年后,与对照相比无显著变化。增温300天(2006.09)和360天(2006.11)后分别提高了13.32%和21.17%,差异显著。增温处理540天(2007.05)到660天(2007.09)期间,与对照相比,不仅没有明显的提升,反而有些月份比对照有所降低,对温度升高的敏感性降低,呈现出对温度升高的适应性。土壤呼吸的日呼吸速率呈现单峰曲线形式,在14:00~20:00期间达到最大值,在4:00~10:00期间具有最低值。土壤呼吸的季节变化,呈现出与外界环境温度相一致的趋势,在7月份(夏季) 最高,11月份(冬季)最低。土壤呼吸与2 cm土壤温度、5 cm土壤温度和空气温度均呈极显著指数相关,与0~10 cm土壤含水量呈线性相关,相关性达到显著水平,但低于土壤呼吸与温度的相关性。 The past century has seen a marked increase in atmospheric carbon dioxide concentrations and a concomitant warming that has drawn scientific attention to the link between global carbon stocks and climate change. In particular, the decomposition and turnover of soil organic matter is recognised as an important determinant of carbon driven climate change. The slightly variation in soil organic carbon will result in the increase of atmospheric carbon dioxide concentrations and reinforce the tendency of warming. The experiment was conducted in Subalpine coniferous forest in western Sichuan province. Subalpine coniferous forest in western Sichuan was a important part of eastern Qinghai-Tibetan Plateau, which play a important role in reseaching the sensitivity of forest ecosystem to climate change. To investigate the effects of elevated temperature on soil organic carbon content, soil respiration rates, and soil enzyme activities in subalpine Picea asperata plantations, a esimulated warming measure was applied with Open-top chambers. The results were as followed: 1) During the period from Nov. 2005 to Sep. 2007, mean air temperature and soil temperature were respectively 0.43℃ and 0.27℃ the ambient higher. Soil water content decreased to different exent in different months in warmed plots than in unwarned plots at depth of 0-10 cm. 2) In general, elevated temperature enhanced the soil enzyme activities of invertase, protease, and urease. In the first year of warming—after 300 days’ treatment (in Sep,2006), the activities of invertase, protease, and urease increased by 36.36%, 12.90% and 31.37% respectively at the depths of 0-10 cm,among which the activity of invertase reached statistic significance. In the second year of warming, invertase activity increased by 24.31% after 540 days’ treament (in May, 2007), 14.54% after 600 days’ treament (in Jul, 2007) and 7.22% after 660 days’ treatment (in Sep, 2007) at the depths of 0-10 cm, and the differences in July and Septemmber were statistically significant. Elveated temperature also increased the activity of urease in the second year of warming and had significant effects in May and July. The activity of protease in warmed plots was also higher than in unwarmed plots at depths of 0-10 cm, but there was no significant difference. Elevated temperature had no significant effects on all soil enzyme acitivities at the depths of 10-20 cm in the first and sencond year. The values of above-mentioned soil enzyme all decreased with soil layers. 3) Eleavted temperature enhanced the activities of catalase and polyphenol oxidase in the first year of warming while they turned out downtrend in the second year. The activity of catalase increased by 3.76% and 5.54% at depths of 0-10 cm and 10-20 cm respectively in the first year—after 300 days’ warming (in Sep, 2006), the differences of which had no statistical significance. The activity of polyphenol oxidase was significantly increased by 49.25% at depths of 0-10 cm and not significantly increased by 29.67% at depths of 10-20 cm after 300 days’ warming. In the second year of warming, the catalase activity was significantly decreased by 27.70% after 540 days’ treament (in May, 2007) and not significantly decreased by 4.34% and 1.47% after 600 days’ (in Jul, 2007) and 660 days’ treament (in Sep, 2007) respectively. The activities of catalase and polyphenol oxidase at depths of 10-20 cm were decreased to different extent, but there was no significant difference. Catalase activity stepped down with soil layers while polyphenol oxidase activity stepped up. 4) Increased temperature in both the first year and the second year resulted tendency of decrease in the contents of soil organic carbon and soil organic matter, and C/N ratios at soil depths of 0-10 cm and 10-20 cm. However, with the prolonged warming, the tendency of decrease gradually tapered off and the extent of decrease in the second year of experiment were lower than that in the first year. The contents of soil organic carbon and soil organic matter were all decreased 8.69% by warming in the first year and dcreased 4.35%, 3.80% and 2.44% in May, July and September of the second year, but no significant difference were found. The C/N ratios increased 8.52% in the first year of warming and had less increment in the second year, all of which were not statistical significant. Eleveated temperature had no obvious effect on the content of tatol N in two year consecutive warming experiment. The contents of soil organic carbon and soil organic matter, total N and C/N ratios all had the tendency of dcreasing with soil layers. 5) Soil respiration rates were significantly enhanced by 13.32% and 21.17% after 300 days’ (in Sep, 2006) and 360 days’ (in Nov, 2006) treament in the first year of warming, but the same showed no obvious difference in the second year of treatment, which was assumed the adaptability of soil respiration with a certain heightened temperature. Diurnal soil resspiration showed a daily variation with a minimum value between 4:00 and 10:00 h and a maximum value between 14:00 and 20:00 h, coinciding with the minimum and maximum values of soil temperature at 2 cm. Soil respiration rates exhibited a pronounced seasonal variation with minimum values in Novmber and a maximum value in July, approximately coinciding with the seasonal variation of air and soil temperature. An exponential function provided the best fit for soil respiration with temperature while a quadric equation was used to estimate the effect of soil moisture on soil respiration, which were all significantly correlated. Soil respiraion rate was more highly correlated with the soil temperature than soil moisture.
Resumo:
青稞(Hordeum vulgare L.var.nudum Hook.f.),即裸大麦,是兼食用、饲用和酿造于一体的作物,有着重要的利用价值。淀粉是青稞籽粒中含量最多、最重要的碳水化合物,淀粉含量、直支淀粉比将会直接影响淀粉的功能特性,进而影响淀粉的应用领域。我国青藏高原青稞的栽培和食用历史悠久,特色青稞资源极其丰富。目前关于青藏高原青稞淀粉特性的报道还不多见,筛选和培育特色淀粉青稞利于拓展青稞的应用领域, 从而提高其经济价值。 本研究以114份青藏高原青稞品种(系)为实验材料,通过SDS-PAGE对材料的胚乳淀粉颗粒结合蛋白(SGAPs)进行分离,确定各蛋白的分子量大小、组合类型和多态性等。然后按照国标法测试材料的籽粒总淀粉含量和直链淀粉含量,通过微型糊化粘度仪分析相应的淀粉糊化特性,最后使用显微镜观察比较了青稞的淀粉颗粒形态特征。主要结果如下: 1、114种青稞中共分离出20种不同的SGAP条带,条带分子量为35.00~112.39 KDa,分布频率为12.28~97.37%。材料含有的SGAPs条带数从10到14不等,超过一半的材料含11种SGAP条带。20种条带形成16种组合类型,其中西藏地区青稞包含所有16个组合类型,四川地区青稞包含其中12个组合类型。青藏高原青稞籽粒淀粉颗粒结合蛋白的差异很大,遗传多样性丰富。 2、114份青稞的总淀粉含量、直链淀粉含量、直支淀粉比、峰值粘度、糊化温度和峰值温度的变幅分别为51.26~66.70%、14.64~29.74%、0.17~0.42、194~1135BU、58.8~65.2℃和81.4~92.4℃,相应的平均值分别为59.82%、23.60%、0.31、722.30BU、62.1℃和88.8℃。群体在总淀粉含量、直链淀粉含量、直支淀粉比、峰值粘度、糊化温度和峰值温度上的分布具有明显的正态性;所有胚乳淀粉体的淀粉粒都呈复粒结构。对西藏和四川的材料进行了分组比较, 两地区的青稞在直链淀粉含量和直支淀粉比上的差异达到显著水平。 3、筛选出18份具有特殊淀粉特性的青稞品种,其中5份材料的总淀粉含量超过65%,包括NB63-1、NB67、甘孜白六棱、98221-1和NB63;3份材料的直链淀粉含量大于29%,包括藏青85、藏青3号和喜马拉6号;8份材料的直支淀粉比小于0.25,包括99033-6、春青稞、阿坝330、Jan-03、米麦114、396、NB63-1和92013;7份材料的糊化温度低于60℃,同时材料的峰值粘度大于1000BU,并且峰值温度低于90℃,包括足捉春、Jan-03、阿坝330、米麦114、春青稞、20003和阿青5号。 4、各淀粉特性间存在高度相关性。直链淀粉含量和直支淀粉比与糊化温度成极显著正相关,与峰值粘度成极显著负相关,与A型淀粉粒数量和大小呈负相关。不同SGAPs组合的品种之间,淀粉含量和淀粉糊化特性间差异均达显著水平。SGAP2、SGAP5、SGAP6和SGAP7可能对籽粒直链淀粉含量、直支淀粉比和糊化温度有正向效应;SGAP3、SGAP9∼SGAP20可能对峰值粘度有正向效应。 本研究对青藏高原青稞淀粉资源进行了较为全面的评价,对该区青稞淀粉特性有了系统的认识。研究筛选出的特殊青稞品种可作为青稞育种和青稞淀粉工业应用的潜在资源,淀粉特性差异巨大的众多青稞品种也为拓宽青稞应用领域提供了丰富的资源保障。本研究对部分SGAPs在性质上的鉴定和功能上的初步推断为青稞材料的筛选提供了指导,也为品质育种提供了理论参考。 Hulless barley (naked barley, Hordeum vulgare L.) is a short- season, early maturing crop with a wide range of adaptation. It has been attracting more and more attention due to its superior nutrition and extensive industrial applications. Starch is the main ingredient in hulless barley seeds which makes up 65 percent of hulless barley’s dry weight. The ratio of the amylose/amylopectin and the size, shape, distribution of starch granules can affect the physico-chemical and functional properties of starch, which may turn affect its utilizations. The Qinghai-Tibet Plateau, which is located in southwestern China, is a typical area of vertical agricultural ecosystem and one of the barley origin centers with abundant hulless barley resources. There are little reports about hulless barley in Qinghai-Tibet Plateau at present. To screen and cultivate some characteristic hulless barley can improve its value. An improved SDS-PAGE was used to identify SGAPs combination of 114 hulless barley varieties. Starch content (total starch and amylose starch) was determined according to the standard methods GB5006-85 and GB/T 15683 using PerkinElmer M341 Precision Automatic Polarimeter and UV spectrophotometer 755B respectively. The pasting properties were measured by BRABENDER Micrio Visco-Amylo- Graph 803201. The morphology of starch granules were observed and compared with Axioplan 2 Imaging light microscopy. The following were the results obtained: 1. There were 20 major SGAPs presented in 114 varieties, with the molecular weight ranged from 35.00 to 112.39 KDa, and the frequencies ranged from 12.28% to 97.37%. The number of SGAP bands in each accession varied from 10 to 14, more than half of the population had 11 bands. There were 16 distinct SGAP patterns in the 114 varieties, the Tibet hulless barley had all of the 16 types and the Sichuan hulless barley had 12 types. The results indicated the Qinghai-Tibet Plateau hulless barley had a polymorphism of the SGAPs. 2. The ranges of the total starch content, amylose content, Am/Ap, peak viscosity, pasting temperature and peak temperature of the 114 hulless barley were 51.26~66.70%,14.64~29.74%,0.17~0.42,194~1135BU,58.8~65.2 and 81.4℃~92.4, with an average of ℃59.82%, 23.60%, 0.31, 722.30BU, 62.1 and 88.8,℃℃ respectively. The distributions of the total starch content, amylose content, Am/Ap, peak viscosity, pasting temperature and peak temperature were visibly normal school. All of the amyloplasts in endosperm of varieties showed bimodal size distributions.The main starch properties of hulless barley from Tibet and Sichuan were separated and compared, the differences on amylose content and Am/Ap were obvious. 3. Eighteen accessions which had special starch properties were screened out. Five accessions with total starch content beyond 65%, including NB63-1, NB67, Ganzibailiuleng, 98221-1 and NB63; three accessions, Zangqing85, Zangqing3 and Ximala6, with the highest amylose content (>29%); five accessions with Am/Ap less than 0.25, including 99033-6, Chun Qingke, A Ba 330, Jan-03, Mi Mai114, 396, NB63-1 and 92013; seven accessions had a pasting temperature under 60, ℃meanwhile their peak viscosity beyond 1000BU and their peak temperature under 90℃,including Zu Cuochun, Jan-03, A Ba 330, Mi Mai 114, Chun Qingke, 20003 and A Qing 5. 4. There were high correlations between starch properties. Amylose content and Am/Ap were positively correlated to pasting temperature, negatively correlated to peak viscosity, negatively correlated to the number and granule size of A-type granule. Different SGAP combinations caused significant diversities in starch content and pasting properties. SGAP2, SGAP5, SGAP6 and SGAP7 may have positive effect on amylose content, Am/Ap and pasting temperature; SGAP3, SGAP9∼SGAP20 may have positive effect on peak viscosity. Our research made a comprehensive evaluation on the hulless barley starch from the Qinghai-Tibet Plateau, we can get a systemic understanding. Some special accessions were screened out can be used on the hulless barley breeding lines and industries utilization.The combination of the SGAPs may become a criterion to evaluate the hulless barley endosperm starch quality. Consequently, the results will be good information for further studies on the hulless barley.
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本文主要研究了从造纸厂碱性土壤中筛选得到的,能够产生耐碱木聚糖酶的两株放线菌X24-14和X15-17。通过16 S rRNA基因序列分析并结合菌株的形态特征以及生理生化特性,初步认为菌株X15-17为拟诺卡氏菌属(Nocardiopsis)的一个潜在新种;菌株X24-14为纤维化纤维菌(Cellulosimicrobium cellulans)。 在此基础上探索了菌株X24-14和菌株X15-17所产木聚糖酶的基本酶学性质。研究发现,两株菌所产的木聚糖酶的耐碱性均较强: 1)菌株X24-14所产的木聚糖酶,在pH 4.2~9.4的范围内能维持较高的活力,pH 9.4条件下,仍能保持80%的酶活力;2)菌株X15-17所产的木聚糖酶在pH 4.0~9.0的范围内能维持较高的活力,pH 9.0条件下,仍能保持80%的酶活力;3)两株菌所产的木聚糖酶均具有较好的pH稳定性,在pH 2.0~11.0范围内稳定,pH 11.0、4 ℃条件下处理24 h仍具有75%的活力。 本文还重点研究了菌株X24-14在不同培养基成分及不同培养条件下的产酶情况,确定了其适宜的产酶条件。结果显示,菌株X24-14的最适碳源为麸皮;最适氮源为蛋白胨;最适产酶pH为pH 8.5。菌株X24-14适宜的产酶条件为:麸皮60 g/L,蛋白胨10 g/L,K2HPO4 7.0 g/L,pH 8.5,接种量为5%,37 ℃,200 r/min发酵培养108 h。 Two strains of actinomycetes, X24-14 and X15-17, which produced alkali-tolerant xylanase were screened from the soil samples collected from a pulp mill in china. Based on the morphological, physiochemical characteristics and 16S rRNA sequence, X24-14 was priminarily identified as cellulosimicrobium cellulans ; X15-17 was priminarily identified as a new species of Nocardiopsis. The investigation examined the enzyme activities which produced by X24-14 and X15-17 under different pH and different temperatures. The results showed that : 1)The xylanase from X24-14 had characteristic of alkali-tolerance: It remains 80% relative activity at pH ranges between pH 4.2 and pH 9.4 under 50℃. 2)The xylanase from X15-17 also showed characteristic of alkali-tolerance, it remains 80% relative activity at pH ranges between pH 4.0and pH 9.0 under 50℃. 3)The xylanase from the two strains showed alkali-stable characteristics. They were stable at pH ranges between pH 2.0 and pH 11.0, showing 75% of its maximal activity remaining under 24 hours of treatment at 4℃. We also studied the effect of different growth conditions: carbon source, nitrogen sources, inoculum size, and initial pH on the production of xylanase of strain X24-14. The results showed that :The optimal carbon source was wheat bran; The optima nitrogen source was peptone; The maximum xylanase activity was achieved in the medium containing 60 g/L wheat bran, 10 g/L peptone, 7 g/L K2HPO4, inoculum size 5% and pH 8.5, under 37℃ in 108 h.
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我们从成都东郊垃圾堆里分离到一株产生水不溶性葡聚糖降解酶的菌株CIB871,经鉴定为假单孢菌。CIB871在30℃生长良好。适宜的产酶培养条件是在含有一定金属离子的盐溶液中加入氮源多胨(终浓度0.3%)和碳源IG(终浓度0.03%)或甘露醇(终浓度1%)。上清液酶浓度在培养60-65小时达到最高。利用饱和度50%-70%的硫酸铵沉淀该酶。酶作用的最佳PH为7.0,最佳温度37℃,热稳定性不良。5mM的Ag+,Co2+,Hg2+, Mg2+, Zn2+ 对酶有抑制作用。Fe2+,Fe3+对酶有激活作用。