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Mapping the polysaccharide degradation potential of Aspergillus niger
Mikael R Andersen, Malene Giese, Ronald P de Vries, Jens Nielsen
BMC Genomics , 2012, DOI: 10.1186/1471-2164-13-313
Abstract: Through the compilation of information from 203 articles, we have systematized knowledge on the structure and degradation of 16 major types of plant polysaccharides to form a graphical overview. As a case example, we have combined this with a list of 188 genes coding for carbohydrate-active enzymes from Aspergillus niger, thus forming an analysis framework, which can be queried. Combination of this information network with gene expression analysis on mono- and polysaccharide substrates has allowed elucidation of concerted gene expression from this organism. One such example is the identification of a full set of extracellular polysaccharide-acting genes for the degradation of oat spelt xylan.The mapping of plant polysaccharide structures along with the corresponding enzymatic activities is a powerful framework for expression analysis of carbohydrate-active enzymes. Applying this network-based approach, we provide the first genome-scale characterization of all genes coding for carbohydrate-active enzymes identified in A. niger.
Linking aggregation of Aspergillus niger spores to surface electrostatics: a theoretical approach
Andreas Wargenau, Ingo Kampen and Arno Kwade
Biointerphases , 2013, DOI: 10.1186/1559-4106-8-7
Abstract: The effect of medium pH on conidial aggregation during submerged cultivation of Aspergillus niger is considered to originate from the electrostatic surface properties of the spores. As previously shown, these properties are greatly influenced by the presence of a melanin-containing surface coating covering the outer spore wall layer. The present study was designed to elucidate the impact of such a coating on the spores' surface potential and their electrostatic repulsion under acidic conditions. A Poisson-Boltzmann model was proposed and potential profiles across the surface coating of noninteracting and interacting spores were calculated. The surface potentials thus obtained were in line with the observed pH dependence of the zeta potential. This dependence was consistent with the outcome of aggregation experiments. Apparently contradictory results regarding the zeta potential and the aggregation behavior of the spores were obtained when the ionic strength was varied. However, both of these observations could be explained by the model.
Optimization extraction methods of polysaccharide of chlamydospores wall in Ustiloginoidea virens
稻曲病菌厚垣孢子壁多糖的提取方法优选

WANG N,REN Zuo-Hu,DENG Lin-Wei,MAO Ying,CHEN Juan-Fang,LIU Er-Ming,
王娜
,任佐华,邓林伟,毛莹,陈娟芳,刘二明

微生物学通报 , 2011,
Abstract: To reveal the content and composition of polysaccharide in chlamydospore wall of Ustiloginoidea. virens, a study of the optimum method to extract polysaccharide of the chlamydospore wall was conducted. Five different methods were adopted to extract polysaccharide of its black chlamydospore wall, and the contents of polysaccharide were determined by phenol-sulfuric acid method. The results showed that the optimum extracting method was the complex enzyme-hot water extraction-sevag and the most appropriately extracting conditions were that the complex enzyme, pH 4 extracting tempera-ture extracting time and the material ratio were 4%, 70 °C for 120 min, 1:75 (V/V), respectively. Based on above the optimum method, the relatively crude polysaccharide and polysaccharides rates in the black and yellow chlamydospore wall were separately 21.2% and 72.3%, and 17.5% and 66.7%. Con-sequently, the complex enzyme-hot water extraction-sevag and its optimizing conditions among the five different methods were simple, efficient and particularly suitable to the determination polysaccharide in chlamydospores wall of U. virens.
张泌  [PDF]
周子瑜?
天府新论 , 1988,
Abstract: 张泌,五代前蜀词人,《花间集》列于牛峤、毛文锡之间,可见年辈较高,称张舍人。从其《江城子》有“浣花溪上见卿卿”句看,他少年与邻家女发生爱情即在成都浣花溪上,可知他为成都人,或祖籍外地而成长于成都。后来,南唐复有与前蜀词人张泌同姓名者二:一为常州人,官至内史舍人;一为淮南人,为句容县尉。过去词论者多将三人混为一人,胡适对此曾有辩析:“……《花间集》集结于940年,其时南唐建国,不及四年
JUDGMENT AGGREGATION AND PREFERENCE AGGREGATION
Joanna Ochremiak
Decyzje , 2011,
Abstract: In the paper we present an introduction to the theory of judgment aggregation and discuss its relation to the theory of preference aggregation. We compare the formal model of judgment aggregation, based on logic, with the formal model of preference aggregation. Finally, we present a theorem in judgmentaggregation which is an exact analogue of Arrow's theorem for strict preferences.
Yucca (manihot esculenta crantz) starch polysaccharide dextrination through biological procedures.
Villalba,Pedro; Bula,Antonio; San Juan,Homero; ávila,Adrián;
Interciencia , 2008,
Abstract: the yucca (manihot esculenta) starch dextrination process using aspergillus niger has been evaluated in order to obtain fermentable sugars from the original polysaccharide. the maximum glucose concentration (2466mg·l-1) was obtained at 30°c for a period of three days. the statistical analysis (p=0.05) of the experimental results revealed a second order behavior for the process. the interaction between the variables time (days) and temperature significantly affected the glucose production due to the enzymatic action of the a. niger on the substrate. response surface analysis showed an optimal point for the process at 37oc and 2.75 days, and a significant interaction between temperature and time. it is concluded that the catalytic action of a. niger strongly depends on the environmental conditions in which the process is carried out.
湿地植物根系泌氧的特征  [PDF]
邓泓,叶志鸿,黄铭洪
华东师范大学学报(自然科学版) , 2007,
Abstract: 研究了10种湿地植物的根系泌氧(radialoxygenloss,ROL)特征及其相关因素.泌氧不仅在物种间存在差异,而且在根系的不同部位也有明显不同.根据泌氧速率在根不同部位的变化趋势可将湿地植物的根部泌氧方式分为3种类型.类型Ⅰ为ROL在根的任意部位均较高,且沿氧传输方向逐渐降低;类型Ⅱ为ROL在根尖区域最高,之后沿根基部方向迅速降低;类型Ⅲ为ROL在根的任何位置泌氧速率非常低,且不随根的部位而变化.溶液培养条件下,缺氧胁迫能使植物根的直径增粗,根孔隙度提高,通气组织更加发达,诱导根基部泌氧屏障的生成,使泌氧速率和泌氧方式发生变化.
白蜡虫泌蜡研究Ⅰ.不同地理种源泌蜡比较  [PDF]
陈晓鸣,陈勇,周朝鸿,王自力,叶寿德,王绍云
林业科学研究 , 1998,
Abstract: 本文对云南昆明、昭通和四川金口河三个不同地理种源白蜡虫的泌蜡状况进行了研究。结果表明,昆明虫泌蜡历时最长,泌蜡量最高,昭通虫泌蜡历时和泌蜡量次之,金口河虫泌蜡历时短,泌蜡量低。在泌蜡周期中,白蜡虫泌蜡有高峰期,昆明虫泌蜡高峰期在泌蜡后50d,昭通虫在泌蜡后30d,金口河虫在泌蜡后20d。酯酶同工酶和过氧化物酶同工酶测定结果表明,三个不同地理种源的白蜡虫种群已产生了分化,昆明种虫与昭通种虫分化较小,昆明种虫和昭通种虫与金口河种虫的分化较大。
The Principle of Polysaccharide Gels  [PDF]
Masakuni Tako
Advances in Bioscience and Biotechnology (ABB) , 2015, DOI: 10.4236/abb.2015.61004
Abstract: For several decades attention has been directed to natural polysaccharide gels and synthesized polymer gels. The structure-function relationships at molecular level in water of polysaccharides, κ-carrageenan, ι-carrageenan, agarose (agar), and gellan family of polysaccharides (gellan, welan, rhamsan, S-657, deacetylated rhamsan and native gellan gum), which are industrially useful polysaccharides extracted from family of red seaweeds and bacteria, in principle are discussed on the view point of rheological aspects. The polysaccharide molecules (0.1% - 1.0%) play a dominant role in the center of the tetrahedral cavities occupied by water molecules (99.0% - 99.9%), and the arrangement is similar to a tetrahedral structure in a gelation process. The cage and hydrophobic effect play thermal dynamically dominant role in gelation process which gives lowest entropy to electrons of sugar residues. Though the chemical structure of these polysaccharides similar each other, their rheological (gelling) characteristics are quite different. Many investigations about the gelling properties of the polysaccharides have been undertaken to elucidate the structure-function relationship, but no other researchers have established mechanism at the molecular level. There is consistency in our investigations. Thus, the rheological analysis is one of significant methods for understanding the structure-function relationship of polysaccharides in aqueous media. The discussion provides many important information not only in academic field, but also in industrial one, such as food, cosmetic, pharmaceutical, drug delivery and tissue industries, and biotechnology.
The Principle of Polysaccharide Gels  [PDF]
Masakuni Tako
Advances in Bioscience and Biotechnology (ABB) , 2015, DOI: 10.4236/abb.2015.61004
Abstract: For several decades attention has been directed to natural polysaccharide gels and synthesized polymer gels. The structure-function relationships at molecular level in water of polysaccharides, κ-carrageenan, ι-carrageenan, agarose (agar), and gellan family of polysaccharides (gellan, welan, rhamsan, S-657, deacetylated rhamsan and native gellan gum), which are industrially useful polysaccharides extracted from family of red seaweeds and bacteria, in principle are discussed on the view point of rheological aspects. The polysaccharide molecules (0.1% - 1.0%) play a dominant role in the center of the tetrahedral cavities occupied by water molecules (99.0% - 99.9%), and the arrangement is similar to a tetrahedral structure in a gelation process. The cage and hydrophobic effect play thermal dynamically dominant role in gelation process which gives lowest entropy to electrons of sugar residues. Though the chemical structure of these polysaccharides similar each other, their rheological (gelling) characteristics are quite different. Many investigations about the gelling properties of the polysaccharides have been undertaken to elucidate the structure-function relationship, but no other researchers have established mechanism at the molecular level. There is consistency in our investigations. Thus, the rheological analysis is one of significant methods for understanding the structure-function relationship of polysaccharides in aqueous media. The discussion provides many important information not only in academic field, but also in industrial one, such as food, cosmetic, pharmaceutical, drug delivery and tissue industries, and biotechnology.
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