金龟子绿僵菌深层培养产几丁质酶的研究

金龟子绿僵菌(Metarhiziumanisopliae)是一种重要的昆虫寄生真菌,从自然罹病死亡的金龟子体内分离到一株金龟子绿僵菌(Metarhiziumanisopliae)M-6。研究了该菌深层培养产几丁质酶的情况,几丁质酶合成的最佳碳源和诱导物为几丁质,在以0.5%(w/v)几丁质为碳源时,其产几丁质酶活达0.126IU?mL?1,在一定范围内增加培养基中几丁质浓度,葡萄糖浓度,微量元素盐浓度和碳氮比都能提高几丁质酶活。胆汁酸和吐温80作为表面活性剂能显著提高几丁质酶活。通过摇瓶试验得到优化培养基和培养条件。根据优化条件在摇瓶和3.7L发酵罐中分别进行产酶试验,实验结果表明,几丁质酶活分别达到0.231IU?mL?1和0.273IU?mL?1。最适反应温度为55℃,最适反应pH6.0,在45℃,pH3.0~9.5较为稳定。Zn2+、Ca2+、Ba2+和Mn2+离子对几丁质酶活性有明显的促进作用,而Hg2+、Co2+和Fe2+离子完全抑制几丁质酶的活性。     

几丁质酶高产菌的筛选及其产酶条件的优化研究

利用平板分离法,从土壤中分离出一株能产几丁质酶的细菌,经初步鉴定为短芽孢杆菌属(Brevibacillusshida.Agri)。研究了菌种在不同温度、pH值、氮源、碳源下的产酶情况并进行了产酶条件优化。结果表明,此细菌的最适产酶条件是:30℃、pH值7.0、蛋白胨10g.L-1、细粉几丁质10g.L-1。优化条件下的几丁质酶活力达1.25U.mL-1。     

重组基因工程菌几丁质酶C的可溶性表达研究

在不同培养温度条件下对产几丁质酶C的基因工程菌BL21（DE3）进行诱导,使其表达可溶性蛋白.随后在较佳培养温度诱导条件的基础上向培养基中添加不同浓度的甘油,甘氨酸,山梨醇/甜菜碱等成分来更进一步的提高几丁质酶C的可溶性表达.其结果是在25℃诱导条件下,以添加2g/L葡萄糖的LB培养基作为基础培养基进行培养,在基础培养基中添加3g/L甘油的总酶活最高,达到了18.17 U/mL,较之仅含2g/L葡萄糖的LB培养基在37℃及25℃诱导培养条件下酶活力分别提高了41.6％和20.3％;添加0.3％甘氨酸约90％的可溶性几丁质酶表达到了胞外,胞外酶活达到14.68 U/mL;添加0.5 M山梨醇/2.5 mM甜菜碱工程菌胞内酶活达到最高,为8.43 U/mL.结果表明适当降低工程菌诱导表达时的培养温度提高了几丁质酶C的可溶性表达,在较佳温诱导表达的基础上向培养基中添加不同浓度的甘油,甘氨酸,山梨醇/甜菜碱更进一步的提高了几丁质酶C的可溶性表达.     

几丁质酶高产菌株JX-5的产酶条件优化

利用实验室自筛的几丁质酶菌株JX-5作为出发菌株,分别从菌种的营养条件和培养条件两方面来优化菌株产酶条件,最终优化的数据如下:碳源选用粉末几丁质,氮源采用胰蛋白胨,金属离子为Fe~(3+),培养温度为35℃,接种量为7%,装液量为50mL时,几丁质酶的酶活最高可达2.48u/mL。     

云芝木聚糖酶的培养和Tween80对其产酶的促进作用

本文研究了不同碳源和吐温80（Tween80）对云芝木聚糖酶产醇的影响，当以1％滤纸为碳源时，木聚精酶活最高可达11U／mL，用微晶纤维素为碳源时也能产生很高的木聚精酶．而以1％木聚糖为碳源时，只能产生很低的木聚精酶活．Tween80对木聚糖酶的产生具有明显的促进作用，分别可达3倍（微晶纤维素为碳原）和30％以上（滤纸为碳源），这主要由于Tween80能促进木糖耷醉的分泌，提高胞外木糖苷酶的活性。     

几丁质合成与抑制的研究进展

几丁质是自然界中储量仅次于纤维素的第二大天然多糖，广泛存在于真菌、昆虫和甲壳类动物中。虽然对几丁质的研究己长达数十年，但我们对复杂的几丁质形成和沉积过程仍不清楚，或者说是部分清楚。此外，对由几丁质合成抑制剂如酰基脲类昆虫生长调节剂(IGRs)引起的生化变化的确切过程大多不清楚。近年来，对真菌及昆虫几丁质合酶(CS)基因的分离和测序研究将有助于阐明几丁质生化和抑制的各种过程。本文综述了几丁质合成与抑制的基本过程及研究现状，以期对这一重要生化过程作较为全面的介绍。     

斜纹夜蛾几丁质酶仰制剂生测新方法

几丁质酶是一种在昆虫蜕皮过程中起关键作用的酶，是昆虫生长调节剂的一个重要靶标。已报道的几丁质酶抑制剂只有阿洛氨菌素和它的衍生物，因此，需要通过更加简单有效的生测方法来寻找新的昆虫几丁质酶抑制剂。对于胶体几丁质的生物降解，是通过A610光吸收的降低来测定的，所以胶体几丁质的均匀分散是非常重要的，而通过Jeuniaux方法制备的胶体几丁质溶液在测定中总是不能达到均匀分散的目的，从而导致以前报道的、利用从斜纹夜蛾蛹制成的几丁质酶溶液的测定方法在敏感性和可靠性上均有所欠缺。日本Okayama大学Nitoda等人对昆虫几丁质酶…     

由真菌产生的大分子昆虫几丁质酶抑制剂的筛选和活性鉴定

几丁质酶是昆虫蜕皮过程中的一个关键酶 ,人们一直努力尝试将几丁质酶抑制剂开发成为具有生物合理性的昆虫生长调节剂。先前曾有文献报道阿洛氨菌素 (allosamidin)或其他一些低活性化合物为几丁质酶抑制剂 ,但都未进入商业化使用阶段。因此 ,科研人员在积极寻求开发新颖的昆虫几丁质酶抑制剂。在前期研究中 ,日本Okayama大学的TeruhikoNitoda等人研制出一种对斜纹夜蛾 (Spodopteralitu ra)几丁质酶抑制活性的测试方法 ,可应用于昆虫几丁质酶抑制剂的快速、灵敏筛选。使用该测试方法 ,他们对一系列真菌培养物进行了筛选。试验菌株生长于静…     

绿僵菌几丁质酶的分离纯化及性质

从自然罹病死亡的金龟子体内分离到一株金龟子绿僵菌（Metarhizium anisopliae）,它在几丁质的诱导下能产生较高活性的几丁质酶.发酵液经硫酸铵盐析、DEAE纤维素柱层析、Phenyl Sepharose^TM 6 Fast Flow疏水柱层析等方法,得到电泳纯的几丁质酶.用SDS-PAGE测得该酶相对分子质量为61.5 kD,而经质谱分析为57.14 kD.最适反应温度为55 ℃,最适反应pH值为6.0,酶的等电点pI为4.02,其N末端序列为VIGPAAPL,用硫酸-酚法测得其含糖量为56.2%.水解几丁质的K_m为14.5 μmol•L^-1.该酶在45 ℃,pH值3.0～9.5较为稳定.Zn²⁺、Ca²⁺、Ba²⁺和Mn²⁺离子对几丁质酶活性有明显的促进作用,而Hg²⁺、Co²⁺和Fe²⁺离子完全抑制几丁质酶的活性.此酶还可被EDTA所抑制,表明金属离子为其活性所必需.PMSF试剂对几丁质酶的活力影响比较大,丝氨酸可能是酶活力的必需基团.     

制备几丁质及脱乙酰几丁质的改良方法

鉴于几丁质及脱乙酰几丁质生产中出现的一些弊端,提出了降低生产成本、提高收率及产品质量的改良方法。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.