灵芝超高压突变株漆酶的纯化和酶学性质

灵芝超高压突变株G1502的发酵液经浓缩、DEAE-纤维素柱层析,纯化出一种漆酶。其最适作用温度为45℃,在不高于45℃的条件下保存5 h,残余酶活在97%以上;最适pH为4.4,在pH=3.8~6.6内保存,残余酶活在80%以上。漆酶催化愈创木酚的υmax和Km分别为2.28μmol.L-1.min-1和1.94×10-4mol.L-1。金属离子K+和Cu2+对酶有激活作用,Fe2+、Co2+、Ca2+、Na+、Ba2+对酶活有很大的抑制作用。     

灰树花漆酶的酶学性质及其脱色作用研究

通过对液体发酵灰树花漆酶的酶活、Km常数、温度和p H值的测定,探讨了Cu2+、Fe3+、Ca2+对漆酶酶活的影响,观察了漆酶对5种染料的脱色作用效果。结果表明:灰树花发酵液中漆酶氧化ABTS的Km为1.35×10-5mol·L-1,在p H值2~6的范围内均表现酶活,最适p H值为3.0,在25~70℃温度时范围内均有酶活,在50~55℃时酶活性最高。Cu2+、Fe3+、Ca2+对漆酶的活性均有抑制作用,Ca2+离子的抑制作用较弱。灰树花漆酶对甲基橙、甲基红、溴甲酚绿、甲基蓝和亚甲基蓝染料的脱色率分别为85.77%,81.10%,72.68%,22.02%和4.22%。介体ABTS对漆酶处理甲基蓝的脱色有促进效果,而对亚甲基蓝、溴甲酚绿和甲基红的脱色促进效果较弱,对甲基橙的脱色无促进作用。结论:本研究中灰树花漆酶最适p H值为3.0,在50~55℃时酶活性最高;灰树花漆酶对甲基橙、甲基红、溴甲酚绿染料的脱色效果理想。     

甲氰菊酯的酶促降解

阴沟肠杆菌w10j15中提取到甲氰菊酯降解酶,测定了其对甲氰菊酯的降解特性。研究结果表明,降解酶在40℃、pH7 5时对甲氰菊酯显示最大的降解活性,对甲氰菊酯的降解率为65%。经实验测定,其每毫克酶蛋白质最大降解速率Vmax为48 08 nmol·mL-1·min-1,米氏常数(Km)为332 23 nmol·mL-1。     

Kitasatospora sp.MY 5-36中e-聚赖氨酸降解酶的纯化及酶学性质

对Kitasatospora sp. MY 5-36中e-聚赖氨酸降解酶(PLD酶)进行了纯化和酶学性质研究. 通过DEAE-Sepharose, Source 15Q, Mono Q三步阴离子交换层析从细胞中得到纯酶，收率达40.7%，纯化倍数为500倍. 经SDS-PAGE电泳、凝胶过滤层析检测PLD酶由2个同聚亚基组成，亚基和全酶相对分子量分别为43.6和87.0 kDa. PLD酶的最适反应温度为30℃，最适pH值为7.0, 20~40℃保存时酶活力稳定，50~60℃保存时酶活力迅速下降，最大反应速率Vmax=0.112 mmol/(L×min), 米氏常数Km=0.216 mmol/L. PLD酶是一种金属酶，能够被Co2+激活、被Ca2+抑制.     

葡糖酸苷酶生产菌株的筛选及其酶学特性的研究

以生物合成单葡糖苷酸基甘草次酸为目的,建立了一种合成单葡糖苷酸基甘草次酸生物催化剂的筛选方法,并筛选到一株青霉菌属真菌,表达的葡糖酸苷酶具有高度底物特异性,能定向水解甘草酸生成单葡糖苷酸基甘草次酸,且研究了其酶学特质.结果表明:该催化反应的活化能E0为116.072 kJ·mol-1,反应动力学常数Km为0.328 mmol·L-1,最大反应速度Vmax为3.53×10-3 mmol·L-1·min-1.催化体系的最适反应温度为50℃,最适反应pH为4.2.该催化剂在45℃以下较稳定,pH稳定性维持在4.6～5.8,Mg2 对催化活力有一定促进作用,而Cu2 、Fe2 、Fe3、Ag 有较大抑制作用.     

陶瓷-壳聚糖复合材料固定真菌漆酶酶学性质研究

以陶瓷为第一载体、壳聚糖为二次载体、戊二醛为交联剂,采用共价结合和吸附联用法制备固定化漆酶,并研究了固定化漆酶的性质.固定化酶最适pH为3.0,最适温度分别为25℃和50℃,均与游离酶相同.在pH 3.0,温度25℃时,固定化酶对ABTS的表观米氏常数为66.64 μmol/L.与游离酶相比,固定化酶的热稳定性明显提高,并具有良好的贮存和操作稳定性.     

纳米羟基磷灰石颗粒固定化漆酶的研究木

利用羟基磷灰石对漆酶进行了固定化研究,确定了羟基磷灰石对漆酶固定的最适条件,并研究了不同温度下游离漆酶与固定化漆酶活力的差异,同时也对游离漆酶与固定化漆酶的Km值进行了研究.结果表明:0.08 g羟基磷灰石固定1 mL粗酶液,当固定化过程pH为6,交联剂戊二醛浓度为6%,固定化时间为1 h时,酶活力达到最大.当温度在3...     

大麦α-葡萄糖苷酶的提取与性质研究

从大麦中提取并部分纯化了α-葡萄糖苷酶,探索了其性质及活性影响因素.结果表明:丙酮沉淀,硫酸铵盐溶盐析和透析相结合的纯化方法可有效提高酶活到10.60倍.动力学研究得酶的Km=3.77 mol/L,Vmax＝719 U/min;其pH值范围4～12,最适为6.81,酶反应温度30 ～70℃,以40℃为最佳,实验证明大麦...     

固定化漆酶对二氯酚的脱氯作用

采用活性炭吸附与海藻酸钙凝胶包埋相结合的方法使Coriolus versicolor漆酶固定化.利用固定化漆酶对2,4-二氯酚进行脱氯反应,其最适pH值为4.5、最适温度为40℃.与游离酶相比,固定化酶反应的pH值和温度范围更宽,其稳定性得到了明显改善.使用柱式固定化酶反应器处理2,4-二氯酚,在批式反应工艺条件下,当底物浓度为1 mmol•L^-1、反应3～5 h, 2,4-二氯酚的去除率可达99.5%以上（脱除的氯离子浓度达0.5 mmol•L^-1）.连续8批反应的结果表明：固定化漆酶性能稳定、催化效率高,在环境污染废水治理方面具有良好的应用前景.     

超氧化物歧化酶的固定化及其酶学性质

目的制备固定化超氧化物歧化酶(SOD),并分析其酶学性质。方法以壳聚糖为载体,戊二醛为交联剂,制备固定化超氧化物歧化酶。以邻苯三酚自氧化法分别测定溶液酶与固定化酶的活力,并计算回收率。对固定化酶的温度和pH稳定性、半衰期、重复使用的回收率及米氏常数(Km)进行测定。结果固定化超氧化物歧化酶活力为333U/g,酶活回收率为86.32%,半衰期为43.8d;固定化酶室温保存5d后,相对酶活力仍保持在80%以上,最适反应温度为45℃,使用一次后回收率为70.12%,重复使用两次后回收率为51.72%;固定化酶与溶液酶在pH6时活性最强,Km分别为0.18mmol/L和0.16mmol/L。结论该固定化酶较溶液酶的稳定性得到提高,便于贮存,在食品、药品、日用品等领域有良好的应用前景。     

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.