添加蜗牛酶对纤维素酶产生菌发酵的影响初探

从上海市郊农村草堆的土壤中分离到一株分解纤维素的菌,经初步鉴定为绿色木霉。该菌最适生长温度为２８℃。在本实验条件下,该菌的产酶高峰在９６ｈ左右;对木薯渣的水解能力最强,滤纸的水解活力（Ｆｉｌｔｅｒ Ｐａｐｅｒ Ａｃｔｉｖｉｔｙ,ＦＰＡ）为１０．８ｕ／ｍｌ发酵液。其酶的最适反应温度为５０℃,最适ｐＨ为４．８。用添加蜗牛酶的方法进行绿色木霉菌发酵,结果显示,分泌纤维素酶的能力提高１２％左右。     

Immunity of the greater wax moth Galleria mellonella

Investigation of insect immune mechanisms provides important information concerning innate immunity, which in many aspects is conserved in animals. This is one of the reasons why insects serve as model organisms to study virulence mechanisms of human pathogens. From the evolutionary point of view, we also learn a lot about host–pathogen interaction and adaptation of organisms to conditions of life. Additionally, insect‐derived antibacterial and antifungal peptides and proteins are considered for their potential to be applied as alternatives to antibiotics. While Drosophila melanogaster is used to study the genetic aspect of insect immunity, Galleria mellonella serves as a good model for biochemical research. Given the size of the insect, it is possible to obtain easily hemolymph and other tissues as a source of many immune‐relevant polypeptides. This review article summarizes our knowledge concerning G. mellonella immunity. The best‐characterized immune‐related proteins and peptides are recalled and their short characteristic is given. Some other proteins identified at the mRNA level are also mentioned. The infectious routes used by Galleria natural pathogens such as Bacillus thuringiensis and Beauveria bassiana are also described in the context of host–pathogen interaction. Finally, the plasticity of G. mellonella immune response influenced by abiotic and biotic factors is described.     

从白蚁中分离到具有纤维素酶活的贪噬菌

以黄胸散白蚁Reticulitermes flaviceps后肠为材料,分离培养具有降解纤维素能力的微生物,以进一步了解白蚁后肠微生物的种类。通过以羧甲基纤维素钠(CMC-Na)为唯一碳源的富集及选择培养基培养、筛选,获得一株具有纤维素酶活的菌株R3063。形态学鉴定、革兰氏染色观察及16S rDNA基因序列分析表明该菌株属于贪噬菌(Variovorax sp.)。目前尚未见贪噬菌具有纤维素酶活的报道。     

昆虫几丁质酶及其在植物保护中的应用

本文从生理学、生物化学和分子生物学３个方面综述了昆虫几丁质酶的研究进展,并概述了它在害虫防治、主要是在抗虫育种中作为重要的基因源中的应用。e     

信息素在文物害虫防治中的应用与展望

文物害虫会对文物古建筑造成不可逆的破坏,因此害虫防治是文物保护的重要工作。随着博物馆引入有害生物综合防治(Integrated Pest Management, IPM)策略,博物馆的害虫防治也开始遵循“预防为主,防治结合”理念。昆虫体外信息素是IPM中重要的技术手段。该技术可对害虫进行监测与诱杀,有利于对害虫发生规律的研究与数量控制。且信息素具有用量少,不接触文物等优点。本文概述信息素的发展、种类与功能,整理了文物害虫信息素及其应用中的遇到的问题,并展望信息素的应用前景。     

Effects of Alpine land‐use changes: Soil macrofauna community revisited

Although soil invertebrates play a decisive role in maintaining ecosystem functioning, little is known about their structural composition in Alpine soils and how their abundances are affected by the currently ongoing land‐use changes. In this study, we re‐assessed the soil macrofauna community structure of managed and abandoned Alpine pastureland, which has already been evaluated 14 years earlier. Our results confirm clear shifts in the community composition after abandonment, in that (1) Chilopoda and Diplopoda were recorded almost exclusively on the abandoned sites, (2) Coleoptera larvae and Diptera larvae were more abundant on the abandoned than on the managed sites, whereas (3) Lumbricidae dominated on the managed sites. By revisiting managed and abandoned sites, we infer community patterns caused by abandonment such as changes in the epigeic earthworm community structure, and we discuss seasonal and sampling effects. Our case study improves the still limited understanding of spatio‐temporal biodiversity patterns of Alpine soil communities.     

里氏木霉与米根霉混合固态发酵产纤维素酶

以里氏木霉及米根霉单菌固态发酵为对象,考察不同混合发酵形式对里氏木霉与米根霉混合固态发酵产纤维素酶的影响。结果表明:同时接种里氏木霉与米根霉,试验考察的两菌种接种量比1∶1(以孢子个数计)及5∶1条件下,两菌未产生明显协同产酶作用。米根霉延时(24 h)接种且菌种量比5∶1以及米根霉延时(48 h)接种且菌种量比1∶1,2种发酵形式产酶情况类似,滤纸酶活(FPA)及羧甲基纤维素酶(CMCase)酶活相对米根霉单菌发酵有所提高,而β-葡萄糖苷酶(β-GA)酶活相对里氏木霉单菌固态发酵结束时分别增加4.66及4.40倍,可以发现两菌产生一定协同作用。在米根霉延时(48 h)接种且菌种量比5∶1的发酵形式下,FPA及CMCase在发酵第7天酶活分别达到44.04 IU/g、627.14 U/g(以1 g干曲计),分别是里氏木霉固态单菌发酵产酶达到稳定期时酶活的1.36和1.63倍,两菌产生了有效的协同作用。     

烟芽夜蛾囊泡病毒3h株编码的3H-117蛋白能干扰AcMNPV的口服活性

[目的]囊泡病毒是一类体液传播的昆虫病毒,具有特殊的致病历程和良好的生防应用潜力.烟芽夜蛾囊泡病毒3h株(Heliothis virescens ascovirus 3h,HvAV-3h)是我国分离的第一株囊泡病毒,其编码的3H-117蛋白被报道为HvAV-3h病毒粒子的结构蛋白.[方法]为了进一步探究3h-117基因...     

酶法制备功能性纤维低聚糖的研究

研究里氏木霉(Trichoderma reesei)Rut C30纤维素酶单一组分EGI、EGII和CBHI降解纤维素的机理及纤维低聚糖酶法制备技术,进而初步研究纤维低聚糖对青春双歧杆菌的增殖作用。以内切葡聚糖酶EGII酶法制备纤维低聚糖,每克纤维素最佳酶用量1 U,最佳酶解时间90 min,制备得到的纤维低聚糖中纤维二糖、纤维三糖和纤维四糖占总糖的比例分别为43.8%、34.8%和7.9%。以纤维二糖、纤维低聚糖为C源增殖青春双歧杆菌,菌体质量浓度增殖倍数分别为2.14、2.84。     

稻草秸秆预处理方法对烟曲霉产纤维素酶的影响

采用机械粉碎、高温、酸碱处理等方法对稻草秸秆进行预处理,以烟曲霉为实验菌株,研究预处理方法对菌株产纤维素酶的影响。结果表明,取机械粉碎后的稻草（30~120目）进行121℃高压蒸汽处理20min（即灭菌处理）,有利于菌株的生长与纤维素酶的产生;与未粉碎的稻草秸秆相比,烟曲霉羧甲基纤维素钠（CMC）酶、微晶纤维素酶、β-葡萄糖苷酶和滤纸（FPA）酶的活力分别提高了63.2%、164.0%、10.2%和14.1%。而采用不同种类、不同浓度的酸碱常温处理稻草秸秆4d或100℃高温处理30min,纤维素酶活力均出现了不同程度的下降。