地衣芽孢杆菌对实验性家兔阴道炎金葡菌的消除作用

本文以地衣芽孢杆菌菌液对实验性家兔金葡萄感染阴道炎进行治疗,观察把衣芽孢杆菌对阴道内葡菌的消除作用。结果表明,地衣芽孢杆菌对金黄色葡萄球菌有明确的消除作用,可逆转由金葡菌引起的阴道感染性炎症。     

地衣芽孢杆菌WL1菌株质粒的初步研究

地衣芽孢杆菌是一种较为重要的工业生产菌,现在发现它的染色体DNA与枯草芽孢杆菌有24％的同源性,用地衣芽孢杆菌噬菌体SP-15进行转导和其它方法建立了它的遗传图,发现与枯草芽孢杆菌的遗传图也十分相近。由此可见,它不仅是一个很有开发潜力的工业生产菌,而且也可能成为重要的遗传学材料。目前,在大肠杆菌和枯草芽孢杆菌之间的基因转     

苏芸金杆菌伴孢晶体和芽孢孢衣的蛋白质组分及其与毒力的关系

研究了苏芸金杆菌(Bacillus thuringiensis)3个变种6个菌株的提纯伴孢晶体和芽孢对大蜡螟(Galleria mellonella)和大菜粉蝶(Pieris brassicae)的毒力、晶体的蛋白质和多肽成分及芽孢衣中的类晶体蛋白质成分.生物测定表明,晶体毒力高于芽孢,在总数量相同的情况下,晶体和芽孢近1:1的混合物的毒力高于单独的晶体或芽孢.芽孢衣中存在一种类似晶体蛋白质的成分,无晶体突变株及无效野生株的芽孢则无此种蛋白质且对两种昆虫无毒.变种wuhanensis和变种galleriae的晶体含MW138000的主要蛋白质和63000的次要蛋白质,经碱性缓冲液溶解后,上清液含MW138000的蛋白质,沉淀中含MW63000的蛋白质;变种aizawai的晶体中仅含138000的蛋白质.对大蜡螟无毒的HD-11(var.aizawai)晶体的蛋白质成分有别于上述晶体,其胰蛋白酶消化物的SDS凝胶电泳图型显示少2条多肽带,但对大菜粉蝶仍有效.结果表明,苏芸金杆菌的芽孢在昆虫病理中有重要作用,伴孢晶体的蛋白质和多肽成分与它们对昆虫的毒力特性之间有密切关系.     

武夷山地衣表生和内生芽孢杆菌种群的多样性

摘要:【目的】分析武夷山地衣表生和内生芽孢杆菌种群的多样性。【方法】从武夷山自然保护区采集扁枝衣属(Evernia)、珊瑚枝属(Stereocaulon)、孔叶衣属(Menegazzia)等分属于7科9属的地衣样品9份,分离地衣表面附生(表生)和内生芽孢杆菌,并根据16S rRNA基因序列同源性对分离得到的芽孢杆菌进行种的鉴定。【结果】未从扁枝衣属、树花属(Ramalina)和茶渍属(Lecanora)的3个样品中分离出表生或内生芽孢杆菌,从另外6个样品中分离出芽孢杆菌34株,分别鉴定为芽孢杆菌属(Bacillus)、类芽孢杆菌属(Paenibacillus)、短芽孢杆菌属(Brevibacillus)、赖氨酸芽孢杆菌属(Lysinibacillus)和绿芽孢杆菌属(Viridiibacillus)的24个种。类芽孢杆菌属、芽孢杆菌属是这些地衣表生、内生芽孢杆菌的优势种群,分别占分离得到菌株的41.2%(14株)和35.3%(12株);短芽孢杆菌属、赖氨酸芽孢杆菌属和绿芽孢杆菌属为首次报道从地衣中分离获得。从不同的地衣样品分离的表生和内生芽孢杆菌的种类、数量存在差异。蜈蚣衣属(Physcia)表生的芽孢杆菌数量最多、可达3.85×106 cfu/g,而珊瑚枝属表面附生和内生芽孢杆菌的种类最多、共有12个种。分离到的芽孢杆菌大部分来自单独的一种地衣;台中类芽孢杆菌(Paenibacillus taichungensis)、土壤短芽孢杆菌(Brevibacillus agri)等4个种存在于2－3种地衣中;蕈状芽孢杆菌(Bacillus mycoides)分布最广,在蜈蚣衣属、珊瑚枝属等4种地衣中都有存在。【结论】武夷山地衣表生和内生芽孢杆菌存在种类和数量的多样性。     

雪茄茄衣人工发酵过程中叶面微生物区系研究

在恒温恒湿箱内对海南光村茄衣发酵42 d,并对整个过程中烟叶表面微生物进行分离、纯化和鉴定,研究探讨了茄衣人工发酵过程中叶面微生物区系的变化。结果显示:在茄衣人工发酵过程中细菌为优势菌群,霉菌所占比例很小,没有检测出放线菌和酵母菌;所有细菌均为芽孢杆菌,数量由高到低依次是:巨大芽孢杆菌枯草芽孢杆菌蜡状芽孢杆菌环状芽孢杆菌蕈状芽孢杆菌嗜热脂肪芽孢杆菌短小芽孢杆菌凝结芽孢杆菌;茄衣表面各菌种数量在发酵过程前24 d内呈急剧下降趋势;巨大芽孢杆菌和枯草芽孢杆菌为雪茄茄衣人工发酵中的优势菌种,分别占芽孢杆菌数量的50%以上和19%左右。     

PspA外源表达对枯草芽孢杆菌168蛋白质分泌的影响

PspA同源物广泛存在于细菌和高等生物的组织中.在本研究中克隆了来源于地衣芽孢杆菌的PspA基因,并将其克隆于用于大肠-芽孢穿梭诱导表达载体pDG-StuI中构建重组质粒pDG-PspA.将构建的诱导表达型的重组质粒转化到Bacillus subtilis 168中,研究PspA的外源表达对该菌的生长,总蛋白分泌,以及Sec分泌途径中α-淀粉酶分泌的影响,结果表明,PspA基因的外源表达,在发酵过程后期能在一定程度上提高总蛋白的分泌量,在发酵过程后期能在一定程度上提高分泌的α-淀粉酶浓度.     

化学助剂对苏云金芽孢杆菌的影响及新型悬乳剂的研制

研究了由乳化剂、湿润剂、防腐剂和少量氯氰菊醴配制的几种乳剂组合对苏云金芽孢杆菌芽孢和伴孢晶体的影响及所形成的悬乳剂的稳定性。分析了不同化学助剂组合与孢晶混合物在不同贮存期的毒力变化、晶体蛋白质的降解及芽孢存活率。从供试的助剂组合中获得了一种最佳组合,可发展为一种新型的苏云金杆菌悬乳剂。     

蜡状芽孢杆菌LW9809芽孢生成条件及发酵代谢产物研究

对影响蜡状芽孢杆菌 (Bacilluscereus)LW 980 9的芽孢生成条件进行了研究 ,确定了影响芽孢生成的主要因素。对其代谢产物进行了分析测定 ,为合理应用微生态制剂提供了理论依据。     

苏云金芽孢杆菌转座因子研究进展

近年来的研究发现苏云金芽孢杆菌转座因子和许多毒力因子可能是紧密联系的。由于转座因子的特殊性质,使它们在现代农业生物技术中有着广泛的应用前景,科学家对苏云金芽孢杆菌转座因子的研究也在不断深入。本文主要针对苏云金芽孢杆菌转座因子的研究进展进行综述,并对发展前景进行展望。     

枯草芽孢杆菌形成芽孢时母细胞中基因表达的调控

枯草芽孢杆菌是典型的模式微生物,其芽孢形成过程一直是细胞分化领域研究的热点,近年来取得了重大进展。其形成芽孢时,细胞进行不对称分裂而产生两个子细胞:前芽孢(forespore)和母细胞(mother cell),它们的基因表达程序是完全不同的,但又相互影响。枯草芽孢杆菌被广泛应用于各种酶的生产,这些酶主要是在母细胞中合成。该文综述了母细胞中基因表达的调控机制。母细胞中基因表达的变化是由母细胞特异性转录因子Spo0A、σE和σK调控的。     

Spore germination

The germination of dormant spores of Bacillus species is the first crucial step in the return of spores to vegetative growth, and is induced by nutrients and a variety of non-nutrient agents. Nutrient germinants bind to receptors in the spore's inner membrane and this interaction triggers the release of the spore core's huge depot of dipicolinic acid and cations, and replacement of these components by water. These latter events trigger the hydrolysis of the spore's peptidoglycan cortex by either of two redundant enzymes in B. subtilis, and completion of cortex hydrolysis and subsequent germ cell wall expansion allows full spore core hydration and resumption of spore metabolism and macromolecular synthesis.     

Spore probiotics

Data on probiotic preparations prepared from spore-forming bacteria is reviewed. Information on indications for use, effectiveness and the mechanism of action is given. Preparations being produced in Russia (Biosporin, Sporobacterin and Bactosporin) are evaluated in detail as well as the prospects of the application of probiotics from spore-forming bacteria.     

Microsporidian Spore Envelope Keratins Phosphorylate and Disassemble During Spore Activation

The microsporidian spore stage of the nerve parasite, Spraguea lophii, consists of outer envelope stabilized in part by keratins, including K4 and K13. The nonepidermal K4 and K13 keratins were found only in the spore envelope and were absent in the internal microsporidian sporoplasm. At the time of spore activation, the keratin-based outer spore envelope assemblage dissociated and became phosphorylated when the spores were placed in the presence of labeled ATP. Verapamil or lanthanum, agents which block S. lophii spore activation, also blocked spore envelope keratin disassembly and phosphorylation when the spores were incubated in activation medium with labeled ATP. However, after the removal of the verapamil or lanthanum, the spores regained the capacity to activate in discharge medium and the keratin analogues appeared to dissociate and phosphorylate.     

Spore productivity in Cladosporium

The high incidence ofCladosporia in the airspora indicates a prolific production of spores. Six species ofCladosporium were sampled over a period of 9 weeks, using dry and wet (mist-laden) air, and over a period of 4 weeks using humid air. Many more spores were released in wet air than in dry air: numbers released in humid air were generally intermediate between those of wet and dry samples. None of the cultures was exhausted of spores at the end of the sampling periods although samples generally decreased in size from the fifth or sixth week onwards. Removal of spores would seem to be conducive to further sporulation provided the substrate is not exhausted. Maximum productivities recorded for the six species (all in mist-laden air) ranged from 730 to 26 100 spores per mg dry weight of mycelium. Differences in the levels of spore production in culture by the six species do not correlate with their individual frequencies in the airspora, indicating that the latter are more dependent on the distribution and substrate relationships of each species.     

Bacillus subtilis Spore Coat

In response to starvation, bacilli and clostridia undergo a specialized program of development that results in the production of a highly resistant dormant cell type known as the spore. A proteinacious shell, called the coat, encases the spore and plays a major role in spore survival. The coat is composed of over 25 polypeptide species, organized into several morphologically distinct layers. The mechanisms that guide coat assembly have been largely unknown until recently. We now know that proper formation of the coat relies on the genetic program that guides the synthesis of spore components during development as well as on morphogenetic proteins dedicated to coat assembly. Over 20 structural and morphogenetic genes have been cloned. In this review, we consider the contributions of the known coat and morphogenetic proteins to coat function and assembly. We present a model that describes how morphogenetic proteins direct coat assembly to the specific subcellular site of the nascent spore surface and how they establish the coat layers. We also discuss the importance of posttranslational processing of coat proteins in coat morphogenesis. Finally, we review some of the major outstanding questions in the field.     

Spore Discharge in Basidiomycetes: III. Spore Liberation from Narrow Hymenial Tubes

The hymenial tubes of Polyporus betulinus were shown to be approximatelycylindrical,and to have a sporulating hymenium over the greater part oftheir surface. Sporophores were tilted through measured anglesfrom the vertical in the field and in the laboratory, and theeffect on spore liberation was measured by determining the numberof spores liberated from particular tubes in standard time.All tilting caused a reduction in spore liberation. The amountof this reduction was found to compare closely with that predictedfrom calculation of the amount of hymenium lying directly abovethe orifice at various angles of tilt. It is therefore concludedthat liberation from the tube can be accounted for by the initialviolent discharge of the spore and gravitational attractionalone. An addendum corrects an earlier paper (1959) in thisseries. It shows that the variation in density of spore depositscollected from Trametes gibbosa was due to air currents in theapparatus, not to variation in sporulation rate.