糖多孢菌属的多相分类

在糖多孢菌属的分类学研究中,最初是根据形态特征、培养特征及生理生化特征等表观分类学指征进行研究。随着“多相分类”方法的广泛应用,化学分类和分子分类在糖多孢菌属的分类学研究中起到越来越重要的作用。糖多孢菌是寻找新的生物活性物质的重要菌源,某些种能产生重要的生物活性物质,如抗生素、酶类、维生素、藻类促生长因子、纤维素降解促进因子、免疫抑制剂等。     

高温放线菌属分类研究进展

高温放线菌属(Thermoactinomyces)于1899年由Tsiklinsky首次描述^[1]。它是20世纪前人类所发现的为数不多的几个放线菌属之一。这个属的特征是在高温下生长快,在气丝和基丝上均有单个孢子形成,存在内生孢子的结构和特性,革兰氏染色不定,细胞壁含meso—DAP(III型),无特征性糖(糖类型G)。常见于自然界的高温场所,如堆肥、稻草、甘蔗渣等。有抗性的孢子可在土壤、水或海洋基质中存活^[2-6]。     

小单孢菌属的一个新种

从云南省丽江地区的高寒山区采集的土样中分离到两株小单孢菌Y81—917和Y81一558。它们不产生气生菌丝体。基内菌丝体蓝色。产生蓝色可扩散色素。孢子单个着生,表面皱褶。细胞壁化学组分II型。它们与所有已知的小单孢菌都不同,认为是小单孢菌属中的一个新种,定名为玉龙小单孢菌(Micromonospora yulongensis n. sp.),菌株Y81-917为模式株。     

小单孢菌属的分类及应用研究

小单孢菌在自然界分布广泛,但由于分离、分类方法所限,绝大多数还没有被人们所认识。在小单孢菌的分类学研究中,最初主要依据的是形态特征、培养特征及生理生化特征等表观分类学指征,随着“多相分类”的广泛应用,分子分类在小单孢菌的分类学研究中起到了越来越重要的作用。小单孢菌是寻找新的生物活性物质的重要菌源,某些种能产生抗生素,如庆大霉素、利福霉素、新霉素等;某些种能降解天然橡胶和纤维素。近年来的研究表明,小单孢菌能产生具有独特化学结构的生物活性物质,对肿瘤细胞有靶向和识别作用,并能有效地杀死肿瘤细胞。     

中国单格孢属分类研究Ⅰ

匍柄霉属1个新种和1个新记录种,新种是矩卵单格孢Ulocladium oblongo-obovoideum,新记录种是倒卵单格孢U.obovoideum。新种的模式标本和新记录种的标本保存于山东农业大学植物病理系标本室（HSAUP）。     

PCR-SSCP技术在嗜盐放线菌链单孢菌属快速筛选中的应用

为提高嗜盐放线茵的研究效率,快速、准确的从大量分离菌株中去除重复菌株、筛选出目的菌株,在特异性引物快速定属的基础上,以嗜盐放线茵链单孢茵属的34株菌株为研究对象,采用与PCR相结合的单链构象多态性分析(PCR-SSCP),扩增出16S rRNA基因中的两个高变区,根据结果对34株菌株进行聚类分析,并将其16S rRNA基因片段测序予以验证.结果表明,聚类后34株菌株可大致分为3类,且与16S rRNA基因片段分析结果一致.从而可快速去除重复菌株并反映出菌株间的系统进化关系.同时实验数据可构建成库,使后续分离菌株的筛选工作只需比对数据即可完成,利于提高工作效率,降低实验成本.     

尾孢菌属和假尾孢属新记录种

报道中国尾孢菌属和假尾孢属3个新记录种,寄生在波状补血草Limonium sinuatum上的海岛尾孢Cercospora insulana,寄生在夹竹桃Nerium indicum上的来间岛假尾孢Pseudocercospora kurimensis和匍匐假尾孢P.repens。提供了形态描述和绘图。研究的标本保存在中国科学院菌物标本馆(HMAS)。     

Amylolytic activity of Thermomonospora fusca

Amylases which produce maltotriose as the major end-product from starch are relatively rare. The thermophilic actinomycete, Thermomonospora fusca, produced an extracellular -amylase which generated maltotriose as 61% of the identified products. The addition of maltotriose to a glucose-adapted exponential phase culture at 55°C in mineral salts medium caused rapid induction of amylase biosynthesis. Addition of glucose to cells growing on starch did not repress amylase biosynthesis because the actinomycete had a marked preference for maltotriose over glucose. The pH and temperature optima for the amylase activity of concentrated, washed extracellular protein were 6.0 and 65°C, respectively, with an energy of activation of 59kJ/mol. The thermostability of the concentrated, washed amylase was increased by the presence of its starch reaction products, but not by added Ca2+.     

Effects of the detergent Tween 80 on Thermomonospora curvata

Tween 80 (0.1%, v/v) added to Thermomonospora curvata growing in minimal medium caused a transient lowering of the dry cell mass, decreased the optimal growth temperature of the thermophile from 62 to 54°C, and increased extracellular esterase activity. Cells grown in the presence of Tween 80 had decreased concentrations of branched chain fatty acids and increased concentrations of oleic acid. The detergent removed surface protuberances from mycelia and increased the liberation of enzymes active against crystalline cellulose, but did not stimulate liberation of enzymes active against carboxymethylcellulose, starch or pectin.     

Application of cellulases from an alkalothermophilic Thermomonospora sp. in biopolishing of denims

Use of cellulase for denim washing is a standard eco-friendly technique to achieve desirable appearance and softness for cotton fabrics and denims. But enzymatic washing of denim till date involved acid cellulase (Trichoderma reesei) and neutral cellulase (Humicola isolens) the use of which has a drawback of backstaining of the indigo dye on to the fabric. Though it has been suggested that pH is a major factor in controlling backstaining there are no reports on use of cellulase under alkaline conditions for denim washing. In this study for the first time an alkali stable endoglucanase from alkalothermophilic Thermomonospora sp. (T-EG) has been used for denim biofinishing under alkaline conditions. T-EG is effective in removing hairiness with negligible weight loss and imparting softness to the fabric. Higher abrasive activity with lower backstaining was a preferred property for denim biofinishing exhibited by T-EG. The activities were comparable to acid and neutral cellulases that are being regularly used. The enzyme was also effective under non-buffering conditions which is an added advantage for use in textile industry. A probable mechanism of enzymatic finishing of cotton fabric has been represented based on the unique properties of T-EG.     

1株喜盐Actinopolyspora菌属新种的系统分类

1株嗜盐、产丝放线菌新种TRM4064分离自四川大英盐湖。它的分类地位通过多相分类技术被证明。16S rRNA基因序列系统发育分析表明:菌株TRM4064在多孢放线菌属中形成一个独立的分支单元,同近缘物种Actinopolyspora mortivallis的同源性为98.8%,与它的DNA-DNA杂交值为23.2%,同Actinopolyspora菌属另外有效命名物种的相似性小于97%。菌株TRM4064的最适生长温度是37℃,最适生长pH为7.0,最适生长盐浓度为13%;细胞水解糖为木糖、葡萄糖、核糖和阿拉伯糖,主要的醌型是MK-10(H4)(38.2%)、MK-9(H4)(25.1%)、MK-9(H2)(28.6%)和MK-8(H4)(7.3%),主要的脂肪酸是anteiso-C17:0(36.9%)和iso-C17:0(19.3%),细胞磷脂是心磷脂、磷脂酰甘油、卵磷脂、磷脂酰肌醇和2个未知的磷脂类型。综合其表型、化学型及其分子遗传学等指标表明菌株TRM4064为多孢放线菌属的一个新成员。     

高温放线菌分类的研究进展

回顾了高温放线菌的分类历史、分类地位的变化,阐述了高温放线菌的最新分类研究进展,并描述了高温放线菌5个属的特征和各自的模式菌株。     

葡糖杆菌属分类及其主要应用的研究进展

葡糖杆菌是醋酸菌科的一个重要属,与人类关系密切,该属中部分菌株在维生素C、米格列醇的工业生产及合成中起着重要作用;此外,该属菌株还能氧化葡萄糖生成葡糖酸盐和酮基葡糖酸等工业重要中间体。综述了葡糖杆菌的研究进展,主要介绍了葡糖杆菌的生理生化特征、分类进展及其主要应用,可以为广大醋酸菌研究者提供参考。     

Fragmentation of cellulose by the major Thermomonospora fusca cellulases, Trichoderma reesei CBHI, and their mixtures

In this study, the fragmentation activities of Thermomonospora fusca cellulases E(2), E(3), E(5), Trichoderma reesei CBHI, and their mixtures were measured to study synergism in fragmentation. Fragmentation studies revealed that only two pure cellulases, T. fusca E(2) and E(5) had significant fragmentation activity. T. fusca E(3) shows strong synergism in fragmentation both in the production of reducing sugars and in fragmentation with both T. fusca endoglucananses and with T. reesei CBHI. Most mixtures containing CBHI produced higher rates of fragmentation than comparable mixtures containing E(3). The highest rate and extent of reducing sugar formation and the highest fragmentation activity were obtained with a mixture of E(2), E(3), and CBHI. (c) 1992 John Wiley & Sons, Inc.     

Co-operative actions and degradation analysis of purified xylan-degrading enzymes from Thermomonospora fusca BD25 on oat-spelt xylan

AIMS: To determine and quantify the products from the degradation of xylan by a range of purified xylan-degrading enzymes, endoxylanase, beta-xylosidase and alpha-l-arabinofuranosidase produced extracellularly by Thermomonospora fusca BD25. METHODS AND RESULTS: The amounts of reducing sugars released from oat-spelt xylan by the actions of endoxylanase, beta-xylosidase and alpha-l-arabinofuranosidase were equal to 28.1, 4.6 and 7% hydrolysis (as xylose equivalents) of the substrate used, respectively. However, addition of beta-xylosidase and alpha-l-arabinofuranosidase preparation to endoxylanase significantly enhanced (70 and 20% respectively) the action of endoxylanase on the substrate. The combination of purified endoxylanase, beta-xylosidase and alpha-l-arabinofuranosidase preparations produced a greater sugar yield (58.6% hydrolysis) and enhanced the total reducing sugar yield by around 50%. The main xylooligosaccharide products released using the action of endoxylanase alone on oat-spelt xylan were identified as xylobiose and xylopentose. alpha-l-Arabinofuranosidase was able to release arabinose and xylobiose from oat-spelt xylan. In the presence of all three purified enzymes the hydrolysis products of oat-spelt xylan were mainly xylose, arabinose and substituted xylotetrose with lesser amount of substituted xylotriose. CONCLUSIONS: The addition of the beta-xylosidase and alpha-l-arabinofuranosidase enzymes to purified xylanases more than doubled the degradation of xylan from 28 to 58% of the total substrate with xylose and arabinose being the major sugars produced. SIGNIFICANCE AND IMPACT OF THE STUDY: The results highlight the role of xylan de-branching enzymes in the degradation of xylan and suggest that the use of enzyme cocktails may significantly improve the hydrolysis of xylan in industrial processes.     

60Coγ射线诱变褐色高温单孢菌及其在粪便发酵中的应用研究

本试验以褐色高温单孢菌(Therm om onospora fusca)为出发菌株,通过60Coγ射线诱变孢子悬液,采用透明圈法初筛和摇瓶培养复筛的方法,获得了一株纤维素酶高产菌株AV5,与出发菌株相比,其产酶能力提高1.8倍。接种牛粪发酵后,牛粪中粗纤维含量降低率为32.95%,是接种出发菌株相对降解率的1.7倍。     

Intraclass Evolution and Classification of the Colpodea (Ciliophora)

ABSTRACT. Using nine new taxa and statistical inferences based on morphological and molecular data, we analyze the evolution within the class Colpodea. The molecular and cladistic analyses show four well‐supported clades: platyophryids, bursariomorphids, cyrtolophosidids, and colpodids. There is a widespread occurrence of homoplasies, affecting even conspicuous morphological characteristics, e.g. the inclusion of the micronucleus in the perinuclear space of the macronucleus. The most distinct changes in the morphological classification are the lack of a basal divergence into two subclasses and the split of the cyrtolophosidids into two main clades, differing mainly by the presence vs. absence of an oral cavity. The most complex clade is that of the colpodids. We partially reconcile the morphological and molecular data using evolutionary systematics, providing a scenario in which the colpodids evolved from a Bardeliella‐like ancestor and the genus Colpoda performed an intense adaptive radiation, giving rise to three main clades: Colpodina n. subord., Grossglockneriina, and Bryophryina. Three new taxa are established: Colpodina n. subord., Tillinidae n. fam., and Ottowphryidae n. fam. Colpodean evolution and classification are far from being understood because sequences are lacking for most species and half of their diversity is possibly undescribed.