The culturable leaf mycobiome of Viscum album subsp. austriacum

In Poland's pine forests, mistletoe (Viscum album subsp. austriacum) abundance has increased over the past 20 years. This mistletoe infestation has decreased the growth and vigour of Scots pine trees. In this study, we surveyed the culturable fungi from healthy and diseased V. album subsp. austriacum leaves from two stands in Poland. In total, 63 distinct species were identified, 99.8% of which belonged to the phylum Ascomycota. The community compositions of fungi in mistletoe leaves were similar in healthy and diseased leaves as Alternaria alternata, Aureobasidium pullulans, Botryosphaeria visci, Fusarium paeoniae and Microsphaeropsis olivacea were consistently found in leaves of all symptom types. The most frequently isolated fungus from asymptomatic leaves was M. olivacea, followed by A. alternata, A. pullulans and Hypoxylon rubiginosum. In comparison, the most frequently isolated fungi from leaves with rusty-brown necrotic spots were (in decreasing order) M. olivacea, B. visci, F. paeoniae and A. alternata, while the most frequently isolated fungi from leaves with black or dark brown spots were M. olivacea, A. alternata, A. pullulans, Epicoccum layuense and F. paeoniae. This study was the first comprehensive report showing that certain fungal species may be pathogens of V. album subsp. austriacum in Poland. This study was also the first report of F. paeoniae, F. juglandicola, Diaporthe vacuae and Heterotruncatella spartii from V. album, and the first report of D. vacuae and H. spartii in Poland.     

苯酚—硫酸法测定普鲁兰含量

苯酚—硫酸法是测定多糖的常用方法,其基本原理是:选用乙醇除去样品中的单糖、低聚糖等干扰成分,然后用去离子水提取样品中所含的多糖类成分。多糖在浓硫酸作用下,水解成单糖,并迅速脱水生成糠醛衍生物,与苯酚缩合成有色化合物,然后用比色法测定其多糖含量。选用苯酚—硫酸法进行普鲁兰多糖测定条件的研究,获得最佳测定条件为:水浴时间15min,水浴温度100℃,浓硫酸5.0mL,苯酚1.0mL,放置时间5min。     

土豆淀粉废水发酵普鲁兰多糖的研究

普鲁兰多糖是一种具有重要应用价值的微生物胞外多糖。淀粉废水是加工淀粉过程中不可避免的一种产物,成份复杂,营养丰富。利用淀粉废水作为碳源制得普鲁兰多糖,不仅使多糖的生产成本降低,变废为宝,还会减少环境污染。本文通过比较实验获得用土豆淀粉废水(potato starch waste)制多糖产率高于其它碳源,并且确定最佳发酵培养基为(%):土豆淀粉废水10,KH2PO40.6 NaCL0.2(NH4)2SO40.08。     

Evaluation of Microbial Antagonists for Biological Control of Botrytis cinerea Stem Infection in Cucumber and Tomato

Of fifteen isolates of yeasts, filamentous fungi and bacteria and a commercial product, tested in a bioassay with stem segments, eleven isolates consistently reduced incidence of disease and sporulation of Botrytis cinerea Pers; Fr in tomato and seven isolates in cucumber. Several isolates reduced disease by more than 75% in all experiments. Six antagonists that performed well in the bioassays and that were fairly easy to produce in vitro, were selected for further testing in two glasshouse experiments with cucumbers. After application of spores of B. cinerea and the antagonists or the fungicide tolylfluanid to pruning wounds, disease incidence was reduced by 50–100% by all antagonists in both experiments and only in one experiment by tolylfluanid.For Trichoderma harzianum T39, Aureobasidium pullulans and Cryptococcus albidus, biological control efficacy in bioassays with cucumber stem segments was not strongly influenced by temperatures in the range between 18 and 30°C, but at 24°C the efficacy of the three antagonists strongly decreased at relative humidities of 90% and 80% (vapour pressure deficits 0.299 and 0.598kPa, respectively) compared to 100.     

出芽短梗霉（Aureobasidium pullulans）生物合成普鲁兰多糖的研究进展

普鲁兰多糖是由出芽短梗霉(A ureobasidium pullulans)发酵产生的一种胞外多糖,其特殊的结构赋予了它许多优良的理化性质,广泛应用于食品、制药、化工、石油及其他制造业.在普鲁兰多糖生物合成过程中,普鲁兰多糖的化学结构、产率及颜色的深浅等受到多种营养条件和环境因素的影响.介绍了普鲁兰多糖的结构、性质,重点综述了国内外学者对发酵条件优化的研究现状,最后总结了普鲁兰多糖生物合成研究的发展方向.     

出芽短梗霉菌菌株PA-2的除草活性及对作物的安全性

从青海省平安县发病杨树叶片上分离得到菌株 PA-2,其发酵滤液对多种阔叶杂草表现出较好的除草活性。对该菌株的培养特征和16S rDNA基因序列分析后,确定其为短梗霉属出芽短梗霉菌Aureobasidium pullulans。盆栽试验表明,其发酵滤液对供试阔叶杂草猪殃殃、藜、冬葵、酸模叶蓼及禾本科野燕麦的鲜重防效分别达到87.25%、78.46%、82.25%、62.11%、80.27%。作物安全性试验结果表明,其发酵滤液对小麦、蚕豆、青稞很安全,对油菜、豌豆有轻微影响。综上所述,菌株 PA-2具有作为微生物除草剂的开发潜力。     

Endophytische Pilze in Blättern und Zweigen von Quercus petraea

Endophytic fungi in leaves and twigs of Quercus petraea . Surface sterilized leaf and twig samples taken in 1989 from sessile oak (Quercus petraea) in Austria yielded host-specific as well as unspecific ubiquistic endophytes. In leaves, Aureobasidium apocryptum and Apiognomonia quercina were the most frequent taxa, while Colpoma quercinum was the dominant species in twigs. The colonization rates of individual species were subjected to seasonal variation.     

出芽短梗霉菌PA-2脂肽类物质抑菌活性及其发酵条件优化

探究出芽短梗霉菌(Aureobasidium pullulans)PA-2脂肽类物质的抑菌活性,并以脂肽类物质的产量为响应值对其发酵条件进行优化,为脂肽类物质的生产与应用奠定理论基础。采用酸沉淀法对脂肽类物质进行粗提,通过原位酸水解-茚三酮显色法对脂肽粗提物进行定性检测,并用琼脂打孔扩散法对其抑菌活性进行测定,通过中心组合设计(central composite design,CCD)构建响应面对其发酵条件进行优化。最终初步判定粗提物为环状脂肽类物质;该物质对金黄色葡萄球菌(Staphylococcus aureus)、酿酒酵母菌(Saccharomyces cerevisiae)、大肠埃希菌(Escherichia coli)、樱桃球腔菌(Mycosphaerella cerasella)和大麦网斑病(Pyrenophora teres)具有明显的抑制作用,抑菌圈分别为3.65、1.95、2.15、1.35、2.18 cm;优化后的最适发酵条件为:接种量6.8%、转速216 r·min ^-1、温度26 ℃、装液量125 mL、pH 7。在此条件下模型预测的脂肽类物质产量为0.94 g·L ^-1,实际为0.92 g·L ^-1,比优化前的产量(0.61 g·L ^-1)提高了51%。优化后的发酵条件可提高脂肽类物质产量,降低发酵成本,可用于上述有抑制效果的菌株防治。     

出芽短梗霉及其生物产品研究进展

出芽短梗霉是一类具有典型细胞多形性的腐生真菌,不同的出芽短梗霉能产生胞外多聚糖类、胞外酶类及黑色素、聚苹果酸、嗜铁素等发酵产物,可广泛应用于医药、食品、生物防治、化妆品和烟草工业等众多领域。本文综述了出芽短梗霉及其生物产品的研究进展,展望今后通过全基因测序,找到更多出芽短梗霉的新基因与生物产品。     

辽宁省玉米北方炭疽病菌的分离鉴定及生物学特性

为明确辽宁省疽病的致病菌及其生物学特性,通过形态学和分子生物学方法鉴定了致病菌,并利用十字交叉法和血球计数板计数法研究了致病菌的生物学特性。系统发育树显示,分离菌株SYND-12与出芽短梗霉Aureobasidium pullulans亲缘关系最近,位于同一分支,并与玉蜀黍出芽短梗霉Aureobasidium zeae聚为一类,分子鉴定结果与形态学鉴定结果一致,表明引起辽宁省玉米北方炭疽病的致病菌为玉蜀黍出芽短梗霉A.zeae(Narita et Hiratsuka)Dingley。该病菌菌丝生长温度范围为10~30℃,最适温度为25℃,最适p H为7,光照条件为全黑暗,适宜的碳、氮源和培养基分别为蔗糖、硝酸钾和马铃薯葡萄糖琼脂培养基;其分生孢子产生的最适碳源为葡萄糖,其它最适宜生长条件与菌丝相同,该病菌在添加不同氮源的水琼脂培养基中均不产生分生孢子;其分生孢子萌发的最适条件为28℃、p H 8、光暗交替,最适碳、氮源分别为麦芽糖和牛肉膏,单一氮源条件对分生孢子的萌发有抑制作用。