短梗霉产liamocins研究进展

短梗霉真菌（Aureobasidium spp.）是一种世界性的酵母样真菌,因其产生黑色素而被称为黑酵母。短梗霉的许多菌株都能分泌细胞外脂质liamocins。Liamocins具有表面活性、良好的抗癌和抗菌活性。本文综述了分泌liamocins的短梗霉的多样性及影响其产生liamocins的因素,总结了liamocins生物合成途径的研究进展,并对短梗霉真菌合成liamocins的进一步研究提出了建议。     

ε-多聚赖氨酸和谷胱甘肽影响抗真菌药物对烟曲霉作用效果

为了解多肽ε-多聚赖氨酸和谷胱甘肽对常见抗真菌药物体外抗人类病原真菌烟曲霉效果的影响,利用平板点菌实验、最低抑菌浓度实验中的微量液基法和E-test法,以及ROS检测等方法研究ε-多聚赖氨酸和谷胱甘肽在抗真菌药物体外抗烟曲霉过程中的作用以及可能的作用机制。通过基因定点敲除谷胱甘肽合成酶基因gcsA和gshA观察细胞内谷胱甘肽对于烟曲霉生长的重要性。结果显示,ε-多聚赖氨酸与抗真菌药物尤其是卡泊芬净和伊曲康唑呈协同作用;而谷胱甘肽则能够明显地拮抗伊曲康唑和卡泊芬净的抗烟曲霉作用。ε-多聚赖氨酸与伊曲康唑联用时菌体内的ROS含量比单独使用伊曲康唑时显著增多,而谷胱甘肽与伊曲康唑联用时菌体内的ROS含量比伊曲康唑单独使用时减少。基因敲除实验结果显示γ-L-谷氨酰-L-半胱氨酸合成酶基因gcsA为烟曲霉生长必需基因,而谷胱甘肽合成酶基因gshA对生长没有明显影响。结果表明,ε-多聚赖氨酸与谷胱甘肽影响了伊曲康唑和卡泊芬净对烟曲霉的作用。ε-多聚赖氨酸通过促进伊曲康唑刺激细胞产生ROS诱导烟曲霉死亡从而实现协同作用。谷胱甘肽为细胞内必需还原型多肽,通过消除胞内伊曲康唑诱导产生的ROS从而产生拮抗作用。     

植物病原真菌1,8-间苯二酚黑色素研究进展

黑色素是一种广泛分布于生物体中的酚类聚合物疏水色素,分为1,8-间苯二酚(1,8-dihydroxynaphthalene,DHN)黑色素和3,4-二羟基苯丙氨酸(3,4-dihydroxyphenylalanine,L-DOPA)黑色素两种,其中DHN黑色素多存在于子囊菌门的植物病原真菌中。基因组和转录组技术的发展及功能基因组研究的深入,使DHN黑色素合成途径上关键基因在不同病原真菌中被鉴定,而且黑色素与真菌抗逆、发育和致病的关系受到越来越多的关注。本文阐述了DHN黑色素合成途径及其在真菌抗辐射与抗极端温度中的作用,以及黑色素对真菌侵染和细胞发育的影响,旨在加深人们对黑色素介导真菌与环境和寄主协同进化的认识,这对黑色素的基础研究和开发利用具有重要意义。     

条件致病真菌烟曲霉麦角甾醇合成通路遗传调控机制研究进展

环境中普遍存在的腐生性条件致病真菌——烟曲霉是引起人类侵袭性曲霉病的重要病原,因此,研究烟曲霉的致病机理,开发有效的治疗药物是全球关注的热点。麦角甾醇是真菌细胞膜的主要成分,参与细胞内许多生物学过程,麦角甾醇合成通路中的羊毛甾醇14-α-去甲基化酶Erg11A (Cyp51A同源蛋白)是抗曲霉病唑类药物的重要靶点,其受到转录因子Srb A与CCAAT结合复合物(CBC)的协同调控作用。文中阐述了主要的抗真菌药物以及抗真菌唑类药物的作用靶点-麦角甾醇及其合成途径的遗传调控机制的研究进展,同时分析了烟曲霉产生抗性的机制,期望为认识烟曲霉耐药产生和研发新型抗真菌药物提供帮助。     

山西省不同地区柴胡根部可培养内生真菌的多样性分析

为研究柴胡（Bupleurum chinense DC.）根部可培养内生真菌的多样性，分析山西省不同地区柴胡根部可培养内生真菌多样性的差异性，建立柴胡根部内生真菌库。本文以山西省不同产地的柴胡根为材料，采用传统植物组织平板分离法对柴胡根部可培养内生真菌进行分离培养和分子鉴定。从25个不同产地的柴胡样品根部中共分离培养得到705株真菌，经分子生物学鉴定，其中695株真菌归属为4门14纲23目32科55属119种。晋南地区的优势菌属为镰刀菌属（Fusarium, 32.18%）、亚隔孢壳属（Didymella, 15.96%）、曲霉属（Aspergillus, 8.24%）、异茎点霉属（Paraphoma, 6.91%）、茎点球属（Phoma, 5.32%）、链格孢属（Alternaria, 5.05%），晋北地区的优势菌属为镰刀菌属（31.66%）、曲霉属（15.36%）、链格孢属（9.09%）、亚隔孢壳属（8.15%）、异茎点霉属（7.52%），亚隔孢壳属、曲霉属、链格孢属等优势属的相对丰度差异较大；晋南地区的优势物种为Didymella bellidis（11.44%）、三线镰刀菌（Fusarium tricinctum, 7.98%）、腐皮镰刀菌（Fusarium solani, 7.45%）、锐顶镰孢菌（Fusarium acuminatum, 5.85%）、烟曲霉（Aspergillus fumigatus, 5.85%），晋北地区的优势物种为锐顶镰孢菌（14.11%）、烟曲霉（11.91%）、三线镰刀菌（9.40%）、菊异茎点霉（Paraphoma chrysanthemicola, 5.64%）、D. bellidis（5.64%）、链格孢菌（Alternaria alternata, 5.64%），D. bellidis、锐顶镰孢菌、烟曲霉等优势种的相对丰度差异较大。差异性分析表明晋南地区的生物多样性显著高于晋北地区，D. bellidis、锐顶镰孢菌、烟曲霉等优势种的相对丰度差异较大，为进一步研究柴胡根内生真菌相对丰度差异较大的物种及其不同菌株对柴胡皂苷积累的影响提供参考。     

花魔芋软腐病原真菌分离鉴定

魔芋软腐病是魔芋生产过程中的重要病害,也是限制魔芋产业发展的主要因素。目前,已有报道魔芋软腐病主要由细菌引起,鲜有真菌引起魔芋球茎软腐发病的报道。为明确云南曲靖市花魔芋(Amorphophallus konjac)软腐病的病原种类和侵染特征,该研究通过组织分离法,对采集自云南曲靖市的花魔芋病样进行了真菌的分离,通过形态学结合基于ITS与LSU序列分析的分子鉴定方法对分离真菌进行鉴定,并根据柯赫氏法则进行致病性测定,并对鉴定出的病原真菌同魔芋软腐病原细菌进行了双回接试验分析。结果表明:(1)从形态学和分子水平鉴定了轮纹镰刀菌(Fusarium concentricum)、尖孢镰刀菌(F. oxysporum)和F. ambrosium 3种镰刀菌,1种毛霉属真菌(Mucor sp.),1种根霉属真菌(Rhizopus sp.),1种青霉属真菌(Penicillium sp.)和1种粉红螺旋聚孢霉属真菌(Clonostachys sp.)。(2)统计分析发现,轮纹镰刀菌的相对丰度最高,为45.45%。(3)柯赫氏法则检测发现轮纹镰刀菌具有致病性。(4)轮纹镰刀菌和病原细菌胡萝卜果胶杆菌(Pectobacterium aroidearum)双接种魔芋球茎发现软腐病发病更快,病变组织重量显著高于单接种轮纹镰刀菌或果胶杆菌处理。综上表明,魔芋软腐病可能是由真菌和细菌复合侵染引发。该研究结果为魔芋软腐病的防治提供了理论依据。     

急性侵袭性真菌性鼻-鼻窦炎大鼠模型的建立

目的建立稳定且易操作的急性侵袭性真菌性鼻-鼻窦炎大鼠模型,以促进对急性侵袭性真菌性鼻-鼻窦炎的实验研究,指导临床。方法将SD大鼠随机分为4组。A组,免疫抑制+右侧鼻腔填塞Merocel海绵条+右侧鼻腔滴入烟曲霉孢子悬液;B组,右侧鼻腔填塞Merocel海绵条+右侧鼻腔滴入烟曲霉孢子悬液;C组,免疫抑制+右侧鼻腔滴入烟曲霉孢子悬液;D组:对照组。A、B、C组大鼠连续3 d鼻内滴入烟曲霉孢子悬液,4组大鼠均于第1次滴菌后第4天处死。取内眦静脉血监测大鼠免疫抑制情况,对鼻部组织行真菌培养和组织病理学观察。结果免疫抑制组大鼠血中性粒细胞明显降低,接种烟曲霉当天中性粒细胞计数0.1×109/L,其余两组变化不明显。病理结果显示A组90%(9/10)大鼠鼻腔鼻窦组织被烟曲霉侵袭,10%(1/10)肺部可见侵袭;B、C、D组大鼠无鼻部烟曲霉感染,但C组中20%(2/10)大鼠肺部可见烟曲霉侵袭。真菌培养结果显示A组71%(5/7)大鼠鼻部组织烟曲霉培养阳性,其他组均为阴性。结论单纯对大鼠进行免疫抑制或单纯造成大鼠鼻腔堵塞均不易造成大鼠鼻腔被真菌侵袭;免疫抑制基础上,对大鼠鼻腔填塞Merocel海绵条后再滴入烟曲霉可以成功建立急性侵袭性真菌性鼻-鼻窦炎模型,其成模率高,模型稳定,操作简易,有利于对此疾病在免疫、病理、药物等方面的深入研究。     

中国灵芝属一新种和一新记录

本文描述了灵芝属一新种:兼性灵芝Ganoderma bicharacteristicum X.Q. Zhang,和一个新记录种:奇异灵芝Ganoderma mirabile(Lloyd) Humphrey.作者为新种提供了拉丁文特征提要及英文描述。上述两种所引证的标本保藏在中国科学院微生物研究所真菌标本室(HMAS)。     

高磷土壤中丛枝菌根真菌的分离鉴定

【背景】丛枝菌根(arbuscular mycorrhiza,AM)真菌具有广泛的寄主范围、环境适应性和优良的植物促生能力。然而,土壤的高磷水平严重抑制了AM真菌生长及AM形成。【目的】分离鉴定出耐较高有效磷含量的华南土著AM真菌菌株,为菌根学研究工作提供新颖材料。【方法】采用经典形态学和分子系统学方法鉴定高磷土壤中AM真菌。【结果】从有效磷含量为53-131 (平均值±标准差为88.2±17.6) mg/kg的根区土壤中鉴定出7属25种AM真菌,包括无梗囊霉属(Acaulospora) 12种、球囊霉属(Glomus) 7种、隔球囊霉属(Septoglomus) 2种、近明球囊霉属(Claroideoglomus) 1种、根孢囊霉属(Rhizophagus) 1种、硬囊霉属(Sclerocystis) 1种和类球囊霉属(Paraglomus) 1种,其中幼套近明球囊霉(Claroideoglomus etunicatum)和蜜色无梗囊霉(Acaulospora mellea)是优势种。在(87.7±8.0) mg/kg的高磷水平下,AM真菌仍能形成丛枝和泡囊。但当有效磷含量达到(99.7±1.2) mg/kg时,菌根侵染率和丛枝丰度显著下降,但仍能够形成泡囊。【结论】从广州市南沙区有效磷含量为(88.2±17.6) mg/kg的耕地植物根区土壤中,鉴定出具有耐高磷潜力的7属25种AM真菌,幼套近明球囊霉和蜜色无梗囊霉等分离株可作为后续高磷抑制机制解析及耐高磷AM真菌菌剂研发工作的试验菌株。     

广西北部湾茅尾海浮游真菌群落结构及其影响因子

浮游真菌在海洋食物网和生物地球化学循环中发挥着关键作用。【目的】为解析广西北部湾茅尾海不同季节浮游真菌群落结构及其关键环境影响因子，于2017年7月(夏季)、9月(秋季)、12月(冬季)和2018年3月(春季)期间在该海域设置7个站点，采集表层海水样品。【方法】利用内部转录间隔区(internal transcribed spacer, ITS)基因高通量测序技术，分析茅尾海浮游真菌群落结构与多样性。【结果】茅尾海海域浮游真菌隶属6个门、26个纲、71个目、167个科、282个属和374个种。主要浮游真菌类群为子囊菌门(Ascomycota, 82.14%)和担子菌门(Basidiomycota, 10.74%)，共占浮游真菌总丰度的92.88%。茅尾海浮游真菌群落Shannon指数和Simpson指数在春季最高，Chao1指数和丰富度(richness)指数在冬季最高。主坐标分析(principal coordinates analysis, PCoA)和相似性分析(analysis of similarities, ANOSIM)结果显示，不同季节浮游真菌群落的β多样性具有极显著差异(R=0.591 2, P<0.001)。通过随机森林模型分析(random forest modeling analysis, RF)，发现黄曲霉(Aspergillus flavus)、二色胶孔菌(Gloeoporus dichrous)、杂色曲霉(Aspergillus subversicolor)和微扁沃利雅炭皮菌(Whalleya microplaca)、翹鱗香菇(Lentinus squarrosulus)等20种海洋浮游真菌对环境变化敏感，可用于评估茅尾海富营养化状况。Spearman相关性分析表明，浮游真菌α多样性与海水pH、盐度和溶解氧(dissolved oxygen, DO)呈显著正相关关系(P<0.05)，与温度、叶绿素-a (chlorophyll a, Chl-a)以及总有机碳(total organic carbon, TOC)呈显著负相关关系(P<0.05)。方差分解分析(variance partitioning analysis, VPA)发现营养因子是浮游真菌群落结构的主要驱动因子。【结论】本研究可为揭示北部湾海洋浮游真菌多样性提供理论参考，并为茅尾海生态环境监测与资源利用提供科学依据。     

Effects of Conidia of Various Aspergillus Species on Apoptosis of Human Pneumocytes and Bronchial Epithelial Cells

Aspergillus species can cause mycoses in human and animals. Previously, we demonstrated that A. fumigatus conidia from a human isolate inhibited apoptosis in human pneumocytes and bronchial epithelial cells. In the current study, we studied the effects of A. fumigatus conidia non-human origin and A. flavus, A. nidulans, A. niger and A. oryzae conidia on human cells apoptosis. Human pneumocytes or bronchial epithelial cells were simultaneously exposed to apoptotic inductors and aspergilli conidia. The cell cultures were analyzed by flow cytometry, immunoblotting, and examination of nuclear morphology. Similar to A. fumigatus conidia, A. flavus conidia inhibited cellular apoptosis while A. nidulans, A. niger and A. oryzae conidia did not affect apoptosis. We further studied the species specificity of conidia: there were no differences in the inhibition of apoptosis by A. fumigatus conidia from either human or bird isolates. In order to determine whether the inhibition of apoptosis by conidia is limited to certain strains, the effect on human cell apoptosis of different A. fumigatus human clinical isolates and A. fumigatus of environmental origin was evaluated. All A. fumigatus isolates inhibited apoptosis; an anti-apoptotic factor was released by conidia. For TNF-induced apoptosis, the anti-apoptotic effect of conidia of all isolates was found to be associated with a reduction of caspase-3 in human cells. The results suggest that suppression of apoptosis may play a role in reducing the efficacy of host defense mechanisms during infection with Aspergillus species. F. Féménia and D. Huet made an equal contribution to this work.     

Silencing of mitochondrial alternative oxidase gene of <Emphasis Type="Italic">Aspergillus fumigatus</Emphasis> enhances reactive oxygen species production and killing of the fungus by macrophages

We previously demonstrated that conidia from Aspergillus fumigatus incubated with menadione and paraquat increases activity and expression of cyanide-insensitive alternative oxidase (AOX). Here, we employed the RNA silencing technique in A. fumigatus using the vector pALB1/aoxAf in order to down-regulate the aox gene. Positive transformants for aox gene silencing of A. fumigatus were more susceptible both to an imposed in vitro oxidative stress condition and to macrophages killing, suggesting that AOX is required for the A. fumigatus pathogenicity, mainly for the survival of the fungus conidia during host infection and resistance to reactive oxygen species generated by macrophages.     

纤维素降解菌烟曲霉HZ1的基因组测序及生物信息学分析

【目的】烟曲霉Aspergillus fumigatus作为一类具有纤维素降解能力的真菌,对其基因组的研究,将有利于从A. fumigatus中挖掘和开发利用与纤维素降解相关的酶资源。【方法】利用CMC选择培养基和刚果红染色法从长足大竹象肠道中分离和筛选出纤维素降解菌A. fumigatus HZ1,同时采用Illumina PE150平台进行基因组测序,随后进行了相关的生物信息学分析,此外还利用了DNS法测定了其纤维素酶活。【结果】纤维素降解菌A. fumigatus HZ1基因组大小为27.45 Mb,GC含量为49.43%;通过NR、KOG、GO、Swissprot、eggNOG、KEGG和Pfam数据库注释结果表明基因组包含9473个基因;同时碳水化合物活性酶(CAZyme)注释结果表明基因组含有534个CAZyme基因,并与其他4种A. fumigatus基因组CAZyme分布无显著差异;本研究还鉴定出多种与木质纤维素降解相关的纤维素酶基因、半纤维素酶基因和木质素酶基因;此外纤维素酶活结果表明,在CMC培养基中其酶活呈上升趋势且具有较高活性。【结论】本研究首次对A. fumigatus HZ1基因组进行了测序和分析,探讨了其纤维素降解的遗传基础,并通过酶活验证了其纤维素降解潜力,为该菌的实际应用提供了理论基础。     

Cloning and expression of pkaC and pkaR,the genes encoding the cAMP-dependent protein kinase of Aspergillus fumigatus

This report describes the cloning and expression of both subunits of PKA in the opportunistic fungal pathogen Aspergillus fumigatus. The predicted translation product of the regulatory subunit, pkaR, is defined as a type II regulatory subunit. The gene encoding the A. fumigatus catalytic subunit, pkaC, contains the conserved kinase and activation domains that are characteristic of PkaC proteins. Both subunit mRNAs are expressed throughout the asexual life cycle of A. fumigatus. Message levels of pkaR and pkaC are higher during co-cultivation with alveolar epithelial cells than during culture alone.This revised version was published online in October 2005 with corrections to the Cover Date.     

Production of xylanases byAspergillus fumigatus andAspergillus oryzae on xylan-based media

Aspergillus fumigatus andA. oryzae were cultivated in laboratory fermenters on media containing xylan as the main carbon source.A. fumigatus produced xylanase on unsubstituted, insoluble beech xylan but growth and enzyme production on soluble xylo-oligosaccharides from the steaming of hardwood were poor due to the presence of inhibitors. An essential prerequisite for good xylanase production byA. fumigatus was decrease in the pH of the cultivation below 3.0 At higher pH values, the production of proteolytic enzymes caused degradation of the xylanase activity already produced.A. oryzae produced rather less xylanase activity thanA. fumigatus on the beech xylan medium but, after adaptation, was capable of efficient enzyme production on the steamed substrate.M.J. Bailey and L. Viikari are with the VTT, Biotechnical Laboratory, PO Box 202, SF-02151 Espoo, Finland     

金属还原酶FreB2对烟曲霉铁吸收及氧化压力应答的影响

利用构建的烟曲霉金属还原酶基因(AFUA-1G00350,Fre B2)缺失突变株,对烟曲霉金属还原酶基因Fre B2功能进行初步研究,为揭示该基因与烟曲霉的致病关系提供依据。比较野生株和基因缺失突变株在AMM和无铁AMM液体培养基中生长时高铁还原酶的活性,绘制不同时间野生株和基因缺失突变株在AMM和无铁AMM液体培养基中生长时高铁还原酶活性曲线。利用Real-Time PCR方法分析Sre A、Sid A、Fet C、Ftr A和Fre B这些与铁的吸收相关基因的mRNA的表达量变化。测定野生株和基因缺失突变株对氧化压力的敏感性及胞内活性氧物质含量。不论在AMM液体培养基中还是在无铁AMM液体培养基中培养时,突变株高铁还原酶的活性都明显高于野生株高铁还原酶活性。与野生株相比培养60 h时,突变株Sre A、Sid A、Fet C、Ftr A和Fre B这些与铁的吸收相关基因的表达量出现明显上调。氧化压力敏感性实验显示,基因缺失突变株对H2O2的敏感性显著增强,同时胞内活性氧物质含量明显增多。金属还原酶基因Fre B2在烟曲霉铁吸收及氧化压力应答过程中发挥作用;烟曲霉与铁吸收相关基因之间存在功能互补效应。     

Detection of IgG and IgE antibodies to Aspergillus fumigatus in human sera by immunogold assay

An immunogold assay (IGA) was developed to detect IgG and IgE antibodies to Aspergillus fumigatus. Sixteen sera from patients with allergic bronchopulmonary aspergillosis (ABPA), aspergilloma, and normal controls were studied. All sera were also evaluated for antibodies against A. fumigatus by biotin-avidin linked enzyme immunosorbent assay (BALISA) and by agar gel double diffusion method. A. fumigatus specific IgG and IgE antibodies could be detected by IGA in all the patients' sera but not in the sera of normal controls. Both IgG and IgE antibodies to A. fumigatus could be demonstrated in all the sera by BALISA and normal controls showed only low levels of these antibodies. There was a positive correlation between the degree of reactivity detected by IGA, the BALISA titer and the precipitins by agar gel diffusion. It can be concluded that IGA is a reliable, sensitive and simple method capable of detecting both IgG and IgE antibodies against A. fumigatus in patient serum.     

The effects of dsRNA mycoviruses on growth and murine virulence of Aspergillus fumigatus

Some isolates of the opportunistic human pathogenic fungus Aspergillus fumigatus are known to be infected with mycoviruses. The dsRNA genomes of two of these mycoviruses, which include a chrysovirus and a partitivirus, have been completely sequenced and an RT-PCR assay for the viruses has been developed. Through curing virus-infected A. fumigatus isolates by cycloheximide treatment and transfecting virus-free isolates with purified virus, as checked by RT-PCR, isogenic virus-free and virus-infected lines of the fungus were generated whose phenotypes and growth have been directly compared. Mycovirus infection of A. fumigatus with either the chrysovirus or the partitivirus resulted in significant aberrant phenotypic alterations and attenuation of growth of the fungus but had no effect on susceptibility to common antifungals. Chrysovirus infection of A. fumigatus caused no significant alterations to murine pathogenicity.     

Isolation and toxigenicity of Aspergillus fumigatus from moldy silage

Thirty-nine silage samples were collected from various siloson Terceira Island in the Azores. Samples were examined for the presence of total fungi, and isolates of Aspergillus fumigatus were analyzed for their ability to produce fumitremorgens B and C, fumigaclavines B and C, and gliotoxin. Thirty-four silage samples (87%) were contaminated with fungi, and A. fumigatus was isolated from 27 samples (69%). Samples that were taken from the surface of silos had significantly higher populations of both total fungi and A. fumigatus than did samples taken from the middle of silos. Analysis of 27 A. fumigatus isolates (one representing each positive sample) showed that 59.3% produced fumitremorgen B; 33.3% produced fumitremorgen C; 29.6% produced fumigaclavine B; 7.4% produced fumigaclavine C; and 11.1% produced gliotoxin. Fifty-two percent of the isolates produced multiple toxins, and 25.9% did not produce any of these toxins. Gliotoxin and fumigaclavine C were always produced in combination with other toxins. Because of the demonstrated potential of these A. fumigatus isolates to producemycotoxins, it is important to properly construct and manage silos to prevent their contamination with A. fumigatus.This revised version was published online in October 2005 with corrections to the Cover Date.     

Toxinogenèse in vitro d'Aspergillus du groupe fumigatus. Production de fumitoxines

A new class of mycotoxins has been characterized from a strain of Aspergillus fumigatus: the fumitoxins A, B, C and D. The in vitro production of these metabolites is studied. Fumitoxins are common in cultures extracts of most strains of A. fumigatus. They are not detected from A. fischeri. Variations of the levels of these products during the incubation of cultures, and also by using different media, are noted. At all events, the toxicity of crude extracts of the mould, for the chick embryo, is equal to the one of the fumitoxins.