内蒙古固沙造林树木真菌病害区系

系统调查了内蒙古固沙造林树木真菌病害状况,采集到罹病树木１６科３７种（属）,鉴定出病害１２６种、病原真菌７６种,比较了不同树种及不同组织器官的病害类型和病原生态群落组成的差异。根据沙区不同的水热指标与地理条件,讨论了病原物的生态地理区系,并分为乌兰布和沙漠固沙造林区、毛乌素沙地固沙造林区和科尔沁沙地固沙林区。     

3种典型荒漠灌木内生固氮菌及固氮酶基因nifH多样性分析

具有特殊生境的内生固氮菌,对改善植物营养、增强植物抗逆性及群落稳定性具有重要作用,是一类潜力巨大、尚待开发的微生物资源。以新疆3种典型荒漠灌木多枝柽柳（Tamarix ramosissima）、黑果枸杞（Lycium ruthenicum）、盐穗木（Halostachys caspica）为材料,从根和枝条组织中分离筛选获得137个内生固氮菌菌株,采用16S rDNA PCR-RFLP、16S rDNA序列测定、BOXAIR-PCR指纹图谱、nifH PCR-RFLP等方法分析其遗传多样性及系统发育关系。结果表明：分离菌株经16SrDNA PCR-RFLP酶切图谱聚类划分为9个遗传类型。序列测定和系统发育分析显示,代表菌株分属于拉恩氏菌属（Rahnella）、假单胞菌属（Pseudomonas）、泛菌属（Pantoea）、芽孢杆菌属（Bacillus）、寡养单胞菌属（Stenotrophomonas）和申氏杆菌属（Shinella）,其中Rahnella为优势种群。一个测定菌株的16SrDNA序列同源性低于97%,提示可能为一个潜在的新种。BOXAIR-PCR分析优势种群的基因组结构特征,获得12种指纹图谱类型,显示出该种群具有丰富的基因组多样性。nifH PCR-RFLP分析分离内生固氮菌菌株固氮酶基因nifH的分子多态性,将其划分为3种基因型,体现了nifH具有高度保守性,同时在不同固氮微生物种群和菌株间也存在一定的多样性。研究结果丰富了固氮微生物物种资源库和基因库,对于内生固氮菌资源的保护和利用奠定了科学基础。     

海洋红树林植物黄槿内生真菌Aspergillus sydowii EN-198化学成分研究

对采自海南东寨港的海洋红树林植物黄瑾(Hibiscus tiliaceus)叶中分离到的一株内生真菌Aspergillus sydowii EN-198的次生代谢产物进行了研究.利用正相与反相硅胶柱层析、葡聚糖凝胶Sephadex LH-20柱层析以及制备薄层层析(PTLC)等分离手段从其发酵液中分离得到14个化合物,通过一维、二维核磁共振技术、质谱技术等鉴定了所有化合物的结构,分别为:环-(S-脯氨酸-S-苯丙氨酸)(1),环-(S-脯氨酸-S-亮氨酸)(2),环-(S-苯丙氨酸-S-色氨酸)(3),(1S)-1-(4 '-间羟基苯甲酸)-1,1,5,5-二甲基己二醇(4),曲酸(5),N-[2-(4-吲哚)乙基]乙酰胺(6),N-[2-(4-对羟基苯酚)乙基]乙酰胺(7),胸腺嘧啶脱氧核苷(8),尿嘧啶脱氧核苷(9),尿嘧啶核苷(10),过氧化麦角甾醇(11),麦角甾醇(12),(2S,2'R,3R,3 'E,4E,8E)-N-(2’-羟基-3’-十六烯酰基)-9-甲基-4,8-二十碳二烯-1,3-二醇(13)以及1-O-β-D-葡萄糖基-(2S,2'R,3R,3'E,4E,8E)-N-(2’-羟基-3’-十六烯酰基)-9-甲基-4,8-二十碳二烯-1,3-二醇(14);其中化合物1和2为首次从Aspergillus sydowii中分离得到.对所有化合物测试其抑菌活性,发现化合物5与7对金黄色葡萄球菌有较好抑制活性.     

几株真菌对铊吸附作用的初步研究

铊是13种优先控制的有毒有害重金属元素之一,研究微生物与铊之间的相互作用有重要的理论意义和应用价值。在黔西南滥木厂铊矿区采集土壤和沉积物,借助平板筛选法在铊浓度为1000 mg/L水平筛选得到九株高耐受性菌株,用于真菌对铊的胞外吸附作用实验,并采用液体发酵法考察真菌对铊的胞外吸附作用,实验设计了1000 mg/L、1200 mg/L和1500mg/L三种铊处理水平,借助ICP-MS检测分析样品的铊含量,以此计算吸附效率。结果表明,三种处理水平中,真菌菌株对铊的吸附效率为4.63%~16.89%,且随着环境中铊浓度的上升,菌丝体(或菌丝球)生物量明显减少,导致吸附效率的下降;真菌对常量元素如钙、钠、钾的吸附与对铊的吸附呈显著正相关。这表明真菌细胞对钙、钾的吸附方式可能与对铊的吸附方式类似。     

Chemical constituents of marine algal-derived endophytic fungus Exophiala oligosperma EN-21

Seven compounds (1–7) were identified from the cultivation of the endophytic fungus Exophiala oligosperma (EN-21) that was isolated from the inner tissue of the marine red alga Laurencia similis. Their structures were identified with spectroscopic and chemical methods as 2-phenoxynaphthalene (1), (2S, 3R, 4E, 8E)-1-O-β-D-glucopyranosyl-3-hydroxy-2-[(R)-2′-hydroxyoctadecanoyl] amino-9-methyl-4, 8-octadeca-diene (2), (22E,24R)-ergosta-7,22-dien-3β,5α,6β-triol (3), (22E, 24R)-3β, 5α, 9α-trihydroxy- ergosta-7, ...     

陇南食用菌生产中的气象问题及其对策

经过１９９４～１９９８年对食用菌的栽培研究,结合陇南山区温、湿、风等气象要素和暴雨、连阴雨、干旱等灾害性天气时空分布及其变化规律分析,提出陇南山区食用菌生产中存在的气象问题和对策。     

Responses of marine-derived Trichoderma fungi to seawater and their potential antagonistic behaviour

To explore the metabolic responses of marine-derived Trichoderma fungi to environmental stresses, the survivability, metabolism, and antagonism of ten marine isolates have been examined. Their survival in both freshwater and seawater indicates them to be facultative marine fungi, but they are more adaptable to marine environment. Most of them feature strain-specific and positive metabolic responses to seawater, which also usually result in the higher proportions of heteroatom-bearing and unsaturated units in mycelial constituents. Seawater factors can promote many strains to produce bioactive metabolites, including plant pathogen- and marine phytoplankton-inhibitory and marine animal-toxic ones, but the eff ects of NaCl are often weak or negative. The inhibition of marine phytoplankton corresponds to the intracellular accumulation of heteroatom-bearing and unsaturated units under seawater condition, and the varied toxicities to marine animals further signify the divergences of lipophilic exudates under diff erent conditions. The results may contribute to further understanding and mining the structural diversity and biological activity of secondary metabolites from marine-derived Trichoderma fungi.     

Structures and antiviral activities of butyrolactone derivatives isolated from Aspergillus terreus MXH-23

A new butyrolactone derivative, namely butyrolactone VIII(1), and six known butyrolactones(2-7) were separated from the ethyl acetate(Et OAc) extract of the fermentation broth of a fungus, Aspergillus terreus MXH-23. The chemical structures of these metabolites were identified by analyzing their nuclear magnetic resonance(NMR) and mass spectrometry(MS). Known butyrolactone derivatives contain an α,β-unsaturated γ-lactone ring with α-hydroxyl and γ-benzyl, and butyrolactone VIII(1) was the first butyrolactones contains α-benzyl and γ-hydroxyl on α,β-unsaturated lactone ring. All of the butyrolactone derivatives were tested for their anti-influenza(H1N1) effects. Derivatives 4 and 7 showed moderate antiviral activities while the newly-identified, derivative 1, did not.     

Secondary metabolites of a deep sea derived fungus Aspergillus versicolor CXCTD-06-6a and their bioactivity

In order to obtain novel secondary metabolites, a deep sea inhabiting fungus Aspergillus versicolor CXCTD-06-6a was investigated. One new diketopiperazine brevianamide W(1a), as well as five known diketopiperazine alkaloids, diketopiperazine V(1b), brevianamide Q(2), brevianamide R(3), brevianamide K(4), and brevianamide E(5), were isolated from the Et OAc extract of the fermentation broth. Their structures were elucidated by spectroscopy techniques(NMR, MS). The six compounds exhibited moderate radical scavenging activity against DPPH with clearance ratio of 55.0%(1a and 1b), 53.7%(2), 46.2%(3), 61.4%(4) and 19.3%(5) at a concentration of 13.9 μmol L-1, respectively; while the positive control ascorbic acid showed a ratio of 70.3% at the concentration of 28.4 μmol L-1.     

一株海绵共附生真菌Pleosporaceae sp.中甾体类化合物及其生物活性

在生物活性测定指导下,综合运用硅胶柱层析、凝胶柱层析以及半制备HPLC等方法,从南海海绵Xestospongiatestudinaria来源的一株共附生真菌Pleosporaceae sp.发酵液的乙酸乙酯提取物中分离鉴定出5个甾体类化物,通过NMR,MS等波谱技术鉴定其结构分别为:(22E,24R)-5α,8α-epidioxy-ergosta-6,22-dien-3β-ol(1),(22E,24R)-5α,8α-epidioxy-ergosta-6,9,22-trien-3β-ol(2),(22E)-ergosta-5,7,22-trien-3β-ol(3),ergosta-6α-hydroxy-4,22-dien-3-one(4),(22E)-5α-cholesta-7,22-diene-3β,5α,6β-triol(5)。这些化合物均为首次从Pleosporaceae属真菌中分离获得。化合物1,4和5具有较强的卤虫Ar-temia salina致死活性,化合物1还显示强的抗藤壶Balanus amphitrite附着活性,其EC50为0.85μg/mL。