连作土壤中施加球毛壳ND35菌肥对杨树生理特性的影响

在山东农业大学林学实验站杨树连作土壤中施加不同剂量(0.17、0.33、0.67、1.00、1.33和1.67 g·kg^-1)的球毛壳ND35菌肥,测定不同处理下一年生杨树叶片的光响应过程、叶绿素荧光以及叶黄素循环等光合生理生化指标,研究球毛壳ND35菌肥对杨树根系和光合生理性能的影响.结果表明: 随连作土壤中菌肥含量的增加,杨树叶片的叶绿素含量(Chl)呈增加趋势,电子传递速率(ETR)、净光合速率(P_n)、量子效率(Φ)、硝酸还原酶(NR)活性以及根系活力等生理指标均呈先增加后降低的趋势,依赖于叶黄素循环的光合热耗散呈降低趋势,而非光化学淬灭(NPQ)呈先降低后增加的趋势.在土壤施加菌肥剂量0.67和1.00 g·kg^-1处理时,光合机构的过剩光能减少,向光化学反应方向分配的光能增多,光能利用效率提高.在连作土壤中施加适量(0.67～1.00 g·kg^-1)的球毛壳ND35菌肥,能在一定程度上提高杨树的根系生理活性,提高杨树叶片对光能的利用效率,有利于改善杨树叶片的光合机构运转状态,提高叶片的光合作用效率.     

Onychomycosis caused by Chaetomium globosum Kunze

In this paper we report a case of onychomycosis caused by Chaetomium globosum. The patient had lesions of the fingernails of the left hand. The direct microscopical examination of the nails showed light-brown hyphae with thick-walled cells. The histopathological examination revealed thick aggregated hyphal element in the nail plate. Amongst the antimycotics tested oxiconazole with MIC values of 0.3 g/ml^–1 was found to be most effective in vitro against Chaetomium globosum.     

Microbial transformation of baicalin and baicalein

As a result of microbial transformation of baicalin and baicalein the products of 4′-hydroxylation of the B ring, O-methylation at C-6, and both O-methylation at C-6 and hydroxylation at C-4′ were obtained. Transformations of baicalin were accompanied by the reaction of hydrolysis.     

一株毛壳霉属真菌中新结构活性聚酮类化合物研究

采用硅胶、凝胶柱层析以及反相高效液相色谱等分离技术,从一株毛壳霉属真菌的固体发酵提取物中分离纯化了5个聚酮类化合物chaetomones A-E(1-5),其结构主要通过分析核磁共振数据确定。生物活性测试结果表明化合物5具有抗白色念珠菌Candida albicans(ATCC10231)的活性,其IC50为20.0μmol/L。     

Degradation of catechin and purification and partial characterization of catechin oxygenase fromChaetomium cupreum

An enzyme capable of cleaving catechin was present in the mycelium ofCheatomium cupreum. Maximum synthesis of the enzyme occurred after 15 days growth. Sucrose and maltose increased enzyme synthesis among the carbon sources tested. Catechol, protocatechuic acid and phloroglucinol carboxylic acid were the intermediates of catechin degradation.Cheatomium cupreum containedmeta-cleaving enzymes for catechol and protocatechuic acid metabolism. Pyruvate was identified as an end-product. Catechin oxygenase from the mycelium ofC. cupreum was purified to homogeneity. It was optimum at pH 7.0 and 50°C and was highly specific for catechin, with a K_m of 4 m. Its molecular size was 40 kDa, as determined by gel filtration and gel electrophoresis, and it had a pI of 9.1.p-Chloromercuric benzoate, iodoacetate, N-ethylmaleimide, 2,2-dipyridyl and EDTA markedly inhibited the enzyme activity. It was a glycoprotein.T. Sambandam was and A. Mahedevan is with the Center for Advanced Studies in Botany, University of Madras, Guindy Campus, Madras-600025, India. T. Sambandam is now with the Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.     

Two new species of pyrenomycetous ascomycetes from New Caledonia

Two new species of Pyrenomycetes from forest soil in New Caledonia,Anthostomella pacifica andChaetomium novaecaledonicum, are described and illustrated.Anthostomella pacifica is characterized by non-ostiolate ascomata, cylindrical asci with an amyloid apical apparatus, and two-celled ascospores (dark apical cylindrical and hyaline basal dwarfed cells) with longitudinal germ slits.Chaetomium novae-caledonicum is characterized by ostiolate ascomata, straight terminal hairs, arcuate lateral hairs with a recurved tip, and very small, ovoid-flattened ascospores.This research was supported in part by Monbusho International Scientific Research Program: Field Research, No. 05041093.     

Role of antibiosis in the biological control of spot blotch (Cochliobolus sativus) of wheat by Chaetomium globosum

Chaetomium globosum Kunze, has been identified as a potential antagonist of Cochliobolus sativus (S. Ito & Kurib.) Deschler ex Dastur. (Syn = Drechslera sorokiniana). Production of antifungal compounds by Chaetomium globosum (Cg) and their role in suppression of spot blotch of wheat caused by this fungus under in vitro and in vivo has been evaluated. Interaction between Chaetomium globosum isolates and C. sativus showed mycoparasitism by isolates Cg 1 and Cg 6 whereas isolates Cg 2, Cg 3, Cg 4 and Cg 5 showed antibiosis. Syringe filtered culture extracts of Cg 2 completely inhibited mycelial growth of C. sativus in liquid broth. In vitro bioassays were undertaken by amending the medium with crude extracts and agar diffusion method in order to assess the fungistatic activity of crude extracts from culture filtrates of different isolates of Chaetomium globosum. Significant differences in antagonism between isolates were observed. Antifungal metabolite profiling, on TLC (Thin Layer Chromatography) plates identified 13 compounds in isolate Cg 2, 11 compounds in Cg 3 and 7 compounds in Cg 6. Isolate Cg 1 produced only two faint bands and Cg 5 produced two bands of the same Rf value but of higher intensity. The production of antifungal compounds by isolates was positively correlated with antagonism to C. sativus on seedlings in glasshouse studies. The results showed high antifungal metabolite production by isolate Cg 2, which also gave maximum bioefficacy under laboratory and glasshouse conditions.     

Comparative Characterization of Laminarinases from the Filamentous Marine Fungi Chaetomium Indicum Corda and Trichoderma Aureviride Rifai

Marine filamentous fungi (103 strains) isolated from various marine habitats were studied for their ability to produce extracellular O-glycosylhydrolases. Cultural filtrates of these strains were shown to contain a series of glycanases (laminarinases, amylases, cellulases, pustulanases) and glycosidases (β-glucosidases, N-acetyl-β-glucosaminidases, β-galactosidases, α-mannosidases).Two species of marine fungi from different habitats were chosen for isolation of laminarinases and detailed study on enzyme properties. The fungus Chaetomium indicum associated with the alga Fucus evanescens C. Agardh was collected near the Kuril Islands, and T. aureviride was sampled from bottom deposits of South China Sea. Properties of extracellular laminarinases were similar: temperature optimums (40–45 ^∘C), molecular masses (54–56 kDa), K _m (0.1–0.3 mg ml⁻¹). Temperature stability of laminarinase of C. indicum was significantly higher than those from T. aureveride. It is shown that these enzymes are specific to β-1,3-bonds in glucans, release predominantly glucose from laminaran and do not catalyze reaction of transglycosylation. Accoding to these data enzymes are exo-1,3-β-D-glucan-glucanohydrolases (EC 3.2.1.58). Inhibitor analysis demonstrated the significant role of tryptophan and tyrosine residues in the catalytic activity of enzymes. Molecules of T. aureviride laminarinase contained the functionally important thiol group.     

秦岭南坡松栎林群落演替过程中种间联结性和相关性研究

对从银杏叶片中分离的1株具有高抗氧化活性的内生真菌SG0016,并对SG0016菌株进行形态学和分子生物学鉴定,以发酵液DPPH自由基清除率为指标,采用单因素和正交试验对SG0016菌株的接种量、培养温度、装液量、培养时间和碳源、氮源等培养条件进行优化,以提高其发酵液抗氧化活性。结果显示,SG0016菌为球毛壳菌(Chaetomium globosum);其发酵液抗氧化活性最佳培养条件为:接种量10%、培养温度23℃、装液量100 mL(250mL的三角瓶)、培养时间7d,葡萄糖为碳源,酵母膏为氮源。在此条件下,发酵液的DPPH自由基清除率最高,为96.17%,比优化前提高了23.6%。银杏内生真菌球毛壳菌SG0016代谢产物具有较好的抗氧化活性,为天然抗氧化剂的开发提供了新的来源。