金龟子绿僵菌在森林土壤中的分布及对松墨天牛致病性测定

松墨天牛是重大森林植物检疫性病害——松材线虫病的主要媒介昆虫。本研究于2005年8月～2006年8月从福建、江西两省共110个林分样区(其中松林88个样区)采集土壤样品330份,采用选择性培养基分离土壤中的金龟子绿僵菌。从21个样区的26份土样中分离出的金龟子绿僵菌占采集样区的19．1％和样品的7．9％,成菌落数(CFU)500～72500CFU/g,表明金龟子绿僵菌在森林土壤中有较为广泛的分布。对分离到的9个产孢量高的菌株,采用浸渍法(1×10~7孢子/mL)接种3～4龄健康松墨天牛幼虫,采用跗节接种法接种2～15日龄健康成虫,测定其致病力。结果表明,MaYTTR-03、MaYTTR-04菌株对松墨天牛幼虫和成虫均有较高致病力,表现出良好的生防潜力。     

Aquatic fungi of Algeria: Achlya radiosa Maurizio

Achlya radiosa Maurizio is reported from Algeria. This is the first record for the African continent. Culture methods and morphological and reproductive characters of the fungus are given.     

Metarhizium brachyspermum sp. nov. (Clavicipitaceae), a new species parasitic on Elateridae from Japan

Ascomata of a Metarhizium species were collected from Tochigi Prefecture, Japan. The ascomata were similar to M. kalasinense in its host preference for elaterids, olive-green clavate stromata, and obliquely immersed perithecia, but the asci and ascospores were significantly shorter in length than those of the latter species. Furthermore, phylogenetic analyses based on the internal transcribed spacer region of nuclear ribosomal DNA and the elongation factor 1-alpha gene showed that the Japanese species was phylogenetically distinctive in the M. anisopliae lineage, including M. kalasinense. Accordingly, we describe a new species, M. brachyspermum. Isolates of this species produced olive-green conidial masses on the surface of the colony. Also, hyphal anastomoses between two metulae were often observed on conidiophores.     

Secondary metabolite as therapeutic agent from endophytic fungi Alternaria longipes strain VITN14G of mangrove plant Avicennia officinalis

Endophytic fungi, especially from mangrove plants, are rich source of secondary metabolites, which plays a major role in various pharmacological actions preferably in cancer and bacterial infections. To perceive its role in antidiabetic activity we isolated and tested the metabolites derived from a novel strain Alternaria longipes strain VITN14G obtained from mangrove plant Avicennia officinalis. The crude extract was analyzed for antidiabetic activity and subjected to column chromatography. The isolated fractions were screened in vitro for α-glucosidase and α-amylase inhibitory activities. The cytotoxicity of the isolated fractions was studied on L929 cell lines. Following which, the screened fraction 2 was allowed for structure elucidation using gas chromatography-mass spectrometry, one-dimensional, two-dimensional nuclear magnetic resonance spectroscopy, ultraviolet, and Fourier-transform infrared analysis. The binding energies of the isolated fraction 2 with glycolytic enzymes were calculated by molecular docking studies using AutoDock Vina. The isolated fraction 2 identified as 2,4,6-triphenylaniline, showed no significant difference in α-amylase inhibition rates and a significant difference of 10% in α-glucosidase inhibition rates than that of the standard drug acarbose. Further, the cytotoxicity assay of the isolated fraction 2 resulted in a cell viability of 73.96%. Supportingly, in silico studies showed 2,4,6-triphenylaniline to produce a stronger binding affinity toward the glycolytic enzyme targets. The compound 2,4,6-triphenylaniline isolated from A. longipes strain VITN14G exhibited satisfactory antidiabetic activity for type 2 diabetes in vitro, which will further be confirmed by in vivo studies. Successful outcome of the study will result in a natural substitute for existing synthetic antidiabetic drugs.     

AM Fungal Diversity in Selected Medicinal Plants of Kanyakumari District,Tamil Nadu,India

The association of Arbuscular Mycorrhizal Fungi (AMF) with three medicinally important plants viz., Eclipta prostrata, Indigofera aspalathoides, I. tinctoria collected from three different localities of Kanyakumari District, South India was examined. The study reports the colonization percentage, diversity and species richness of different AM fungi in the rhizosphere of the three medicinal plants and discusses the impact of soil physicochemical characteristics such as soil texture, pH and available macro- and micro nutrient content on AM fungal communities. A total 21 AM fungal species were identified in field conditions of the three plants from three sites. AM fungal species richness, colorization percentage and Shannon index were found to be high in the two Indigofera sp. growing in the hilly areas of Kanyakumari District and were low in E. prostrata collected from the damp regions in the foothills of the three study sites. Five species registered 100% frequency in all the study sites of the three medicinally important plants with Glomus as the dominant genera. The study states that the mean colonization and diversity patterns were dependant on edaphic factors and type of vegetation.     

前体及诱导子和发酵条件对烟曲霉TMS-26产紫杉醇发酵体系优化

紫杉醇是一种广谱的抗癌药物,因其具有独特的抗癌机制、良好的抗癌效果和供不应求的市场等特征而备受关注。紫杉醇具有重大经济效益,但产量受到制约,价格极为昂贵,通过内生真菌发酵法生产紫杉醇能在一定程度上缓解其来源困难的问题。在产紫杉醇内生真菌TMS-26发酵液中添加前体物质和诱导子,并通过对接种量、装液量、初始pH和发酵时间等条件进行优化研究。单因素及正交试验表明在PDB培养基中加入苯丙氨酸20mg/L、苯甲酸钠30mg/L、乙酸钠8g/L、甘氨酸15mg/L、CuSO₄ 0.05mg/L、H₂O₂ 6mmol/L、3,5-二硝基水杨酸15mg/L时能有效提高紫杉醇产量,比优化前增产46.64%,达到446.28µg/L,并且发现最适菌株TMS-26的发酵条件为pH7.5、接种量5%、装液量120mL/250mL、发酵时间为10d。     

Keratinolysis by Absidia cylindrospora and Rhizomucor pusillus: biochemical proof

Absidia cylindrospora and Rhizomucor pusillus, causal agents of phycomycoses, were cultured on sterile natural keratins in a mineral solution and the keratin degradation products analyzed. The excess of sulphur was removed by oxidation to inorganic sulphate and thiosulphate, which were the main products of sulphitolysis of keratin. The proteolytic activity of the two fungi depended on the nature of the keratin substrate. Human scalp hair was the most favoured keratin substrate by both the fungi.     

Effect of lignin-related phenols and their methylated derivatives on the growth of eight white-rot fungi

When various lignin-related para-phenolic benzoic acids, para-phenolic cinnamic acids, para-phenolic phenylpropionic acids, the corresponding unsubstituted and 4-O-methylated derivatives, and 4-hydroxyl substituted benzaldehydes were tested on the growth of eight white-rot fungi, methylation of the 4-hydroxy substituent resulted, in most cases, in increased inhibition of fungal growth. This effect was most notable with monomethoxylated compounds. When the aromatic ring contained additional methoxyl substituents, the toxicity of the 4-O-methylated derivative was less pronounced. Marked inhibition of fungal growth was also observed with aromatic compounds lacking a para-substituent. Higher concentrations of aromatic aldehydes were manifestly more toxic than the corresponding carboxylic acid.J.A. Buswell is with the Department of Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong. K.-E.L. Eriksson is with the Department of Biochemistry, The University of Georgia, Athens, Georgia, 30602, USA.     

PCR-RFLP analysis of chitinase genes enables efficient genotyping of Metarhizium anisopliae var. anisopliae

A new genotyping tool has been developed and evaluated for Metarhizium anisopliae var. anisopliae. The tool is based on Restriction Fragment Length Polymorphism (RFLP) analysis of three chitinase genes that are functionally linked to insect-pathogenicity of this fungus. It allowed for discrimination of 14 genotypes among 22 M. anisopliae var. anisopliae strains of a world wide collection. Analyses revealed that the approach may also be applicable to other Metarhizium varieties. The new tool will be useful for genetic characterization of M. anisopliae var. anisopliae strains, and it is applicable for laboratories with limited access to molecular diagnostic equipment.     

吉林松辽平原暨西部草原湿地土壤中的暗色丝孢菌

从吉林松辽平原暨西部草原湿地不同生态环境中采集土壤样品42份,采用土壤平板法和稀释法,从中分离出116个暗色丝孢菌分离物,经鉴定分属于25属,46种。其中,倒卵平脐蠕孢Bipolaris obovoidea为新种;二色单格孢Monodictys bicolorata、刚毛黑团孢Periconia hispidula和草色串孢小四变型Torula herbarum f. quaternella为中国新记录种。研究过的标本（干制培养物）及活菌种保存在山东农业大学植物病理学标本室（HSAUP）,等模式标本（干制培养物）存放在中国科学院真菌标本室（HMAS）。