Hemagglutinating activity of the fungusLentinus edodes (Berk.) sing [Lentinus edodes (Berk.) Pegler]

The hemagglutinating (HA) activity of the submerged mycelium and the culture liquid (CL) of four strains ofLentinus edodes was studied. The HA activity of the CLs proved to be much higher than that of mycelia. The carbohydrate specificity of fungal agglutinating factors was determined. HA activity was investigated as a function of the inoculum size, cultivation temperature, and culture age. The agglutinating activity of different morphogenetic structures ofL. edodes F-249, including mycelium, brown mycelial mat (MM), primordia, and fruiting bodies, was studied. MM was found to possess the maximum HA activity, which can be explained by the possible involvement of agglutinins in the formation of MM, which is composed of glued hyphae.     

Hemagglutinating activity of Lentinus edodes (Berk.) Sing [Lentinula edodes (Berk.) Pegler]

The hemagglutinating (HA) activity of the submerged mycelium and the culture liquid (CL) of four strains of Lentinus edodes was studied. The HA activity of CLs proved to be much higher than that of mycelia. The carbohydrate specificity of fungal agglutinating factors was determined. HA activity was investigated as a function of the inoculum size, cultivation temperature, and culture age. The agglutinating activity of different morphogenetic structures of L. edodes F-249, including mycelium, brown mycelial mat (MM), primordia, and fruiting bodies, was studied, MM was found to possess the maximum HA activity, which can be explained by the possible involvement of agglutinins in the formation of MM, which is composed of glued hyphae.     

Characterization of an extracellular glycolipid from Lentinus edodes (Berk.) Sing [Lentinula edodes (Berk.) Pegler]

Submerged mycelium of a xylotrophic basidiomycete Lentinus edodes produces an extracellular glycolipid, S3, associated with a lectin. Galactose glycan residue, as well as the lipid pool composition, which includes nonhydroxylated short-chain fatty acids, is uncommon for basidiomycetes. The glycolipid consists of D-galactopyranose (15% of S3 contains galactose sulfate) acylated by octadecanoic and nonadecanoic fatty acid residues (28 and 72%, respectively). The glycolipid structure and composition are confirmed by physicochemical analysis. The glycolipid is assumed to be a regulator of lectin activity.     

Relationship between the molecular structure of nitrogen source and the activity of the extracellular lectins of Lentinus edodes (Berk.) Sing [Lentinula edodes (Berk.) Pegler] upon submerged cultivation

The activity of the extracellular lectins of Lentinus edodes (Berk.) Sing [Lentinula edodes (Berk.) Pegler] and the formation of a pigmented mycelial film by this fungus upon submerged cultivation in a synthetic medium were found to depend on the presence of some amino acids (particularly, asparagine) and Ca2+ and Mn2+ ions in the medium. Quantum chemical calculations suggest that the different character of the interaction of amino acids with the aforementioned ions is due to differences in the hydrophobicity of the amino acids rather than to differences in the electron structure of the amino acid zwitterions.     

Relationship between the Molecular Structure of the Nitrogen Source and the Activity of the Extracellular Lectins of Lentinus edodes (Berk.) Sing [Lentinula edodes (Berk.) Pegler] upon Submerged Cultivation

The activity of the extracellular lectins of Lentinus edodes (Berk.) Sing [Lentinula edodes (Berk.) Pegler] and the formation of a pigmented mycelial film by this fungus upon submerged cultivation in a synthetic medium were found to depend on the presence of some amino acids (particularly, asparagine) and Ca²⁺ and Mn²⁺ ions in the medium. Quantum-chemical calculations suggest that the different character of the interaction of amino acids with the aforementioned ions is due to differences in the hydrophobicity of the amino acids rather than to differences in the electron structure of the amino acid zwitterions.     

Antibiotic properties of the strains of the basidiomycete Lentinus edodes (Berk.) sing]

Antibiotic properties of the extracts from the fermentation broth and mycelium of 15 strains of the edible and medicinal basidiomycete L. edodes were studied and it was shown that the extracts were active against grampositive and gramnegative bacteria, yeasts and mycelial fungi, including dermatophytes and phytopathogens. The strains differed by the set of the organisms susceptible to the action of the extracts. Strains of L. edodes combining marked antibiotic properties and high yields of water soluble polysaccharides were screened. The active compounds were detected by preparative TLC. Two of them were identified with UV- and mass spectrometry as lentinamycin B and erytadenine (lentinacin). Lentinamycin B was found to be the main component responsible for the antibiotic activity of the L. edodes strains.     

一种含有单链RNA的香菇球状病毒

从生长不正常的香菇(Lentinus edodes(Berk.)Sing)菌株中分离到一种等轴对称含单链RNA的病毒颗粒。病毒颗粒在电镜下直径为33～34nm,在SDS-聚丙烯酰胺凝胶电泳中病毒外壳蛋白分子量为22000道尔顿。病毒核酸径DNase1和SI酶解试验及热变性紫外吸收曲线试验证明为单链RNA,在1.5％的琼脂糖凝胶电泳中,病毒核酸呈现一条带,分子量为2.38×10~6道尔顿。     

香菇子实体蛋白我糖的分离纯组成结构分析

香菇〔Lentinus edodes（Berk.）Sing.〕子实体经热水提取,乙醇沉淀,得多糖粗品（Le）。Le脱游离蛋白,脱色,经DEAE－纤维素柱及纤维素凝胶柱层析分离酏化和到Le－1、Le－2和 Le－33个级分。经聚丙烯酰胺凝胶电泳和SepharoseCL－6B柱层析鉴定为分子量分布均一的蛋白多糖。凝胶渗透色谱法测得Le－1、Le－2和 Le－3分子量分别为954000,90000和14000。3个级分均由阿拉伯糖、木糖、甘露糖、半乳糖、葡萄糖和葡萄糖醛酸组成,气相色谱测得Le－1的阿拉伯糖、木糖、甘露糖、半乳糖、葡萄糖的摩尔比为0．39：0．46：1．00：0．93：14．13;Le－2为0．19：0．41：1．00：0．93：10．72;Le－3为0．31：0．47：1．00：1．15：8．92。Le－1、Le－2和 Le－3葡萄糖 醛酸含量（％）分别为24．10、34．77和40．05,蛋白质含量（％）分别为2．01、7．28和25．31,红外扫描确定Le－1和Le－2 的糖苷键为a型,Le－3为β型。     

Auxin synthesis by the higher fungus Lentinus edodes (Berk.) Sing in the presence of low concentrations of indole compounds

The auxin formation in a submerged culture of the xylotrophic basidiomycete Lentinus edodes (Berk.) Sing (Lentinula edodes (Berk.) Pegler) (shiitake) is studied. Biologically active substances of an indole nature are identified, "the effect of small doses" of which lies in not only the stimulation of growth of the mycelium (indole-3-acetic acid, 2 x 10(-7)-2 x 10(-4) g/l), but also in the induction of tryptophan-independent paths of auxin biosynthesis. The above-mentioned path is realized in the presence of exogenous indole (1 x 10(-3)-1 x 10(-4) g/l), as well as while inducing the biosynthesis of indole-3-acetic acid by its microadditives (1 x 10(-5)-1 x 10(-8) g/l), and is accompanied by the formation of anthranilic acid (up to 1.5 mg/l). Induction of the generative development stage ofshiitake by indole derivatives is revealed. It was found that among the studied compounds only indoleacetamide at a concentration of an order of x 10(-4) g/l in the culture fluid of L. edodes had a pronounced stimulatory effect on the formation of shiitake's brown mycelial film.     

Auxin synthesis by the higher fungus Lentinus edodes (Berk.) sing in the presence of low concentrations of indole compounds

The auxin formation in a submerged culture of the xylotrophic basidiomycete Lentinus edodes (Berk.) Sing (Lentinula edodes (Berk.) Pegler) (shiitake) is studied. Biologically active substances of an indole nature are identified, “the effect of small doses” of which lies in not only the stimulation of growth of the mycelium (indole-3-acetic acid, 2 × 10⁻⁷–2 × 10⁻⁴ g/l), but also in the induction of tryptophan-independent paths of auxin biosynthesis. The above-mentioned path is realized in the presence of exogenous indole (1 × 10⁻³–1 × 10⁻⁴ g/l), as well as while inducing the biosynthesis of indole-3-acetic acid by its microadditives (1 × 10⁻⁵−1 × 10⁻⁸ g/l), and is accompanied by the formation of anthranilic acid (up to 1.5 mg/l). Induction of the generative development stage of shiitake by indole derivatives is revealed. It was found that among the studied compounds only indoleacetamide at a concentration of an order of ×10⁻⁴ g/l in the culture fluid of L. edodes had a pronounced stimulatory effect on the formation of shiitake’s brown mycelial film.     

Letinula edodes (Berk.) Pegler (Shiitake) modulates genotoxic and mutagenic effects induced by alkylating agents in vivo

We evaluated the antimutagenic effect of Letinula edodes (Berk.) Pegler (Shiitake) on the frequency of micronuclei in mice treated with N-ethyl-N-nitrosourea (ENU) or cyclophosphamide (CP). Mice were orally (gavage) pretreated for 15 consecutive days with solutions of Shiitake (0.6 ml per day, gavage) prepared at three different temperatures: 4, 21 (RT), and 60 degrees C. Then, the animals were intraperitoneally injected on day 15 with CP (25 or 50mg/kg) or ENU (50 mg/kg) and killed 24 or 48 h after treatment for evaluation of micronucleated polychromatic erythrocytes (MNPCEs) in bone marrow and micronucleated reticulocytes (MNRETs). A mixture of L. edodes lineages (LE 95/016, 96/14, 96/17, 96/22, 96/23, 97/27, and 97/28) significantly decreased the frequencies of MNPCEs and MNRETs induced by CP (25 and 50mg/kg). When a single lineage from the mixture (LE 96/17) was tested we also found a significant reduction in the frequencies of MNPCEs and MNRETs induced by both CP or ENU (50mg/kg). The comet assay was also performed 3h after ENU treatment using mice pretreated with the single lineage (LE 96/17) of L. edodes. The results showed a high degree of variability with some indications of an antigenotoxic effect. Taken together, our data show that solutions from Shiitake inhibit in vivo mutagenicity of CP and ENU.     

The detection of single-stranded RNA in an isometric virus-like particle from Shiitake mushroom [Lentinus edodes (Berk.) Sing.]

Isometric virus-like particles (VLPs) with diameter of approximately 34 nm containing ss-RNA were purified from abnormal mycelium of Shiitake mushroom, Lentinus edodes (Berk.) Sing. SDS-polyacrylamide gel elec-trophoresis demonstrated that the virions contain a single capsid polypeptide with molecular weight of about 22 000 daltons. The nucleic acid extract from purified VLPs preparations showed only one band with a size of approximately 7.3 kilobases. The susceptibility to RNase 1 and S1 digestions, resistance to DNase and thermal denaturation behaviour of the viral genome indicated that it is a single-stranded RNA. To our knowledge, isometric single-stranded RNA VLPs isolated from Shiitake mushroom mycelia have not been reported before.     

Endophytic Fungi in Four Winter Wheat Cultivars (Triticum aestivum L.) Differing in Resistance Against Stagonospora nodorum (Berk.) Cast. & Germ. =Septoria nodorum (Berk.) Berk.

Four winter wheat cultivars with different levels of resistance to Septoria nodorum were investigated at four locations during two vegetation periods. Forty plants per cultivar and site were collected at random at seven defined growth stages from crop emergence to harvest. Samples from roots, culms, leaves, glumes and kernels were examined for the occurrence of endophytic fungi after surface sterilization. 83% of the 26944 isolates sporulated and were assigned to 213 species. The most frequent were: Septoria nodorum (20.1%), Alternaria tenuissima (9.8%), Epicoccum purpurascens (9.1%), Idriella bolleyi (6.9%), Fusarium graminearum (5.3%), Fusarium culmorum (4.0%), Cladosporium oxysporum (3.7%), Didymella exitialis (3.1%), Fusarium nivale (2.8%) and Rhizoctonia solani (2.1%). Each species occurred preferentially in one or more plant organs. A factorial analysis of variance showed that plant organ, sampling site, vegetation, period and cultivar in decreasing order of importance influenced the quantitative and qualitative composition of the fungal populations. No relationship between endophytic fungi was found to be constantly antagonistic or mutualistic. Septoria nodorum was isolated mainly from culms. The number of S. nodorum isolates differed significantly between cultivars in culms and glumes but not in flag leaves. The results are discussed in relation to resistance breeding and the effect endophytic fungi, might have on yield.     

Stenocarpella maydis (Berk.) Sutton Colonization of Maize Ears

A study was undertaken to determine the ramification of maize shank, cob and kernel tissues by Stenocarpella maydis. Trials consisting of inoculated and uninoculated treatments were planted at two localities. Shank, cob and kernels of each treatment were divided into segments and S. maydis colonization was determined. Infection of the pedicel portion of maize kernels was significantly higher than the apical portion. Preferential colonization of the embryo's of kernels was observed. Colonization of cobs occurred primarily at the attachment end of the cob, with sclerenchymatous tissues showing the greatest re-isolation frequency. Shank segments did not show significant differences in S. maydis re-isolation frequency, although a tendency for higher re-isolations was observed at the stalk-attachment end. It is concluded that S. maydis colonization occurs at the base of the ear with mycelial ramification toward the tip of the ear. The sclerenchyma and placentae were the primary colonized cob tissues. as were the embryos in the kernels.     

香菇蛋白质氨基酸的分析

分析结果表明,香菇的菌柄与菌盖中蛋白质氨基酸均为18种,缺少谷氨酰胺(Gln)和天冬酰胺(Asn),其中,含量最高的是谷氨酸(菌柄为11.03 mg/gDW,菌盖为12.57 mg/gDW)。菌盖与菌柄均含必需氨基酸、半必需氨基酸10种,其中精氨酸含量(菌柄为10.73 mg/gDW,菌盖为11.84 mg/gDW)。必需氨基酸的含量十分接近于非必需氨基酸的含量(比率为1.00∶1.04),无论总氨基酸含量还是必需氨基酸含量,菌盖中的皆略高于菌柄中的。     

Beobachtungen anCordyceps sinensis (Berk.) Sacc. und verwandten Pilzen

Ohne Zusammenfassung     

A toxic metabolite of Nigrospora oryzae (Berk and Br.) petch

Nigrospora oryzae was isolated from dallisgrass (Paspalum dilatatum Poir.) collected in Auburn and from hay shipped under refrigeration to Florida. Some of these samples were eaten by cattle and horses that subsequently developed lameness. Metabolites of N. oryzae were separated by thin layer chromatography and tested for toxicity. Only one metabolite was toxic. Metabolite A showed toxicity to brine shrimp with an LD₅₀=500 g/ml in 8 h. It also had an antibiotic effect on Bacillus megaterium ATCC 14581 with a minimum inhibitory level of 10.1 g/disc. As little as 435 g of a crude methanolic extract of N. oryzae showed mild toxicity to chick embryos. The metabolite was not toxic to mice nor rats at the levels tested. Quantitative procedures developed for the determination of metabolite A showed that the maximum production occurred in yeast extract-sucrose liquid medium with an initial pH of 5–6, when incubated as a stationary culture for 28 days at 25 °C. It was concluded that metabolite A is a weak antibiotic rather than a mycotoxin, and was probably not associated with the symptoms of lameness observed in cattle and horses. The antibiotic is not one previously reported for N. oryzae.Alabama Agricultural Experiment Station Journal No. 6-84744