红茶菌抗菌蛋白产生方式的初步研究*

从红茶菌液中分离得到膜醋酸菌与裂殖酵母。采用单菌培养与混合菌培养,探讨了各菌对红茶菌抗菌蛋白的产生所起的作用。初步推断,裂殖酵母先合成相关蛋白,该蛋白经膜醋酸菌产生的酶修饰后,抗菌活力显著提高。不同属酵母与膜醋酸菌共培养,结果表明裂殖酵母优于其它酵母。     

猪苓菌丝形成菌核结构的特点

对猪苓(Grifola umbellata(Pers.)Pilat)菌丝在人工条件下形成菌核及繁殖过程、人工菌核与野生菌核及培养基上未形成菌核的猪苓菌丝的显微结构进行了系统研究.研究证明:人工菌核的结构与野生菌核的结构相似,均具有菌髓和皮层结构.人工菌核中的菌丝与培养基表面未形成菌核的猪苓菌丝存在着显著的差异,人工菌核是由培养基上纯培养的菌丝分化为膨大菌丝再由此形成有高度组织分化的猪苓菌核.     

一种简单高效的食用真菌总RNA提取方法

以金针菇为材料,建立了一种适合于富含RNase、多酚、多糖和糖蛋白的食用真菌RNA的提取方法,此方法在高浓度变性剂存在的条件下2次用苯酚-氯仿-异戊醇进行抽提去除DNA、蛋白质,并用异丙醇和乙酸钠选择性沉淀RNA、去除多糖,得到完整、均一的RNA样品。 Abstract:With Flammulina velutipes material,an improved method was developed for extracting total RNA from domestic fungus that are rich in RNase,polyphenols,polymeric carbohydrates and proteoglycans..Phenol-chloroform-isoamyl alcohol were used twice to clear DNA and protein under higher concentration of denaturing solution and isopentanol,sodium acetate were used to precipitate RNA selectively.Pure and intact RNA can be effectively prepared by this method.     

New γ-pyranone and nucleoside derivatives from Penicillium sp.

Peniopyranone (1) and 2-methoxyl-β-l-Arabinofuroside uracil (2), together with six known compounds were isolated from the broth of Penicillium sp. (NO. 64). And their structures were established by comprehensive analysis of NMR, MS and CD spectra, the absolute configurations of Peniopyranone (1) were determined as 7S, 8S and 9R by calculating its ECD. The eight obtained metabolites were subjected to evaluate the preliminary cytotoxic activities to four cancer cell lines, but they showed no significant data with IC₅₀ > 50 μmol/mL. The results of acetylcholinesterase inhibiting assay showed that peniopyranone (1) displayed the inhibition activity to acetylcholinesterase with IC₅₀ at 15.2 μmol/mL.     

Aspergillus salviicola,a new species from imported spice

A new species ofAspergillus, A. salviicola, has been isolated from Turkish sage, an imported spice in Japan. The species, characterized by white to rosy buff conidial heads, pinkish smooth-walled conidiophores, large biseriate aspergilla, globose smooth-walled conidia, absence of sclerotia and thermotolerant growth, is considered to represent an interface species in the subgenusCircumdati.     

Heteroatom-Containing Antibacterial Phenolic Metabolites from a Terrestrial Ampelomyces Fungus

Two new sulfur-containing phenolic compounds, 7-hydroxy-5-hydroxymethyl-2H-benzo[1,4]thiazin-3-one (1) and 2,5-dihydroxy-3-methanesulfinylbenzyl alcohol (2), along with two known compounds, 3-chloro-2,5-dihydroxybenzyl alcohol (3) and 2-hydroxy-6-methylbenzoic acid (4), were isolated from the mycelial solid culture of a soil-derived Ampelomyces fungus by antibacterial assay-guided fractionation. Their structures were elucidated on the basis of spectroscopic analysis. Compounds 1–3 showed structure and microbial dependent antibacterial activities.     

Host age and pathogen exposure level as factors in the susceptibility of the house fly,Musca domestica (Diptera: Muscidae) to Beauveria bassiana

Adult house flies, Musca domestica L., of four ages, <1, 3, 7, and 14 day post-eclosion, were exposed to three strains of Beauveria bassiana (P89, L90 and 447). Flies were exposed to moistened filter paper treated with either a low (1.57×10⁴ conidia/cm²) or high (1.57×10⁵ conidia/cm²) concentration of each fungal strain for 6 h. Strain 447 was superior to the two house fly-derived B. bassiana strains in inducing host infection and mortality. Significant spikes in infection and mortality occurred as early as 5 days post-exposure with higher concentration exposures acting more quickly. Few differences were observed in either infection or mortality among the four fly age classes. On Day 10 post-exposure, 77% of the high-concentration, 447-exposed flies were infected, compared with only 24% of the flies from the P89 low-concentration exposure. Potential applications of these results in integrated house fly management programs are discussed.     

Comparing virulence of North American Beauveria brongniartii and commercial pathogenic fungi against Asian longhorned beetles

In the USA, the development and field application of Beauveria brongniartii (Sacc.) Petch (Hypocreales: Clavicipitaceae) to control the invasive Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) have been hampered because it was unknown whether this fungal species is native to North America. With the recent confirmation of the occurrence of B. brongniartii in North America there is renewed interest in this species, particularly as it is an effective pathogen of cerambycids in Japan. However, based on partial sequences of the nuclear intergenic BLOC region the commercially available B. brongniartii strain NBL 851 (Idemitsu Kosan, Tokyo, Japan) belongs instead to the species Beauveria asiatica Rehner and Humber. Further, bioassays using two inoculation methods confirmed that commercially available strains of B. asiatica (NBL 851) and Metarhizium brunneum (F52) (Hypocreales: Clavicipitaceae) were significantly more virulent and resulted in lower median survival times (9.5–7.5 d) of A. glabripennis adults than two North American B. brongniartii isolates (ARSEF 6215 and ARSEF 10279) (24–31 d). The virulence of North American B. brongniartii isolates is not well-documented in the literature. To our best knowledge this is the first account of the virulence of native North American B. brongniartii being evaluated for biological control of any invasive insect pest.     

Thermal behavior of biodegraded lime wood

The effects of the soft-rot fungus Trichoderma viride Pers., on the thermal behavior of lime wood (Tillia cordata Mill.) were investigated. The lime wood pieces were inoculated with the fungus over a 12-week period. At pre-established time intervals two samples were withdrawn from the medium and analyzed by thermogravimetry and differential calorimetry, and the results were correlated with mass loss. Fungal activity was indicated by continuous decrease of sample mass.Modification of the wood because of the presence of the fungus was evidenced by structural changes that affected its thermal properties, both in respect to the hydrophilicity of the wood (evidenced mainly in desorption process) and in its decomposition behavior. The shape of DTG curves depends on the exposure time of wood to the action of microorganisms. The peak temperature assigned to the decomposition of wood components increases, while the global kinetic parameters for the main peak decrease with increasing exposure time of the wood to the attack by microorganisms.The increased characteristic temperatures of water desorption and cellulose decomposition processes and lower thermal stability could be explained by newly formed structures, mainly the oxidized ones.