杨树内生菌球毛壳抗生物质的培养基优化、检测和动力学

以杨树内生真菌球毛壳ND35为供试菌株,采用L<,16>(4<'5>)正交试验法对液体培养基进行优化;利用pH纸色谱、捷克八溶剂系统纸色谱方法及紫外-可见光谱扫描法对该内生菌的抗生物质进行理化性质初步分析;用薄层层析、高效液相色谱及平板抑菌法检测分析该菌粗提液的活性成分及对杨树腐烂病菌的抑菌效果;对抗生物质液体培养的主要动力学指标进行分析.结果表明:优化后培养基配方为:1%葡萄糖,1%蔗糖,0.5%牛肉膏,0.02%硫酸亚铁,0.01%维生素B<,1>,pH值为7.球毛壳ND35菌株的抑菌作用分为活菌体的抑菌作用和代谢活性物质的抑菌作用,液体培养后的菌丝胞内和胞外均产生抗生物质,并具有较好的热稳定性.该抗生物质pH值为7,易溶于有机溶剂,难溶于水.球毛壳ND35抗生物质在221 nm处有最大的吸收峰,该抗生物质有4个组分,均对杨树腐烂病菌有抑菌活性.生长动力学表明,在液体发酵培养过程中,球毛壳ND35抗生物质的产量、吸光值、pH及其抑菌率是连续变化的.     

微波消解ICP-AES联用测定食用菌中锌、铁、锰和铜的含量

采用微波消解技术处理食用菌样品,用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定锌、铁、锰、铜等微量元素的含量。实验结果表明:优化的消解剂用量为每0.25g食用菌子实体4.5mL HNO3+4.5mL H2O2;该方法适合测定食用菌中的锌、铁、锰、铜等微量元素,具简便、快速、稳定、准确等优点。方法的检出限为0.77～1.54μg/L,加标回收率为91.0%～101%,相对标准偏差为0.95%～7.10%。     

食用菌废料的综合利用研究

在食用菌生产中,任意丢弃或堆制废料,是目前食用菌肥料处理上存在的一大问题.食用菌废料可以从以下8个方面进行重复利用:菌糠用于双孢菇制种,废料做家畜、家禽饲料,做农家肥料、燃料,做蔬菜育苗时代替覆土,提取激素和农药,废料饲养昆虫等.2001～2003年,周口市8县两区对食用菌废料综合利用的累计经济效益达2.5亿元.     

无摇床式液体菌种生产工艺及其培养装置研究

根据常规的摇床式食用菌液体菌种生产原理,设计了经济而简便的无摇床式生产新工艺和相应培养装置。经使用,效果理想。该装置已获国家专利(专利号:942165241)。     

捕食线虫真菌酯酶同工酶谱和可溶性蛋白质谱分析

 本文对5个属14个种共33株捕食线虫真菌采用聚丙烯酰胺凝胶电泳技术进行了酯酶同工酶谱和可溶性蛋白质谱分析。结果表明,酯酶同工酶谱带少,但各属的特征谱带是明显的,在同属不同种之间,多数种都有自已的特征谱带与其它种相区别,同种不同菌株间没有明显差异;蛋白质谱带较多,在每个属中均有1~2条特征谱带,属间的谱带差异明显,同属不同种和同种不同菌株间蛋白质谱带都表现出多型性。     

Biotransformation of soil humic acids by blue laccase of Panus tigrinus 8/18: an in vitro study

We describe here the role of the polyphenoloxidases in the oxidation of recalcitrant soil organic compounds and consider what changes occur in their structure during experiments on the biotransformation of soil and peat-derived humic acids (HA). These transformations were carried out by laccase (EC 1.10.3.2.) of the white-rot basidiomycete Panus tigrinus 8/18. It was shown that purified laccase alone is capable both of polymerizing and depolymerizing HA in vitro. The direction of transformations depends on the nature and properties of HA. Those fractions of HA are affected by laccase, which cause the lowest inhibitory effect on the enzyme. Contrary to previous studies depolymerization of HA was not necessarily accompanied by decolorization: chernozem-derived HA showed increase in absorbance of its aqueous solution in the region of 240-500 nm during depolymerization, while peat-derived HA showed decrease in absorbance throughout the entire spectrum during polymerization. All studied HA were competitive inhibitors of laccase towards oxidation of synthetic substrate 2,2′-azino-bis-(3-ethylthiazoline-6-sulfonate) (ABTS). When studying the nature of the inhibitory effect, it was shown that more ‘hydrophobic’ HA as well as more ‘hydrophobic’ HA fragments were stronger inhibitors of blue laccase.     

Host range comparison of the causal agents of pepper yellow vein and lettuce big vein

A number of solanaceous and composite plant species were tested as hosts for the causal agents of pepper yellow vein (PYVA) and lettuce big vein (LBVA), transmitted by a pepper and a lettuce isolate ofOlpidium brassicae, respectively. The agents had the following artificial hosts in common:Lycopersicon esculentum, Solanum melongena, Physalis floridana, Nicandra physaloides, Lactuca sativa, Sonchus oleraceus andL. virosa. Capsicum annuum, S. villosum, S. nigrum, Crepis vesicaria andSenecio vulgaris were infected by PYVA, but not by LBVA.Cichorium endivia andTaraxacum officinalis were not infected by any of the two agents.N. physaloides, although not colonized by the pepper isolate ofOlpidium, still became infected by PYVA.     

In vitro screening of novel treatments for Aphanomyces invadans

Forty‐nine compounds were tested in vitro for fungicidal activity against hyphae of the fish‐pathogenic Oomycete fungus, Aphanomyces invadans. These comprised: (a) chemicals with previous reported activity against Oomycete fungi; (b) chemicals in use in Asia to treat ulcerative disease outbreaks; (c) commercial biocides and fungicides; (d) natural products with potential antimicrobial activity; and (e) surfactants tested separately and in combination with some of the above treatments. No compounds tested proved as effective as malachite green, but some low‐toxicity natural compounds and particular surfactants showed potential for further studies. Some compounds that are currently in use in Asian aquaculture were shown to have no effect on A. invadans hyphae at recommended treatment rates. A range of compounds that demonstrated activity against the mycelium were selected for further testing in a zoospore motility assay. Lower treatment concentrations were required to inhibit zoospore motility than were required to inhibit hyphal growth. Zoospore activity ceased within 1 h of exposure to 2.5 parts per million (p.p.m.) coconut diethanol‐ amide; 1.25 p.p.m. propolis + 0.5 p.p.m. 13/6.5; 5 p.p.m. neem (Azadirachta siamensis) seed extract + 0.01 p.p.m. OP10; 20 p.p.m. tea tree (Melaleuca alternifloria) oil; and 25 p.p.m. D‐limonene + 0.05 p.p.m. E‐Z‐Mulse^TM. The treated spores were shown to be non‐viable in culture medium. Selected compounds were further tested for ability to inhibit zoospore production by A. invadans mycelium over a 72‐h period. In toxicity trials, silver barb, Barbodes gonionotus (Bleeker), exposed to 2.5 p.p.m. coconut diethanolamide; 2.5 p.p.m. OP10; 0.5 p.p.m. E‐Z‐Mulse^TM; 20 p.p.m. neem seed extract + 0.5 p.p.m. OP10; and 5 p.p.m. D‐limonene + 0.5 p.p.m. E‐Z‐Mulse^TM suffered no mortalities and no obvious behavioural changes. Similarly, rainbow trout, Oncorhynchus mykiss (Walbaum), exposed to 25 p.p.m. propolis + 1 p.p.m. OP10; 10 p.p.m. neem seed extract + 0.01 p.p.m. 13/6.5; and 10 p.p.m. D‐limonene + 0.01 p.p.m. OP10 suffered no mortalities and no obvious behavioural changes.     

昆虫病原丝状菌产生的杀虫性毒素

昆虫病原丝状菌Nomuraea rileyi产生的杀虫性毒素是用有机溶剂从菌体中提取的.色谱法分离及成分分析表明,此毒素是一种多肽.其氨基酸组成与以前发现的这类毒素不同,可能是一种新的杀虫性毒素.     

Specific resistance to soybean stem canker conferred by the Rdm4 locus

The Rdm4 gene from soybean cv. Hutcheson has been extensively used to incorporate resistance to soybean stem canker (SSC), caused by Diaporthe phaseolorum var . meridionalis (Dpm), into soybean commercial cultivars. The objective of this work was to characterize the inheritance of the Rdm4 locus in different populations derived from the cross: J77-339 ( rdm / rdm , susceptible) × Hutcheson ( Rdm4 / Rdm4 , resistant) in independent interactions with two local isolates of Dpm. Four F₂ populations were obtained and two were advanced to the F₃ generation as separate F_2:3 families to perform progeny tests. Each population was inoculated with the CE109 and/or CE112 isolates of Dpm. Within each plant–pathogen interaction, the resistance gene segregated as completely dominant. However, cross resistance, or opposite disease reactions, to CE109 and CE112 isolates of Dpm were observed in four F_2:3 families, indicating an intergenic recombination event between two nonallelic genes interacting specifically with each isolate of Dpm. The distance between them, estimated as the recombination fraction, was 29%, suggesting that both genes were not tightly linked, but close enough to segregate together in most crosses. Results indicated the existence of a genomic region in cv. Hutcheson composed of race-specific resistance loci with at least two Rdm genes: the previously recognized Rdm4 and a novel gene, tentatively named Rdm5 , conferring specific resistance to Dpm isolates CE109 and CE112.