东北地区木耳"白毛菌病"的病原菌

"白毛菌病"是近年来东北地区木耳栽培中一种常见病害.其病原菌在盛夏伏天侵染木耳子实体,在木耳耳片腹面生长一层白色网状霉层,对木耳生长及商品形态造成严重危害.从黑龙江省尚志地区染病耳片上分离得到两株病原菌,经对它们进行形态学特征观察、rDNA ITS序列分析和致病性测定,证明这两株病菌为尖孢镰孢和厚垣镰孢,二者均对栽培木...     

叉子圆柏上的胶锈菌一新种

描述了采自新疆哈密叉子圆柏Sabina vulgaris上的胶锈菌属一新种,即天山胶锈菌Gymnosporangium tianschanicum。此种因产生夏孢子阶段和单胞冬孢子（少量混生于夏孢子堆中）而不同于胶锈菌属的其它已知种。     

蚕沙有机肥的养分特性及其肥效

将废弃蚕沙进行无害化处理和适度发酵开发出蚕沙有机肥,分析了其养分特点,并采用盆栽试验研究了蚕沙有机肥的肥效.结果表明:发酵蚕沙有机肥的全氮、全磷、全钾含量与堆肥前相比显著提高,分别比堆肥前提高了58.0%、84.4%和29.7%;添加微生物菌剂可有效缩短发酵时间,并能减少堆肥过程的碳、氮损失.施用发酵后蚕沙的小白菜和番茄种子的发芽指数均大于80%,对作物发芽没有抑制作用.施用发酵蚕沙有机肥不仅可提高小白菜产量、营养养分、Vc含量,减少硝酸盐积累量,还可提高土壤pH值,增加土壤速效养分和有机质含量,增强土壤酶活性,其效果优于发酵羊粪有机肥处理.     

Modelling the effect of temperature, water activity and pH on the growth of Serpula lacrymans

Aims: To predict the risk factors for building infestation by Serpula lacrymans, which is one of the most destructive fungi causing timber decay in buildings. Methods and Results: The growth rate was assessed on malt extract agar media at temperatures between 1·5 and 45°C, at water activity (a_w) over the range of 0·800–0·993 and at pH ranges from 1·5 to 11·0. The radial growth rate (μ) and the lag phase (λ) were estimated from the radial growth kinetics via the plots radius vs time. These parameters were then modelled as a function of the environmental factors tested. Models derived from the cardinal model (CM) were used to fit the experimental data and allowed an estimation of the optimal and limit values for fungal growth. Optimal growth rate occurred at 20°C, at high a_w level (0·993) and at a pH range between 4·0 and 6·0. The strain effect on the temperature parameters was further evaluated using 14 strains of S. lacrymans. The robustness of the temperature model was validated on data sets measured in two different wood‐based media (Quercus robur L. and Picea abies). Conclusions: The two‐step procedure of exponential model with latency followed by the CM with inflection gives reliable predictions for the growth conditions of a filamentous fungus in our study. The procedure was validated for the study of abiotic factors on the growth rate of S. lacrymans. Significance and Impact of the Study: This work describes the usefulness of evaluating the effect of physico‐chemical factors on fungal growth in predictive building mycology. Consequently, the developed mathematical models for predicting fungal growth on a macroscopic scale can be used as a tool for risk assessment of timber decay in buildings.     

蛇足石杉内生真菌产黄青霉菌MT-40中xanthocillin类似物生物合成基因簇的挖掘及鉴定

Xanthocillin具有显著的抗菌活性,结构中含有独特的异腈基。本文通过对蛇足石杉(Huperzia serrata)内生真菌产黄青霉菌(Penicillium chrysogenum)MT-40基因组的测序分析,利用本地BLAST等生物信息学分析工具挖掘具有合成xanthocillin类似物潜力的基因簇,结合米曲霉(Aspergillus oryzae)NSAR1异源表达技术实现基因簇中关键基因的功能鉴定。结果成功从内生真菌P.chrysogenum MT-40中发现一个合成xanthocillin类似物的生物合成基因簇(命名为for),for基因簇中的关键生物合成基因forB编码的异腈基合成酶可以催化合成2-formamido-3-(4-hydroxyphenyl)acrylic acid,基因forG编码的P450酶可以催化2-formamido-3-(4-hydroxyphenyl)acrylic acid的二聚化生成xanthocillin类似物N,N′-(1,4-bis(4-hydroxyphenyl)buta-1,3-diene-2,3-diyl)diformamide。本文研究结果为进一步从真菌中发现xanthocillin类似物提供参考。     

Biodegradation of olive oil mill wastewaterby Coriolus versicolor and Funalia trogii:effects of agitation, initial COD concentration, inoculum size and immobilization

The biodegradation of olive oil mill wastewater (OOMW) by Coriolus versicolor and Funalia trogii was investigated. Initial COD concentration, agitation and inoculum size were all found to be significant for biodegradation. Adding glucose, sulphate or nitrogen had no effect on biodegradation. During growth in optimum conditions, C.versicolor removed approximately 63% COD, 90% phenol and 65% colour within 6 days and F. trogii removed approximately 70% COD, 93% phenol and 81% colour of the OOMW used. The fungi also excreted large amounts of extracellular laccase into the medium. High biodegradation yields were also obtained by fungi immobilized in calcium alginate gels.     

喀麦隆咯贝河中几种星形丝孢真菌的鉴定

从喀麦隆南部咯贝河入海处鉴定出6种链状分生孢子真菌,分别为灯芯草水枝孢Dendrosporajuncicola, 具缢链趾孢Phalangispora constricta Nawawi, 纳瓦链趾孢 P. nawawii, 具柄旋生孢Speiropsis pedatospora, 形旋生孢S. scopiformis, 连合韦氏孢Wiesneriomyces conjunctosporus。另有2类星形分生孢子归到枝孢属Dendrospora,但未鉴定到种。咯贝河的星形分生孢子真菌与来自马来西亚及其它热带地区的种类相似。     

Mycorrhizal‐mediated nitrogen acquisition in switchgrass under elevated temperatures and N enrichment

Arbuscular mycorrhizal fungi (AMF) can perform key roles in ecosystem functioning through improving host nutrient acquisition. Nitrogen (N) is an essential nutrient for plant growth, however, anthropogenic N loading (e.g. crop fertilization and deposition from combustion sources) is increasing so that N now threatens ecosystem sustainability around the world by causing terrestrial and aquatic eutrophication and acidification. It is important to better understand the capacity of AMF to directly uptake N from soils and transfer it to host plants because this process may increase N recycling and retention within ecosystems. In addition to understanding the role of AMF in the N cycle in the present day it is important to understand how AMF function may change as global change proceeds. Currently the net effects of N enrichment and elevated temperature predicted with global change on AMF are unknown. In this study, we examined the effects of N enrichment by simulated N‐deposition loading, elevated temperatures expected by future global changes and their interactions on growth and AMF‐mediated N acquisition of switchgrass (Panicum virgatum var. Alamo), an important species for biofuel production. Switchgrass plants were grown in microcosm units that divided mycorrhizal roots from AMF hyphae and organic residues enriched with ¹⁵N by compartments separated by an air gap to reduce N diffusion. While AMF did not enhance switchgrass biomass, mycorrhizas significantly increased ¹⁵N in shoots and total shoot N. Neither N enrichment nor elevated temperatures influenced this mycorrhizal‐mediated N uptake and transfer. Results from this study can aid in developing sustainable bioethanol and switchgrass production practices that are less reliant on synthetic fertilizers and more dependent on internal N recycling from AMF.