过量钠盐和盐渍土壤提取液对3种外生菌根真菌生长的影响

美味牛肝菌(Boletusedulis)、红绒盖牛肝菌(Xerocomuschrysenteron)和铆钉菇(Gomphidiusviscidus)3种外生菌根真菌在不同浓度钠盐(0.05、0.10和0.20mol·L-1)和东营地区盐渍土壤提取液中培养,结果表明:钠盐处理促进了美味牛肝菌菌丝生长,生物量积累增加,而红绒盖牛肝菌和铆钉菇菌丝生长明显受到抑制。在土壤提取液培养条件下,供试3菌种菌丝的生长均受到极显著抑制。在不同浓度钠盐处理下,菌丝中钠元素的含量随培养基中钠盐浓度的增加而提高,说明菌丝对钠元素有较强的吸收能力。但不同菌种菌丝对钠元素的吸收和积累方式存在显著差异。     

Mycoremediation of diclofenac using Mucor hiemalis

Diclofenac (DCF) is a pharmaceutical drug widely found in the aquatic environment, where it represents a persistent, anthropogenic hazard to all biota. Owing to the reported inefficiency of water treatment strategies to remove pharmaceuticals, the present study aimed to investigate the ability of the aquatic fungus Mucor hiemalis to take up and accumulate DCF. Cultures of M. hiemalis were exposed to varying concentrations of DCF (10, 25 and 50 µg/L) over a period of 144 h. In the presence of M. hiemalis, DCF concentrations in the media decreased by 95% within 24 h. This early removal was most likely due to extracellular metabolism of DCF, as low proportions of the pharmaceutical were found in the mycelium of the fungus, thereby excluding bioaccumulation as the main mode of removal. However, adsorption of DCF onto the surface of the M. hiemalis pellets cannot be excluded. Our study provides the first report of DCF remediation using M. hiemalis and is the first successful step towards a feasible and inexpensive bioremediation technique for DCF.     

Effects of long-term land use on arbuscular mycorrhizal fungi and glomalin-related soil protein

The maintenance of soil health and productivity is a central aim of sustainable agriculture. Arbuscular mycorrhizal fungi (AMF) are soil biota fundamental for soil fertility and plant nutrition, which may be used in the evaluation of the impact of agronomic practices on soil quality. In the present study we evaluated the influence of three different land uses on AMF populations and correlated glomalin-related soil protein (GRSP) content with AMF biomass parameters, such as spore density and biovolume. Among the differently managed sites – maize monoculture, grassland and poplar grove – maize soil showed the lowest AMF spore number and GRSP content. The same morphological taxa were found in the three sites, except for one additional morphotype in poplar grove. A good correlation between GRSP and spore biovolume was found, suggesting that GRSP may represent a useful biochemical parameter for the assessment of biological soil fertility in sustainable agriculture.     

Properties of mercuric reductase from a HgCl2-resistant fungus

Mercuric reductase is detected in Cephalosporium tabacinum F2.The enzyme, which is an intracellular one,catalyzes the reduction of mercuric ions to elemental mercury,which requires NADH as an electron donor and added sulfhydryl compound.The optimum temperature and pH of the enzymatic reaction are 30℃ and 7.0- 8. 0,respectively.The enzyme activity is stable in the range of 25- 30℃ for 40min,and stable at pH 7. 0 for 2 hours. Metal ions such as Ag⁺ ,CO²⁺), Cu²⁺,Zh²⁺, Mn²⁺,Ni²⁺ show different degrees of inhibitory effect on the enzyme activity,other compounds such as phenylmercury acetate and potassium ferricyanide also partially inhibit the enzyme activity.     

Effects of copper, manganese and pH on the growth and several enzyme activities of mycorrhizal fungus Cenococcum geophilum Fr.

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电子产品常用有机涂层防霉特性研究

对于电子产品中不防霉的材料和零部件,为防止其长霉影响整个产品,采用防霉涂层和喷涂保护剂是最经济有效的措施.通过对1280件电子产品(或主要组成材料和工艺试片)霉菌试验结果的统计分析,总结出各种电子产品常用材料,特别是几种常用有机涂层的防霉特性.     

真菌(Aspergillus sp.)吸附Cu2+的研究

利用真菌Aspergillus sp.制备生物吸附剂,吸附重金属离子铜,实验分析了影响吸附率和吸附量的因素,结果表明,优化条件下,30℃, pH值5.0,起始Cu2+浓度50mg/L,摇床转速150r/min,经1mol/L NaOH预处理的吸附剂用量为5g/L,吸附时间45min,该吸附剂对Cu2+的吸附率达到92.22%.通过细胞显微观察和X-射线光电子能谱技术手段推断该菌细胞壁是Cu2+ 吸附的主要部位.     

Colonial recognition of fungus in the fungus-growing ant Acromyrmex subterraneus subterraneus (Hymenoptera: Formicidae)

Summary. Leaf cutting ants live in symbiosis with a basidiomycete fungus that is exploited as a source of nutrients for the ant larvae. Tests of fungus transport demonstrated that Acromyrmex subterraneus subterraneus workers discriminate concolonial fungus from alien fungus, and rejected the latter. Larvae and pupae of the ant were used as controls. Chemical analysis of the fungus revealed a great similarity between its hydrocarbon profile and that found on the ant brood. Experiments with lures showed that chemical extracts from the fungus are responsible for this discrimination process. Moreover, the presence of brood inside the fungus seemed to be important for discrimination of the fungus by workers. Resident workers accepted concolonial broodless fungus less than concolonial fungus inoculated with brood odor. Fungus seems to acquire colonial odor passively, simply by contact with the brood. The impact of fungus volume present in the nest on closure of the colony is discussed. We show here for the first time the importance of a symbiotic vegetal organism in colonial recognition in social insects. Received 14 April 2000; accepted 29 September 2000     

岛屿生境下苦槠丛枝菌根(AM)与根际土壤磷酸酶活性的相关性研究

以浙江千岛湖典型生境片断化区域苦槠(Castanopsis sclerophylla)为材料,研究了水库形成后岛屿化导致的群落生境差异对苦槠AM侵染率的影响以及AM侵染率与根际土壤磷酸酶活性的相关性.结果表明,以生境面积为因子进行单因素方差分析,则不同岛屿生境对苦槠AM侵染率影响差异不显著;但以Pearson相关性分析,AM侵染率与岛屿面积之间呈显著负相关.苦槠根际土壤酸性磷酸酶活性在中岛、大岛与陆地间差异显著,但与AM侵染率之间无显著相关性.     

外加不同铁源和丛枝菌根对砷污染土壤上玉米生长及磷、砷吸收的影响

通过盆栽模拟试验研究了添加不同铁源及接种丛枝菌根真菌(Arbuecular mycorrhizal fungi,AMF)对高砷污染土壤上玉米生长及其吸收磷、砷、铁、锰、铜和锌的影响.试验结果表明,与对照相比,添加硫酸亚铁并接种AMF显著地提高了土壤有效铁、锰含量,降低了土壤中水溶性砷、磷含量以及玉米地上部砷的含量,并极大地增加了植株对磷的吸收,提高了植株体内磷砷吸收量之比,从而明显地改善了植株的菌根建成和生长状况.在不接种情况下,硫酸亚铁和石灰混合处理显著地降低了土壤水溶性砷、磷含量及根系砷含量,并明显增加了磷的吸收以及磷、砷吸收量的比值,使玉米植株生物量和根长增加的幅度较其它铁源处理时更大.尽管添加铁尾矿砂增加了土壤水溶性磷的含量以及植株磷的吸收而在一定程度上改善了玉米的生长,但这种效果以不接种时更为明显,因而有必要根据土壤的污染程度调整铁尾矿砂的添加量和接种抗性菌株,以强化植物的抗砷能力.