首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到10条相似文献,搜索用时 46 毫秒
1.
Polyextremotolerant black yeast-like fungi thrive in moderately hostile environments where they are concomitantly subjected to several types of stress, such as toxicity, scarce nutrient availability, and high or low temperature extremes. Their ability to assimilate alkylbenzenes (toxic environmental pollutants) enhances their growth in harsh conditions, including on railway ties. Samples were collected using cotton swabs, premoistened with physiological saline, from 658 oak and concrete railway ties at six train stations in Turkey at altitudes ranging between 1026 and 1427 m. The samples were inoculated on malt extract agar supplemented with chloramphenicol, and incubated at 26 °C for 4 weeks. Twenty-four samples (3.6 %), 17 from oak and 7 from concrete (5.6 % vs. 2 %; P = 0.02), tested positive for fungi. Exophiala crusticola was found to be the most common species (n = 13), followed by Exophiala phaeomuriformis (n = 7) and Exophiala heteromorpha (n = 4). These results suggest that hydrocarbons, particularly creosote-treated oak woods, support the growth of black yeasts, some of which are opportunists in humans.  相似文献   

2.
Between 2008 and 2010 the Zoological gardens in Rheine, Stuttgart, Karlsruhe, Cologne and Zurich took part in a research project initiated by scientists of the Institute of Animal Science, University of Bonn. Saliva was collected from various zoo animals to determine certain dietary adaptations on enzymatic and physiological levels that might explain or change our current understanding of animal nutrition and the feeding in zoo environments. The interest was primarily focused on species with specialized nutritional needs or fermentation strategies such as geladas, chimpanzees, camels and zebras. The work produced highly valuable data especially on geladas, which, despite from their adaptation to grass diet, revealed to have the enzymatic precondition (salivary amylase) to use starch-rich food items very effectively. Therefore, to prevent obesity in captive geladas, the reduction of starchy food in their daily rations is mandatory. Finally, saliva sampling is an easy, cost-effective and non-invasive procedure, the use of which is both practical and attractive in a zoo environment. In the future, the world-wide emerging field of salivary research might give birth to new applications of saliva as a tool to detect biomarkers of physiology and diseases in zoo animals.  相似文献   

3.
4.
The felid-specific urinary odour compound 3-mercapto-3-methylbutanol and its precursors have been found in several felid species in captivity, but its presence in wild felids has not previously been investigated. We analysed the naturally deposited scent marks from three species of wild, free-ranging big cats in Northern Botswana and found 3-mercapto-3-methylbutanol in four samples of leopard urine (N = 13), but not in lion urine (N = 15) or cheetah urine (N = 6). Individual variation in the presence of the tomcat compound in samples from big cats in the wild may reconcile conflicting results from captive cats.  相似文献   

5.
Numerous dinosauroid footprints which showing sometimes manus imprint mark were gathered, since 1960, from the lower sandstones Triassic formations of the eastern border of the Massif Central (France). Tracks bearing levels are dated from palynological, micropalaeontological and palichnological data. They belong to the period upper Anisian-lower Ladinian. The paleontological results show bipedal digitigrade reptiles with erected, long hind limbs, having also pentadactyl mani and (II-IV) tridactyl feet. The osteological feet inferred structure is like that of Ceratosauria of Late Triassic age. The skeletons of first Dinosauria, diversified already well, are known in summit Ladinian and lower Carnien and those of their ancestors, Dinosauriformes, in Ladinian. And, for this reason, the aniso-ladinian dinosauroid footprints are ascribed to these last animals which thus appeared earlier, to Anisan even to late Olenekian. The chirotheroid hands show a “pseudosuchian” origin which possibly took place during the late Olenekian; feet modifications of these Crurotarsi being characterized by I and V digits reduction and a meso-tarsal joint. The Anisian-Ladinian dinosauroid footprints are ascribed to the ichnospecies Coelurosaurichnus perriauxi and Anchisauripus bibractensis. The discriminant analysis computed from these latter ichnospecies, and others from the German Triassic, French and USA Hettangian indicate that C. perriauxi and A. bibractensis can not be included into Grallator sensu Lull, 1953 or Coelurosaurichnus of Franconie. By this way, these taxa are well original and till now, there was no reason to change their nomenclature. Nevertheless because the numerous changes of Grallator which gathers now, most of dinosauroid footprints, it could be possible to include them into Grallator for the feet and into Atreipus when the manus trace is connected with the foot.  相似文献   

6.
β-环柠檬醛(β-cyclocitral)是由微囊藻产生的主要藻源性异味污染物之一。利用稀释涂平板法,从采集到的微囊藻水华水样中分离得到两株降解β-环柠檬醛的菌株DH16和DH18,16S rRNA序列比对和系统进化树分析表明它们分别属于食酸菌属(Acidovorax)和不动杆菌属(Acinetobacter)。实验室保藏的微囊藻毒素降解菌Novosphingobium sp.THN1对β-环柠檬醛也有降解效果,该菌属于新鞘氨醇杆菌属(Novosphingobium)。对三株菌进行以β-环柠檬醛为唯一碳源的培养实验,气相色谱检测分析表明DH18和THN1两株菌具有高效降解β-环柠檬醛的能力,可以作为研究β-环柠檬醛生物降解机理的理想材料。  相似文献   

7.
8.
Populations of Pratylenchus brachyurus on cotton were increased significantly in the presence of either Meloidogyne incognita or M. arenaria.This occurred with either simultaneous inoculation or prior invasion by M. incognita. P. brachyurus penetrated cotton roots previously invaded by, or simultaneously inoculated with, M. incognita, as well as, or better than, in the absence of M. incognita. Prior invasion by M. incognita, however, suppressed P. brachyurus populations on tomato, while it had no effect on alfalfa and tobacco. Populations of M. incognita on cotton were generally inhibited by the presence of P. brachyurus. Simultaneous inoculation with, or previous invasion by, P. brachyurus also inhibited root penetration by M. incognita. These findings emphasize the importance of host susceptibility in the study of concomitant nematode populations.  相似文献   

9.
White-nose syndrome (WNS)  of bats, caused by the fungus previously known as Geomyces destructans, has decimated populations of insectivorous bats in eastern North America. Recent work on fungi associated with bat hibernacula uncovered a large number of species of Geomyces and allies, far exceeding the number of described species. Communication about these species has been hindered by the lack of a modern taxonomic evaluation, and a phylogenetic framework of the group is needed to understand the origin of G. destructans and to target closely related species and their genomes for the purposes of understanding mechanisms of pathogenicity. We addressed these issues by generating DNA sequence data for the internal transcribed spacer (ITS) region, nuclear large subunit (LSU) rDNA, MCM7, RPB2, and TEF1 from a diverse array of Geomyces and allies that included isolates recovered from bat hibernacula as well as those that represent important type species. Phylogenetic analyses indicate Geomyces and allies should be classified in the family Pseudeurotiaceae, and the genera Geomyces, Gymnostellatospora, and Pseudogymnoascus should be recognized as distinct. True Geomyces are restricted to a basal lineage based on phylogenetic placement of the type species, Geomyces auratus. Thus, G. destructans is placed in genus Pseudogymnoascus. The closest relatives of Pseudogymnoascus destructans are members of the Pseudogymnoascus roseus species complex, however, the isolated and long branch of P. destructans indicates that none of the species included in this study are closely related, thus providing further support to the hypothesis that this pathogen is non-native and invasive in eastern North America. Several conidia-producing isolates from bat hibernacula previously identified as members of Pseudeurotium are determined to belong to the genus Leuconeurospora, which is widespread, especially in colder regions. Teberdinia hygrophila is transferred to Pseudeurotium as Pseudeurotium hygrophilum, comb. nov., in accordance with the one name per fungus system of classification, and two additional combinations are made in Pseudogymnoascus including Pseudogymnoascus carnis and Pseudogymnoascus pannorum. Additional sampling from other regions of the world is needed to better understand the evolution and biogeography of this important and diverse group of fungi.  相似文献   

10.
The position of the Iberian Peninsula during the Early Cretaceous, sandwiched between Laurasia and Gondwana, makes it an important area for the biogeography study of terrestrial ecosystems. Relevant data are, however, scarce. The discovery of silicified wood in the west of the Cameros Basin, in the village Hacinas (Spain), is the first record of the genus Protopodocarpoxylon in Spain and the seventh of Agathoxylon. A new species, Protopodocarpoxylon haciniensis sp. nov., is described. The anatomy of the samples studied shows that paleoclimatic conditions during the Early Cretaceous in the western part of the Cameros Basin were favorable to tree growth, with good water supply during the growth season. Although much impoverished in comparison with Western Europe, the Iberian Early Cretaceous wood floras are clearly Laurasian in affinity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号