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181.
Norman L. Carreck Tariq M. Butt Suzanne J. Clark Ludmilla Ibrahim Elizabeth A. Isger Judith K. Pell Ingrid H. Williams 《Biocontrol Science and Technology》2007,17(2):179-191
Pollen beetles (Meligethes aeneus) and cabbage seed weevils (Ceutorhynchus assimilis) are major pests of oilseed rape (Brassica napus) throughout Europe. In field cage experiments in both winter and spring rape, honey bees (Apis mellifera) effectively transported the entomopathogenic fungus Metarhizium anisopliae to the flowers, causing infection and mortality of both adult and larval pollen beetles, as well as of adult seed weevils. External conidiation was observed on many of the dead pest insects. Although some external conidiation also occurred on dead honey bees, reduction in honey bee colony size during the experiments appeared unrelated to the fungus. The potential of this technique for integration into pest management strategies for the crop, particularly in association with a trap crop, is discussed. 相似文献
182.
Anderson S. Dias Jackson V. Araújo Artur K. Campos Fabio R. Braga Thiago A. Fonseca 《World journal of microbiology & biotechnology》2007,23(9):1245-1252
The viability of a formulation of Duddingtonia flagrans was assessed in the control of parasite gastrointestinal nematodes of cattle. Two groups (A and B) of eight crossbred Holstein × Zebu
cattle, approximately one year old, were placed in Brachiaria decumbens pasture. Each animal in group B (treated) received orally 20 g sodium alginate pellets containing mycelial mass of the D. flagrans fungus, while the animals in the group A (control) received pellets without fungus for seven months, starting in March 2005.
The egg per gram of feces counting the gastrointestinal nematodes showed a difference (P < 0.05) in the treated group in June, July and August, with reductions of 58% (June), 47% (July) and 51% (August) compared
to the control group. The infective larvae recovered in the pastures collected up to 20 cm from distance of the fecal dung
in group B differed (P < 0.01) from the larvae recovered in group A. At the end of the experimental period, the animals in group B presented a greater
weight gain (P < 0.01) compared to the untreated group (A). The treatment of cattle with pellets containing the D. flagrans nematophagous fungus, at the dose and duration used was effective in controlling the infective larvae of gastrointestinal
nematodes of cattle. 相似文献
183.
Bryan J. Culbertson Jaymie Krone Erastus Gatebe Norbert C. Furumo Steven L. Daniel 《World journal of microbiology & biotechnology》2007,23(10):1357-1362
The impact of various supplemental carbon sources (oxalate, glyoxylate, glycolate, pyruvate, formate, malate, acetate, and
succinate) on growth and oxalate formation (i.e., oxalogenesis) by Sclerotinia sclerotiorum was studied. With isolates D-E7, 105, W-B10, and Arg-L of S. sclerotiorum, growth in an undefined broth medium (0.1% soytone; pH 5) with 25 mM glucose and 25 mM supplemental carbon source was increased
by the addition of malate and succinate. Oxalate accumulation occurred in the presence of glucose and a supplemental carbon
source, with malate, acetate, and succinate supporting the most oxalate synthesis. With S. sclerotiorum Arg-L, oxalate-to-biomass ratios, an indicator of oxalogenic potential, were dissimilar when the organism was grown in the
presence of different carbon sources. The highest oxalate-to-biomass ratios were observed with pyruvate, formate, malate,
acetate, and succinate. Time-course studies with acetate-supplemented cultures revealed that acetate and glucose consumption
by S. sclerotiorum D-E7 coincided with oxalogenesis and culture acidification. By day 5 of incubation, oxalogenesis was halted when cultures
reached a pH of 3 and were devoid of acetate. In succinate-supplemented cultures, oxalogenesis essentially paralleled glucose
and succinate utilization over the 9-day incubation period; during this time period, culture pH declined but never fell below
4. Overall, these results indicate that carbon sources can regulate the accumulation of oxalate, a key pathogenicity determinant
for S. sclerotiorum. 相似文献
184.
185.
In the thermophilic archaeon Sulfolobus tokodaii, there are two genes homologous to PduO-type ATP:cob(I)alamin adenosyltransferase, ST1454 and ST2180. To address the structure and function of these two sequence-related proteins from one organism, we prepared them by using the Escherichia coli expression system and analyzed them by immunoblotting, matrix-assisted laser desorption ionization-time-of-flight mass spectroscopy, circular dichroism spectrometry, ATP:cobalamin adenosyltransferase assay, and X-ray crystallography. Immunoblotting and matrix-assisted laser desorption ionization-time-of-flight mass spectroscopy analyses showed that both these proteins are expressed in S. tokodaii cells as soluble proteins and are spontaneously digested at the N-terminal region. ATP:cob(I)alamin adenosyltransferase activity was detected for ST1454 but not for ST2180. ST2180 reduced the concentration of cob(I)alamin, suggesting that ST2180 might recognize cob(I)alamin as a ligand. The secondary structure of ST1454 was retained even in 7 M guanidine hydrochroride, whereas that of ST2180 was melted in 4.5 M guanidine hydrochloride. The X-ray crystal structural analysis revealed that the proteins shared a common structure: a trimer of five-helix bundles with a clockwise kink. There is a pocket surrounded by highly conserved residues, in which a polypropylene glycol 400 in the crystal structure of ST1454 was captured, suggesting that it is an active site. Structural comparison between these two proteins showed the difference in the number of ion pairs around the proposed active site. On the basis of these results, we propose that ST1454 and ST2180 have related but distinct functions. 相似文献
186.
餐厨垃圾高温好氧生物减量菌种的筛选及特性 总被引:1,自引:1,他引:0
【背景】随着餐厨垃圾产生量的逐步提高,如何实现其快速降解,成为餐厨垃圾处理亟待解决的问题。餐厨垃圾的高温好氧生物减量技术是一种可以快速降解餐厨垃圾的有效方法。【目的】筛选能够适应餐厨垃圾环境且具有高效降解餐厨垃圾中有机物能力的菌株,以提高餐厨垃圾的降解效率和减量效果。【方法】采用温度梯度耐受性实验和餐厨垃圾浸出液高油高盐耐受性实验进行菌种初筛,并利用产酶培养基复筛及餐厨垃圾生物减量实验验证。【结果】通过初筛、复筛和功能验证,最终获得4株生物减量效果优良的菌株N3-1、C7、N3-3和G6-1,其对餐厨垃圾挥发性固体(volatile solid,VS)的降解率分别为36.95%、33.23%、32.83%和31.91%,是对照组的3.02、2.71、2.68和2.61倍。经鉴定,这4株菌分别属于热嗜油地芽孢杆菌(Geobacillus thermoleovorans)、史氏芽孢杆菌(Bacillus smithii)、热解木糖地芽孢杆菌(Geobacillus caldoxylosilyticus)和立陶宛地芽孢杆菌(Geobacillus lituanicus)。【结论】筛选出的4株菌均具有较强的餐厨垃圾原料适应性和高效的生物降解能力,为开发餐厨垃圾高温好氧复合菌剂奠定了基础,并为实现餐厨垃圾减量化、无害化处理和资源化利用提供了技术支持。 相似文献
187.
The white‐nose syndrome (WNS), caused by the fungal pathogen Pseudogymnoascus destructans, is threatening the cave‐dwelling bat fauna of North America by killing individuals by the thousands in hibernacula each winter since its appearance in New York State less than ten years ago. Epidemiological models predict that WNS will reach the western coast of the USA by 2035, potentially eliminating most populations of susceptible bat species in its path (Frick et al. 2015; O'Regan et al. 2015). These models were built and validated using distributional data from the early years of the epidemic, which spread throughout eastern North America following a route driven by cave density and winter severity (Maher et al. 2012). In this issue of Molecular Ecology, Wilder et al. (2015) refine these findings by showing that connectivity among host populations, as assessed by population genetic markers, is crucial in determining the spread of the pathogen. Because host connectivity is much reduced in the hitherto disease free western half of North America, Wilder et al. make the reassuring prediction that the disease will spread more slowly west of the Great Plains. 相似文献
188.
Matthew H. Becker Jenifer B. Walke Shawna Cikanek Anna E. Savage Nichole Mattheus Celina N. Santiago Kevin P. C. Minbiole Reid N. Harris Lisa K. Belden Brian Gratwicke 《Proceedings. Biological sciences / The Royal Society》2015,282(1805)
Symbiotic microbes can dramatically impact host health and fitness, and recent research in a diversity of systems suggests that different symbiont community structures may result in distinct outcomes for the host. In amphibians, some symbiotic skin bacteria produce metabolites that inhibit the growth of Batrachochytrium dendrobatidis (Bd), a cutaneous fungal pathogen that has caused many amphibian population declines and extinctions. Treatment with beneficial bacteria (probiotics) prevents Bd infection in some amphibian species and creates optimism for conservation of species that are highly susceptible to chytridiomycosis, the disease caused by Bd. In a laboratory experiment, we used Bd-inhibitory bacteria from Bd-tolerant Panamanian amphibians in a probiotic development trial with Panamanian golden frogs, Atelopus zeteki, a species currently surviving only in captive assurance colonies. Approximately 30% of infected golden frogs survived Bd exposure by either clearing infection or maintaining low Bd loads, but this was not associated with probiotic treatment. Survival was instead related to initial composition of the skin bacterial community and metabolites present on the skin. These results suggest a strong link between the structure of these symbiotic microbial communities and amphibian host health in the face of Bd exposure and also suggest a new approach for developing amphibian probiotics. 相似文献
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190.