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21.
P. L. Bolen C. P. Kurtzman J. M. Ligon B. M. Mannarelli R. J. Bothast 《Antonie van Leeuwenhoek》1992,61(3):195-205
Five strains of the heterothallic yeastSaccharomycopsis crataegensis have been previously shown to contain DNA and/or RNA plasmidlike molecules (Shepherd et al. 1987). Three DNA plasmids, designated pScrl-1,-2 and -3, were found in strain NRRL Y-5902, while two were identified in each of NRRL strains Y-5903 and Y-5904. DNA plasmids were not identified inS. crataegensis strains Y-5910 or YB-192. FourS. crataegensis strains (Y-5903, Y-5904, Y-5910 and YB-192) were also shown to possess double-stranded RNA (dsRNA) molecules not found in strain Y-5902 (Shepherd et al. 1987). Hybridization studies now demonstrate the DNA plasmids in Y-5903 and Y-5904 to be highly homologous to their respective size counterparts (pScrl-1 and pScrl-2) in Y-5902 and to show some homology to pScrl-3. Restriction endonuclease mapping studies confirm the linear nature of each plasmid and establish identical restriction maps for a 1.4 kilobase (kb) region in pScrl-2 and -3. This 1.4 kb region accounts for the hybridization homology of pScrl-2 and pScrl-3 noted by Shepherd et al. (1987) and for homology of the plasmids of Y-5903 and Y-5904 to pScrl-3 of Y-5902. The pScrl plasmids show no homology to the dsRNA molecules ofS. crataegensis, the 2 M circular DNA ofStaccharomyces cerevisiae, the killer plasmids ofKluyveromyces lactis, or the linear DNA plasmids ofPichia inositovora.In crosses between linear DNA plasmid-containing and dsRNA-containing strains, only progeny containing the pScrl plasmids were recovered. Poor spore viability and a lack of complete tetrad recovery limited the extent of the analysis, but the findings suggest a cytoplasmic mode of inheritance for these linear DNAs.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned. 相似文献
22.
J. Wolstrup P. Nansen J. Gronvold S. A. Henriksen M. Larsen 《Journal of nematology》1996,28(2):129-132
In a series of laboratory and field experiments where the nematophagous fungus Arthrobotrys oligospora was mixed directly with feces it has been demonstrated that it is possible to use nematophagous fungi for biological control of animal parasitic nematodes. A procedure used for selection of nematophagous fungi that can pass the digestive tract of ruminants, horses, and pigs is described. The selected fungus, Duddingtonia flagrans, has been used in further field experiments, and the results have confirmed that by the addition of D. flagrans to feed supplement it is possible to reduce the parasitic burden significantly. 相似文献
23.
《Molecular & general genetics : MGG》1996,253(3):315-323
A clone containing a Neocallimastix frontalis cDNA assumed to encode the β subunit of succinyl-CoA synthetase (SCSB) was identified by sequence homology with prokaryotic
and eukaryotic counterparts. An open reading frame of 1311 bp was found. The deduced 437 amino acid sequence showed a high
degree of identity to the β-succinyl-CoA synthetase of Escherichia coli (46%), the mitochondrial β-succinyl-CoA synthetase from pig (48%) and the hydrogenosomal β-succinyl-CoA synthetase from Trichomonas vaginalis (49%). The G+C content of the succinyl-CoA synthetase coding sequence (43.8%) was considerably higher than that of the 5′
(14.8%) and 3′ (13.3%) non-translated flanking sequences, as has been observed for other genes from N. frontalis. The codon usage pattern was biased, with only 34 codons used and a strong preference for a pyrimidine (T) in the third positions
of the codons. The coding sequence of the β-succinyl-CoA synthetase cDNA was cloned in an E. coli expression vector encoding a 6(His) tag. The recombinant protein was purified by affinity binding and used to produce polyclonal
antibodies. The anti-succinyl-CoA synthetase serum recognized a 45 kDa protein from a N. frontalis fraction enriched for hydrogenosomes and similar polypeptides in two related anaerobic fungi, Piromyces rhizinflata (45 kDa) and Caecomyces communis (47 kDa). Immunocytochemical experiments suggest that succinyl-CoA synthetase is located in the hydrogenosomal matrix. Staining
for SCS activity in native electrophoretic gels revealed a band with an apparent molecular weight of approximately 330 kDa.
The C-terminus of the succinyl-CoA synthetase sequence was devoid of the typical targeting signals identified so far in microbody
proteins, indicating that N. frontalis uses a different signal for sorting SCSB into hydrogenosomes. Based on comparisons with other proteins we propose a putative
N-terminal targeting signal for succinyl-CoA synthetase of N. frontalis that shows some of the features of mitochondrial targeting sequences.
Received: 16 October 1995 / Accepted: 29 July 1996 相似文献
24.
25.
Fungal spore populations in the outdoor and indoor atmosphere of Ismailia have been studied during the period from March 1992
to May 1993. A total of 23 350 cfu and 73 species were recorded,Cladosporium cladosporioides, Aureobasidium pullulans andAspergillus flavus were the most abundant. The indoor and outdoor mycoflora showed marked quantitative and qualitative differences. In view
of count, recorded species could be categorized into three groups as follows: (a) species showing higher counts in out- than
indoor, (b) species showing the opposite trend i.e. lower counts in out-door than indoor, (c) species showing approximately
equal counts in out- and indoor. Regarding seasonal periodicity, March and either September or October showed the highest
count for both normal fungal flora (NFF) and opportunistic fungal flora (OFF). While January and July showed the lowest count
of them both, May but not July was the lowest as for outdoor NFF. 相似文献
26.
Sewage sludge from the Upper Silesia Region of Poland were surveyed for keratinolytic fungi. Out of 100 Petri dishes examined, 89 were positive for these micro-organisms. Altogether, 185 fungal appearances belonging to 10 species were observed. Trichophyton terrestre with its teleomorph Arthroderma quadrifidum, T. ajelloi with A. uncinatum, Microsporum gypseum with Arthroderma sp., and Chrysosporium keratinophilum with Aphanoascus keratinophilus prevailed in the sludges. The sewage treatment technologies together with the sludge structure, humidity and pH were found to be critical factors determining the occurrence of keratinolytic fungi in the sludge environment. The qualitative and quantitative composition of keratinolytic fungi could be a useful tool in evaluation of sludge treatment processes. 相似文献
27.
The qualitative fungal composition of Turin 's atmospheric environment was surveyed, carrying out a twelve-month study and collecting with a single stage volumetric sieve sampler on Dermasel agar supplemented with 0.4 g l–1 cycloheximide and 0.05 g l–1 chloramphenicol. We isolated 165 species and 2 varieties of mesophilic fungi from 58 genera and 26 thermotolerant species from 12 genera. Penicillium, Aspergillus, Acremonium, Chrysosporium, Scopulariopsis, Malbranchea, Paecilomyces, Phialophora and Cladosporium were in sequence the genera most rich in mesophilic species; Aspergillus, Penicillium, Chrysosporium and Scopulariopsis the most rich in thermotolerant species. Many of the species isolated are rarely or never recorded in the atmospheric environment. Cycloheximide can thus be said to select among airborne fungi, giving a characteristic picture.Abbreviation CH
Cycloheximide
- cfu
colony forming unit 相似文献
28.
Corné M. J. Pieterse Anne-Marie C. E. Derksen Jindra Folders Francine Govers 《Molecular & general genetics : MGG》1994,244(3):269-277
The ipiB and ipiO genes of the potato late blight fungus Phytophthora infestans (Mont.) de Bary were isolated from a genomic library in a screen for genes induced in planta. Expression of these genes was studied during pathogenesis on various host tissues and different host plants, some of which show specific resistance against P. infestans infection. During pathogenesis on leaves and tubers of the fully susceptible potato cultivar (cv.) Ajax and on leaves of the fully susceptible tomato cv. Moneymaker, the P. infestans ipiB and ipiO genes show a transient expression pattern with highest mRNA levels in the early stages of infection. During the interaction with leaves of the partially resistant potato cv. Pimpernel, the expression is also transient but accumulation and disappearance of the mRNAs is delayed. Also in P. infestans inoculated onto a race-specific resistant potato cultivar and onto the nonhost Solanum nigrum, ipiB and ipiO mRNA is detectable during the initial stages of infection. Apparently, the expression of the ipiB and the ipiO genes is activated in compatible, incompatible and nonhost interactions. In encysted zoospores, ipiB and ipiO mRNA accumulation was not detectable, but during cyst germination and appressorium formation on an artificial surface the genes are highly expressed. Expression studies in mycelium grown in vitro revealed that during nutrient starvation the expression of the ipiB and ipiO genes is induced. For ipiO gene expression, carbon deprivation appeared to be sufficient. The ipiO gene promoters contain a sequence motif that functions as a glucose repression element in yeast and this motif might be involved in the regulation of ipiO gene expression. 相似文献
29.
J. Błaszkowski 《Mycorrhiza》1994,5(1):71-88
In the years 1985–1989, the occurrence of arbuscular fungi and mycorrhizae on the Hel Peninsula (Poland) was investigated with the help of 45 soil and root samples collected under 20 plant species of eight families. Except for Zea mays, the other plant species were from uncultivated sites. All soil samples contained spores of arbuscular fungi, of which about 45% were of the genus Glomus. Acaulospora spp. preferred members of the Cupressaceae. Spores of Gigaspora occurred rarely and only in two plant families. Glomus spp. were most frequently associated with plants of the Rosaceae, and species of Scutellospora were found at markedly higher frequencies among roots of plants of the Gramineae and Cupressaceae. A total of 29 spore-forming species and Glomus tenue (a fungus recognizable by its distinctive infections) were found. The most frequently recovered fungus, Glomus tenue, was present in roots of 56.8% of examined plants. Of the spore-forming fungi, the most frequently isolated spores were those of Scutellospora dipurpurascens, then Glomus constrictum, Acaulospora 61, and Glomus microcarpum. The overall spore density in examined samples averaged 99.8 in 100 g dry soil in the range 1 to 547, and was highest in a sample taken from around roots of Festuca arundinacea. The dominant fungi forming spores in sampled soils were Glomus constrictum, Glomus microcarpum, and Scutellospora dipurpurascens. The average species density was 3.9 in 100 g dry soil in the range 1 to 10, and was highest in Corynephorus canescens, Rosa canina, and Thuja occidentalis. Levels of colonization by arbuscular fungi ranged from 0.0 to94.0% (mean 23.3%) of the root length and were highest in Festuca arundinaceae and Zea mays. 相似文献
30.