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1.
Interspecific hybridizations were made between species of theE. semicostatus group, viz.,E. semicostatus (Nees exSteud.)Meld.,E. validus (Meld.)B. Salomon,E. abolinii (Drob.)Tzvel., andE. fedtschenkoi Tzvel., and species of theE. tibeticus group, viz.,E. pendulinus (Nevski)Tzvel.,E. tibeticus (Meld.)Singh,E. shandongensis B. Salomon, andE. gmelinii (Ledeb.)Tzvel., as well as among species within theE. tibeticus group. All species are tetraploid (2n = 4x = 28) and possess SY genomes. Meiotic pairing data from 24 hybrids involving 17 interspecific combinations are presented. The average number of chiasmata per cell ranged from 17.91 to 26.20 in hybrids within theE. tibeticus group, compared with 7.26 to 22.04 in hybrids between the two species groups. Despite the extensive collection of cytological data, there was no definite evidence for confirming or disproving the separate existence of the two groups.  相似文献   

2.
Enigmagraptus n. gen. comprises a group of the smallest known graptolites, with problematical evolutionary ancestors. The species described, all of Přídolí age are:E. yassensis (Rickards &Wright, 1999),E. cf.yassensis, E. mitchelli (Rickards &Wright, 1999) andE. pennyae n. sp.   相似文献   

3.
Eight strains isolated from birds, reptiles, and water constitute a new DNA hybridization group that is 37–58% related toEdwardsiella tarda and less than 10% related to other species of Enterobacteriaceae (SI nuclease method). This homogeneous group (78–100% relatedness within the group) constitutes a new species that is namedEdwardsiella hoshinae sp. nov. (type strain, CIP 78.56 ATCC 33379). Strains of this species produce acid fromd-mannitol, sucrose,d-trehalose, and salicin, and give a positive malonate test. Seven other strains that produced acid fromd-mannitol and sucrose (but not fromd-trehalose and salicin) and were malonate negative were found to belong to theEdwardsiella tarda DNA hybridization group. The base composition of the DNAs ofE. tarda andE. hoshinae is 55–58 mol% G+C.  相似文献   

4.
The structure of Eubacterium nodatum cell wall peptidoglycan was investigated. The peptide subunit of E. nodatum peptidoglycan has the following structure: L-Ala-D-Glu (Gly)-L-Orn-D-Ala. The carboxyl group of alanine occupying position 4 is attached to the -amino group of ornithine of an other subunit by the cross-linking bridge L-Ala-L-Ala-L-Orn. All glycine molecules are connected with the -carboxyl group of glutamic acid with the ratio being 0.5–1. The hydrolysis of E. nodatum peptidoglycan by the S. albus G enzyme proceeds primarily due to the activity of alanyl-alanine endopeptidase, ornithyl-ornithine endopeptidase, ornithyl-alanine endopeptidase, N-acetyl-muramyl-alanine amidase, N-acetylmuramidase and N-acetylglucosaminidase.  相似文献   

5.
Résumé Des souches d'Entomophthora du groupesphaerosperma isolées respectivement de chenilles deTortrix viridana L., d'imagos d'Agriotes sputator L. et de nombreuses espèces d'Aphididae doivent être classées dans trois espèces distinctes:E. sphaerosperma Fres.,E. elateridiphaga Turian etE. phalloides Batko. Les différences essentielles concernent la dimension et la forme des conidies primaires et celles des conidies formées à l'extrémité de tubes capillaires ainsi que les exigences nutritives.
Summary Entomophthora strains belonging to thesphaerosperma group were isolated from caterpillars ofTortrix viridana L., from adults ofAgriotes sputator L. and from various Aphid species. They respectively belong to 3 separated species ofEntomophthora: E. sphaerosperma Fres. s.str., E. elateridiphaga Turian (originally described as subspecies ofsphaerosperma), E. phalloides Batko. The shape of the secondary conidia which are formed at the top of capillary tubes furnish the best character for discrimination.E. sphaerosperma grows very fast on various media including Sabouraud;E. elateridiphaga grows slowly on Sabouraud andE. phalloides requires adjunction of egg yolk.
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6.
l-Cysteine is an important amino acid in terms of its industrial applications. We previously found marked production of l-cysteine directly from glucose in recombinant Escherichia coli cells by the combination of enhancing biosynthetic activity and weakening the degradation pathway. Further improvements in l-cysteine production are expected to use the amino acid efflux system. Here, we identified a novel gene involved in l-cysteine export using a systematic and comprehensive collection of gene-disrupted E. coli K-12 mutants (the Keio collection). Among the 3,985 nonessential gene mutants, tolC-disrupted cells showed hypersensitivity to l-cysteine relative to wild-type cells. Gene expression analysis revealed that the tolC gene encoding the outer membrane channel is essential for l-cysteine tolerance in E. coli cells. However, l-cysteine tolerance is not mediated by TolC-dependent drug efflux systems such as AcrA and AcrB. It also appears that other outer membrane porins including OmpA and OmpF do not participate in TolC-dependent l-cysteine tolerance. When a low-copy-number plasmid carrying the tolC gene was introduced into E. coli cells with enhanced biosynthesis, weakened degradation, and improved export of l-cysteine, the transformants exhibited more l-cysteine tolerance and production than cells carrying the vector only. We concluded that TolC plays an important role in l-cysteine tolerance probably due to its export ability and that TolC overexpression is effective for l-cysteine production in E. coli. Natthawut Wiriyathanawudhiwong and Iwao Ohtsu contributed equally to this work.  相似文献   

7.
R. Ciferri 《Mycopathologia》1943,3(3-4):340-342
Riassunto Si critica la combinazione Aspergillus variecolor creata da Thom e Raper per l'Emericella variecolor sulla base dell'identità della forma conidica (Aspergillus), senza tenere in nessun conto la notevole diversità di morfologia delle ascospore di E. variecolor rispetto a quelle di Aspergillus nidulans, nel quale gruppo Thom e Raper vorrebbero porre E. variecolor.
Summary The new combination Aspergillus variecolor for Emericella variecolor, made by Thom and Raper, on the base of identity of the conidic form, and without taking in consideration the different morphology of the ascospores of E. variecolor in comparison with those of Aspergillus nidulans (a group including also E. variecolor, according the above quoted students) is criticized.

Zusammenfassung Man kritisiert die Kombination des Aspergillus variecolor, die von Thom und Raper durch Emericella variecolor auf Basis der Identität der konidischen Form (Aspergillus) geschaffen wurde, ohne jegliche Berücksichtigung der bemerkenswerten Verschiedenheit der Morphologie zwischen den Askosporen des E. variecolor und denen des Aspergillus nidulans (in die letzte Gruppe wollen Thom und Raper den E. variecolor einreihen).

Sumario La combinaoión Aspergillus variecolor, creada por Thom y Raper por Emericella variecolor en base a la identidad de la forma conidica (Aspergillus), sin tener en cuenta la notable diferencia entre la morfologia de las ascosporas de E. variecolor frente aquellas de Aspergillus nidulans (en el cual grupo los cienciados americanos quieren situar E. variecolor) está considerata como criticable.
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8.
Recombinant strains of Escherichia coli K-12 for the production of the three aromatic amino acids (l-phenylalanine, l-tryptophan, l-tyrosine) have been constructed. The largest demand is for l-phenylalanine (l-Phe), as it can be used as a building block for the low-calorie sweetener, aspartame. Besides l-Phe, an increasing number of shikimic acid pathway intermediates can be produced from appropriate E. coli mutants with blocks in this pathway. The last common intermediate, chorismate, in E. coli not only serves for production of aromatic amino acids but can also be used for high-titer production of non-aromatic compounds, e.g., cyclohexadiene-transdiols. In an approach to diversity-oriented metabolic engineering (metabolic grafting), platform strains with increased flux through the general aromatic pathway were created by suitable gene deletions, additions, or rearrangements. Examples for rational strain constructions for l-phenylalanine and chorismate derivatives are given with emphasis on genetic engineering. As a result, l-phenylalanine producers are available, which were derived through several defined steps from E. coli K-12 wild type. These mutant strains showed l-phenylalanine titers of up to 38 g/l of l-phenylalanine (and up to 45.5 g/l using in situ product recovery). Likewise, two cyclohexadiene-transdiols could be recovered.  相似文献   

9.
Ribose-5-phosphate isomerase from Clostridium thermocellum converted d-psicose to d-allose, which may be useful as a pharmaceutical compound, with no by-product. The 12 active-site residues, which were obtained by molecular modeling on the basis of the solved three-dimensional structure of the enzyme, were substituted individually with Ala. Among the 12 Ala-substituted mutants, only the R132A mutant exhibited an increase in d-psicose isomerization activity. The R132E mutant showed the highest activity when the residue at position 132 was substituted with Ala, Gln, Ile, Lys, Glu, or Asp. The maximal activity of the wild-type and R132E mutant enzymes for d-psicose was observed at pH 7.5 and 80°C. The half-lives of the wild-type enzyme at 60°C, 65°C, 70°C, 75°C, and 80°C were 11, 7.0, 4.2, 1.5, and 0.6 h, respectively, whereas those of the R132E mutant enzymes were 13, 8.2, 5.1, 3.1, and 0.9 h, respectively. The specific activity and catalytic efficiency (k cat/K m) of the R132E mutant for d-psicose were 1.4- and 1.5-fold higher than those of the wild-type enzyme, respectively. When the same amount of enzyme was used, the conversion yield of d-psicose to d-allose was 32% for the R132E mutant enzyme and 25% for the wild-type enzyme after 80 min.  相似文献   

10.
Phylogenetic relationships among the 12 species of the green ash group of eucalypts were examined using allozyme data, to investigate the causes of rarity in three localized endemics of the group. The relationships suggested by the allozyme data showed both similarities to and differences from those estimated from morphological data byLadiges and coworkers. The phylogenetic relationships suggest that rarity inEucalyptus burgessiana may be related to recent divergence, whileE. paliformis andE. rupicola are relatively old species, more likely to be relicts, and/or restricted to a rare habitat.  相似文献   

11.
M. Hayat 《BioControl》1972,17(1):99-106
An account of the Indian species of the genusEretmocerus Haldeman is given. Three new species (E. indicus sp. n.,E. mashhoodi sp. n.,E. gunturiensis sp. n.) are described. Three species (E. haldemani Howard,E. mundus Mercet,E. corni Haldeman) are reported for the first time from India. A revised key to the known species of the genus is also given.
Résumé Une révision des espèces indiennes du genreEretmocerus Haldeman est donnée. Trois nouvelles espèces (E. indicus, E. mashhoodi, E. gunturiensis) sont décrites, trois autres espèces (E. haldemani Howard,E. mundus Mercet,E. corni Haldeman) sont signalées pour la première fois de l’Inde. Une clé révisée des espèces connues de ce genre est proposée.
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12.
A strategy, termed alanine-scanning mutagenesis, was used to identify the amino acid residues which are critical to the antigenicity of Escherichia coli l-asparaginase (l-ASP). Three continuous alkaline residues, 195RKH197, were mutated to Ala selectively. Four mutant recombinant l-ASPs were constructed and expressed in E. coli, and then purified. The purified mutants showed a single band by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and were more than 95% pure by reverse high-perfomance liquid chromatography. The activities of wild-type and m l-ASPs in the fermentative medium were all about 130 U/mL. The change from 195RKH 197 to 195AAA 197 reduced the antigenicity ofhe enzyme greatly as shown in competition enzyme-linked immunosorbent assay using polyclonal antibodies raised against the wild-type l-ASP from rabbits. The results show that residues 195RKH197 of E. coli l-ASP are critical to its antigenicity. These authors contributed equally to this work.  相似文献   

13.
Summary Five proteases were isolated from the digestive fluid of the lugworm, Arenicola marina L. The enzymes (molecular weight 24.0–24.6 kDa) were classified as serine proteases. Three enzymes showed a cleavage specificity corresponding to mammalian trypsin (E.C. 3.4.21.4). One protease possessed a chymotrypsin-like cleavage pattern (E.C. 3.4.21.1), and the fifth preferred cleavage behind short-chain amino acids like an elastase (E.C. 3.4.21.36). Detailed investigations revealed differences in molecular characteristics and cleavage patterns compared to mammalian proteases, especially in the chymotrypsin- and the elastase-like enzymes.Abbreviations APNE N-acetyl-d/l-Phe -naphthyl ester - BANA N-benzoyl-d/l-Arg -naphthylamide - BAPNA N-benzoyl-d/l-Arg-4-nitroanilide - BIGGANA N-benzoyl-l-Ile-l-Glu-Gly-l-Arg-4-nitroanilide - BLPNA N-benzoyl-d/l-Lys-4-nitroanilide - BTEE N-benzoyl-l-Tyr ethyl ester - enzyme T1/T2/T3 trypsin-like enzyme - enzyme ChT chymotrypsin-like enzyme - enzyme E elastase-like enzyme - GPANA N-glutaryl-l-Phe-4-nitroanilide - MUF 4-methylumbelliferryl - MW molecular weight - PMSF phenylmethylsulphonyl fluoride - SAAPPNA N-succinyl-l-Ala-l-Ala-l-Pro-l-Phe-4-nitroanilide - SBTI soybean trypsin inhibitor - SPPNA N-succinyl-l-Phe-4-nitroanilide - TAME N-tosyl-l-Arg methyl ester - TFA trifluoracetic acid - TLCK N-tosyl-l-Lys chloromethyl ketone - TPCK N-tosyl-l-Phe chloromethyl ketone - TRIS tris(hydroxymethyl)aminomethane  相似文献   

14.
Veronica allahuekberensis A. Öztürk, spec. nova, probably endemic to the Allahuekber mountain in N.E. Anatolia, belongs toV. orientalis group of sectionVeronica and resemblesV. cuneifolia D. Don subsp.cuneifolia, endemic to S.W. Anatolia.
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15.
An electron microscopic examination of the KOSHEWNIKOW gland of the honeybee showed that the origin of the draining ductule extended into the gland cell through an invagination without actual cytoplasmic connection being made. The structure of the wall of the dendritic apical ramifications of the duct cell is very loose where it is in juxtaposition to the microvilli of the wall of the gland cell. In contrast, the rest of the duct wall is very dense.

Gekürzte Dissertation der Fakultät für Chemie, Biologic, Geologic und Mineralogio der Technischen Hochschule Darmstadt; D I7. Danken möchte ich meinem verstorbenen Lehrer, Herrn Prof. Dr. W. Luther, Herrn Prof. Dr. D. B. E. Magnus and ganz besonders Herrn Prof. Dr. K. E. Wohlfarth-Bottermann für seine hilfsbereite Beratung in Fragen der Elektronenmikroskopie.  相似文献   

16.
Summary A thermostable lipase gene from Pseudomonas fluorescens SIK W1 was overexpressed in Escherichia coli BL21 using expression vector pTTY2. The amount of lipase produced by E. coli BL21 with pTTY2 was more than 40% of the total cell proteins when induced with isopropyl--d-thiogalactopyranoside. The lipase was produced as inclusion bodies in the cytoplasm of E. coli. They were solubilized by 8 m urea and refolded into biologically active form. The refolded lipase showed high thermostability; the time required for 90% inactivation of the enzyme (D-value) was 4 h at 95°C and the increment of temperature to reduce heating times by 90% (z d value) was 76°C.Offprint requests to: J. S. Rhee  相似文献   

17.
Zusammenfassung Bei einer Reihe von S?ugetieren in Suriname fanden sich in der Milz bei der Untersuchung von Tupfpr?paraten intracellul?r und gelegentlich auch extracellul?r gelagerte Gebilde, die von Histoplasma nicht zu unterscheiden waren. In einer Reihe von F?llen liessen sich die Parasiten auf weisse M?use verimpfen und bei diesen gleichfalls in der Milz zurückfinden. Mitt.:W. A. Collier, A. E. Wolff undA. E. G. Zaal, Documenta Med. Geogr. et Trop.4, 92, 1952; 2. Mitt.:W. A. Collier undW. E. F. Winckel, Z. f. Hyg. [im Druck; 3. Mitt.:C. F. A. Bruyning, Documenta Med. Geogr. et Trop.4, 171, 1952; 4. Mitt.:W. A. Collier undD. A. de la Parra, Documenta Med. Geogr. et Trop. im Druck; 5. Mitt.:W. E. F. Winckel, W. A. Collier undA. E. G. Treurniet, Documenta Med. Geogr. et Trop. im Druck.  相似文献   

18.
Riassunto Da uve di paesi subtropicali (Brasile) sono stati isolati più ceppi diEndomycopsis. Il loro studio comparativo ha suggerito di riconvalidareEnd. lindneri Saito passata daLodder &Kreger van Rij in sinonimia conE. fibuliger, e di istituire una nuova varietà di quest' ultima specie:E. fibuliger, var.energica n. var.
Summary From grape must of a subtropical country (Brasil) some strains ofEndomycopsis had been isolated. Their comparative study was suggestive to confirm again the speciesE. lindneri Saito. Moreover, the same studies permitted us to establish a new variety:E. fibuliger v.energica, n. var.

Resumo Foram isoladas algumas culturas deEndomycopsis de mosto de uvas cultivadas no Estado de S. Paulo, Brasil.Os estudo comparativos dessas cepas sugeriram considerar como valida a especieE. lindneri Saito, queLodder &Kreger van Rij dao como sinonimo deE. fibuliger.Foi sugerido tambem instituir uma nova variedade, aE. fibuliger var.energica.
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19.
Multivariate analysis of vegetative and reproductive characters was used to examine morphological relatedness amongAntennaria alborosea A. E. Porsild,A. corymbosa E. Nels.,A. marginata Greene,A. microphylla Rydb.,A. parvifolia Nutt.,A. rosea Greene, andA. umbrinella Rydb. Both pistillate and staminate plants were examined. Some of the characters examined were variable in one species, but stable in another (i.e., presence or absence of papillae on the achenes). Our analyses indicate that the seven species are morphologically distinct. It is hypothesized that theA. rosea agamic complex arose through hybridization amongA. corymbosa, A. microphylla, A. umbrinella, and possiblyA. dioica (L.)Gaertn. However, hybridization between the three former species and others, as well as their subsequent morphological responses to different environmental conditions causes confusion in recognizing the taxa.Antennaria angustifolia Rydb.,A. arida E. Nels.,A. confinis Greene,A. scariosa E. Nels.,A. foliacea humilis Rydb.,A. concinna E. Nels., andA. viscidula E. Nels. are considered to represent F 1 hybrids.  相似文献   

20.
Chemical composition of Eubacterium alactolyticum cell wall peptidoglycan   总被引:2,自引:0,他引:2  
The mechanism of lysis of Eubacterium alactolyticum cell walls by Streptomyces albus G enzyme was studied. The analysis of the peptide terminal groups and peptide subunits isolated from the cell wall digest, released during solubilization of the cell walls, revealed that lytic action of S. albus G enzyme was mainly due to D-alanyl-A2pm endopeptidase, N-acetylmuramyl-L-alanine amidase, N-acetylmuramidase and N-acetylglucosaminidase. E. alactolyticum cell wall peptidoglycan is composed mainly of glucosamine, muramic acid, D-glutamic acid, L- and D-alanine, meso-diaminopimelic acid and glycine. The peptide subunit consists of L-alanyl-D-glutamyl-meso-A2pm-D-alanine. D-Alanine is connected directly with the amino group of the meso-A2pm residue of another peptide subunit. All of the L-amino groups of meso-diaminopimelic acid are involved in cross-linking.The possible structure of the peptide moiety of E. alactolyticum cell wall peptidoglycan is presented.  相似文献   

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