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1.
Dana Bernátová 《Biologia》2008,63(2):175-176
The paper brings information on an isolated occurrence and morphological characters of Carex × involuta and C. juncella populations in the Vel’ká Fatra Mts. Their presence has been known neither from the territory of Slovakia nor from the whole
Western Carpathians till now. 相似文献
2.
The lipase Lip2 of the edible basidiomycete, Pleurotus sapidus, is an extracellular enzyme capable of hydrolysing xanthophyll esters with high efficiency. The gene encoding Lip2 was expressed
in Escherichia coli TOP10 using the gene III signal sequence to accumulate proteins in the periplasmatic space. The heterologous expression under
control of the araBAD promoter led to the high level production of recombinant protein, mainly as inclusion bodies, but partially
in a soluble and active form. A fusion with a C-terminal His tag was used for purification and immunochemical detection of
the target protein. This is the first example of a heterologous expression and periplasmatic accumulation of a catalytically
active lipase from a basidiomycete fungus. 相似文献
3.
Background
The presence of β-lactamases in Y. enterocolitica has been reported to vary with serovars, biovars and geographical origin of the isolates. An understanding of the β-lactamases in other related species is important for an overall perception of antibiotic resistance in yersiniae. The objective of this work was to study the characteristics of β-lactamases and their genes in strains of Y. intermedia and Y. frederiksenii, isolated from clinical and non-clinical sources in India. 相似文献4.
Despite the widespread distribution of Astyanax bockmanni in streams from Upper Paraná River system in central, southeastern, and southern Brazil, just recently, it has been identified
as a distinct Astyanax species. Cytogenetic studies were performed in two populations of this species, revealing conservative features. A. bockmanni shows 2n = 50 chromosomes, a karyotypic formula composed of 10 M + 12SM + 12ST + 16A and multiple Ag-NORs. Eight positive signals
in subtelocentric/acrocentric chromosomes were identified by fluorescent in situ hybridization (FISH) with 18S rDNA probes.
After FISH with 5S rDNA probes, four sites were detected, comprising the interstitial region of a metacentric pair and the
terminal region on long arms of another metracentric pair. Little amounts of constitutive heterochromatin were observed, mainly
distributed at distal region in two chromosomal pairs. Additionally, heterochromatin was also located close to the centromeres
in some chromosomes. No positive signals were detected in the chromosomes of A. bockmanni by FISH with the As-51 satellite DNA probe. The studied species combines a set of characteristics previously identified in
two different Astyanax groups. The chromosomal evolution in the genus Astyanax is discussed. 相似文献
5.
6.
Matías Maggi Natalia Damiani Sergio Ruffinengo David De Jong Judith Principal Martín Eguaras 《Experimental & applied acarology》2010,50(3):269-279
We undertook a field study to determine whether comb cell size affects the reproductive behavior of Varroa destructor under natural conditions. We examined the effect of brood cell width on the reproductive behavior of V. destructor in honey bee colonies, under natural conditions. Drone and worker brood combs were sampled from 11 colonies of Apis mellifera. A Pearson correlation test and a Tukey test were used to determine whether mite reproduction rate varied with brood cell
width. Generalized additive model analysis showed that infestation rate increased positively and linearly with the width of
worker and drone cells. The reproduction rate for viable mother mites was 0.96 viable female descendants per original invading
female. No significant correlation was observed between brood cell width and number of offspring of V. destructor. Infertile mother mites were more frequent in narrower brood cells. 相似文献
7.
Summary. 2H-Pyran-2-ones 1 were transformed with various hydrazines into (E)- or (Z)-α,β-didehydro-α-amino acid (DDAA) derivatives 4 (and 7) containing a highly substituted pyrazolyl moiety attached at the β-position. With heterocyclic hydrazines, the products 4 were accompanied also by decarboxylated enamines E-6. In order to separate (E/Z)-mixtures of acids, they were transformed to the corresponding methyl esters 9 and 10 by the application of diazomethane. Catalytic hydrogenation under high pressures with Pd/C as a catalyst resulted in the formation
of racemic alanine derivatives 11.
Received January 29, 2002 Accepted May 27, 2002 Published online December 18, 2002
RID="*"
ID="*" Dedicated with deep respect to Professor Waldemar Adam on the occasion of his 65th birthday.
Acknowledgements We thank the Ministry of Education, Science and Sport of the Republic of Slovenia for the financial support (P0-0503-103).
Dr. B. Kralj and Dr. D. Žigon (Center for Mass Spectroscopy, “Jožef Stefan” Institute, Ljubljana, Slovenia) are gratefully
acknowledged for the mass measurements.
Authors' address: Prof. Marijan Kočevar, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana,
Slovenia, E-mail: marijan.kocevar@uni-lj.si 相似文献
8.
M. Zapater M. Catterou B. Mary M. Ollier L. Fingar E. Mignot F. Ferchaud L. Strullu F. Dubois M. Brancourt-Hulmel 《Bioenergy Research》2017,10(1):115-128
The sustainable development of miscanthus as a bioenergy feedstock requires optimizing its fertilizer inputs and, therefore, determining its nitrogen (N) requirements. The ‘critical nitrogen dilution curve’ is a powerful tool to characterize such N requirements; it relates the N concentration ([N]) in aboveground organs to their biomass, defining two domains depending on whether the N factor limits biomass growth or not. We aimed to develop such a tool in miscanthus. Using a rhizome N depletion strategy with green cutting pre-treatment over several years before the start of the experiment, we grew, in 2014, two cultivated species, Miscanthus × giganteus (M×g) and Miscanthus sinensis (Msin), at four fertilizer levels (0, 80, 160 and 240 kg N ha?1). We found a strong nitrogen fertilization effect. The shoot [N] decreased as the aboveground biomass increased in both species and in all of the treatments. [N] was strongly correlated with leaf/stem biomass ratio. The N treatments enabled the identification of the observed critical points, i.e. points with the maximum biomass (W) and the lowest [N], on each measurement date. These points could be fitted to the following critical dilution curve that was common between M×g and Msin: N concentration (Nc) (critical [N], g N kg?1) = 27.0 W ?0.48 when W > 1 t ha?1 and Nc = 27.0 when W ≤ 1. This curve was validated by literature data, separated into N-limited or not-limited conditions. The similarity of the curves between the two species was due to compensation between leaf/stem biomass ratio and [N] in the stems. This curve is helpful to diagnose the crop N status and define the optimal fertilizer requirements of miscanthus crops. 相似文献
9.
Bimal Kumar Ghimire Eun Soo Seong Jung Dae Lim Kweon Heo Myong Jo Kim Ill-Min Chung John A. Juvik Chang Yeon Yu 《Plant Cell, Tissue and Organ Culture》2008,95(3):265-274
Efficient transformation of leaf disc-derived callus of Codonopsis lanceolata was obtained using Agrobacterium tumefaciens strain LBA4404 harboring a binary vector, pYBI121, that carries the neomycin phosphotransferase (npt II) gene as a selectable marker. The green shoots recovered from agroinfected explants on selection medium (containing 0.1 mg/l
α-naphthaleneacetic acid (NAA), 1 mg/l 6-benzylaminopurine (BAP), 100 mg/l kanamycin, and 250 mg/l cefotaxime) were rooted
on Murashige and Skoog (MS) medium supplemented with 2 mg/l IBA and 10 mg/l kanamycin. To optimize the transformation conditions,
several factors were assessed, including the co-cultivation period, the duration of pre- and post-culture in darkness and
light, the kanamycin concentration, and the Agrobacterium densities. We produced transgenic Codonopsis lanceolata overexpressing γ-tocopherol methyltransferase (γ-TMT) by this protocol. Moreover, the α-tocopherol content of the plants was enhanced by the overexpression of this gene.
Bimal Kumar Ghimire and Eun Soo Seong contributed equally to this work. 相似文献
10.
Abdul Ghaffar Sher Afzal Khan Zahid Mukhtar Muhammad Ibrahim Rajoka Farooq Latif 《Molecular biology reports》2011,38(5):3227-3233
We studied heterologous expression of xylanase 11A gene of Chaetomium thermophilum in Pichia pastoris and characterized the thermostable nature of the purified gene product. For this purpose, the xylanase 11A gene of C. thermophilum was cloned in P. pastoris GS115 under the control of AOX1 promoter. The maximum extracellular activity of recombinant xylanase (xyn698: gene with intron) was 15.6 U ml−1 while that of recombinant without intron (xyn669) was 1.26 U ml−1 after 96 h growth. The gene product was purified apparently to homogeneity level. The optimum temperature of pure recombinant
xylanase activity was 70°C and the enzyme retained its 40.57% activity after incubation at 80°C for 10 min. It exhibited quite
lower demand of activation energy, enthalpy, Gibbs free energy, entropy, and xylan binding energy during substrate hydrolysis
than that required by that of the donor, thus indicating its thermostable nature. pH-dependent catalysis showed that it was
quite stable in a pH range of 5.5–8.5. This revealed that gene was successfully processed in P. pastoris and remained heat stable and may qualify for its potential use in paper and pulp and animal feed applications. 相似文献
11.
Pueyo A Figueiras AM Benito C 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(4):513-517
The menadione reductase (MNR), the nicotinamide adenine dinucleotide dehydrogenase (NDH) and diaphorase (DIA) isozymes were
studied in the allohexaploid Triticum aestivum cv ”Chinese Spring” and in five diploid Triticeae species. The Mnr1, Ndh3 and Dia1 loci were located on the chromosome arms 3AL, 3BL and 3DL of T. aestivum, respectively. These loci were also located on the 3H chromosome of Hordeum vulgare cv ”Betzes”, the 3L chromosome of Aegilops longissima and the 6RL chromosome arm of Secale cereale cv ”Imperial”. The chromosomal location results together with the segregation studies support a tetrameric behaviour of the
MNR1, NDH3 and DIA1 isozymes. The Ndh1 and Dia3 loci were located on homoeologous group 4 showing a monomeric behaviour. The chromosomal locations and linkage data of the
Mnr, Ndh and Dia loci suggest that Mnr1=Ndh3=Dia1; Ndh1=Dia3 and Ndh2=Dia2.
Received: 3 June 2001 / Accepted: 11 July 2001 相似文献
12.
Özge Özden William M. Ciesla Wayne J. Fuller David J. Hodgson 《Biodiversity and Conservation》2008,17(12):2821-2832
We analysed the influence of contemporary geography on butterfly diversity for islands in the Mediterranean Basin. We found
that island size and distance from the mainland has a significant effect on the number of species. We also used butterflies
as an indicator group to identify the importance of forest habitats for biodiversity conservation in the island of Cyprus.
To understand the relative importance of local vegetation characteristics of butterflies in the Pentadaktylos mountains transect
counts were used to assess the abundance and butterfly diversity in two different forest types. A total of 1,602 butterflies
and 23 species were recorded during this research. We observed highly significant effects of forest type on abundance and
species richness of butterflies. For example, number of butterflies was significantly higher in old forest than young pine
forest. Also, the abundance of endemic butterflies was highest in old forest habitats. Therefore, the survival of the majority
of endemic butterflies in Cyprus may depend on conservation of old forests and their understorey plants. 相似文献
13.
There are three most important bacterial causative agents of serious infections that could be misused for warfare purposes: Bacillus anthracis (the causative agent of anthrax) is the most frequently mentioned one; however, Fracisella tularensis (causing tularemia) and Yersinia pestis (the causative agent of plague) are further bacterial agents enlisted by Centers for Disease Control and Prevention into the category A of potential biological weapons. This review intends to summarize basic information about these bacterial agents. Military aspects of their pathogenesis and the detection techniques suitable for field use are discussed. 相似文献
14.
L. Gigliarelli L. Lucentini A. Palomba G. Sgaravizzi H. Lancioni L. Lanfaloni P. Willenz E. Gaino F. Panara 《Hydrobiologia》2008,605(1):265-269
The two freshwater sponges Ephydatia fluviatilis and Ephydatia mülleri belong to the widespread Spongillidae family. Their morphological tracts are very similar and can be distinguished mainly
on the basis of their gemmuloscleres. However, when gemmules are absent it is essential to have an unambiguous species attribution
for a population genetic study based on fresh tissues and historical collections. This article reports a simple Polymerase
Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) analysis, applied to DNA extracted from both gemmules and
fresh tissues in order to discriminate between the two congeneric E. fluviatilis and E. mülleri. Such a biomolecular method is based on the discriminative enzymes’ digestion of each of the three amplified fragments 5.8S-ITS2-28S,
D3 domain of the 28S subunit and COI. Two restriction enzymes were tested for a 620–642 bp fragment of 5.8S-ITS2-28S and for
a 342 bp fragment of the D3 domain of the 28S, one restriction enzyme was tested for a 681 bp fragment codifying for COI.
Obtained digestion patterns were diagnostic for each of the two species, providing a relatively simple, fast and cheap method
for species attribution compared to sequencing.
Handling editor: C. Sturmbauer 相似文献
15.
Agnieszka Szopa Paweł Kubica Halina Ekiert 《Plant Cell, Tissue and Organ Culture》2018,134(3):467-479
In methanolic extracts of the biomass from agitated cultures of Aronia arbutifolia and Aronia?×?prunifolia grown on four variants of the Murashige and Skoog (MS) medium, with different concentrations of plant growth regulators (PGRs): BA and NAA (0.5–3.0 mg/l), the quantities of phenolic acids (19 compounds) and flavonoids (11 compounds) were estimated using the LC-DAD method. The amounts of individual metabolites and total contents were dependent on the concentration of PGRs in MS medium variant. The maximum total amounts of phenolic acids and flavonoids reached 360.80 and 65.26 mg/100 g DW, and 659.51 and 78.34 mg/100 g DW for A. arbutifolia and A. × prunifolia, respectively. The main metabolites in the biomass of both plants were chlorogenic acid, rosmarinic acid and quercitrin (max. 175.94, 147.98 and 41.14 mg/100 g DW, and 260.34, 225.26 and 78.34 mg/100 g DW, respectively). The cells of both plants convert the exogenously supplied hydroquinone into its β-D-glucoside—arbutin. The maximal total content of the product accumulated in the biomass and media reached 83.55 and 73.62 mg/g DW. The obtained results demonstrated for the first time a high biosynthetic potential of agitated cultures of both plants. 相似文献
16.
Root segments from seedlings of Panax ginseng produced adventitious roots directly when cultured on 1/2 MS solid medium lacking NH4NO3 and containing 3.0 mg l−1 IBA. Using this adventitious root formation, we developed rapid and efficient transgenic root formation directly from adventitious
root segments in P. ginseng. Root segments were co-cultivated with Agrobacterium tumefaciens (GV3101) caring β-glucuronidase (GUS) gene. Putative transgenic adventitious roots were formed directly from root segments on medium with 400 mg l−1 cefotaxime and 50 mg l−1 kanamycin. Kanamycin resistant adventitious roots were selected and proliferated as individual lines by subculturing on medium
with 300 mg l−1 cefotaxime and 50 mg l−1 kanamycin at two weeks subculture interval. Frequency of transient and stable expression of GUS gene was enhanced by acetosyringon (50 mg l−1) treatment. Integration of transgene into the plants was confirmed by the X-gluc reaction, PCR and Southern analysis. Production
of transgenic plants was achieved via somatic embryogenesis from the embryogenic callus derived from independent lines of
adventitious roots. The protocol for rapid induction of transgenic adventitious roots directly from adventitious roots can
be applied for a new Agrobacterium tumefaciens-mediated genetic transformation protocol in P. ginseng. 相似文献
17.
Hubert J Dolecková-Maresová L Hýblová J Kudlíková I Stejskal V Mares M 《Experimental & applied acarology》2005,35(4):281-291
The stored-product mites are the most abundant and frequent group of pests living on the stored food products in Europe. They endanger public health since they produce allergens and transmit mycotoxin-producing fungi. Novel acaricidal compounds with inhibitory effects on the digestive enzymes of arthropods are a safe alternative to the traditional neurotoxic pesticides used for control of the stored-product pests. In this work, we explored the properties of acarbose, the low molecular weight inhibitor of -amylases (AI), as a novel acaricide candidate for protection of the stored products from infestation by Acarus siro (Acari: Acaridae). In vitro analysis revealed that AI blocked efficiently the enzymatic activity of digestive amylases of A. siro, and decreased the physiological capacity of mites gut in utilizing a starch component of grain flour. In vivo experiments showed that AI suppressed the population growth of A. siro. The mites were kept for three weeks on experimental diet enriched by AI in concentration range of 0.005 to 0.25%. Population growth of A. siro was negatively correlated with the content of AI in the treated diet with a half-population dose of 0.125%. The suppressive effect of AIs on stored-product mites is discussed in the context of their potential application in GMO crops 相似文献
18.
K. Škrlep M. Bergant G. M. De Winter B. Bohanec J. Žel R. Verpoorte F. Van Iren M. Camloh 《Biologia Plantarum》2008,52(2):329-333
Different lines of cell suspension cultures of Taxus × media Rehd. and Taxus floridana Nutt. were cryopreserved with a two-step freezing method using a simple and inexpensive freezing container instead of a programmable
freezer. Four to seven days old suspension cell cultures were precultured in growth medium supplemented with 0.5 M mannitol
for 2 d. The medium was then replaced with cryoprotectant solution (1 M sucrose, 0.5 M glycerol and 0.5 M dimethylsulfoxide)
and the cells incubated on ice for 1 h. Before being plunged into liquid nitrogen, cells were frozen with a cooling rate of
approximately −1 °C per min to −80 °C. The highest post-thaw cell viability was 90 %. The recovery was line dependent. The
cryopreservation procedure did not alter the nuclear DNA content of the cell lines. The results indicate that cryopreservation
of Taxus cell suspension cultures using inexpensive freezing container is possible. 相似文献
19.
Jörg Maletz 《Pal?ontologische Zeitschrift》2010,84(4):501-522
Graptolites from the Jaeger collection at the Museum für Naturkunde (Berlin, Germany) provide important information on structural
details of Silurian (Wenlock–Ludlow) retiolitids as well as for the biostratigraphic and biogeographic distribution of these
magnificent graptolites. Species of the genera Cometograptus, Spinograptus and Plectograptus are described from isolated glacial boulder material, collected in northern Germany and from shale specimens found in the
Lower Graptolite Shale of Thuringia. The biostratigraphic placement of material derived from glacial erratic boulders, however,
is far from being precise. The fauna associated with the neotype of Plectograptus macilentus in the ‘Unterer Graptolithenschiefer’ of Thuringia is discussed and illustrated. Cometograptus alfeisenacki from the Cyrtograptus lundgreni Biozone is recognized as a new species. The genus is discovered for the first time in North German glacial erratic boulders. 相似文献
20.
Of the genes involved in galactose metabolism, GAL7, GAL10, and GAL1 are tightly linked in this order on chromosome II in Saccharomyces cerevisiae. While several species of the order Saccharomycetales have similar gene organization, Kazachstania naganishii is unique, in which GAL7 and GAL1 are close to each other whereas GAL10 is substantially apart from them on chromosome XI. In this study, we inserted the recognition sequence of I-SceI homing-endonuclease into GAL10 and also into the intervening segment of GAL7-GAL1. By cleaving chromosome DNA of the gene-manipulated strain with I-SceI, we obtained evidence that chromosome XI (610 kbp) was replaced with three fragments (305, 265, and 40 kbp). Using appropriate
probes, we further found that GAL10 was about 40 kbp apart from the GAL7-GAL1 cluster and that orientation of GAL10 was reversed comparing to the S. cerevisiae counter part. We, therefore, contend that comparison of the organization of the GAL cluster among Saccharomycetales is of importance to elucidate evolution of chromosomes and that the experimental scheme developed
in this study is useful for this line of investigation. 相似文献