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1.
Dae-Sung Lee Min-Seung Kang Hye-Jin Hwang Sung-Hwan Eom Ji-Young Yang Myung-Suk Lee Won-Jae Lee You-Jin Jeon Jae-Sue Choi Young-Mog Kim 《Biotechnology and Bioprocess Engineering》2008,13(6):758-764
We have been attempting for some time to discover a compound evidencing antibacterial activity against methicillin-resistant
Staphylococcus aureus (MRSA). The dieckol isolated from Ecklonia stolonifera has been shown to exhibit antibacterial activity against methicillin-susceptible S. aureus (MSSA) and MRSA. The minimum inhibitory concentrations (MICs) of dieckol were determined in a range of 32 to 64 μg/mL against
standard MSSA and MRSA strains. Furthermore, dieckol clearly reversed the high-level ampicillin and penicillin resistance
of MRSA. The MICs of ampicillin against two standard strains of MRSA were dramatically reduced from 512 to 0.5 μg/mL in combination
with 1/4 MIC of dieckol (16 μg/mL). The fractional inhibitory concentration (FIC) indices of ampicillin and penicillin were
measured from 0.066 to 0.266 in combination with 8 or 16 μg/mL of dieckol against all tested MRSA strains, thereby suggesting
that dieckol-ampicillin or dieckol-penicillin combinations exert a synergistic effect against MRSA. The results of this study
indicate that dieckol, administered in combination with β-lactams, may prove effective in the treatment of MRSA infections.
Our finding may also contribute to the development of an alternative phytotherapeutic anti-MRSA agent. 相似文献
2.
Gaye Öngen Gaye Güngör Bahar Kanberoglu 《World journal of microbiology & biotechnology》2007,23(4):519-524
Aspergillus section Nigri strains Aspergillus aculeatus Ege-K 258, A.
foeditus var. pallidus Ege-K156, A. niger Ege-K 4 and A. tubingensis Ege-K 265 were used to treat olive mill wastewater (OMW) in an investigation aimed at exploring their dephenolisation and
decolourisation ability and, consequently, the economic feasibility of using any or all of these strains in a pre-treatment
step in the processing of OMW. Of these strains A. tubingensis Ege-K 265 resulted in an 80% decolourisation of twofold-diluted OMW and a 30% decolourisation of undiluted OMW; in addition,
it was able to remove approximately 30% of all phenolic compounds in both twofold-diluted and undiluted OMW. We conclude that
A. tubingensis Ege-K 265 could be effectively used in the pre-treatment step of a combined aerobic-anaerobic process to solve the environmental
problems caused by OMW in Mediterranean countries. 相似文献
3.
L. Y. Solís-Ramos T. González-Estrada S. Nahuath-Dzib L. C. Zapata-Rodriguez E. Castaño 《Plant Cell, Tissue and Organ Culture》2009,96(3):279-287
Capsicum chinense is a recalcitrant species for in vitro morphogenesis, and up to date there is no efficient system for genetic transformation
and regeneration of this species via somatic embryogenesis. Here, we carried out an in vitro transformation of C. chinense via Agrobacterium tumefaciens co-cultivation with a system that expresses the heterologous gene WUSCHEL from Arabidopsis thaliana. WUSCHEL has been shown to promote the transition from vegetative to embryogenic state when overexpressed. We tested if the expression
of WUSCHEL in C. chinense would promote an embryogenic response in this species. After 15 days of induction, the segments of transformed stems begun
to form globular structures, suggesting that heterologus WUSCHEL was active and involved in the process of morphogenesis. 相似文献
4.
Emira Noumi Mejdi Snoussi Hajer Hentati Kacem Mahdouani Lucas del Castillo Eulogio Valentin Rafael Sentandreu Amina Bakhrouf 《Mycopathologia》2010,169(4):269-278
Several virulence factors in Candida albicans strains such as production of hydrolytic enzymes and biofilm formation on surfaces and cells can contribute to their pathogenicity.
For this, control of this opportunistic yeast is one of the factors reducing the nosocomial infection. The aim of this study
was to investigate biofilm formation on polystyrene and polymethylmethacrylate and the production of hydrolytic enzymes in
Candida albicans strains isolated from the oral cavity of patients suffering from denture stomatitis. All strains were identified by macroscopic,
microscopic analysis and the ID 32 C system. Our results showed that 50% of the total strains produced phospholipase. Furthermore,
protease activity was detected in seven (35%) strains. All Candida albicans strains were beta haemolytic. All C. albicans strains adhered to polystyrene 96-well microtiter plate at different degrees, and the metabolic activity of C. albicans biofilm formed on polymethylmethacrylate did not differ between tested strains. The atomic force micrographs demonstrated
that biofilm of Candida albicans strains was organized in small colonies with budding cells. 相似文献
5.
G. Lorda J. D. Breccia V. Barbeito F. Pagliero S. Boeris C. Castaño A. Pordomingo F. Altolaguirre M. D. Pastor 《World journal of microbiology & biotechnology》2007,23(1):1-5
The addition of xanthan to high water retention capacity peat (HWRC) inoculants did not show differences on the survival of
Bradyrhizobium japonicum E109. In low water retention capacity peats (LWRC) however, xanthan increased the survival of B.japonicum significantly. Xanthan showed the best effect at 0.1 g/l for B. japonicum, in contrast to Sinorhizobium fredii USDA205 where the concentrations evaluated (0–1.0 g/l) did not affected significantly its survival. Nevertheless, when the
symbiotic performance on soybean was evaluated, the presence of 0.1 g xanthan/l increased the nodule number for both strains. 相似文献
6.
7.
Yongxia Shi Wenli Ma Meijin Yuan Fan Sun Yi Pang 《World journal of microbiology & biotechnology》2007,23(4):501-507
Forty-one Bacillus thuringiensis (Bt) standard reference strains and 118 Bt local isolates were screened for vip1/vip2 genes by PCR amplification, with only three strains (HD201, HD109 and HD12) producing the desired bands. Southern blot showed
that vip1/vip2 genes were located on a 10 Kb EcoRV fragment of their total DNAs. Furthermore, the vip1Ca/vip2Ac genes were cloned from a partial genomic library of HD201. Sequence homologous analysis revealed that vip2Ac gene was highly conserved and encoded a protein possibly having ADP-ribosyltransferase activity, and that vip1Ca gene was of low homology, especially at its 3-terminus. Western blot showed that Vip1Ca and Vip2Ac proteins could be detected
from middle logarithmic phase to the stationary phase in Bt HD201. However, bioassays of HD201 supernatants exhibited no activity
against Culex quinquefasciatus, Spodoptera exigua, S. litura, Helicoverpa amigera and Tenebrio molitor larvae. Whether Vip1Ca and Vip2Ac proteins have any toxicity to other susceptible targets still needs to be investigated. 相似文献
8.
Kamiel Spoelstra Serge Daan 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2008,194(3):235-242
Mutations in each of the genes mPer1, mPer2, mCry1 and mCry2 separately cause deviations from the wild type circadian system. Differences between these mutant strains have inspired the
hypothesis that the duality of circadian genes (two mPer and two mCry genes involved) is related to the existence of two components in the circadian oscillator (Daan et al., J Biol Rhythms 16:105–116,
2001). We tested the predictions from this theory that the circadian period (τ) lengthens under constant illumination (LL)
in mCry1 and mPer1 mutant mice, while it shortens in mCry2 and mPer2 mutants. mCry1
−/−
and mCry2
−/−
knockout mice both consistently increased τ with increasing light intensity, as did wild type mice. With increasing illumination,
rhythmicity is reduced in mCry1, mCry2 and mPer1, but not in mPer2 deficient mice. Results for mPer mutant mice are in agreement with data reported on these strains earlier by Steinlechner et al. (J Biol Rhythms 17:202–209,
2002), and also with the predictions from the model. The increase in cycle length of the circadian system by light in the
mCry2 deficient mice violates the predictions. The model is thereby rejected: the mCry genes do not play a differential role, although the opposite responses of mPer mutants to light remain consistent with a functional Evening–Morning differentiation. 相似文献
9.
R. Ramirez-Malagon I. Aguilar-Ramirez A. Borodanenko L. Perez-Moreno J. L. Barrera-Guerra H. G. Nuñez-Palenius N. Ochoa-Alejo 《In vitro cellular & developmental biology. Plant》2007,43(6):660-665
Mammillaria species are the most numerous within Cactaceae family, and some of them are threatened with extinction as a result of human
activities. In this work, results of in vitro propagation are presented for ten Mammillaria species, testing 20 combinations of indole-3-acetic acid (IAA) and kinetin. Best results on shoot formation were obtained
using kinetin at two levels: 27.9 and 46.5 μM. All IAA levels tested were able to induce de novo shoot formation in M. bocasana, M. densispina, M. hahniana, M. hutchisoniana, M. orcutii, M. pectinifera, M. perbella, M. picta, M. rhodantha, and M. zephyranthoides. Depending on the IAA level tested, four responding groups were observed concerning their highest shoot-formation number.
For all species, the highest average of shoot formation was achieved with 5.7:46.5 or 11.4:46.5 μM IAA/kinetin, yielding 4.8
and 4.7 shoots per explant, respectively, in 60 d. Rooting of regenerated shoots was achieved by leaving the explants in their
shoot-induction medium or transferring them to half-strength MS medium. Hardening of regenerated plants was successfully achieved
by planting them in peat moss substrate after a desiccation treatment at room temperature for 3 d. 相似文献
10.
Tarun Kumar Verinder Wahla Piyush Pandey R. C. Dubey D. K. Maheshwari 《World journal of microbiology & biotechnology》2009,25(2):277-285
Biological control of the cyst forming nematode Heterodera cajani was studied on sesame using plant growth promoting rhizobacteria (PGPR) Pseudomonas aeruginosa LPT3 and LPT5. Based on plant growth promoting attributes, two fluorescent pseudomonads, LPT3 and LPT5 were evaluated for
their efficacy against cyst forming nematode Heterodera cajani that parasitize Sesamum indicum. Pseudomonas aeruginosa LPT5 produced IAA, HCN, chitinase, glucanase and siderophore, and also solubilized inorganic phosphate in vitro. Moreover,
LPT5 resulted in mortality of second stage juveniles of H. cajani, which was 13% higher as compared to P. aeruginosa LPT3. Interestingly, when both strains were inoculated together for the management of H. cajani on Sesamum indicum the population of H. cajani was reduced significantly, in field trial. Approximately 60% reduction in cyst and juveniles population was recorded with
LPT5 coated seeds, while LPT3 resulted in 49% reduction in cyst and juvenile population as compared to control. Plants grown
with seeds bacterized with LPT5 and reduced doses of urea, diammonium phosphate (DAP), muriate of potash (K) and gypsum gave
maximum increase in yield, in comparison to that of plants raised under the influence of recommended or full doses of the
chemical fertilizers. Pseudomonas aeruginosa LPT5 also showed excellent root colonization. 相似文献
11.
Indeok Hwang Dilli Prasad Paudyal Seong-Ki Kim Hyeonsook Cheong 《Biotechnology and Bioprocess Engineering》2007,12(2):157-164
Inhibitors are very important in the study of hormone function. Brasinazole (Brz) is a specific inhibitor of brassinosteroids
(BRs) biosynthesis. To expand our knowledge of the molecular mechanisms of plant steroid signaling, we performed genetic screening
using medium containing Brz under dark conditions. Mutants insensitive to Brz developlonger hypocotyls than their wild type
counterparts. We isolatedabz453 as a Brz insensitive mutant. TAIL-PCR and the segregation ratio of T2 plants indicated a single T-DNA insertion at the 24-Sterol
C-methyltransferase (SMT2) gene in theabz453 mutant. Recapitulation for putative FCP serine phosphatase (FSP), the gene neighboringSMT2, indicated no significant phenotypes, but theSMT2 anti-sense (SMT2-AS) line developed longer hypocotyls than the wild type in medium containing Brz. Additionally, theSMT2-AS line displayed similar phenotypes to theabz453 line in soil including enhanced growth and smaller silique. Theabz453 andSMT2-AS mutants showed phenotypes similar to those of wild type in medium containing benzylaminopurine, pacrobutrazol and ACC (precursor
for ethylene) under dark conditions. However, when brassinolide (BL) dose response was observed, theabz453 andSMT2-AS lines showed higher sensitivity than wild type. Theabz453/det2 andabz453/bri1-119 double mutants showed enhanced growth compared to thedet2 andbri1-119 line under both dark and light conditions. Specially, in dark conditions double mutants displayed nearly 2- and 1.5-fold
longer hypocotyls thandet2 andbri1-119 plants. Brz insensitivity to theSMT2 knock-out mutant and phenotypes of double mutants indicate that not only do BRI1 and DET2 influence the BRs response, as
evidenced by hypocotyl elongation, but another sterol derived signals may also be affected in mutants, suggesting that another
pathway is involved in hypocotyl elongation due to SMT2. 相似文献
12.
A general in vitro cloning system was established for four Helleborus species: H. argutifolius, H. foetidus, H. niger and H. orientalis. The plant material was introduced in vitro from axillary buds. A Murashige and Skoog (MS)—based medium (Murashige and Skoog
1962) was used supplemented with 2% (w/v) sucrose, 2-isopentenyladenine (2-iP) and 6-benzylaminopurine (BA). Multiplication
rates depended on the genotype and varied from 1.3 for H. foetidus till 3.8 for H. niger. The first results showed that the rooting phase could be done ex vitro. Rooting was induced by a drench for one week in
a solution of indole-3-butyric acid (IBA -3 mg l−1) and 1-naphthaleneacetic acid (NAA-1 mg l−1) at 5°C. 相似文献
13.
As a step toward greater understanding of the genetics of verticillium wilt resistance in plants, we report the sequencing
of a candidate wilt resistance gene, mVe1, from the mint diploid model species, Mentha longifolia (Lamiaceae). mVe1 is a putative homolog of tomato (Solanum lycopersicum L.) verticillium wilt (Ve) resistance genes. The mVe1 gene has a coding region of 3,051 bp. The predicted mVe1 protein contains a leucine-rich repeat domain, a common feature of plant disease resistance proteins. We compared 13 mVe1 alleles from three mint species. These alleles shared 96.2–99.6% nucleotide identity. We analyzed four M. longifolia populations segregating with respect to mVe1 alleles and wilt resistance versus susceptibility and found one association between mVe1 genotype and wilt phenotype. We conclude that mVe1 may play a role in mint verticillium wilt resistance, but variation for resistance in our segregating progenies is likely
polygenic. Therefore, further investigations of mVe1 and identification of additional candidate genes are both warranted. 相似文献
14.
S. E. Dawson 《Kew Bulletin》2008,63(3):517-517
Summary The name Pavetta modesta (Hiern) S. E. Dawson is a later homonym of P. modesta Bremek. Pavetta crystalensis is proposed as a new name. 相似文献
15.
Eustáquio Souza Dias Cláudia Regina Gontijo Labory Karina Marjorie Silva Herrera Alexandre Alonso Alves Giovana Augusta Torres Danny Lee Rinker 《World journal of microbiology & biotechnology》2008,24(11):2473-2479
Agaricus brasiliensis is a medicinal mushroom native to Brazil. It was first identified as Agaricus blazei and its scientific name continues to be debated. We examined the cytology of different Brazilian commercial strains of A. brasiliensis and the nuclear behavior of strain CS1 during basidiospore development using fluorescent microscopy. All strains have multinucleate
hyphae and no significant differences in nuclei numbers were observed between them. Basidia from A. brasiliensis strain CS1 are typically tetrasporics and produce binucleate basidiospores, demonstrating that a postmeiotic mitosis occurs
during basidiospore development. This result suggests that A. brasiliensis is primarily a heterothallic species. 相似文献
16.
Megan N. Hemming Sarah Fieg W. James Peacock Elizabeth S. Dennis Ben Trevaskis 《Molecular genetics and genomics : MGG》2009,282(2):107-117
Activity of the VERNALIZATION1 (VRN1) gene is required for flowering in temperate cereals such as wheat and barley. In varieties that require prolonged exposure
to cold to flower (vernalization), VRN1 is expressed at low levels and is induced by vernalization to trigger flowering. In other varieties, deletions or insertions
in the first intron of the VRN1 gene are associated with increased VRN1 expression in the absence of cold treatment, reducing or eliminating the requirement for vernalization. To characterize natural
variation in VRN1, the first intron of the barley (Hordeum vulgare) VRN1 gene (HvVRN1) was assayed for deletions or insertions in a collection of 1,000 barleys from diverse geographical regions. Ten alleles of
HvVRN1 containing deletions or insertions in the first intron were identified, including three alleles that have not been described
previously. Different HvVRN1 alleles were associated with differing levels of HvVRN1 expression in non-vernalized plants and with different flowering behaviour. Using overlapping deletions, we delineated regions
in the HvVRN1 first intron that are associated with low levels of HvVRN1 expression in non-vernalized plants. Deletion of these intronic regions does not prevent induction of HvVRN1 by cold or the maintenance of increased HvVRN1 expression following cold treatment. We suggest that regions within the first intron of HvVRN1 are required to maintain low levels of HvVRN1 expression prior to winter but act independently of the regulatory mechanisms that mediate induction of HvVRN1 by cold during winter.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under the accession numbers 1179825, 1179833,
1179836, 1179858. 相似文献
17.
A simple and random genome deletion method combining insertion sequence (IS) element IS31831 and the Cre/loxP excision system generated 42 Corynebacterium glutamicum mutants (0.2–186 kb). A total of 393.6 kb (11.9% of C. glutamicum R genome) coding for 331 genes was confirmed to be nonessential under standard laboratory conditions. The deletion strains,
generated using only two vectors, varied not only in their lengths but also the location of the deletion along the C. glutamicum R genome. By comparing and analyzing the generated deletion strains, identification of nonessential genes, the roles of genes
of hitherto unknown function, and gene–gene interactions can be easily and efficiently determined.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
18.
The luminous marine bacterium Photobacterium mandapamensis was synonymized several years ago with Photobacterium leiognathi based on a high degree of phenotypic and genetic similarity. To test the possibility that P. leiognathi as now formulated, however, actually contains two distinct bacterial groups reflecting the earlier identification of P. mandapamensis and P. leiognathi as separate species, we compared P. leiognathi strains isolated from light-organ symbiosis with leiognathid fishes (i.e., ATCC 25521T, ATCC 25587, lequu.1.1 and lleuc.1.1) with strains from seawater originally described as P. mandapamensis and later synonymized as P. leiognathi (i.e., ATCC 27561T and ATCC 33981) and certain strains initially identified as P. leiognathi (i.e., PL-721, PL-741, 554). Analysis of the 16S rRNA and gyrB genes did not resolve distinct clades, affirming a close relationship among these strains. However, strains ATCC 27561T, ATCC 33981, PL-721, PL-741 and 554 were found to bear a luxF gene in the lux operon (luxABFE), whereas ATCC 25521T, ATCC 25587, lequu.1.1 and lleuc.1.1 lack this gene (luxABE). Phylogenetic analysis of the luxAB(F)E region confirmed this distinction. Furthermore, ATCC 27561T, ATCC 33981, PL-721, PL-741 and 554 all produced a higher level of luminescence on high-salt medium, as previously described for PL-721, whereas ATCC 25521T, ATCC 25587, lequu.1.1 and lleuc.1.1 all produced a higher level of luminescence on low-salt medium, a characteristic of P. leiognathi from leiognathid fish light organs. These results demonstrate that P. leiognathi contains two evolutionarily and phenotypically distinct clades, P. leiognathi subsp. leiognathi (strains ATCC 25521T, ATCC 25587, lequu.1.1 and lleuc.1.1), and P. leiognathi subsp. mandapamensis (strains ATCC 27561T, ATCC 33981, PL-721, PL-741 and 554).Electronic Supplementary Material Supplementary material is available for this article at . 相似文献
19.
Igor Loncaric Josua T. Oberlerchner Birgit Heissenberger Rudolf Moosbeckhofer 《Antonie van Leeuwenhoek》2009,95(2):165-178
Intra-specific diversity of 200 Aureobasidium pullulans strains isolated from different sources and their relatives Kabatiella lini CBS 125.21 T and Hormonema prunorum CBS 933.72 T were studied by assessment of macromorphological, and physiological tests, sodium dodecyl sulfate-polyacrylamide
gel electrophoresis technique (SDS–PAGE) of whole-cell proteins as well as enterobacterial repetitive intergenic consensus
(ERIC)-, repetitive extragenic palindromic (REP)- and BOX-PCR techniques (collectively known as rep-PCR). Rep-PCR is an efficient
procedure for discrimination of A. pullulans in terms of simplicity and rapidity. RFLP-PCR technique was applied for the identification of A. pullulans isolates and distinction from related species. This technique was insufficient for investigation of intra-specific diversity.
The tested strains of A. pullulans could be divided into two groups based on their macromorphological, protein patterns obtained after SDS-PAGE as well as rep-PCR
patterns. The first group of strains shared similar characteristics and was very different from the second one, designated
as “complex group”, consisting of strains with very little similarities within the group. Phenetic analysis of ERIC banding
patterns failed to group the isolates on the basis of their substrate or geographical origin. Using 18S rDNA gene sequence
analysis of selected isolates, three strains: HoHe3 km, A. pullulans DSM 62074 and H. prunorum CBS 933.72 T were distinguished from all other analysed members of genera Aureobasidium and Kabatiella.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献