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1.
Optimization of conditions for hydroquinone biotransformation into its β-d-glucoside, arbutin, in agitated shoot cultures of Ruta graveolens L. and Hypericum perforatum L. allowed us to obtain a maximum content of this important therapeutic and cosmetic product of 7.8 and 7.2% (dry weight),
respectively. These contents are higher than respective values required for standardization of known arbutin-containing plant
raw materials according to the European Pharmacopoeia and national pharmacopoeias of European countries. 相似文献
2.
Haoran An Hui Zhou Ying Huang Guohong Wang Chunguang Luan Jing Mou Yunbo Luo Yanling Hao 《Molecular biotechnology》2010,45(2):155-160
Lactic acid bacteria (LAB) are generally sensitive to hydrogen peroxide (H2O2), Lactobacillus sakei YSI8 is one of the very few LAB strains able to degrade H2O2 through the action of a heme-dependent catalase. Lactobacillus rhamnosus strains are very important probiotic starter cultures in meat product fermentation, but they are deficient in catalase. In
this study, the effect of heterologous expression of L. sakei catalase gene katA in L. rhamnosus on its oxidative stress resistance was tested. The recombinant L. rhamnosus AS 1.2466 was able to decompose H2O2 and the catalase activity reached 2.85 μmol H2O2/min/108 c.f.u. Furthermore, the expression of the katA gene in L. rhamnosus conferred enhanced oxidative resistance on the host. The survival ratios after short-term H2O2 challenge were increased 600 and 104-fold at exponential and stationary phase, respectively. Further, viable cells were 100-fold higher in long-term aerated cultures.
Simulation experiment demonstrated that both growth and catalase activity of recombinant L. rhamnosus displayed high stability under environmental conditions similar to those encountered during sausage fermentation. 相似文献
3.
Luiz Eduardo Baggio Savio Leandro Vieira Astarita Eliane Romanato Santarém 《Plant Cell, Tissue and Organ Culture》2012,108(3):465-472
Hypericum perforatum L. is a medicinal plant that has been extensively studied because of its bioactive properties. The objective of this study
was to establish a system that could lower the cost of in vitro propagation by using liquid medium, as well as to evaluate
the secondary metabolism in the systems tested. Nodal segments of H. perforatum were obtained from in vitro shoots and grown in three liquid culture systems: total immersion (TI), partial immersion (PI),
and paper bridge support (PB). Semi-solid medium (3 g L−1 Phytagel™) was used as control (SS). The organogenic responses were evaluated, and phenolic compounds, hypericin, and the
activity of polyphenol oxidases (PPO) and peroxidases (POX) were quantified. After 80 days of culture, induction and proliferation
of adventitious shoots were similar in the PI and SS systems (65.3 and 71.3 shoots, respectively), whereas PB resulted in
the fewest shoots per explant (29.5 shoots). Longer shoots were obtained under the PI conditions. Hyperhydricity was observed
in the shoots from the TI system. Browning was visible in shoots from the TI and PB systems. The highest concentrations of
phenolic compounds and hypericin were observed in shoots derived from PI and PB, at 80 days of culture. POX activity was higher
in shoots cultured in PI at 40 days, whereas PPO was significantly more active at 80 days of culture. Likely, POX was more
related to shoot growth, whereas PPO played a later role in response to the culture environment and medium stress. 相似文献
4.
Arif Demirdaş Mustafa Nazıroğlu Ishak Suat Övey 《Cellular and molecular neurobiology》2017,37(1):133-144
Calcium ions (Ca2+) are important second messengers in neurons. Ketamine (KETAM) is an anesthetic and analgesic, with psychotomimetic effects and abuse potential. KETAM modulates the entry of Ca2+ in neurons through glutamate receptors, but its effect on transient receptor potential melastatin 2 (TRPM2) and transient receptor potential vanilloid 1 (TRPV1) channels has not been clarified. This study investigated the short-term effects of KETAM on oxidative stress and TRPM2 and TRPV1 channel gating in hippocampal and dorsal root ganglion (DRG) neurons of rats. Freshly isolated hippocampal and DRG neurons were incubated for 24 h with KETAM (0.3 mM). The TRPM2 channel antagonist, N-(p-amylcinnamoyl)anthranilic acid (ACA), inhibited cumene hydroperoxide and ADP-ribose-induced TRPM2 currents in the neurons, and capsazepine (CPZ) inhibited capsaicin-induced TRPV1 currents. The TRPM2 and TRPV1 channel current densities and intracellular free calcium ion concentration of the neurons were lower in the neurons exposed to ACA and CPZ compared to the control neurons, respectively. However, the values were not further decreased by the KETAM + CPZ and KETAM + ACA treatments. KETAM decreased lipid peroxidation levels in the neurons but increased glutathione peroxidase activity. In conclusion, short-term KETAM treatment decreased oxidative stress levels but did not seem to influence TRPM2- and TRPV1-mediated Ca2+ entry. 相似文献
5.
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
6.
Junxiao Liu Dai Han Yan Li Liangkai Zheng Chengwu Gu Zhongxian Piao William W. Au Xijin Xu Xia Huo 《Neurochemical research》2010,35(3):473-479
Lead (Pb) exposure poses devastating effects on central nervous system development of children. To replicate aspects of this
neurotoxicity, we examined the effect of lead on the expression of apoptosis and of apoptosis-related genes, XIAP (X chromosome-linked
inhibitor of apoptosis protein) and Smac (second mitochondrial activator of caspase), in the hippocampus of developing rats.
A total of 48 rats (30-day old) were randomly divided into four groups for intragastrical perfusion of lead acetate [Pb(Ac)2]: untreated, low (2 mg/kg/d), medium (20 mg/kg/d), and high (200 mg/kg/d) dose groups. Pb content was determined in blood,
and the apoptosis indexes and XIAP and Smac gene expression were analyzed in the hippocampus. There was a significant difference in apoptosis indexes (AI) between the
exposed and control groups (p < 0.01). AI was highest in the high exposure group. XIAP gene expression was reduced in the exposed groups and the expression was negatively correlated with blood lead levels (BLLs)
(p < 0.05). But the four groups did not differ in the expression of Smac (p > 0.05). Our data indicate that exposure to Pb(Ac)2 caused a dose-dependent and significant increase of apoptosis in the hippocampus of developing rats through depressing the
expression of the XIAP but not the Smac genes. 相似文献
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O. V. Golovanova V. I. Konenkov A. V. Shevchenko M. V. Smolnikova 《Russian Journal of Genetics》2009,45(8):981-986
Based on population analysis of the DRB1, DQA1, DQB1 and TNFA allele frequency distribution patterns, regional features of immunogenetic structure of the population of West Siberia were
investigated. Statistically significant linkage disequilibrium within the HLA class II region, as well as between the TNFA and DRB1, DQA1, and DQB1 was demonstrated. Population frequency distribution patterns of two- and multilocus haplotypes were examined. 相似文献
9.
The intron sequence of chloroplast rpS16 and the secondary structure of its pre-mRNA were characterized for the first time in 26 Allium sativum accessions of different ecologo-geographical origins and seven related Allium species. The boundaries and main stem-loop consensus sequences were identified for all six domains of the intron. Polymorphism
was estimated for the total intron and its regions. The structural regions of the rpS16 intron proved to be heterogeneous for mutation rate and spectrum. Mutations were most abundant in domains II and IV, and
transition predominated in domains I, III, V, and VI. In addition to structural elements and motifs typical for group IIB
introns, several Allium-specific micro- and macrostructural mutations were revealed. A 290-bp deletion involving domains III and IV and part of domain
V was observed in A. altaicum, A. fistulosum, and A. schoenoprasum. Several indels and nucleotide substitutions were found to cause a deviation of the pre-mRNA secondary structure from the
consensus model of group II introns. 相似文献
10.
N. Yu. Markelova 《Microbiology》2010,79(6):777-779
Interaction of Bdellovibrio bacteriovorus 100NCJB with bacteria Campylobacter jejuni (strains 1, 2, 3, 4, and 5) and Helicobacter pylori, strain TX30a, was confirmed. The results indicate that lytic activity of bdellovibrios both in liquid media and cells attached
to a surface was observed. The potential use of the antimicrobial activity of predatory bacteria for environmental bioprotection
and public health is discussed. 相似文献
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Xu Ming Yin Pedro S. C. F. Rocha Man Ling Wang Yu Xin Zhu Luo Ye Li Shu Feng Song Xinjie Xia 《Journal of Plant Biology》2011,54(3):180-189
Rice gene Oryza sativa Drought Stress Response-1 (OsDSR-1) was one of the genes identified to be responsive to drought stress in the panicle of rice at booting and heading stages
by both microarray and quantitative real-time PCR analyses. OsDSR-1 encodes a putative calcium-binding protein, and its overexpression in Arabidopsis rendered transgenic plants to produce much shorter lateral roots (LRs) than wild-type (WT) plants in the medium supplemented
with abscisic acid (ABA), suggesting that OsDSR-1 may act as a positive regulator during the process of ABA inhibition of LR development. No significant difference was observed
in the total LR length between WT and transgenic plants in the media with the increase of only osmotic stress caused by NaCl,
LiCl, and mannitol, while transgenic Arabidopsis seedlings appeared to produce larger root systems with longer total LR lengths under high-potassium conditions than WT seedlings.
Further analysis showed that external Ca2+ was required for the production of larger root systems, indicating that the promotion by OsDSR-1 of the LR development of transgenic Arabidopsis seemed to occur in a Ca2+-dependent manner under high-potassium conditions. We propose that OsDSR-1 may function as a calcium sensor of the signal transduction pathway controlling the LR development under high-potassium conditions. 相似文献
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I. Rosario G. Soro S. Déniz O. Ferrer F. Acosta D. Padilla B. Acosta 《Mycopathologia》2010,169(4):315-319
Columba livia is an important reservoir and carrier of Cryptococcus neoformans, Cryptococcus uniguttulatus, Cryptococcus laurentii and Cryptococcus albidus. Upper digestive tract of this species is also known as a habitat for Cryptococcus neoformans. Given the increasing clinical interest of this microorganism, 331 swabs from crop and 174 dropping samples from pigeon lofts
in Grand Canary Island have been studied. The obtained results show an extensive presence samples 81 positive (24.47%) of
Cryptococcus spp. in analysed crops: 32 (9.66%) for C. neoformans, 24 (7.2%) for C. uniguttulatus, 23 (6.9%) for C. albidus and 2 (0.6%) for C. laurentii. In the same way, Cryptococcus spp was also isolated in 82 (47.13%), dropping samples: C. neoformans in 59 (33.9%), C. uniguttulatus, in 9 (5.17%), C. laurentii in 8 (4.59%) and C. albidus in 6 (3.44%) of the investigated samples, respectively. The cryptococcosis produced by species of cryptococci other than C. neoformans has become more important during the last decade, supporting the study on the role of pigeon in the epidemiology of this
disease. 相似文献
17.
To overexpress the chitosanase gene (csn) in F. solani, a vector based on pCAMBIA 1300 was constructed. The csn gene, which is under control of the Aspergillus nidulans
gpdA promoter and A. nidulans trpC terminator, was introduced back into the F. solani genome by Agrobacterium tumefaciens-mediated transformation, and the herbicide-resistance gene bar from Streptomyces hygroscopicus was used as the selection marker. Transformants which showed a significant increase in chitosanase production (~2.1-fold
than control) were obtained. Southern blot analysis indicated that most transformants had a single-copy T-DNA integration. 相似文献
18.
D. V. Fedorov S. V. Kovaltzova V. T. Peshekhonov V. G. Korolev 《Russian Journal of Genetics》2010,46(6):659-665
The yeast genes IXR1 and HMO1 encode proteins belonging to the family of chromatin nonhistone proteins, which are able to recognize and bind to irregular
DNA structures. The full deletion of gene IXR1 leads to an increase in cell resistance to the lethal action of UV light, γ-rays, and MMS, increases spontaneous mutagenesis and significantlly decreases the level of UV-induced mutations. It was earlier
demonstrated in our works that the hmo1 mutation renders cells sensitive to the lethal action of cisplatin and virtually does not affect the sensitivity to UV light.
Characteristically, the rates of spontaneous and UV-induced mutagenesis in the mutant are increased. Epistatic analysis of
the double mutation hmo1 ixr1 demonstrated that the interaction of these genes in relation to the lethal effect of cisplatin and UV light, as well as UV-induced
mutagenesis, is additive. This suggests that the products of genes HMO1 and IXR1 participate in different repair pathways. The ixr1 mutation significantly increases the rate of spontaneous mutagenesis mediated by replication errors, whereas mutation hmo1 increases the rate of repair mutagenesis. In wild-type cells, the level of spontaneous mutagenesis was nearly one order of
magnitude lower than that obtained in cells of the double mutant. Consequently, the combined activity of the Hmo1 and the
Ixr1 proteins provides efficient correction of both repair and replication errors. 相似文献
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Ondřej Koukol 《Mycological Progress》2010,9(3):369-378
Survey of seven strains determined as Septonema ochraceum (Dothideomycetes, inc. sed.) isolated from pine litter or obtained from public collections revealed three new species, Fusicladium cordae, F. sicilianum (Venturiaceae), Cladophialophora matsushimae (Herpotrichiellaceae) and a cryptic species morphologically identical to Devriesia americana (Teratosphaeriaceae), but phylogenetically distinct. Morphological survey and phylogenetic analysis using nucleotide sequence data from the nuclear
ribosomal subunit genes indicate a close relationship within three species colonising pine litter needles, F. cordae, F. pini and F. ramoconidii. F. sicilianum is most related to F. rhodense. C. matsushimae represents a species belonging to one of the lineages of the polyphyletic genus Cladophialophora. None of the strains observed can be classified morphologically as S. ochraceum, of which the type material does not exist. 相似文献