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Anna Vassileva Nikolina Atanasova Viara Ivanova Pascal Dhulster Alexandra Tonkova 《Annals of microbiology》2007,57(4):609-615
Cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19) fromBacillus circulans ATCC 21783 was purified by ultrafiltration and a consecutive starch adsorption. Total enzyme yield of 75.5% and purification factor of 13.7 were achieved. CGTase was most active at 65°C, possessed two clearly revealed pH-optima at 6.0 and 8.6 and retained from 75 to 100% of its initial activity in a wide range of pH, between 5.0 and 11.0. The cyclising activity was enhanced by 1 mM CaCl2 or 4 mM CoCl2. The enzyme was thermostable up to 70°C, and 64% of the original activity remained at 70°C after 30 min heat treatment. Up to 41% conversion into cyclodextrins was obtained from 40 g l?1 starch without using any additives. This CGTase produced two types of cyclodextrins, beta and gamma, in a ratio 73:27 after 4 h reaction time at 65°C. This feature of the enzyme could be of interest for industrial cyclodextrin production. 相似文献
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Jana D. Tchekalarova Natasha Ivanova Dimitrina Atanasova Daniela M. Pechlivanova Nikolai Lazarov Lidia Kortenska Rumiana Mitreva Valentin Lozanov Alexander Stoynev 《Cellular and molecular neurobiology》2016,36(6):927-941
Over the last 10 years, accumulated experimental and clinical evidence has supported the idea that AT1 receptor subtype is involved in epilepsy. Recently, we have shown that the selective AT1 receptor antagonist losartan attenuates epileptogenesis and exerts neuroprotection in the CA1 area of the hippocampus in epileptic Wistar rats. This study aimed to verify the efficacy of long-term treatment with losartan (10 mg/kg) after kainate-induced status epilepticus (SE) on seizure activity, behavioral and biochemical changes, and neuronal damage in a model of co-morbid hypertension and epilepsy. Spontaneous seizures were video- and EEG-monitored in spontaneously hypertensive rats (SHRs) for a 16-week period after SE. The behavior was analyzed by open field, elevated plus maze, sugar preference test, and forced swim test. The levels of serotonin in the hippocampus and neuronal loss were estimated by HPLC and hematoxylin and eosin staining, respectively. The AT1 receptor antagonism delayed the onset of seizures and alleviated their frequency and duration during and after discontinuation of treatment. Losartan showed neuroprotection mostly in the CA3 area of the hippocampus and the septo-temporal hilus of the dentate gyrus in SHRs. However, the AT1 receptor antagonist did not exert a substantial influence on concomitant with epilepsy behavioral changes and decreased 5-HT levels in the hippocampus. Our results suggest that the antihypertensive therapy with an AT1 receptor blocker might be effective against seizure activity and neuronal damage in a co-morbid hypertension and epilepsy. 相似文献
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Pendulum walnut leaves exhibited various adaptive responses related to the regulation of photon interception such as specific
downward orientation, greater leaf area, and larger pigment pool. Changes in the regulation of PS2 such as higher thermal
dissipation (NPQ) and lower quantum efficiency (ΦPS2) that protect the photosynthetic apparatus against damages were also found. The growth and photosynthetic features of pendulum
walnut leaf are interpreted as adaptations that allow the pendulum walnut tree to compensate the impaired ability by appropriate
growth to ensure the energy needs for photosynthesis, respectively for biomass formation.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Gal-Hemed I Atanasova L Komon-Zelazowska M Druzhinina IS Viterbo A Yarden O 《Applied and environmental microbiology》2011,77(15):5100-5109
The scarcity of fresh water in the Mediterranean region necessitates the search for halotolerant agents of biological control of plant diseases that can be applied in arid-zone agriculture irrigated with saline water. Among 29 Trichoderma strains previously isolated from Mediterranean Psammocinia sp. sponges, the greatest number of isolates belong to the Trichoderma longibrachiatum-Hypocrea orientalis species pair (9), H. atroviridis/T. atroviride (9), and T. harzianum species complex (7), all of which are known for high mycoparasitic potential. In addition, one isolate of T. asperelloides and two putative new species, Trichoderma sp. O.Y. 14707 and O.Y. 2407, from Longibrachiatum and Strictipilosa clades, respectively, have been identified. In vitro salinity assays showed that the ability to tolerate increasing osmotic pressure (halotolerance) is a strain- or clade-specific property rather than a feature of a species. Only a few isolates were found to be sensitive to increased salinity, while others either were halotolerant or even demonstrated improved growth in increasingly saline conditions. In vitro antibiosis assays revealed strong antagonistic activity toward phytopathogens due to the production of both soluble and volatile metabolites. Two marine-derived Trichoderma isolates, identified as T. atroviride and T. asperelloides, respectively, effectively reduced Rhizoctonia solani damping-off disease on beans and also induced defense responses in cucumber seedlings against Pseudomonas syringae pv. lachrimans. This is the first inclusive evaluation of marine fungi as potential biocontrol agents. 相似文献
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Corrado Dimauro Massimo Cellesi Giustino Gaspa Paolo Ajmone-Marsan Roberto Steri Gabriele Marras Nicolò PP Macciotta 《遗传、选种与进化》2013,45(1):15
Background
The objective of the present study was to test the ability of the partial least squares regression technique to impute genotypes from low density single nucleotide polymorphisms (SNP) panels i.e. 3K or 7K to a high density panel with 50K SNP. No pedigree information was used.Methods
Data consisted of 2093 Holstein, 749 Brown Swiss and 479 Simmental bulls genotyped with the Illumina 50K Beadchip. First, a single-breed approach was applied by using only data from Holstein animals. Then, to enlarge the training population, data from the three breeds were combined and a multi-breed analysis was performed. Accuracies of genotypes imputed using the partial least squares regression method were compared with those obtained by using the Beagle software. The impact of genotype imputation on breeding value prediction was evaluated for milk yield, fat content and protein content.Results
In the single-breed approach, the accuracy of imputation using partial least squares regression was around 90 and 94% for the 3K and 7K platforms, respectively; corresponding accuracies obtained with Beagle were around 85% and 90%. Moreover, computing time required by the partial least squares regression method was on average around 10 times lower than computing time required by Beagle. Using the partial least squares regression method in the multi-breed resulted in lower imputation accuracies than using single-breed data. The impact of the SNP-genotype imputation on the accuracy of direct genomic breeding values was small. The correlation between estimates of genetic merit obtained by using imputed versus actual genotypes was around 0.96 for the 7K chip.Conclusions
Results of the present work suggested that the partial least squares regression imputation method could be useful to impute SNP genotypes when pedigree information is not available. 相似文献67.
Extracellular polymer substance synthesized by a halophilic bacterium Chromohalobacter canadensis 28
Radchenkova Nadja Boyadzhieva Ivanka Atanasova Nikolina Poli Annarita Finore Ilaria Di Donato Paola Nicolaus Barbara Panchev Ivan Kuncheva Margarita Kambourova Margarita 《Applied microbiology and biotechnology》2018,102(11):4937-4949
Applied Microbiology and Biotechnology - Halophilic microorganisms are producers of a lot of new compounds whose properties suggest promising perspectives for their biotechnological exploration.... 相似文献
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Gold salts and phenylbutazone selectively inhibit the synthesis of PGF2α and PGE2 respectively. Lowered production of one prostaglandin species is accompanied by an increased production of the other. Selective inhibition by these drugs was observed in the presence of adrenaline, reduced glutathione and copper sulphate under conditions when most anti-inflammatory compounds inhibited PGE2 and PGF2α syntheses equally. It is postulated that selective inhibitors may have a different mode of action in vivo and beneficial effects may be related to the endogenous ratio of PGE to PGF required for normal function. 相似文献
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