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1.
A. Knob C. R. F. Terrasan E. C. Carmona 《World journal of microbiology & biotechnology》2010,26(3):389-407
β-Xylosidases are hydrolytic enzymes which play an important role in xylan degradation, hydrolyzing xylobiose and xylooligosaccharides to xylose from the non-reducing end. Filamentous fungi are particularly interesting producers of this enzyme from an industrial point of view, due to the fact that they secrete β-xylosidases into the medium. Besides, fungal β-xylosidases are highly advantageous for their elevated activity levels and specificity. Interest in xylanolytic enzymes has been increasing, for their possible application in many biotechnological processes. This fact has driven the isolation, purification and characterization of several β-xylosidases. In this review, the mechanisms of action, substrate specificities, physicochemical characteristics, regulation at molecular level, molecular cloning and classification of filamentous fungal β-xylosidases are described. The potential industrial applications of fungal β-xylosidases will also be presented. 相似文献
2.
Ernesto Rodríguez Verónica Noya Laura Cervi María Laura Chiribao Natalie Brossard Carolina Chiale Carlos Carmona Cecilia Giacomini Teresa Freire 《PLoS neglected tropical diseases》2015,9(12)
Helminths express various carbohydrate-containing glycoconjugates on their surface, and they release glycan-rich excretion/secretion products that can be very important in their life cycles, infection and pathology. Recent evidence suggests that parasite glycoconjugates could play a role in the evasion of the immune response, leading to a modified Th2-polarized immune response that favors parasite survival in the host. Nevertheless, there is limited information about the nature or function of glycans produced by the trematode Fasciola hepatica, the causative agent of fasciolosis. In this paper, we investigate whether glycosylated molecules from F. hepatica participate in the modulation of host immunity. We also focus on dendritic cells, since they are an important target of immune-modulation by helminths, affecting their activity or function. Our results indicate that glycans from F. hepatica promote the production of IL-4 and IL-10, suppressing IFNγ production. During infection, this parasite is able to induce a semi-mature phenotype of DCs expressing low levels of MHCII and secrete IL-10. Furthermore, we show that parasite glycoconjugates mediate the modulation of LPS-induced maturation of DCs since their oxidation restores the capacity of LPS-treated DCs to secrete high levels of the pro-inflammatory cytokines IL-6 and IL-12/23p40 and low levels of the anti-inflammatory cytokine IL-10. Inhibition assays using carbohydrates suggest that the immune-modulation is mediated, at least in part, by the recognition of a mannose specific-CLR that signals by recruiting the phosphatase Php2. The results presented here contribute to the understanding of the role of parasite glycosylated molecules in the modulation of the host immunity and might be useful in the design of vaccines against fasciolosis. 相似文献
3.
4.
Significance of Polyamines for Flowering in Spirodela punctata 总被引:1,自引:0,他引:1
Spirodela punctata strain O 5, a quantitative long-day plant,flowers only when ethylene-diamine-di-o-hydroxyphenylaceticacid (EDDHA) or salicylic acid was added to the nutrient medium[Scharfetter et al. (1978) Z. Pflanzenphysiol. 87: 445]. Undersuch conditions, cyclohexylamine and methylglyoxal-bis(guanylhydrazone)(both blockers of polyamine synthesis) inhibited flowering withoutsignificant effects on vegetative growth. Supply of spermidineabolished completely the inhibitor effects, but cannot replacethe EDDHA effect on flowering.
1Dedicated to Prof. O. H. Volk, Wurzburg, on his 85th birthday.
2Present address: Facultad de Ciencias Forestales, UniversidadAutónoma de Nuevo León. Ap. Post. 41, 67700 Linares,Nuevo León, México. (Received October 19, 1988; Accepted February 3, 1989) 相似文献
5.
D Barettino G Morcillo J L Díez M T Carretero M J Carmona 《Biochimie et biologie cellulaire》1988,66(11):1177-1185
6.
Influence of maize root mucilage on soil aggregate stability 总被引:9,自引:0,他引:9
This study was undertaken to determine the effects of root exudates on soil aggregate stability. Root mucilage was collected
from two-month old maize plants (Zea mays L.) Mucilage and glucose solutions were added at a rate of 2.45 g C kg−1 dry soil to silty clay and silt loam soils. Amended soils, placed in serum flasks, were incubated for 42 d with a drying-wetting
cycle after 21 d. Evolved CO2 was measured periodically as well as the water-stable aggregates and soluble sugar and polysaccharide content of the soil.
In mucilage-amended soils CO2 evolution started with a lag phase of 2–3 days, which was not observed in glucose-amended soils. There was then a sharp increase
in evolved CO2 up to day 7. During the second incubation period there were only small differences in evolved C between treatments. Incorporation
of mucilage in both soils resulted in a spectacular and immediate increase in soil aggregate stability. Thereafter, the percent
of water-stable aggregates quickly decreased parallel to microbial degradation. On completion of the incubation, aggregate
stability in the silty clay soil was still significantly higher in the presence of mucilage than in the control. This work
supports the assumption that freshly released mucilage is able to stick very rapidly to soil particles and may protect the
newly formed aggregates against water destruction. On the silty clay, microbial activity contributes to a stabilization of
these established organo-mineral bounds. 相似文献
7.
8.
Maria Jos Carmona Antonio Molina Jos Antonio Fernndez Juan Jos Lpez-Fando Francisco García-Olmedo 《The Plant journal : for cell and molecular biology》1993,3(3):457-462
Thionins are cysteine-rich, 5 kDa polypeptides which are toxic to plant pathogens in vitro. Expression of the gene encoding α-thionin from barley endosperm, under the 35S promoter from cauliflower mosaic virus, conferred to transgenic tobacco enhanced resistance to the bacterial plant pathogens Pseudomonas syringae pv. tabaci 153 and P. syringae pv. syringae. The barley α-thionin gene, which has two introns, was correctly spliced in tobacco. The α-thionin in transgenic plants had the expected mobility in the gradient, when separated by high-performance liquid chromatography, reacted with monospecific antibodies and showed the expected antibiotic properties in vitro. 相似文献
9.
J Jiménez-Castellanos A Carmona C J Catalina J Jiménez-Castellanos 《Acta anatomica》1992,143(3):182-187
In the present paper, we describe anatomical variants of the anterior inferior cerebellar artery in man for applicative purposes. Our goal was to provide the surgeon with a detailed anatomical view of the region. This is similar to what he may observe through the surgical microscope using modern microsurgical techniques. We have focused our attention on the segments of the artery comprising its origin, its course until it reaches the cerebellum and its main collateral branches. Our results confirm the great variability of the elements under study, but enable the establishment of a few basic variational patterns. These patterns together with their relative frequency may be helpful in microsurgery. 相似文献
10.
C Saunier R Hennequin B Hannhart P Horsky T Garcia Carmona T Colas 《Comptes rendus des séances de la Société de biologie et de ses filiales》1975,169(1):136-140
An increase in H+ ions concentration by infusion of hydrochloric acid produces a reduction in lactacidemia. This phenomenon is a result of the inhibitory effect of acidosis on phosphofructokinase producing a diminution of intracellular glycolysis. 相似文献