20 research outputs found
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In vitro fermentation of sugar beet arabinan and arabino-oligosaccharides by the human gut microflora
Aims: To determine the fermentation profiles by human gut bacteria of arabino-oligosaccharides of varying degree of polymerization. Materials and Methods: Sugar beet arabinan was hydrolyzed with a commercial pectinase and eight fractions, of varying molecular weight, were isolated by gel-filtration chromatography. Hydrolysis fractions, arabinose, arabinan and fructo-oligosaccharides were fermented anaerobically by gut bacteria. Total bacteria, bifidobacteria, bacteroides, lactobacilli and the Clostridium perfringens/histolyticum sub. grp. were enumerated using fluorescent in situ hybridization. Results: Bifidobacteria were stimulated to different extents depending on molecular weight, i.e. maximum increase in bifidobacteria after 48 h was seen on the lower molecular weight fractions. Lactobacilli fluctuated depending on the initial inoculum levels. Bacteroides numbers varied according to fraction; arabinan, arabinose and higher oligosaccharides (degree of polymerization, dp > 8) resulted in significant increases at 24 h. Only carbohydrate mixtures with dp of 1-2 resulted in significant increases at 48 h (log 8.77 +/- 0.23). Clostridia decreased on all substrates. Conclusions: Arabino-oligosaccharides can be considered as potential prebiotics. Significance and Impact of the Study: Arabinan is widely available as it is a component of sugar beet pulp, a co-product from the sugar beet industry. Generation of prebiotic functionality from arabinan would represent significant added value to a renewable resource
The ultraviolet survey of the Gould Belt: general properties of the Taurus star forming region
The Gould Belt is the local superassociation of star formation. The age of the Belt is some few 10(7) yr, henceforth, its population is dominated by luminous young OB associations and low mass pre-main sequence stars. Attempts to unveil the low mass population have been run making use of the ROSAT all-sky survey. The all sky ultraviolet survey run by the GALaxy Evolution eXplorer (GALEX) maps several regions in the Belt. In this contribution, we present the preliminary analysis of the UV stellar population towards the Taurus region, one of the nearest and best studied regions of star formation
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A comparative in vitro evaluation of the fermentation properties of prebiotic oligosaccharides
Regeneration niche of the Canarian juniper: the role of adults, shrubs and environmental conditions
Canarian Juniper woodlands, now very scarce, are rich in endemic and endangered plants. However,
many aspects of juniper regeneration are almost unknown.
This paper relates occurrence and abundance of recruits of Juniperus turbinata ssp. canariensis to
(1) small-scale soil characteristics; (2) vegetation cover; and (3) distance to conspecific adults in two
contrasting juniper stands in the eastern mountains of Tenerife.We used non-parametric classification
trees and generalised linear models (GLM) to evaluate the effect and importance of each explanatory
variable on the occurrence of juniper saplings.
Sapling density, vitality and growth rate, as well as fruit production by adult trees, but neither cone
density on the ground nor sapling size, varied significantly with respect to slope orientation, representing
environmental stress. Within each stand, distance to nearest adult tree was the most important
variable explaining the spatial distribution of juniper saplings and availability of seeds in cones. Additionally,
saplings were positively associated with shrub cover at the microsite-level, but not with
spiny shrub cover. Soil depth and rock cover had a weak negative effect on sapling establishment, but
only at the south-facing site and in the open space microhabitat.
Results suggest that recruitment of Canarian juniper is facilitated by microhabitats offered by
adults and shrubs. The key factors affecting recruitment are thought to be (1) favourable microenvironmental
conditions and (2) high ambient seed availability. Browsing intensity in recent decades
was very low. The presence of spiny shrubs did not favour juniper establishment. Facilitation therefore
appears to result from amelioration of abiotic conditions rather than from protection against
herbivory.Comunidad Europe