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Medenine, Tunisia

Henry C.,French National Institute for Agricultural Research | Khorchani T.,Institute des Regions Arides | Martin P.,French National Institute for Agricultural Research | Cebo C.,French National Institute for Agricultural Research
Proteomics | Year: 2013

Camel milk has been widely characterized with regards to casein and whey proteins. However, in camelids, almost nothing is known about the milk fat globule membrane (MFGM), the membrane surrounding fat globules in milk. The purpose of this study was thus to identify MFGM proteins from Camelus dromedarius milk. Major MFGM proteins (namely, fatty acid synthase, xanthine oxidase, butyrophilin, lactadherin, and adipophilin) already evidenced in cow milk were identified in camel milk using MS. In addition, a 1D-LC-MS/MS approach led us to identify 322 functional groups of proteins associated with the camel MFGM. Dromedary MFGM proteins were then classified into functional categories using DAVID (the Database for Annotation, Visualization, and Integrated Discovery) bioinformatics resources. More than 50% of MFGM proteins from camel milk were found to be integral membrane proteins (mostly belonging to the plasma membrane), or proteins associated to the membrane. Enriched GO terms associated with MFGM proteins from camel milk were protein transport (p-value = 1.73 × 10-14), translation (p-value = 1.08 × 10-11), lipid biosynthetic process (p-value = 6.72 × 10-10), hexose metabolic process (p-value = 1.89 × 10-04), and actin cytoskeleton organization (p-value = 2.72 × 10-04). These findings will help to contribute to a better characterization of camel milk. Identified MFGM proteins from camel milk may also provide new insight into lipid droplet formation in the mammary epithelial cell. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Belgacem A.O.,Institute des Regions Arides | Tarhouni M.,Institute des Regions Arides | Louhaichi M.,International Center for Agricultural Research in the Dry Areas
Land Degradation and Development | Year: 2013

Ecosystems protected from heavy grazing impacts, such as national parks and refuges, are generally considered to sustain higher plant species diversity and better ecosystem composition and structure compared to heavily grazed areas. To evaluate the impact of livestock grazing, we sampled vegetation characteristics from two areas having different grazing intensity levels. The first site has high protection from grazing and is located inside the Bou Hedma National Park in Southern Tunisia. The second site has a low protection from grazing and is situated within an open area located immediately outside the park boundary where human populations and their livestock have unrestricted access to ecosystem resources. Total plant cover, density, perennial species cover and their contribution were compared between the two grazing level sites. Results show that considerable positive effects occur in the areas protected from grazing. As compared to the overgrazed (open) sites. Several species known for their high palatability, such as Cenchrus ciliaris L., Salvia aegyptiaca L., Echiochilon fruticosum Desf. and Helianthemum sessiliflorum Desf., are more abundant inside the park than outside. These results are very important for managers to apply this technique as a tool for increasing the resilience of arid ecosystems, qualified very vulnerable to climate change. © 2011 John Wiley & Sons, Ltd. Source

The oil extraction process from olive fruits produces a large quantity of liquid waste, so called as olive oil mill wastewaters "Margines" which has a very strong polluting power resulting in high levels of COD (Chemical Oxygen demand) high salinity and a strong phenolic compounds causing environmental pollution. The exploitation of this waste without preliminary treatment is very limited considering its toxicity for soils and plants. In addition, the richness of this effluent in organic compounds and especially on potassic element represents an asset for its agronomic valorization as a fertilizer. This alternative could be regarded as promising if it is practiced in a rational way. It is within this framework that this work has been carried out aiming to study the effect of olive oil mill waste waters spreading on the quantitative and qualitative performance of Barley crop. For developing this work, a randomized complete block design was installed with four amounts of Margines equivalent at 0 m3/ha (T0), 50 m3/ha (T1), 100 m3/ha (T2) and 200 m3/ha (T3), two varieties of barley Arthaoui (local variety) and Pakestani (introduced variety) and 4 replications. The results show a highly significant reduction as well as of the tiller and ears number for the two varieties compared to the control according to the increase of OMWW concentrations. However, the behavior of crop under this effluent presents variability among the two varieties. In addition, the highest amounts either T2 (100 m3/ha) and T3 (200 m3/ha) respectively 100 m3/ha and 200m3/ha recorded a highly significant reduction compared to the control of different yield components such as the number of ears/m2, weight of 1000 seed, the dry matter and seed yield. Although, this reduction was observed but it was less accentuated for the treatment with an amount of 50 m3/ha compared to the other rates. Source

Gorai M.,Institute Superieur Of Biologie Appliquee Of Medenine | El Aloui W.,Institute des Regions Arides | Yang X.,CAS Institute of Botany | Neffati M.,Institute des Regions Arides
Plant and Soil | Year: 2014

Aims: Seeds of Henophyton deserti (Brassicaceae), an endemic saharan shrub in south Tunisia, produce a pectinaceous mucilage layer that can imbibe a large amount of water when wetted. The aim of this study was to explore the role of mucilage in seed germination of this shrub under heterogeneous stressful environments. Methods: Germination of both intact and demucilaged seeds was tested over wide ranges of temperature, and in iso-osmotic solutions of NaCl and PEG. Recovery of germination after NaCl and Polyethylene Glycol (PEG)-6000 treatment was also tested. The effect of mucilage on water uptake was measured and the structure of the seed investigated. Results: A considerable proportion of seed mass (30 %) is made up of mucilage, which is extremely hydrophilic and able to increase seed mass by 550 % over dry seeds. Mucilage water uptake appears to be unaffected by salt concentration, while higher concentrations of PEG inhibit mucilage hydration. Mucilage decreases germination specifically at 10 °C and this effect can be interpreted in relation to oxygen uptake. High concentrations of NaCl and PEG decrease both germination percentage and rate, with some greater tolerance at 15 °C and 20 °C versus 25 °C. Recovery was higher from higher concentrations of NaCl and PEG and lower temperatures, with a clear inhibitory effect of mucilage. Conclusions: The study has shown that the mucilage of H. deserti may act as a physical barrier for regulating diffusion of water and oxygen to the inner tissue of the seed and thereby prevent germination under unsuitable conditions. © 2013 Springer Science+Business Media Dordrecht. Source

Salah M.B.,Institute des Regions Arides
Acta Horticulturae | Year: 2013

Farming operations have a direct effect on the date palm production and fruit quality. Research programs conducted in Tunisia and elsewhere helped to solve many problems and adopting new technologies to improve date palm cultivation and protection. Other techniques were also developed for molecular characterization and varietal distinction. The results were obtained in propagation, pollination, fruit thinning, pruning, harvesting and conservation of the pollen and improvement of the date sector in general. Efforts have been made in chemical and biological control of major pests and diseases of date palm, and some successes were realized. This paper reviews the situation of the research work in date palm cultivation and presents major results obtained during the last years. © ISHS 2013. Source

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