Ziziphus lotus L. (Lam.) and Z. mauritiana Lam., as a widespread species in Tunisia, are well known for their medicinal and food uses. The aim of the present study was to screen the content of total polyphenols, flavonoids, and condensed tannins together with the radical scavenging capacity and the antimicrobial activity of leaves, fruits and seeds extracts of Z. lotus and Z. mauritiana from different localities. Results showed that leaves extracts presented the highest phenolic compounds content for both species. Furthermore, LC-ESI-MS analysis allowed the identification of 28 bioactive compounds regardless of species and organs, with the predominance of quinic acid and rutin. Leaves extract of Z. mauritiana possessed the highest total antioxidant capacity. The antimicrobial tests showed that leaves extracts of Z. mauritiana and Z. lotus from Oued Esseder exhibited the highest activity against four bacterial strains (Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium and Escherichia coli). The main results showed that the studied species of Ziziphus genus are an excellent source of natural bioactive molecules that could be an interesting material for industrial and food purposes.

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Purpose Date palm (Phoenix dactylifera L.) is one of the predominant fruit trees grown in oases ecosystems (Southern Mediterranean regions) and produces several wastes during practicing cultivation since fruit and bunch thinning is frequently applied. Yet, the valorization of date palm wastes as bioresources has received little attention. The main objective for the present research is to assess palm trees compost (P-compost) as organic fertilizer for alfalfa (Medicago sativa L.). Methods The experiment was carried out in an experimental field involving four replicates and three soil amendment treatments (1) control, conventional mineral fertilizer diammonium phosphate, (2) 30 t ha -1 of cow manure, and (3) 30 t ha -1 of palm tree compost (P-compost). Plots were planted on with alfalfa and the measurements of studied traits (growth, yield, seed yield and minerals uptake) were determined for two crop seasons (2010 and 2011). Results Compared with untreated soil, the palm compost application at 30 t ha -1 improved significantly both organic matter and water retention capacity of the soil and decreased the electrical conductivity (-70%).Furthermore, palm compost supply significantly increased fresh biomass production of alfalfa by 21 and 28%, respectively, during the first and second seasons. Also, it enhanced the grain yield and growth rate (stem length and leafs expansion) of this species. At the first crop season, the palm compost application had a positive impact on minerals nutrition compared to the control treatment, with improving rates of ? 32% for phosphorus, ? 25% for potassium and ? 6% for nitrogen. In addition, these contents were higher than in plants grown under cow manure amendment. However, at the second season, the palm compost improved only P and N contents. Conclusions This preliminary finding suggests that palm compost at moderate dose (30 t ha -1 ) could be highly beneficial for forage plant yield.

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Thirty-one rhizobial isolates nodulating native Lupinus angustifolius (blue lupine) plants growing in Northern Tunisian soils were isolated and analysed using different chromosomal and symbiotic gene markers. Phylogenetic analyses based on recA partial sequences grouped them into at least five groups: four of them within the genus Bradyrhizobium (26 isolates) and one into the genus Microvirga (5 isolates). Representative strains were analysed by multilocus sequence analysis of three housekeeping genes rrs-recA-glnII and rrs-gyrB-dnaK for Bradyrhizobium and Microvirga isolates, respectively. Based on this analysis, eight isolates clustered with the previously described strains Bradyrhizobium lupini USDA3051 and Bradyrhizobium canariense BTA-1. However, five of the isolates clustered separately and may constitute a new species within the Bradyrhizobium genus. The remaining five isolates were closely related to the strain Microvirga sp. LmiM8 and may constitute a new Microvirga species. The analysis of the nodC gene showed that all Bradyrhizobium strains nodulating blue lupine belong to the symbiovar genistearum, whereas the Microvirga isolates are associated with the symbiovar mediterranense. The results of this study support that the L. angustifolius root nodule symbionts isolated in Northern Tunisia belong mostly to the B. canariense/B. lupini lineages. However, new clades of Bradyrhizobium and Microvirga have been identified as L. angustifolius endosymbionts.

The present study aims to assess the nutritional quality and the antioxidant capacity of (Punica granatum L. 'Gabsi') and date (Phoenix dactylifera L. 'Bouhattam') juices and their combination at three proportions (PPD 2:1, PD 1:1, and PDD 1:2). This investigation revealed the interesting potentialities in terms of bioactive molecules, natural antioxidants, and high organoleptic characteristics of various prepared juice formulations. For all juices, the sugar contents were averaged to 16°Brix. The highest monosaccharide content was obtained at the pomegranate/ date juice (PDD) (glucose: 9.52 ± 0.88 g/100 ml, fructose: 9.91 ± 0.44 g/100 ml). The comparative study of the five juice formulations based on phenolic contents showed that they are loaded with phenolic compounds. Indeed, the PD juice had the highest polyphenols content (10.77 mg GAE/ml of juice); however, the pomegranate juice had the highest flavonoids content (5.71 mg RE/ml of juice). The assessment of the antioxidant activity was conducted based on three methods: ferric reduction power, DPPH°, and ABTS + assays. Our results confirmed that all juices were loaded with natural antioxidants. Moreover, the sensorial test of the five juice formulations showed an acceptable quality by the tasting panel. To conclude, this study reveals that the formulation of a cocktail pomegranate/date juice seems to be an interesting initiative for the processing of noncommercial varieties.

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