Report on needs and priorities in the field of international cooperation agreements on water management in the target MACs

This report aims to provide a revision of the water related goals within the international agreements joined by the three case study countries,Egypt, Morocco and Tunisia, while emphasizing the critical points that should be developed and reinforced in the near future through an integrated approach for water policies, initiatives and management

Antimicrobial resistance and molecular analysis of non-typhoidal Salmonella isolates from human in Tunisia.

International audienceDuring the period from 2006 to 2007, a total of 32 clinical isolates of Salmonella enterica were isolated from diarrheagenic stool samples and further examined for their susceptibility to various antibiotics. Sixteen of the human isolates were from the capital Tunis, 11 were from Sousse, four were from Nabeul and one was from Mahdia, Tunisia. The isolates were serotyped and identified at the National Centre of Enteropathogenic Bacteria, Pasteur Institute, Tunis (Centre National de Salmonella, Shigella et Vibrio - Institut pasteur de Tunis); nine distinct serovars were identified: Enteritidis (n=20), Typhimurium (n=4), Zanzibar (n=2), Manhattan (n=1), Bovismorbificans (n=1), Amsterdam (n=1), Saint Paul (n=1), Kentucky (n=1) and Muenster (n=1). Our results showed that 25 Salmonella isolates (78.1 %) were resistant to antibiotics with 20 isolates (62.5 %) displayed resistance to ampicillin. Isolates sharing invA gene, as shown by PCR amplification, were further characterized by the techniques of pulsed-field gel electrophoresis (PFGE) using the restriction enzyme XbaI and plasmid analysis to determine possible genetic relationships among Salmonella enterica clinical isolates and to assess genetic diversity. Plasmid profiling identified seven plasmid profiles (with 1-5 plasmids) among the isolates; four isolates (Salmonella Kentucky, Salmonella Muenster, Salmonella Bovismorbificans and Salmonella Zanzibar) did not carry any plasmid. The isolates were differentiated into 10 distinct XbaI-pulsotypes. Our findings show genetic diversity among the different serovars and cluster analysis of compiled serotyping, PFGE, plasmid profiling and antibiotic resistance data provided additional discrimination

Harnessing the power of enzymes for environmental stewardship

Pollution of soils, sediments and especially ground- and surface water by a wide variety of chemicals, including emerging micropollutants necessitates the development of new, powerful strategies of mitigation, restoration and sustainable environmental protection. Micropollutants such as endocrine disruptor chemicals (EDC) represent an increasing concern which is only partially addressed by the use of physicochemical nonspecific approaches such as ozonation. An attractive and ‘greener’ alternative is the use of enzymatic biocatalysis for the removal and detoxification of micropollutants. In addition to the ease and reliability of enzyme usage, the biocatalytic properties of enzymes can be manipulated thanks to protein engineering, enzyme immobilization and bioreactor design. The ligninolytic enzymes of white-rot fungi (WRF) such as peroxidases and laccases are particularly suited to the degradation of micropollutants such as EDC, pharmaceuticals and personal care products. Thanks to their relatively low substrate specificity, these oxidoreductases can oxidize various micropollutants of phenol-like structure plus several non-phenolic substrates indirectly via the oxidized form of mediator molecules. The re-usability of enzymes and their separability from reactants and products is ensured by support-based immobilization or by formation of cross-linked enzyme aggregates (CLEA). These techniques are illustrated by several new technical developments facilitating enzyme retention in reactor systems. Although of high interest for biotechnological applications, reported CLEA conversion efficiencies for oxidative enzymes are still far from fulfilling these needs. Thus, we have identified relevant factors for the production of CLEA of laccases alone or in combination with other oxidoreductases and improved them by applying rational experimental design and optimization methodologies. The resulting CLEA were considerably more robust than their free counterparts. A uniform size distribution of the CLEA was shown using light microscopy, environmental scanning electron microscopy and dynamic light scattering. The results are exploited in continuous membrane reactors for the biotransformation of micropollutants such as bisphenol A or nonylphenol

Pisolithus albus (Sclerodermataceae), a new record for Tunisia

Pisolithus albus was recently collected for the first time in Tunisia. This ectomycorrhizal fungus is found associated with Eucalyptus occidentalis, a new symbiotic relationship, in the urban area of Tunis. The new record of this fungus on this tree permit to expand our knowledge on the ecology and distribution of P. albus in Tunisia. The finding is also important since this fungal symbiont has great potential in forestation efforts. Data on the morphology, molecular identification, distribution and, ecology for P. albus in Tunisia are presented for the first time

Macromycetes' diversity in Tunisia

In Tunisia, about 12% of the country area is covered by forests which have favorable climatic factors likely to harbor a high macrofungal biodiversity. However, this valuable bioresource remains understudied especially regarding their distribution, ecology, abundance and diversity. The initiation of the first national inventory of macrofungi in NorthWestern Tunisian forests was published by our group in 2016. The study covered six governorates, sixty seven sites and enabled the identification of one hundred and twenty-three specimens. Abiotic environmental factors such (as bioclimatic stage, rainfall and edaphic conditions) and biotic factors (plant association and nature and density of the forest) have been studied to determine the distribution and ecology of the collected macromycetes. The obtained results showed a promising diversity of macfungal resources in Tunisia. The present work aims to determine an updated checklist for specimens collected from January 2014 to March 2017. A total of 75 collection and prospecting missions carried out to 105 sites in 11 governorates of northern Tunisia allowed the collection of a total of 1815 specimens. Some of which are considered infrequent or rare. A herbarium at the Laboratory of Microorganisms and Active Biomolecules at the Faculty of Sciences of Tunis and in the Laboratory of Microorganisms of the National Genes Bank of Tunisia was created and an online database with all the photos and data collected was carried out. In addition, a molecular data base of the collected specimens was initiated which currently contains 250 ITS sequences and continues to be regularly enriched. This work will allow the mapping of macromycetes in Tunisia which will be useful to realise the national inventory of macrofungi in our country. Data will be available to interested mycologists, to the silviculturists and to the gatherers of edible mushroom. This may improve the exploitation of these valuable resources and contribute to their best management

Macromycetes' diversity in Tunisia

In Tunisia, about 12% of the country area is covered by forests which have favorable climatic factors likely to harbor a high macrofungal biodiversity. However, this valuable bioresource remains understudied especially regarding their distribution, ecology, abundance and diversity. The initiation of the first national inventory of macrofungi in NorthWestern Tunisian forests was published by our group in 2016. The study covered six governorates, sixty seven sites and enabled the identification of one hundred and twenty-three specimens. Abiotic environmental factors such (as bioclimatic stage, rainfall and edaphic conditions) and biotic factors (plant association and nature and density of the forest) have been studied to determine the distribution and ecology of the collected macromycetes. The obtained results showed a promising diversity of macfungal resources in Tunisia. The present work aims to determine an updated checklist for specimens collected from January 2014 to March 2017. A total of 75 collection and prospecting missions carried out to 105 sites in 11 governorates of northern Tunisia allowed the collection of a total of 1815 specimens. Some of which are considered infrequent or rare. A herbarium at the Laboratory of Microorganisms and Active Biomolecules at the Faculty of Sciences of Tunis and in the Laboratory of Microorganisms of the National Genes Bank of Tunisia was created and an online database with all the photos and data collected was carried out. In addition, a molecular data base of the collected specimens was initiated which currently contains 250 ITS sequences and continues to be regularly enriched. This work will allow the mapping of macromycetes in Tunisia which will be useful to realise the national inventory of macrofungi in our country. Data will be available to interested mycologists, to the silviculturists and to the gatherers of edible mushroom. This may improve the exploitation of these valuable resources and contribute to their best management

Cultivation of some mushrooms species originating from Tunisia and exploration of their valuable metabolites

Mushrooms present interests for consumption as food, as traditional medicine or in bioremediation, due to their nutritional, antioxidant, antimicrobial, therapeutic and enzymatic values. The valorisation of indigenous species of mushrooms requires well characterized collections. Although macrofungi are widespread in Tunisian forests, their diversity and ecology remain generally underexplored which hindered their exploitation. In particular, the in vitro cultivation of the mycelial form could have many advantages: (a) it offers faster growth rates which may have industrial and biotechnological benefits, and (b) will allow better resource management (longer conservation of active forms) and genetic manipulation. To achieve these objectives, more than 55 regular expeditions to Tunisian forests were organized. Several hundreds of indigenous species of mushrooms were collected and macroscopically and microscopically identified. Mycelial cultivation of newly collected specimens allowed obtaining 57 isolates of basidiomycetes. Specific molecular analysis by sequencing ITS regions showed that the isolates belong to the following genera: Agaricus (9), Ganoderma (5), Amanita (5), Boletus (4), Lactarius (3), Lepista (3), Tapinella (3), Pleurotus (3), Macrolepiota (3), Gymnopilus (2), Lentinus (2), Polyporus (2), Tricholomopsis (2), Rhizopogon (2), Hygrophorus (2), Armillaria (2), Pisolithus (1), Paxillus (1), Hericium (1), Russula (1), and Coprinus (1). On the other hand the cultivated species were screened for their enzyme production on specific solid and liquid media namely laccase, cellulase and amylase.Preliminary results showed that the majority of species produce high levels of laccase activity and the number of extracellular laccase isoenzymes seems to be species dependent. Potentially interesting produced enzymes will be purified and characterized. In addition the possibility of submerged cultivation and biologically active polysaccharides production by some medicinal species was also examined. Preliminary results showed that several species are producing antiviral polysaccharides. Further analyses are required to characterize the active biomolecules and to investigate the action mode. Additional tests on immunomodulatory, hypoglycemia, cholesterol lowering, antioxidant, antiinflammatory, antimicrobial and antitumor properties are planned. This work on mushrooms originating from Tunisia may contribute to diversify the range of mushrooms for domestic market and for obtaining innovative products

A preliminary check list of macromycetes in northern Tunisia

Within the last decade, checklists of fungi of several countries have been published or updated. Nevertheless, no checklists of macromycetes have hitherto been published for Tunisia (North Africa) apart from a mycocoenological study reporting 34 listed species. This work presents a list of macromycetes collected from January 2014 to March 2015 in six governorates of northern Tunisia. One hundred and twenty-three species (117 basidiomycetes and six ascomycetes) belonging to 78 genera and 46 families were recorded

Modeling and analysis of the effect of substrate on the flexible piezoelectric films for kinetic energy harvesting from textiles

In the last few years, a lot of research focused on increasing of smart textiles products such as woven and knitted structures, which are able to show significant change in their mechanical properties (such as shape and stiffness), in a practical way in response to the stimuli. In this paper, we investigate the potential of a flexible piezoelectric film stuck onto three woven textile matrices: cotton, polyester/cotton, and Kermel, for harvesting mechanical energy from the textile and converting it into electrical energy. At first, a brief introduction of energy harvesting using the piezoelectric material and smart textile is presented. Furthermore, a basic model showing the operation of polyvinylidene fluoride with 33 mode is established. The second part is focused on standard approach model of energy harvesting based on resistive load and freestanding piezo-polymer for the examination of the performance of 33-mode polyvinylidene fluoride energy harvester and the prediction of harvested energy quantity. A power analytical model generated by a smart structure type polyvinylidene fluoride that can be stuck onto fabrics and flexible substrates is investigated. On the other hand, the effects of various substrates and the sticking of these substrates on the piezoelectric material are reported. Additionally, the output power density of this theoretical model of woven textile matrices could reach a value that was seven times higher than freestanding piezo-polymer. Three types of the substrates have been compared as function of excitation frequency and the compressive applied force

Organic solar cells of enhanced efficiency and stability using zinc oxide:zinc tungstate nanocomposite as electron extraction layer

In this work, the enhanced performance of inverted bulk heterojunction (BHJ) organic solar cells (OSCs) using zinc oxide (ZnO):polyoxometalate (POM), in particular sodium metatungstate (Na6H2W12O40), nanocomposite films as electron extraction layers (EELs) is demonstrated. The addition in the precursor solution of ZnO of sodium metatungstate results in the formation of ZnO:ZnWO4 nanocomposite as evidenced by X-ray diffraction, Fourier transform infrared and photoluminescence measurements. The formation of ZnO:ZnWO4 heterointerface reduces the work function of the nanocomposite material leading to a more favorable electron extraction/transport at the organic blend/electron transport layer interface. Additionaly, the amount of zinc interstitial defects is suppressed having a profound positive effect on device stability. As a result, simultaneously improved open-circuit voltage (Voc), short-circuit current density (Jsc) and fill factor (FF) are obtained in the devices using the ZnO:ZnWO4 nanocomposites. Therefore, both of the inverted BHJ OSCs composed of either poly (3-hexylthiophene) (P3HT):[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) or P3HT:indene-C60 bisadduct (IC60BA) photoactive blends show a significant performance enhancement when using the nanocomposite electron extraction layer, exhibiting a 27% and 23%, respectively, improvement in their power conversion efficiency (PCE) values compared to the reference devices based on pristine ZnO. In addition, the devices with the ZnO:ZnWO4 layer exhibit a remarkable stability enhancement retaining 95% of their initial PCE value upon storage for 500 h. © 2019 Elsevier B.V