Agrobacterium mediated transformation of Tunisian Cucumis melo cv. maazoun

Transgenic Cucumis melo cv. Maazoun containing the neomycin phosphotransferase II (NPT II) chimeric gene conferring resistance to kanamycin were obtained from cotyledons explants inoculatedwith Agrobacterium tumefaciens (GV3101) that contained the binary vector plasmid pADI. Transformed shoots were obtained on Murashige and Skoog medium supplemented with 1.50 mgl-1 IAA, 0.10mgl-1BAP, 0.01 mgl-1 NAA and 6 mgl-1 kinetin. Transformants were selected by using only 100 mgl-1 of kanamycin and 4 days of pre-culture. Putative transformants were confirmed for transgene insertion through polymerase chain reaction (PCR) analysis. From the inoculated explants, 6.66% produced transgenic shoots

Wild Boar (Sus scrofa) as Reservoir of Zoonotic Yeasts: Bioindicator of Environmental Quality

Wildlife animals are recognized as reservoirs for zoonotic fungi and their faeces might play an important role in introducing pathogens into the environment. Thought wild boar (Sus scrofa) population has dramatically increased across Europe, information about their possible role in dissemination of zoonotic pathogenic yeasts in the environment is scant. Therefore, fecal samples (n = 124) from wild boars from Campania region (Southern Italy) were collected and yeasts identified biochemically and molecularly by sequencing of the internal transcribed spacer region and their phylogenetical relationship assessed. The antifungal susceptibility profiles of yeasts were also investigated using AFST-EUCAST method. Yeasts were isolated from 50.1% of the samples with the highest occurrence in samples from the province of Salerno (61.1%). A total of 368 Candida strains belonging to nine species were identified, with Candida albicans (45.7%), followed by Candida krusei (15.2%), Kazachstania slooffiae (9.8%) and Candida parapsilosis (7.6%) as the most prevalent identified species. Among C. albicans four sequence types (i.e., ST1-ST4) were identified with an intraspecific nucleotide difference up to 0.21%. The ML tree grouped all representative sequence types as paraphyletic clades with those of the references yeast species, respectively and supported by high bootstrap values. Fluconazole was the less active drug whereas, posaconazole, voriconazole, and isavuconazole the most active one. No resistance phenomena were observed for C. albicans and high MICs values for 5FC, azoles and echinocandines were registered in non-albicans Candida spp. This study showed, for the first time, the important role of wild boars in dissemination of pathogenic fungi in the environment. The absence of resistance phenomena in the Candida spp. might reflect environmental free from residues of azoles antifungals pollution or chemicals and suggests the role of wild boar as bio indicators of environment quality

Oscillations of charged particles in an external magnetic field about steady motion

We develop a Hamiltonian formalism that can be used to study the particle dynamics near stable equilibria. The construction of an original canonical transformation allowed us to prove the conservation of the linear momentum P3, which permitted the expansion of the Hamiltonian about a fixed point. The definition of the rotational variable h whose Poisson algebra properties played the essential role in the diagonalization of the quadratic Hamiltonian yielding two uncoupled oscillators with definite frequencies and amplitudes. It is through applying this variable near a fixed point that come to light Heisenberg's and Harmonic Oscillator equations of motion of the particles, leading thus the association of the fixed point trajectories with arbitrary trajectories in its immediate neighborhood. The present formalism succeeded to treat the problem of free-electron laser dynamics and may be applied to similar cases

Self-field effects on electron dynamics in a three-dimensional helical wiggler free-electron laser with axial magnetic field

An analytic linear theory of the electron dynamics in a three-dimensional helical wiggler free electron laser (FEL) with axial magnetic field is presented. Orbits are obtained by perturbing the steady state-trajectories in order to determine the characteristic frequencies Ω± of the FEL. The effect of the self-fields on electron dynamics is studied and modified steady-state orbits and their stabilities have been analysed considering variation of electron energy and density. Among the features encountered is that in both group-I and group-II, one of the characteristic frequencies may have either signs affecting then the stability of the motion, while in group-II operation a repulsion of the frequencies at a pseudocrossing leads to highly perturbed trajectories when the wiggler frequency is approximately half the cyclotron frequency. Self-fields effects can significantly impair the stability of the electron orbits. For group-I orbits, they are more important for higher wiggler frequencies and lower beam energies. For group-II orbits, they remain less important for higher wiggler frequencies and lower beam energies before reaching the inversion zone, then they behave as for group-I orbits. It should be remarked that self-fields shift the inversion zone towards higher cyclotron frequencies the thing that is obtained by either decreasing the wiggler frequency or increasing the beam energy. It is shown that the axial velocity-induced self-magnetic field has a diamagnetic effect for both groups orbits, while the wiggler-induced self-magnetic field has a diamagnetic effect for group-I orbits and a paramagnetic effect for group-II orbits. The paramagnetic and diamagnetic effects are more important for higher beam energies and densities

Structural and vibrational study a new potassium lithium ă dihydrogenphosphate KLi(H2PO4)(2)

International audienceThe single crystal of potassium lithium dihydrogenphosphate ă KLi(H2PO4)(2) (notated as KLDP) was synthesized at room temperature and ă its structure determined by single crystal X-ray diffraction. The ă compound was found to crystallize in the monoclinic system with space ă group P2(1)/c (No.14) and the following parameters a = 7.5197(6), b = ă 12.8943(10) and c = 7.3900(6)angstrom, beta = 98.477(3)degrees, Z = 4. ă This feature structure consists of LiO4 tetrahedra linked by corners ă with H2PO4 groups to form infinite layer running along the ab plane. In ă the interlayer, KO8 polyhedra form layers parallel to the same plane. In ă addition, Raman and infrared spectra were measured at room temperature, ă which confirm the presence of H2PO4, LiO4 groups and ABC bands in the ă unit cell. In fact, these fundamental vibrations were proposed by ă analogy with spectra of other phosphate-based hydrogen-bonded compounds

Essential oil chemical diversity of Tunisian Mentha spp. collection

Mints are perennial herbs that are cultivated for medicinal and aromatic purposes. They are highly polymorphic and their taxonomy is difficult. Sixty mint accessions, representing seven Mentha species (M. aquatica L., M. longifolia L., M. piperita L., M. pulegium., M. rotundifolia L., M. spicata L. and M. spicata var. crispa 'moroccan'), were collected at full flowering from 51 Tunisian localities. Essential oil yields were found to vary from 0.45 to 2.5%, (w/w). Analyses of these oils by GC/FID and GC/MS and their subsequent classification by statistical analysis resulted in six clusters with significant variations in their terpenoid compositions: i) ulegone/isomenthone/ menthone; ii) isomenthone/pulegone; iii) menthone/pulegone ; iv) piperitenone oxide; v) linalool/ linalyl acetate/1,8 cineol/myrcene; and vi) carvone/limonene/1.8 cineol. M. pulegium accessions grouped two chemotypes: one rich in pulegone and the second rich in isomenthone. M. longifolia grouped one chemotype rich in pulegone and a second rich in menthone. M. spicata grouped one chemotypes characterized by a moderate to high carvone content and the second pulegone-rich. M. rotoundifolia accessions were piperitone oxide-rich. M. aquatica and M. piperita have linalool and linalyl acetate as major compounds. These results clearly indicate that there were a large biochemical diversity among the investigated Tunisian Mentha spp. accessions. Genetic and ecological diversities may explain this chemical diversity

Bifidobacterium longum l-Arabinose Isomerase—Overexpression in Lactococcus lactis, Purification, and Characterization

Bifidobacterium longum NRRL B-41409 l-arabinose isomerase (L-AI) was cloned and overexpressed in Lactococcus lactis using a phosphate-depletion-inducible expression system. The purified B. longum L-AI was characterized using D-galactose and L-arabinose as the substrates. The enzyme was active and stable at acidic pH with an optimum at pH 6.0–6.5. The enzyme showed the highest activity at 55 °C during a 20-min incubation at pH 6.5. The Km value was 120 mM for L-arabinose and 590 mM for D-galactose. The V max was 42 U mg−1 with L-arabinose and 7.7 U mg−1 with D-galactose as the substrates. The enzyme had very low requirement for metal ions for catalytic activity, but it was stabilized by divalent metal ions (Mg2+, Mn2+). The enzyme bound the metal ions so tightly that they could not be fully removed from the active site by EDTA treatment. Using purified B. longum L-AI as the catalyst at 35 °C, equilibrium yields of 36 % D-tagatose and 11 % L-ribulose with 1.67 M D-galactose and L-arabinose, respectively, as the substrates were reached