Polyploidy induction of Tunisian Trigonella foenumgreaum L. populations

Polyploidy plays an important role in plant evolution and constitutes an important mechanism of diversification and creation of genetic variability. Artificial polyploidy can be induced using the colchicine. The aim of this study was to determine the Trigonella foenum-greacum (2n= 16)  population which resists better to colchicine treatment and which has the highest rate of polyploid formation among 38 populations collected from different Tunisian regions. The comparative study between treated and control plants showed significant increases (p < 0.05) for the parameters survival rate, rate of malformed leaves appearance, stem height and seeds number by pod. The 38 treated populations showed significant variations (p < 0.05) between them for the parameters survival rate, branches number, stem height and seeds number by pod. Results also showed that treatment of the shoot meristem by colchicine allowed to obtain diploid (2n= 16) and mixoploid plants having mixoploid branches (4n = 32 and 2n= 16) and branches entirely tetraploid (4n = 32). The obtained rate of mixoploidy was 65.79% of treated plants. Among the 38 analyzed fenugreek populations, the population 15 of Menzel Temime presented the highest rate of mixoploids formation and survival rate to colchicine treatment.Key words: Fenugreek, induction of chromosome doubling, mixoploidy, colchicine, Tunisia

Advances on antiviral activity of Morus spp. plant extracts: Human coronavirus and virus-related respiratory tract infections in the spotlight

(1) Background: Viral respiratory infections cause life-threatening diseases in millions of people worldwide every year. Human coronavirus and several picornaviruses are responsible for worldwide epidemic outbreaks, thus representing a heavy burden to their hosts. In the absence of specific treatments for human viral infections, natural products offer an alternative in terms of innovative drug therapies. (2) Methods: We analyzed the antiviral properties of the leaves and stem bark of the mulberry tree (Morus spp.). We compared the antiviral activity of Morus spp. on enveloped and nonenveloped viral pathogens, such as human coronavirus (HCoV 229E) and different members of the Picornaviridae family—human poliovirus 1, human parechovirus 1 and 3, and human echovirus 11. The antiviral activity of 12 water and water–alcohol plant extracts of the leaves and stem bark of three different species of mulberry—Morus alba var. alba, Morus alba var. rosa, and Morus rubra—were evaluated. We also evaluated the antiviral activities of kuwanon G against HCoV-229E. (3) Results: Our results showed that several extracts reduced the viral titer and cytopathogenic effects (CPE). Leaves’ water-alcohol extracts exhibited maximum antiviral activity on human coronavirus, while stem bark and leaves’ water and water-alcohol extracts were the most effective on picornaviruses. (4) Conclusions: The analysis of the antiviral activities of Morus spp. offer promising applications in antiviral strategies

Pomegranate Peel Powder as a Green Eco-Friendly Corrosion Inhibitor for Steel rebar’s Embedded in Cement Paste

International audiencePomegranate Peel Powder (PPP) was used as a low-cost natural inhibitor of corrosion of the steel rebar embedded in cement paste. Electrochemical impedance spectroscopy methods were used to evaluate its inhibition efficiency. The results revealed that PPP acts as a corrosion inhibitor. The performance of the electrochemical impedance spectra over time revealed that the PPP extract forms a barrier which prevents the penetration of chloride ions. Actually, this plant extract delays the diffusion of these aggressive ions. The inhibition action was mainly linked to the adsorption of the bioactive phenolic compounds present in the extract solution, on the steel rebar’s surface. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG

Combined system of natural pomegranate as heterogeneous bioadsorbent and photocatalysis for removal of textile dye herbicide in presence of heavy metals: Effect of operating parameters and reaction monitoring

International audienceThe photocatalytic degradation of acid orange II (AOII), which is a toxic dye effluent for textile applications, has been studied using natural pomegranate as heterogeneous bioadsorbent in the presence of TiO2 activated by an external ultraviolet radiation under various conditions. Powder of pomegranate rind and leaves has been tested for heavy metals adsorption. A special attention has been paid to the treatment efficiency of a real dye effluent in the presence of heavy metal, namely zinc (Zn). The experimental results showed that for low values of Zn2+ in the solution (40 mg/L), AOII removal kinetics fastened until reaching an optimum, then slowed down for higher concentrations (100 mg/L). This behavior could be explained by the fact that at low zinc concentrations, Zn2+ could be incorporated in the photocatalytic process because of its photonic character. At high concentrations, zinc is more susceptible of consuming radicals due to competition effect. On the other hand, results showed that no photocatalytic activity of Zn2+ was recorded. The degradation rate was strongly influenced by the presence of heavy metals, initial concentrations of AOII, and amount of crushed powder of pomegranate rind and leaves. Moreover, different ways of adding natural pomegranate in the photocatalytic reactor have been tested in order to keep Zn2+ concentration in optimal conditions. © 2017 Desalination Publications. All rights reserved

Morphology and chemical composition of Tunisian caper seeds: variability and population profiling

Caper, as a spontaneous plant, has a large natural distribution in the Mediterranean Sea basin. It is an interesting crop with an economic importance; especially the species Capparis spinosa. The morphology of seeds and their composition in lipid and protein were studied in 15 wild Tunisian caper populations: 9 populations represented the subspecies C. spinosa subsp. spinosa (thorny caper) and 6 populations represented the subspecies C. spinosa subsp. rupestris (inerm caper). Results show that seeds of C. spinosa are especially attractive because they can be grown to produce oil (ca. 30%) and protein (26%). Principal component analysis (PCA) did not show a geographic separation. A subspecies segregation between C. spinosa subsp. rupestris (as a homogeneous group) and C. spinosa subsp. spinosa (as a heterogeneous group) was clearly detected.Key words: Caper (Cappains spinosa), morphology; lipids, proteins, principal component analysis (PCA)

Innovative and stable TiO2 supported catalytic surfaces removing aldehydes under UV-light irradiation

International audienceThe present study reports the photocatalytic degradation of aldehydes using TiO2 impregnated polyester (PES) and glass fiber (GFT)-TiO2 addressing the photocatalytic degradation aldehydes (air-solid interface). The PES-TiO2 optical absorption was determined by diffuse reflectance spectroscopy (DRS). By X-ray diffraction (XRD), the formation of TiO2 anatase on the PES surface was detected. The photocatalytic oxidation (PCO) of butyraldehyde and isovaleraldehyde was carried out in a batch photo-reactor equipped with a UV-mercury Philips 9W lamp and mediated by glass fiber GFT-TiO2 and PES-TiO2 surfaces. The removal of these two aldehydes was found to be a function of pollutant concentrations. The stable catalytic reuse of both catalysts reported. A Langmuir Hinshelwood (L-H) model describes the degradation kinetics on PES-TiO2 and on GFF-TiO2. The aldehyde degradation by-products were analyzed by gas chromatography mass spectrometry (GC-MS). Three organics intermediates identified during the aldehyde degradation were: acetones, alcohols and fatty acids

Photocatalytic performance of TiO2 impregnated polyester for the degradation of Reactive Green 12: Implications of the surface pretreatment and the microstructure

International audienceIn the present work, we investigate the degradation of recalcitrant industrial textile dye (Reactive green 12) in aqueous solution by TiO2 impregnated polyester at room temperature. The TiO2 loading on polyester was optimized using different polyester pretreatments (plasma surface activation and UV-C photons). The applied surface pretreatments led to slightly different microstructure, crystalline sizes and photocatalytic activities. Both catalyst tests showed no photocatalytic activity for Radio-Frequency plasma (from now as “RF-plasma”) pretreated polyester under visible light and a lower activity compared to UVC-pretreated-impregnated-fabrics under UV light. This was attributed to the TiO2 aggregation on the surface of RF-plasma activated polyester. However, the photocatalytic performance of UV-C activated catalyst was investigated studying the optimal reaction conditions such as pollutant initial concentration, applied light (UV or Visible), catalyst loading and the presence of hydrogen peroxide at different concentrations. Under optimized operating conditions, namely catalyst dose of 5.18 g/L and an initial dye concentration of 2 mg/L, the removal of Reactive green 12 reached 100% under UV light and 87.14% under visible light within 120 min. Moreover, the presence of hydrogen peroxide showed a positive impact on the degradation, since the time needed for total dye decreased to 80 min under UV light irradiation for a [H2O2] to [RG 12]0 ratio in the range 20–30. The kinetic results showed that the removal of this recalcitrant dye nearly followed a Langmuir-Hinshelwood (L-H) model with a regression coefficient (R2) value of 0.926. The catalyst activity was found to be stable for more than five reuse cycles. © 2017 Elsevier B.V