Modulation of the defence responses against Cd in willow species through a multifaceted analysis.

Willow, due to the extensive root system, high transpiration rates and ability to accumulate large amounts of cadmium, is considered particularly useful for green remediation practices. In this study two different willow species, Salix viminalis and Salix alba, were used to assess possible differences in their ability of cadmium accumulation and to analyse in detail the physiology of their response to treatments with this metal using a multidisciplinary approach. Plants were grown in hydroponics and treated with 0, 50 and 100 µM Cd2+ (CdCl2) for 7 and 14 days. Cadmium content, oxidative stress, both evaluated by biochemical and histochemical techniques, antioxidant response, leaf stomatal conductance and photosynthetic efficiency were measured in control and treated roots and/or leaves. The two willow species removed cadmium with a high efficiency from the growth solution; however, the highest contents of Cd recorded in plants grown in the presence of the lower Cd concentrations suggest a limited capacity of metal accumulation. No photochemical limitation characterised treated plants, probably due to the ability to store large amounts of Cd in the root compartment, with reduction of damage to the photosynthetic machinery. S. viminalis, able to uptake cadmium also in the root apical region, seemed to be a more efficient accumulator than S. alba and, thanks to a relatively higher antioxidant response, did not show a higher level of oxidative stress. On the basis of the above, the two plant species, in particular S. viminalis, are confirmed as useful for cadmium phytostabilisation/phytoextraction.

Application of sodium alginate extracted from a Tunisian brown algae Padina pavonica for essential oil encapsulation: Microspheres preparation, characterization and in vitro release study.

In recent years, there has been considerable interest in essential oils encapsulation and in developing biodegradable microparticles. The aim of this present work was to prepare clove essential oil loaded microspheres, by a modified emulsification method, using sodium alginate extracted from a Tunisian Brown seaweed Algae Padina pavonica as biopolymer. The obtained microparticles were characterized by FT-IR, DSC and SEM. Loading capacity yield, encapsulation efficiency (%EE) and in vitro release of the essential oil were also investigated. Sodium alginate microspheres were successfully prepared as confirmed by physico-chemical characterizations. %yield of microspheres and %EE of essential oil were 72.73% and 24.77% ±â€¯7.47%, respectively. SEM showed pseudospherical microspheres with rough surface ranging, in size, from 1500 µm to 3000 µm. In vitro dissolution study indicates a controlled released of the essential oil which follows, mainly, classical Fickian diffusion. Thus, this present work highlighted the potential of this polysaccharide as a biopolymer to formulate polymeric microspheres.