Extraction methods depend mainly on the chemical nature of the extracted molecule. For these reasons, the selection of the extraction medium is a vital part of obtaining these molecules. The extraction of antimicrobial peptides (AMPs) from extremophile plants is important because of its potential pharmaceutical applications. This work focused on the evaluation of several solvents for the extraction of AMPs from the following two extremophile plants: Astragalus armatus and Anthyllis sericea from southern Tunisia. In order to identify the most efficient solvents and extraction solutions, we used sulfuric acid, dichloromethane, phosphate buffer, acetic acid and sodium acetate, and we tested them on leaves and roots of both the studied plants. The extracts obtained using sulfuric acid, dichloromethane and phosphate buffer extraction did not show any antimicrobial activity, whereas the acetic acid and sodium acetate extracts led to growth inhibition of some of the tested bacterial strains. The extracts of leaves and roots of An. sericea and As. armatus obtained by acetic acid and sodium acetate were proven to be active against Gram-positive bacteria and Gram-negative bacteria. Therefore, the most appropriate solvents to use for antimicrobial peptide extraction from both plants are acetic acid and sodium acetate.

Aquatic ecosystems are increasingly affected by anthropogenic pollution, highlighting the need for efficient and advanced water treatment technologies. Poly(vinyl alcohol-co-vinyl acetate) copolymer (PVA-co-PVAc), a partially hydrolyzed copolymer derived from poly(vinyl acetate), has received limited attention for surface water remediation. To address this gap, PVA-co-PVAc was prepared and evaluated as an alternative material for surface water treatment. The polymer identity was inferred from the synthesis route and degree-of-hydrolysis measurements; comprehensive structural characterization was beyond the scope of the present application-focused study. Physico-chemical and microbiological characterization of water samples collected from six locations in Joumine Dam revealed the highest contamination levels at the dam inlet, indicating a substantial pollution load entering the reservoir. Consequently, water from this site was selected to evaluate the treatment performance of the copolymer. Among the tested copolymer concentrations (0.1%, 0.2%, 0.5%, and 1% w/v), the best performance was achieved at 1% (w/v), resulting in a 93% reduction in total cell density determined by direct microscopic counting, together with significant decreases in turbidity and organic matter and an apparent decrease in fluoride concentration, requiring independent analytical confirmation. These findings demonstrate the potential of PVA-co-PVAc to improve selected surface-water quality parameters under laboratory treatment conditions and support further investigation of this material using natural water matrices.