Percorrer por autor "Jos, Angeles"
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- Analysis of the Use of Cylindrospermopsin and/or Microcystin-Contaminated Water in the Growth, Mineral Content, and Contamination of Spinacia oleracea and Lactuca sativaPublication . Llana-Ruiz-Cabello, Maria; Jos, Angeles; Cameán, Ana; Oliveira, Flavio; Barreiro, Aldo; Machado, Joana; Azevedo, Joana; Pinto, Edgar; Almeida, Agostinho; Campos, Alexandre; Vasconcelos, Vitor; Freitas, MarisaCyanobacteria and cyanotoxins constitute a serious environmental and human health problem. Moreover, concerns are raised with the use of contaminated water in agriculture and vegetable production as this can lead to food contamination and human exposure to toxins as well as impairment in crop development and productivity. The objective of this work was to assess the susceptibility of two green vegetables, spinach and lettuce, to the cyanotoxins microcystin (MC) and cylindrospermopsin (CYN), individually and in mixture. The study consisted of growing both vegetables in hydroponics, under controlled conditions, for 21 days in nutrient medium doped with MC or CYN at 10 μg/L and 50 μg/L, or CYN/MC mixture at 5 + 5 μg/L and 25 + 25 μg/L. Extracts from M. aeruginosa and C. ovalisporum were used as sources of toxins. The study revealed growth inhibition of the aerial part (Leaves) in both species when treated with 50µg/L of MC, CYN and CYN/MC mixture. MC showed to be more harmful to plant growth than CYN. Moreover spinach leaves growth was inhibited by both 5 + 5 and 25 + 25 µg/L CYN/MC mixtures, whereas lettuce leaves growth was inhibited only by 25 + 25 µg/L CYN/MC mixture. Overall, growth data evidence increased sensitivity of spinach to cyanotoxins in comparison to lettuce. On the other hand, plants exposed to CYN/MC mixture showed differential accumulation of CYN and MC. In addition, CYN, but not MC, was translocated from the roots to the leaves. CYN and MC affected the levels of minerals particularly in plant roots. The elements most affected were Ca, K and Mg. However, in leaves K was the mineral that was affected by exposure to cyanotoxins.
- In vitro antimicrobial activity of volatile compounds from the Lichen Pseudevernia furfuracea (L.) Zopf. against multidrug-resistant bacteria and fish pathogensPublication . Essadki, Yasser; Hilmi, Adel; Cascajosa-Lira, Antonio; Girão, Mariana; Darrag, El Mehdi; Rosário Martins, Maria; Romane, Abderrahmane; Zerrifi, Soukaina El Amrani; Mugani, Richard; Tazart, Zakaria; Redouane, El Mahdi; Jos, Angeles; Cameán, Ana M.; Vasconcelos, Vitor; Campos, Alexandre; Khalloufi, Fatima El; Oudra, Brahim; Barakate, Mustapha; Carvalho, Maria de FátimaLichens are symbiotic organisms with unique secondary metabolism. Various metabolites from lichens have shown antimicrobial activity. Nevertheless, very few studies have investigated the antimicrobial potential of the volatile compounds they produce. This study investigates the chemical composition and antimicrobial properties of volatile compounds from Pseudevernia furfuracea collected in two regions of Morocco. Hydrodistillation was used to obtain volatile compounds from samples collected in the High Atlas and Middle Atlas. Gas chromatography–mass spectrometry (GC-MS) analysis identified phenolic cyclic compounds as the primary constituents, with atraric acid and chloroatranol being the most abundant. Additionally, eight compounds were detected in lichens for the first time. The antimicrobial activity of these compounds was assessed using disc diffusion and broth microdilution methods. Both samples demonstrated significant antimicrobial effects against multidrug-resistant human bacteria, reference microorganisms, fish pathogens, and Candida albicans, with minimum inhibitory concentrations (MICs) ranging from 1000 µg/mL to 31.25 µg/mL. This study provides the first report on the volatile compounds from Pseudevernia furfuracea and their antimicrobial effects, particularly against fish pathogens, suggesting their potential as novel antimicrobial agents for human and veterinary use. Further research is warranted to explore these findings in more detail.
- Sustainable agriculture with cyanobacterial biomass: Soil experiments on spinach and radish plantsPublication . Massa, Anabella; Martins, Diogo; Azevedo, Joana; Prieto, Ana I.; Camean, Ana M.; Diez-Quijada, Leticia; Jos, Angeles; Reimão, Mariana; Azevedo, Rui; Pinto, Edgar; Almeida, Agostinho; Vasconcelos, Vitor; Campos, Alexandre; Freitas, Marisa; REIMÃO BORGES LOPES DA SILVA, MARIANATo support sustainable food production and improve crop yields, it is essential to explore bio-based plant growth- promoting products. Cyanobacterial biomass has shown potential to enhance soil quality and agricultural productivity. However, some cyanobacteria produce cyanotoxins, such as microcystins, cylindrospermopsin and anatoxin-a, which can adversely affect plant development depending on their concentration. This study evaluated the potential of cyanobacterial biomass as a soil amendment and plant growth stimulant by assessing growth, nutrient content and toxin accumulation in spinach and radish plants. Plants were cultivated in soil treated with no amendment, commercial fertilizer, or cyanobacterial biomass from Microcystis aeruginosa (microcystins-producer), Anabaena sp. (anatoxin-a-producer), Raphidiopsis raciborskii (non-cylindrospermopsin producer), and R. raciborskii (cylindrospermopsin-producer). While biomass additions supplied nutrients to the soil, spinach showed increased sensitivity to microcystins and anatoxin-a, with significantly reduced growth. Overall, mineral concentrations in plant tissues did not increase; most macro- and micronutrients declined, particularly in spinach shoots and radish roots (p ≥ 0.05). Vitamin C content also decreased in most treatments, except in plants treated with the non-cylindrospermopsin-producing R. raciborskii strain, where a significant increase was observed (p ≥ 0.05). Toxic biomass amendments led to the uptake of microcystins-LR and cylindrospermopsin in spinach, and cylindrospermopsin in radish, with cylindrospermopsin levels in spinach exceeding Word Health Organization's tolerable daily intake. These findings underscore the need for a previous detailed characterization of both nutrients and toxins in cyanobacterial biomass to ensure its safe and effective agricultural use, maximizing benefits while protecting food safety.