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- Soluble extracellular polymeric substances and microplastics: exposure-response and circular reuse for removalPublication . Rodrigues, Filipa; Mendonça, Ivana; Faria, Marisa; Gomes, Ricardo; Gómez Pinchetti, Juan L.; Ferreira, Artur; Cordeiro, Nereida; cordeiro, nereidaMicroplastics (MPs) are pervasive in aquatic systems, threatening ecosystems, human health, and microalgal production. Soluble extracellular polymeric substances (S-EPS) can agglomerate particles and aid removal. This study examines S-EPS from the cyanobacterium Cyanocohniella rudolphia (BEA 0786B) to (i) model and optimise S-EPS production, (ii) assess production in water contaminated with polystyrene MPs (PS-MPs), and (iii) test S EPS as a bioflocculant for PS-MPs removal. Response surface methodology (RSM) defined a cost-lean operating window and predicted an optimum S-EPS titre of 113 mg/L at 7 days using 10 g/L nitrogen, 0.98 g/L phosphorus, and a biomass-to-medium ratio of 1:6.87 (w/v). Cultures were challenged with PS-MPs (50 μg/L and 5 mg/L) under static or aerated conditions, and at both exponential and stationary phases, and showed stimulated S-EPS synthesis with increases of up to 34%, depending on hydrodynamics and growth stage. Purified S-EPS were evaluated as a bioflocculant at 2 g/L PS-MPs to probe robustness and rate-limiting mechanisms and to delineate a conservative operating window. Maximum removal of 82% was achieved in freshwater at pH 3.5 with Fe3+ 0.05% (w/w), 25 ◦C, S-EPS dose 400 mg/L (S-EPS:PS-MPs 1:5, w/w), and 60 min flocculation. Zeta potential trends and microscopy support charge neutralisation/bridging as the dominant mechanism. Compatible with standard coagulation/flocculation units, the approach links cost-lean, cultivation-derived S-EPS (typically dis carded) to their reuse as a low-additive pretreatment for algal-cultivation intake waters (freshwater/low salinity), reducing reliance on synthetic coagulants and added salinity/metal-sludge burdens. Overall, C. rudolphia is a promising S-EPS producer, whose production is enhanced by exposure to PS-MPs, and its S-EPS acts as an efficient, bio-based flocculant for PS-MPs. The results support process designs to safeguard microalgal operations and to mitigate microplastic pollution in water. This work integrates RSM-optimised S-EPS produc tion, environmental-level exposure-response, and a high-load removal benchmark, enabling circular, low additive, drop-in pretreatment compatible with standard coagulation/flocculation units.
- Genetic diversity and conservation of the Madeira Island (Portugal) endemic Geranium maderense Yeo (Geraniaceae)Publication . Gouveia, M.; Nyberg, B.; Aedo, C.; Bairos, C.; Sequeira, M. Menezes de; Gouveia, Manuela; Sequeira, MiguelGeranium maderense is a perennial, monocarpic herb, up to 200 cm tall, producing very showy inflorescences, very rare in the wild, although cultivated throughout the world as an ornamental plant. G. maderense is protected under the EC habitats directive (Annex *B-II, IV) and Bern Convention (Annex I) only found, so far, in two cliff associated sites, and classified as a Critically Endangered species (IUCN). Using unmanned aerial vehicle (UAV; drone) technology, two new populations were detected, and a new distribution map is presented. Inter-simple sequence repeat markers were used to detect genetic diversity in natural populations and garden grown plants. Genetic diversity estimates revealed retention of genetic variation and weak genetic structure in G. maderense populations. Cluster and principal component analyses formed coherent groups, indicating that genetic diversity in the studied wild populations of G. maderense is heterogeneously distributed. Our results provide crucial information for the preservation of natural populations of G. maderense, and allow for the revaluation, following IUCN criteria as Endangered (EN).