https://hdl.handle.net/10216/119233 2026-04-17T12:24:05Z https://hdl.handle.net/10216/139639 Title: Role of rhizospheric microbiota as a bioremediation tool for the protection of soil-plant systems from microcystins phytotoxicity and mitigating toxin-related health risk Abstract: Frequent toxic cyanoblooms in eutrophic freshwaters produce various cyanotoxins such as the monocyclic heptapeptides microcystins (MCs), known as deleterious compounds to plant growth and human health. Recently, MCs are a recurrent worldwide sanitary problem in irrigation waters and farmland soils due to their transfer and accumulation in the edible tissues of vegetable produce. In such cases, studies about the persistence and removal of MCs in soil are scarce and not fully investigated. In this study, we carried out a greenhouse trial on two crop species: faba bean (Vicia faba var. Alfia 321) and common wheat (Triticum aestivum var. Achtar) that were grown in sterile (microorganism-free soil) and non-sterile (microorganism-rich soil) soils and subjected to MC-induced stress at 100 µg equivalent MC-LR L−1. The experimentation aimed to assess the prominent role of native rhizospheric microbiota in mitigating the phytotoxic impact of MCs on plant growth and reducing their accumulation in both soils and plant tissues. Moreover, we attempted to evaluate the health risk related to the consumption of MC-polluted plants for humans and cattle by determining the estimated daily intake (EDI) and health risk quotient (RQ) of MCs in these plants. Biodegradation was liable to be the main removal pathway of the toxin in the soil; and therefore, bulk soil (unplanted soil), as well as rhizospheric soil (planted soil), were used in this experiment to evaluate the accumulation of MCs in the presence and absence of microorganisms (sterile and non-sterile soils). The data obtained in this study showed that MCs had no significant effects on growth indicators of faba bean and common wheat plants in non-sterile soil as compared to the control group. In contrast, plants grown in sterile soil showed a significant decrease in growth parameters as compared to the control. These results suggest that MCs were highly bioavailable to the plants, resulting in severe growth impairments in the absence of native rhizospheric microbiota. Likewise, MCs were more accumulated in sterile soil and more bioconcentrated in root and shoot tissues of plants grown within when compared to non-sterile soil. Thereby, the EDI of MCs in plants grown in sterile soil was more beyond the tolerable daily intake recommended for both humans and cattle. The risk level was more pronounced in plants from the sterile soil than those from the non-sterile one. These findings suggest that microbial activity, eventually MC-biodegradation, is a crucial bioremediation tool to remove and prevent MCs from entering the agricultural food chain. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. 2021-08-16T00:00:00Z https://hdl.handle.net/10216/139638 Title: Assessment of constructed wetlands' potential for the removal of cyanobacteria and microcystins (MC-LR) Abstract: Microcystis blooms and the subsequent release of hepatotoxic microcystins (MCs) pose a serious threat to the safety of water for human and livestock consumption, agriculture irrigation, and aquaculture worldwide. Microcystin-LR (MC-LR), the most toxic variant of MCs, has been widely detected in a variety of environments such as water, sediments, plants, and many aquatic organisms. Conventional solutions of water treatment are costly, requiring specific infrastructure, as well as specialized personnel and equipment. Therefore, these solutions are not feasible in many rural areas or in the treatment of large reservoirs. In this regard, low-cost and low-technology solutions, such as constructed wetlands (CWs), are attractive solutions to treat surface waters contaminated with toxic cyanobacteria blooms from lakes, ponds, reservoirs, and irrigation systems. In line with this, the main aim of this work was to evaluate the potential of CWs for the treatment of water contaminated with MC-LR produced by Microcystis aeruginosa-LEGE 91094. For that, microcosms (0.4 x 0.3 x 0.3 m) simulating CWs were assembled with Phragmites australis to treat lake water contaminated with Microcystis aeruginosa cells and MCs. Results showed removal percentages of M. aeruginosa cells above 94% and about 99% removal of MC-LR during 1 week treatment cycles. CWs maintained their functions, regardless the presence of MC-LR in the system, and also showed significant removal of nutrients (ammonium ion removal up to 86%) and organic matter (removal reaching 98%). The present work indicates that CWs have the potential for removal of cyanobacterial cells and cyanotoxins, which can be useful for the treatment of eutrophic waters and provide water of sufficient quality to be used, for instance, in agriculture. © 2019 by the authors. 2020-01-01T00:00:00Z https://hdl.handle.net/10216/139637 Title: First report on cyanotoxin (Mc-lr) removal from surface water by multi-soil-layering (msl) eco-technology: Preliminary results Abstract: Cyanobacteria blooms occur frequently in freshwaters around the world. Some can produce and release toxic compounds called cyanotoxins, which represent a danger to both the environment and human health. Microcystin-LR (MC-LR) is the most toxic variant reported all over the world. Conventional water treatment methods are expensive and require specialized personnel and equipment. Recently, a multi-soil-layering (MSL) system, a natural and low-cost technology, has been introduced as an attractive cost-effective, and environmentally friendly technology that is likely to be an alternative to conventional wastewater treatment methods. This study aims to evaluate, for the first time, the efficiency of MSL eco-technology to remove MC-LR on a laboratory scale using local materials. To this end, an MSL pilot plant was designed to treat distilled water contaminated with MC-LR. The pilot was composed of an alternation of permeable layers (pozzolan) and soil mixture layers (local sandy soil, sawdust, charcoal, and metallic iron on a dry weight ratio of 70, 10, 10, and 10%, respectively) arranged in a brick-layer-like pattern. MSL pilot was continuously fed with synthetic water containing distilled water contaminated with increasing concentrations of MC-LR (0.18–10 µg/L) at a hydraulic loading rate (HLR) of 200 L m−2 day−1. The early results showed MC-LR removal of above 99%. Based on these preliminary results, the multi-soil-layering eco-technology could be considered as a promising solution to treat water contaminated by MC-LR in order to produce quality water for irrigation or recreational activities. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. 2021-05-18T00:00:00Z https://hdl.handle.net/10216/134801 Title: Semi-industrial development of nutritious and healthy seafood dishes from sustainable species Abstract: This study aimed to devise innovative, tailor-made, appealing, tasty and semi-industrialized dishes, using sustainable and under-utilized seafood species (bib, common dab, common carp, blue mussel and blue whiting), that can meet the specific nutritional and functional needs of children (8-10-years), pregnant women (20-40-years) and seniors (≥60-years). Hence, contests were organised among cooking schools from 6 European countries and the best recipes/dishes were reformulated, semi-industrially produced and chemically and microbiologically evaluated. The dishes intended for: (i) children and pregnant women had EPA + DHA and I levels that reached the target quantities, supporting the claim as “high in I”; and (ii) seniors were “high in protein” (24.8%-Soup_S and 34.0%-Balls_S of the energy was provided by proteins), “high in vitamin B12”, and had Na contents (≤0.4%) below the defined limit. All dishes reached the vitamin D target value. Sausages_C, Roulade_P, Fillet_P and Balls_S had a well-balanced protein/fat ratio. Roulade_P presented the highest n-3 PUFA/n-6 PUFA ratio (3.3), while Sausages_C the lowest SFA/UNS ratio (0.2). Dishes were considered safe based on different parameters (e.g. Hg-T, PBDEs, Escherichia coli). All represent dietary sources contributing to meet the reference intakes of target nutrients (33->100%), providing valuable options to overcome nutritional and functional imbalances of the three groups. 2021-09-01T00:00:00Z https://hdl.handle.net/10216/134800 Title: Strategies to reduce sodium levels in European seabass sausages Abstract: Considering the increasing demand towards “ready-to-cook” processed seafood products, recognised as being potential contributors to high sodium (Na) intake by consumers, this study aimed to assess the effect of sodium chloride (NaCl) reduction on physicochemical, microbiological and sensory properties of European seabass (Dicentrarchus labrax) sausages stored in chilling conditions during 5 weeks. Three formulations were tested in comparison with a control (100% NaCl, CTR): (i) 50% NaCl+50% ME (oleoresins microcapsules) (F1); (ii) 50% NaCl+50% KCl (F2); and (iii) only 50% NaCl (F3). The NaCl reduction mainly affected the texture and the salty taste, resulting in softer and perceived as less salty sausages after processing. However, hardness differences disappeared after 5 weeks. It seems that an antioxidant protection was obtained in sausages formulated with oleoresins microcapsules. No or low growth of psychrotrophic and mesophilic bacteria was observed (≤2.40 log CFU/g). Decreasing NaCl content and/or partially replacing it (50%) by KCl or oleoresins microcapsules seem to be suitable solutions to reduce Na (30.9–36.3%) levels, while maintaining the chilled sausages quality for 5 weeks. The partial replacement of NaCl by KCl also allows obtaining a product richer in K (997.2 mg/100 g), which ingestion may contribute for a cardiovascular protective effect. 2021-07-01T00:00:00Z https://hdl.handle.net/10216/131941 Title: Potential control of toxic cyanobacteria blooms with Moroccan seaweed extracts Abstract: Marine macroalgae are a promising source of diverse bioactive compounds with applications in the biocontrol of harmful cyanobacteria blooms (cyanoHABs). In this work, we evaluated the potential algicidal activities of 14 species of seaweed collected from the coast of Souiria Laqdima, Morocco. Methanol extracts were screened in solid and liquid medium against the growth of the toxic cyanobacteria Microcystis aeruginosa and the microalgae Chlorella sp. used as food supplement. The results in solid medium revealed that the algicidal activity was limited to M. aeruginosa with the extract of Bornetia secundiflora showing the highest growth inhibition activity against Microcystis (27.33 ± 0.33 mm), whereas the extracts of Laminaria digitata, Halopytis incurvus, Ulva lactuca, and Sargasum muticum showed no inhibition. In liquid medium, the results indicated that all methanolic extracts of different macroalgae tested have a significant inhibitory effect on M. aeruginosa compared with that of the negative control. The maximum inhibition rates of M. aeruginosa were produced by the extracts of Bifurcaria tuberculata, Codium elongatum, and B. secundiflora. Moreover, the extracts of B. secundiflora recorded the maximum inhibition rate of Chlorella sp. Overall, the results highlight the potential of the extracts from macroalgae to control toxic cyanobacteria species. 2019-03-29T00:00:00Z https://hdl.handle.net/10216/130508 Title: Deciphering the role of cyanobacteria in water resistome: Hypothesis justifying the antibiotic resistance (phenotype and genotype) in Planktothrix genus Abstract: The importance of environmental microorganisms in the emergence and dissemination of antibiotic resistance is an undeniable fact. However, cyanobacteria are not seen yet as putative players in the dynamic of environmental resistome, despite their ubiquity in water environments, where they are exposed to antibiotic pollution and in straight contact with native and pathogenic bacteria harboring antibiotic resistance genes (ARGs). In this work we evaluated the susceptibility of 8 strains of Planktothrix agardhii (from surface freshwaters reservoirs) and 8 strains of Planktothrix mougeotii (from a wastewater treatment plant) to several classes of antibiotics, using a microplate dilution method previously described by us. We also search for ARGs in those strains by molecular methods. None of the 16 tested strains were susceptible to trimethoprim, nalidixic acid and norfloxacin, from 0.0015–1.6 mg/L, but all were susceptible to streptomycin, gentamicin, kanamycin, ceftazidime and ceftriaxone. The minimum inhibitory concentrations (MICs) ranged between 0.05–0.8 mg/L for the aminoglycosides and 0.4–1.6 mg/L for the two β‑lactams. Major differences were found in the susceptibility to amoxicillin and tetracycline, with P. agardhii being susceptible (MIC of 0.05 mg/L and 0.4 mg/L, respectively) and P. mougeotii not susceptible. These distinct responses might be due to differences between species. However, the lower susceptibility of wastewater strains suggests that antibiotic resistance phenotype of cyanobacteria is related with their habitat. The failure to detect acquired genes conferring resistance to trimethoprim/quinolones, strongly supports the hypothesis that cyanobacteria are intrinsically resistant to these antibiotics. Interestingly, we detected a class-1-type integron and a sul1 gene in 3 strains of both P. agardhii and P. mougeotii, which supports the possibility of cyanobacteria to acquire and transfer antibiotic resistance determinants. In conclusion, the identification of ARGs and related integrons, as well as the reduced susceptibility to some antibiotics, suggests that cyanobacteria may play a role on environmental resistome. 2019-01-01T00:00:00Z https://hdl.handle.net/10216/130509 Title: Potential of synthetic chalcone derivatives to prevent marine biofouling Abstract: Biofouling represents a major economic, environmental and health concern for which new eco-friendly solutions are needed. International legislation has restricted the use of biocidal-based antifouling coatings, and increasing efforts have been applied in the search for environmentally friendly antifouling agents. This research work deals with the assessment of the interest of a series of synthetic chalcone derivatives for antifouling applications. Six- teen chalcone derivatives were synthesized with moderate yields (38–85%). Antifouling bioactivity of these com- pounds was assessed at different levels of biological organization using both anti-macrofouling and anti- microfouling bioassays, namely an anti-settlement assay using mussel (Mytilus galloprovincialis) larvae, as well as marine bacteria and microalgal biofilms growth inhibition bioassays. Results showed that three compounds (11, 12, and 16) were particularly active against the settlement of mussel larvae (EC50 7.24–34.63 μM), being compounds 12 and 16 also able to inhibit the growth of microfouling species (EC50 4.09–20.31 μM). Moreover, the most potent compounds 12 and 16 were found to be non-toxic to the non-target species Artemia salina (b10% mortality at 25 μM). A quantitative structure-activity relationship model predicted that descriptors de- scribing the ability of molecules to form hydrogen bonds and encoding the shape, branching ratio and constitu- tional diversity of the molecule were implied in the antifouling activity against the settlement of mussel larvae. This work elucidates for the first time the relevance of synthesizing chalcone derivatives to generate new non- toxic products to prevent marine biofouling. 2018-01-01T00:00:00Z https://hdl.handle.net/10216/130506 Title: White and red LEDs as two-phase batch for cyanobacterial pigments production Abstract: Carotenoids and phycobiliproteins have a high economic value, due to their wide range of biological and industrial applications. The implementation of strategies to increase their production, such as the application of two-phase light cultivation systems, can stimulate pigments production, increasing economic turnover. In this sense, Cyanobium sp. was grown in seven different two-phase white/red cultivation arrangements, varying the time of each light from 0 to 21 days. Biomass, photosynthetic activity, pigments profile and antioxidant capacity were measured along time. Red light increased photosynthetic activity and pigments content (ca. 1.8-fold), and the use of a two-phase cultivation system generally raised bioactivity and production of phytochemicals. Among the studied, the optimal cultivation condition was found with 10 days of white followed by 4 days of red light. The optimized growth led to a productivity of 137.4 ± 0.8 mg L−1 d−1 of biomass, 17.0 ± 0.2 mg L−1 d−1 of total phycobiliproteins and 4.5 ± 0.2 mg L−1 d−1 of carotenoids. © 2020 Elsevier Ltd 2020-01-01T00:00:00Z https://hdl.handle.net/10216/130507 Title: Beyond the beaten path: improving natural products bioprospecting using an eco-evolutionary framework–the case of the octocorals Abstract: Marine natural products (NPs) represent an impressive source of novel bioactive molecules with major biotechnological applications. Nevertheless, the usual chemical and applied perspective leading most of bioprospecting projects come along with various limitations blurring our under- standing of the extensive marine chemical diversity. Here, we propose several guidelines: (i) to optimize bioprospecting and (ii) to refine our knowledge on marine chemical ecology focusing on octocorals, one of the most promising sources of marine NPs. We identified a significant phylogenetic bias in the octocoral bioprospecting, which calls for the development of a con- certed discovery strategy. Given the gap existing between the number of isolated NPs and the knowledge regarding their functions, we provide an ecologically centered workflow prioritizing biological function ahead of chemical identification. Furthermore, we illustrate how -omic technol- ogies should rapidly increase our knowledge on solving different aspects of the ecology and evo- lution of marine NPs. 2018-01-01T00:00:00Z https://hdl.handle.net/10216/130505 Title: Portable sensing system based on electrochemical impedance spectroscopy for the simultaneous quantification of free and total microcystin-LR in freshwaters Abstract: Microcystins are the most worldwide extended and common toxins produced by cyanobacteria in freshwater. Microcystin-leucine arginine (MC-LR), associated with the most toxic incidents involving microcystins, are within the cyanobacteria (intracellular) until released into the surrounding waters (extracellular) during cell lysis. Therefore, the relationship between intracellular and extracellular cyanotoxins will allow a comprehensive risk of cyanobacteria-containing waters, preventing disease and improving human safety. In this work, we present the development of a novel portable microfluidic sensing platform for the simultaneous detection of free (extracellular) and total MC-LR (intracellular and extracellular). The integrated system contains the sample processing and detection modules capable of performing the chemical lysis, filtration, sample mixing with antibodies, and electrochemical detection of MC-LR based on an indirect strategy. The performance of the immunosensors was evaluated by electrochemical impedance spectroscopy, showing a linear dynamic range between 3.3 × 10−4 and 10−7 g L−1 and a limit of detection of 5.7 × 10−10 g L−1. The results demonstrate the potential of the developed portable biosensor platform and its suitable application for the analysis of MC-LR at regulated levels for drinking water. Finally, the integrated system was able to simultaneously detect the free and total MC-LR on a Microcystis aeruginosa culture. To the best of our knowledge this is the first described system that can differentiate between intracellular and extracellular concentration of MC-LR. This novel electrochemical sensing platform avoids the multiple processing steps typically needed for standard MC-LR analysis in the laboratory and provides an early warning system for MC-LR remote monitoring in water. © 2019 Elsevier B.V. 2019-01-01T00:00:00Z https://hdl.handle.net/10216/130503 Title: Light regulating metabolic responses of cyanobium sp. (cyanobacteria) Abstract: Cyanobacteria are an important group of microorganisms of significant economic interest due to, for ex-ample, the antioxidant capacity of their metabolites. Cyanobium sp. LEGE 06113 is a marine cyanobacterium poorly studied, but with promising future applications. The aim of this study was to optimize the light conditions (both source and irradiance) and nutrient (N and P) concentration for Cyanobium sp. production as a source of high-valued com-pounds. The optimization of the processing parameters was performed using two different light sources (fluorescent and low-pressure sodium lamp), four irradiances (50, 100, 200 and 300 µmol photons m-2s-1) and two variations of BG11 medium (BG11 and BG11+, with the second containing double amounts of phosphates and nitrates). The effects of the three factors were evaluated on the biomass production, photosynthetic activity, biochemical composi-tion and antioxidant capacity. A synergistic effect between the light source, light intensity, and medium was observed for all measured parameters, with the greatest impact of light irradiance on the metabolism of Cyanobium sp. The combination of the SOX lamp, BG11+ medium, and a light irradiance of 200 µmol photons m-2s-1 was optimal for the cultivation of Cyanobium sp. This work reports the tools for the production of Cyanobium sp. as a source of high-value products, thus increasing its biotechnological potentials. 2020-01-01T00:00:00Z https://hdl.handle.net/10216/130504 Title: Electrotechnologies applied to microalgal biotechnology – Applications, techniques and future trends Abstract: Electrotechnologies are based on the direct application of an external electric field through a given semi-con- ductive material. These technologies are part of a wide range of biotechnological processes, considered cost- effective and environmentally-friendly in view of the less intensive use of non-renewable resources and high levels of energetic efficiency. In this regard, electrotechnologies are a promising processing tool to overcome some of the microalgae's exploitation limitations. The application of electric field-based techniques can cover upstream (i.e. electroporation for genetic transformation, inactivation of culture contaminants, and improve- ment of growth kinetics) and downstream processes (e.g. harvesting and extraction methods). Pulsed electric fields (PEF) and moderate electric fields (MEF), targeted at microalgae cellular permeabilization and subsequent extraction of valuable compounds, count with a substantial body of fundamental research which puts them on the front row to become mainstream techniques in a near future. This review provides comprehensive knowledge systematization of the current status of the direct application of these techniques on microalgal biotechnology, as wells as future trends and challenges regarding developments in electrotechnologies to be applied to microalgae industrial exploitation. 2018-01-01T00:00:00Z https://hdl.handle.net/10216/130501 Title: Portoamides A and B are mitochondrial toxins and induce cytotoxicity on the proliferative cell layer of in vitro microtumours Abstract: Cyanobacteria are known to produce many toxins and other secondary metabolites. The study of their specific mode of action may reveal the biotechnological potential of such compounds. Portoamides A and B (PAB) are cyclic peptides isolated from the cyanobacteria Phormidium sp. due to their growth repression effect on microalgae and were shown to be cytotoxic against certain cancer cell lines. In the present work, viability was assessed on HCT116 colon cancer cells grown as monolayer culture and as multicellular spheroids (MTS), non-carcinogenic cells and on zebrafish larvae. HCT116 cells and epithelial RPE-1hTERT cells showed very similar degrees of sensitivities to PAB. PAB were able to penetrate the MTS, showing a four-fold high IC50 compared to monolayer cultures. The toxicity of PAB was similar at 4 °C and 37 °C suggesting energy-independent uptake. PAB exposure decreased ATP production, mitochondrial maximal respiration rates and induced mitochondrial membrane hyperpolarization. PAB induced general organelle stress response, indicated by an increase of the mitochondrial damage sensor PINK-1, and of phosphorylation of eIF2α, characteristic for endoplasmic reticulum stress. In summary, these findings show general toxicity of PAB on immortalized cells, cancer cells and zebrafish embryos, likely due to mitochondrial toxicity. 2020-01-01T00:00:00Z https://hdl.handle.net/10216/130502 Title: 4-Oxo-β-apo-13-carotenone from the Cyanobacterium Anabaena cylindrica PCC 7122 Abstract: Apocarotenoids are widely distributed among living organisms (bacteria, fungi, algae, plants and even animals) and have been associated with several signaling functions. These compounds are generated by the activity of carotenoid cleavage dioxygenases (CCDs), whose diversity greatly contributes to the large number of apocarotenoids that have been described so far. It is nevertheless expected that a considerable diversity of these molecules is yet to be discovered. In this work, we describe the isolation and structural elucidation of the apocarotenoid 4‐oxo‐β‐apo‐13‐carotenone from the cultured freshwater cyanobacterium Anabaena cylindrica PCC 7122, corresponding to the first report of this compound from natural sources. 2018-01-01T00:00:00Z https://hdl.handle.net/10216/130499 Title: Characterization of planktonic and biofilm cells from two filamentous cyanobacteria using a shotgun proteomic approach Abstract: Cyanobacteria promote marine biofouling with significant impacts. A qualitative proteomic analysis, by LC-MS/MS, of planktonic and biofilm cells from two cyanobacteria was performed. Biofilms were formed on glass and perspex at two relevant hydrodynamic conditions for marine environments (average shear rates of 4 s−1 and 40 s−1). For both strains and surfaces, biofilm development was higher at 4 s−1. Biofilm development of Nodosilinea sp. LEGE 06145 was substantially higher than Nodosilinea sp. LEGE 06119, but no significant differences were found between surfaces. Overall, 377 and 301 different proteins were identified for Nodosilinea sp. LEGE 06145 and Nodosilinea sp. LEGE 06119. Differences in protein composition were more noticeable in biofilms formed under different hydrodynamic conditions than in those formed on different surfaces. Ribosomal and photosynthetic proteins were identified in most conditions. The characterization performed gives new insights into how shear rate and surface affect the planktonic to biofilm transition, from a structural and proteomics perspective. 2020-01-01T00:00:00Z https://hdl.handle.net/10216/130500 Title: The Extremophile Endolithella mcmurdoensis gen. et sp. nov. (Trebouxiophyceae, Chlorellaceae), A New Chlorella-like Endolithic Alga From Antarctica Abstract: The McMurdo Dry Valleys constitute the largest ice‐free region of Antarctica and one of the most extreme deserts on Earth. Despite the low temperatures, dry and poor soils and katabatic winds, some microbes are able to take advantage of endolithic microenvironments, inhabiting the pore spaces of soil and constituting photosynthesis‐based communities. We isolated a green microalga, Endolithella mcmurdoensis gen. et sp. nov, from an endolithic sandstone sample collected in the McMurdo Dry Valleys (Victoria Land, East Antarctica) during the K020 expedition, in January 2013. The single non‐axenic isolate (E. mcmurdoensis LEGE Z‐009) exhibits cup‐shaped chloroplasts, electron‐dense bodies, and polyphosphate granules but our analysis did not reveal any diagnostic morphological characters. On the basis of phylogenetic analysis of the 18S rRNA (SSU) gene, the isolate was found to represent a new genus within the family Chlorellaceae. 2020-01-01T00:00:00Z https://hdl.handle.net/10216/130497 Title: Cyanobacterial diversity held in microbial biological resource centers as a biotechnological asset: the case study of the newly established LEGE culture collection Abstract: Cyanobacteria are a well-known source of bioproducts which renders culturable strains a valuable resource for biotechnology purposes. We describe here the establishment of a cyanobacterial culture collection (CC) and present the first version of the strain catalog and its online database (http://lege.ciimar.up.pt/). The LEGE CC holds 386 strains, mainly collected in coastal (48%), estuarine (11%), and fresh (34%) water bodies, for the most part from Portugal (84%). By following the most recent taxonomic classification, LEGE CC strains were classified into at least 46 genera from six orders (41% belong to the Synechococcales), several of them are unique among the phylogenetic diversity of the cyanobacteria. For all strains, primary data were obtained and secondary data were surveyed and reviewed, which can be reached through the strain sheets either in the catalog or in the online database. An overview on the notable biodiversity of LEGE CC strains is showcased, including a searchable phylogenetic tree and images for all strains. With this work, 80% of the LEGE CC strains have now their 16S rRNA gene sequences deposited in GenBank. Also, based in primary data, it is demonstrated that several LEGE CC strains are a promising source of extracellular polymeric substances (EPS). Through a review of previously published data, it is exposed that LEGE CC strains have the potential or actual capacity to produce a variety of biotechnologically interesting compounds, including common cyanotoxins or unprecedented bioactive molecules. Phylogenetic diversity of LEGE CC strains does not entirely reflect chemodiversity. Further bioprospecting should, therefore, account for strain specificity of the valuable cyanobacterial holdings of LEGE CC. 2018-01-01T00:00:00Z https://hdl.handle.net/10216/130498 Title: Phycobiliproteins from cyanobacteria: Chemistry and biotechnological applications Abstract: Phycobiliproteinsareagroupofwatersolubleproteinswithanassociatedchromophore,responsibleforthelight-harvestingincyanobacteria.Theyaredividedinfourmaintypes:phycoerythrin,phycocyanin,phycoer-ythrocyanin and allophycocyanin, and they are characterized according to their structure and light qualityabsorption.Phycobiliproteinsfromcyanobacteriahavebeendescribedaspotentialbioactivecompounds,andrecognizedashigh-valuednaturalproductsforbiotechnologicalapplications.Moreover,phycobiliproteinshavebeenassociatedtoantioxidant,anticancerandanti-inflammatorycapacitiesamongothers.Thus,inordertoproducephycobiliproteinsfromcyanobacteriaforindustrialapplication,itisnecessarytooptimizethewholebioprocess,includingtheprocessingparameters(suchaslight,nitrogenandcarbonsource,pH,temperatureandsalinity)thataffectsthegrowthandphycobiliproteinaccumulation,aswellastheoptimizationofphycobili-proteinsextractionandpurification.Theaimofthisreviewistogiveanoverviewofphycobiliproteinsnotonlyin terms of their chemistry, but also in terms of their biotechnological applicability and the advances andchallengesintheproductionofsuchcompounds 2019-01-01T00:00:00Z https://hdl.handle.net/10216/130496 Title: Diketopiperazines and other bioactive compounds from bacterial symbionts of marine sponges Abstract: Humanity faces great challenges, such as the rise of bacterial antibiotic resistance and cancer incidence. Thus, the discovery of novel therapeutics from underexplored environments, such as marine habitats, is fundamental. In this study, twelve strains from the phylum Firmicutes and thirty-four strains from the phylum Proteobacteria, isolated from marine sponges of the Erylus genus, collected in Portuguese waters, were tested for bioactivities and the secondary metabolites were characterised. Bioactivity screenings comprised antimicrobial, anti-fungal, anti-parasitic and anti-cancer assays. Selected bioactive extracts were further analysed for already described molecules through high performance liquid chromatography and mass spectrometry. Several bioactivities were observed against the fungus Aspergillusfumigatus, the bacteria (methicillin-resistant Staphylococcus aureus and Escherichia coli), the human liver cancer cell line HepG2 and the parasite Trypanosoma cruzi. Medium scale-up volume extracts confirmed anti-fungal activity by strains Proteus mirabilis #118_13 and Proteus sp. (JX006497) strain #118_20. Anti-parasitic activity was also confirmed in Enterococcus faecalis strain #118_3. Moreover, P. mirabilis #118_13 showed bioactivity in human melanoma cell line A2058 and the human hepatocellular carcinoma cell line HepG2. The dereplication of bioactive extracts showed the existence of a variety of secondary metabolites, with some unidentifiable molecules. This work shows that bacterial communities of sponges are indeed good candidates for drug discovery and, as far as we know, we describe anti-parasitic activity of a strain of E. faecalis and the presence of diketopiperazines in Proteus genus for the first time. 2020-01-01T00:00:00Z