Short term effects of irradiance on the growth of Pterocladiella capillacea (Gelidiales, Rhodophyta)

Pterocladiella capillacea has been economically exploited for agar extraction in the Azores for many years. Harvesting dropped to a full stop in the early 1990s due to a population collapse, but restarted in 2013. Since then it has been intensively harvested and overexploitation must be prevented, with both sustainable harvesting and effective cultivation practices. This study represents the first attempt to determine optimal conditions for P. capillacea production in the Azores, and evaluates its vegetative growth in two experiments using von Stosch’s medium designed to test entire thallus and tips portions response to different irradiances (30, 70 and 150 μmol photons m¯² s¯¹). The best relative growth rate (RGR) was recorded at 150 μmol photons m¯² s¯¹ for the entire thalli and tips after two-weeks and three-weeks, respectively, indicating that an acclimation period is necessary to assure the growth of this alga under experimental conditions. Higher RGR was obtained at higher irradiance (3.98 ± 2.10% fm day¯¹), but overall, growth rates were low or negative. Epiphytes were a serious problem towards the end of the entire thallus experiments, where Feldmannia irregularis proliferate at all irradiances. Future cultivation approaches complemented with other relevant environmental factors (e.g. pH, photoperiod, salinity), are recommended.FCT – Fundação para a Ciência e Tecnologia projects UID/BIA/00329/2013, 2015 - 2018 and UID/BIA/00329/2019, CIRN (Centro de Investigação de Recursos Naturais, University of the Azores), and CIIMAR (Interdisciplinary Centre of Marine and Environmental Research, Porto, Portugal). RFP was supported by a doctoral grant M3.1.2/F/024/2011, Fundo Regional para a Ciência e Tecnologia.info:eu-repo/semantics/publishedVersio

Tracking relations among bacterial and protozoan communities in wastewater treatment plants

Background: Understanding the interactions between prokaryotic and eukaryotic populations in complex environments can be challenging. Particularly, there is a recognized difficulty in establishing how the interactions between the bacterial and the protozoan populations can affect the performance of wastewater treatment plants (WWTP). Objectives: In order to determine the relationships between microbial communities (protozoa, metazoa and filamentous bacteria) and abiotic parameters (physical-chemical and operational), thirty seven WWTP with activated sludge process were studied in Portugal, during two years, in a trimestral sampling strategy. Methods: Samples were collected to enable a molecular characterization of the microbiota. In order to ensure the diversity of microorganisms, 100 samples were selected based on their geographic localization and time-spaced to track relationships within bacteria and protozoa. A 16S rRNA gene PCR-DGGE approach was carried out for bacterial community fingerprinting. The resulting profiles were analysed together with the results obtained from the survey of the protozoa populations. Finally, the study of the correlations between the physical-chemical and operational parameters and the microbial communities was also investigated. Conclusions: The study of these interactions constitutes a strategy for the understanding of how the different metabolic groups of prokaryotic and protozoa are affected by the relations between this populations, allowing a better prediction of the overall community dynamics. This will allow setting the conditions that better contribute to improve the wastewater treatment while increasing the knowledge of overall communities networking in complex environments

Chitosan and polyethylene glycol based membranes with antibacterial properties for tissue regeneration

The prevention of microbial infections associated with implantable medical devices and superficial wounds represents one of the main research strategies in the field of biomaterials. The present study reports on the development of composite membranes of Chitosan (CS)-Polyethylene glycol (PEG) matrix, incorporating particles of biphasic calcium phosphate (BCP), zinc oxide (ZnO) and copper oxide (CuO). The properties that are relevant for intended applications in tissue regeneration and antibacterial coatings of implants were assessed. It was found that the addition of 1% (w/w - relative to the mass of CS) of each metal oxide promoted satisfactory bacteriostatic activity and exhibited no cytotoxic effects towards the Vero cell line. The formation of bonds between the CS/PEG matrix and ionic species from the powders enhanced the cross-linking degree and mechanical properties of composite membranes in comparison to the non-doped membrane with the same polymer matrix (CS/PEG = 70/30%). A gradual degradation of the composite membranes over the immersion time in simulated body fluid (SBF) was accompanied by a continuous surface deposition of uniform apatite layer.publishe

OPTIMIZATION OF ZIRCONIA INKS TO FABRICATE 3D POROUS SCAFFOLDS BY ROBOCASTING

High-performance bioceramics such as zirconia, alumina, and their composites, are attractive materials for the fabrication of load-bearing bone implants because of their outstanding mechanical properties, biocompatibility, corrosion resistance, and aesthetic quality. A suitable level of porosity and pore sizes with a few hundred microns are required for a good bone integration of the scaffolds. This requirement can be achieved through additive manufacturing, like robocasting. For this purpose, the optimization of colloidal inks is one of paramount importance as the rheological properties of the inks determine the quality of the three-dimensional structures. This target has not been satisfactorily accomplished in previous research works. The present study aims at closing this gap by carrying out a systematic investigation about the influence of the most important parameters that determine the printing ability of zirconia inks. The dispersing ability of the zirconia powder was studied in order to maximize the solids loading while keeping a high degree of homogeneity of the starting suspensions. The viscoelastic properties of the suspensions were then altered by adding suitable doses of a coagulating agent to obtain easily extrudable pastes for the robocasting process. The green samples were dried and sintered at the heating rate of 1ºC/min up to 600ºC, an holding at this temperature for 1 h, followed by an heating rate of 5ºC/min up to 1350ºC and holding for 1 h at this temperature, and then cooling down to room temperature. Zirconia inks with high fraction of solids (48 vol.%) could be successfully prepared. The extruded cylinders exhibited an excellent shape retention in scaffolds with different macropore sizes (200, 300, 400 and 500 mm)

Screening for novel Angiotensin I - Converting Enzyme (ACE) inhibitory peptides from Azorean Macroalgae: Extraction, purification, characterization and evaluation of their antihypertensive activity

Jornadas "Ciência nos Açores – que futuro? Tema Ciências Naturais e Ambiente", Ponta Delgada, 7-8 de Junho de 2013.A descoberta de inibidores naturais da ECA como alternativa às drogas sintéticas tem-se tornado de suma importância na prevenção da hipertensão. O sistema Renina-Angiotensina desempenha um papel importante na regulação da pressão arterial, em particular na ativação da enzima conversora da angiotensina I (ECA), que converte esta na angiotensina II, um ente vasoconstritor, sendo portanto, a inibição da atividade da ECA importante na prevenção da hipertensão. O presente estudo visa contribuir para: (i)a investigação in vitro das propriedades inibitórias da ECA pelos péptidos obtidos das macroalgas mais abundantes dos Açores; (ii) a extração e purificação dos péptidos inibidores da ECA, bem como a determinação do seu perfil de aminoácidos; (iii) a valorização das macroalgas açorianas, com possível impacto na saúde públi - ca, tendo em conta o potencial dos derivados proteicos destas para a produção de alimentos funcionais e/ou produtos farmacêuticos que previnam a hipertensão; (iv) a comparação da atividade inibitória da ECA dos novos produtos biológicos marinhos (péptidos) com os anti-hipertensivos comer - ciais (sintéticos) prescritos aos pacientes e (v) a determinação da composição bioquímica das macroalgas selecionadas. A descoberta no final deste projeto, de constituintes novos das macroalgas dos Açores, particularmente os péptidos inibidores da ECA, terá um impacto para o desenvolvimento futuro da economia regional, e deverá representar um incentivo para a conservação de um ambiente marinho “limpo” e para a proteção da sua biodiversidade. Os resultados podem tam - bém contribuir para uma redução substancial dos fundos destinados aos pacientes hipertensos, especialmente os que são suportados pelo Serviço Regional de Saúde.ABSTRACT: There is a trend towards the searching for natural ACE inhibitors as alternatives to the synthetic drugs prescribed for hypertension. The rennin angiotensin system plays an important role in the regulation of blood pressure particularly with Angiotensin I-Converting Enzyme (ACE) that converts angiotensin I to angiotensin II, a potent vasoconstrictor. Therefore, the inhibition of ACE activity is a major focus in the prevention ofhypertension. The present study aims to contribute to: (i) the searching of the peptides from the most abundant Azorean macroalgae by the evaluation in vitro of their ACE inhibitory properties; (ii) the extraction, purification of the referred peptides and their amino acids profile determination; (iii) the valorization of Azorean macroalgae, with potential impact on public health taking into account the algae´s protein-derivative products for producing functional foods and/or pharmaceutical formulations that prevent hypertension; (iv) the comparison of the ACE inhibitory activity of the novel marine bio-products (peptides) with the prescribed synthetic commercial antihypertensive drugs and v) the determination of the biochemical composition of the selected Azorean macroalgae. At the end of this project, the discovery of such novel macroalgae’s components, particularly the ACE inhibitory peptides, will have the potential for future economic development which in turn can provide an incentive for the conservation of the biodiversity and for the maintenance of a clean environment ocean around the Azores Islands as a natural resource that must be preserved. The results may also contribute to the reduction of funds allocated for hypertensive patients, particularly the ones that are supported by the Regional Health Public Service

Propriedades bioativas de macroalgas comuns nos Açores

A secção UAciência é coordenada pelo Professor Universitário Armindo Rodrigues.[…]. Como e do conhecimento geral, a hipertensão e um dos maiores fatores de risco das doenças cardiovasculares e esta estimado que afeta cerca de 25% da população mundial. Existem varias drogas sintéticas no mercado utilizadas para o seu controlo e prevenção, mas todas apresentam vários efeitos secundários adversos, o que promove a necessidade de encontrar alternativas naturais que evitem ou reduzam estes efeitos secundários. Neste sentido, tem-se desenvolvido investigação na Universidade dos Açores, no Laboratório de Tecnologia Alimentar, sobre a composição nutricional e as atividades biológicas, nomeadamente antioxidantes e anti-hipertensivas, de macroalgas comuns nos Açores, com o objetivo de promover estas espécies como potencial fonte de compostos nutricionais e farmacêuticos importantes. Esta investigação, desenvolvida no âmbito de um projeto de Doutoramento financiado pelo Fundo Regional da Ciência e Tecnologia resultou em informação inovadora, já apresentada a comunidade científica nacional e internacional e já publicada em revistas científicas com revisão por pares. […].info:eu-repo/semantics/publishedVersio

Isolation and characterization of angiotensin I-converting enzyme (ACE) inhibitory peptides from Ulva rigida C. Agardh protein hydrolysate

Ulva rigida protein was hydrolysed with pepsin plus bromelain after a screening of nine enzymes for optimal proteolysis. This hydrolysate, presenting ACE-inhibitory activity with an IC₅₀ value of 0.483 mg/mL, was fractionated by ultrafiltration membranes into three molecular weight ranges (3 kDa). The <1 kDa fraction that exhibited the highest activity (IC₅₀: 0.095 mg/mL) was purified using size-exclusion chromatography and reversed-phase high-performance liquid chromatography, yielding two active ACE-inhibitory purified peptides. Edman degradation revealed its amino acid sequences to be IP and AFL with IC₅₀ values of 0.020 and 0.023 mg/mL, respectively. Both peptides were synthesized to confirm the structure and to validate their ACE-inhibitory activities. Lineweaver–Burk plots suggest that IP acts as a non-competitive and AFL as a competitive ACE-inhibitors. Stability assays showed that both peptides are heat-stable and AFL is hydrolysed by intestinal mucosa peptidases to FL with IC₅₀ value of 0.004 mg/mL that acts as a non-competitive ACE-inhibitor. The results suggest that these peptides might have a potential use in the preparation of antihypertensive drugs or functional foods.This study was financially supported by funds from CIRN (Centro de Investigação de Recursos Naturais, University of the Azores) and by cE3c funding (Ref: UID/BIA/00329/2013). Lisete Paiva was supported by a doctoral grant (Ref: M3.1.2/F/014/2011) awarded by FRC (Fundo Regional da Ciência).info:eu-repo/semantics/publishedVersio

Angiotensin I-Converting Enzyme (ACE) Inhibitory Activity, Antioxidant Properties, Phenolic Content and Amino Acid Profiles of Fucus spiralis L. Protein Hydrolysate Fractions

Food protein-derived hydrolysates with multi-bioactivities such as antihypertensive and antioxidant properties have recently received special attention since both activities can play significant roles in preventing cardiovascular diseases. This study reports, for the first time, the angiotensin I-converting enzyme (ACE)-inhibition and antioxidant properties of ultrafiltrate fractions (UF) with different molecular weight ranges (<1, 1–3 and ≥3 kDa) obtained from Fucus spiralis protein hydrolysate (FSPH) digested with cellulase–bromelain. The amino acids profile, recovery yield, protein, peptide and total phenolic contents of these FSPH-UF, and the in vitro digestibility of F. spiralis crude protein were also investigated. FSPH-UF ≥3 kDa presented remarkably higher ACE-inhibition, yield, peptide and polyphenolic (phlorotannins) contents. Antioxidant analysis showed that FSPH-UF <1 kDa and ≥3 kDa exhibited significantly higher scavenging of 2,2-diphenyl-1-picrylhydrazyl radical and ferrous ion-chelating (FIC) activity. FSPH-UF ≥3 kDa had also notably higher ferric reducing antioxidant power (FRAP). Strong correlations were observed between ACE-inhibition and antioxidant activities (FIC and FRAP). The results suggest that ACE-inhibition and antioxidant properties of FSPH-UF may be due to the bioactive peptides and polyphenols released during the enzymatic hydrolysis. In conclusion, this study shows the potential use of defined size FSPH-UF for the prevention/treatment of hypertension and/or oxidative stress-related diseases.This study was financially supported by cE3c funding (Ref: UID/BIA/00329/2013). Lisete Paiva was supported by a doctoral grant (Ref: M3.1.2/F/014/2011) awarded by FRC (Fundo Regional da Ciência).info:eu-repo/semantics/publishedVersio

Seasonal Variability of the Biochemical Composition and Antioxidant Properties of Fucus spiralis at Two Azorean Islands

This study evaluates, for the first time, the seasonal (winter and summer) and geographical (São Miguel–SMG and Santa Maria–SMA Islands) variability of Fucus spiralis (Fs) biochemical composition (dry weight basis) and antioxidant properties. Protein and carbohydrates presented higher values in Fs-SMGwinter, lipids, total dietary fiber, and energy value in Fs-SMAsummer, and ash and soluble dietary fiber/insoluble dietary fiber ratio in Fs-SMAwinter. The fatty acid (FA) profiles showed a lower SFA in Fs-SMGsummer, whereas MUFA and PUFA presented higher values in Fs-SMGsummer and Fs-SMGwinter, respectively. Excellent dietary ratios of n6/n3 PUFA and hypocholesterolemic/hypercholesterolemic FA were found, with lower values in Fs-SMAwinter and higher in Fs-SMGsummer, respectively. The highest total phenolics was found in Fs-SMAsummer acetone:water extract and total flavonoids showed the higher value in Fs-SMGwinter methanol extract. The best free radical-scavenging activity was observed in the Fs-SMAwinter methanol (EC50 = 0.045 mg/mL) and acetone: water (EC50 = 0.059 mg/mL) extracts. The ferric-reducing antioxidant power showed the best results in Fs-SMAwinter methanol extract (EC50 = 0.016 mg/mL) and Fs-SMAsummer acetone:water extract (EC50 = 0.017 mg/mL). The best ferrous ion-chelating activity was found in Fs-SMGwinter acetone:water extract. Overall, results revealed that F. spiralis nutritional and functional bioactivity values have geographical and seasonal variations and that its regular consumption may add benefits to human health.This study was financially supported by cE3c funding (Ref: UID/BIA/00329/2013). Lisete Paiva was supported by a doctoral grant (Ref: M3.1.2/F/014/2011) awarded by FRC (Fundo Regional da Ciência).info:eu-repo/semantics/publishedVersio

Structure and dynamics of the supercluster of galaxies SC0028-0005

According to the standard cosmological scenario, superclusters are objects that have just passed the turn around point and are collapsing. The dynamics of very few superclusters have been analysed up to now. In this paper we study the supercluster SC0028-0005, at redshift 0.22, identify the most prominent groups and/or clusters that make up the supercluster, and investigate the dynamic state of this structure. For the membership identification, we have used photometric and spectroscopic data from SDSS-DR10, finding 6 main structures in a flat spatial distribution. We have also used a deep multi-band observation with MegaCam/CFHT to estimate de mass distribution through the weak-lensing effect. For the dynamical analysis, we have determined the relative distances along the line of sight within the supercluster using the Fundamental Plane of early-type galaxies. Finally, we have computed the peculiar velocities of each of the main structures. The 3D distribution suggests that SC0028-005 is indeed a collapsing supercluster, supporting the formation scenario of these structures. Using the spherical collapse model, we estimate that the mass within $r = 10$~Mpc should lie between 4 and $16 \times 10^{15} M_\odot$. The farthest detected members of the supercluster suggest that within $\sim 60$~Mpc the density contrast is $\delta \sim 3$ with respect to the critical density at $z=0.22$, implying a total mass of $\sim 4.6$--$16 \times 10^{17} M_\odot$, most of which in the form of low-mass galaxy groups or smaller substructures.Comment: 12 pages, 9 figures, Accepted for publication in MNRA