Microalgae have the ability to grow rapidly, synthesize and accumulate large amounts (approximately 20-50% of dry weight) of lipids. A successful and economically viable algae based oil industry will depend on the selection of appropriate microalgal strains and the selection of the most suitable lipid extraction method. In this paper, five extraction methods were evaluated regarding the extraction of lipids from Chlorella vulgaris: Bligh and Dyer, Chen, Folch, Hara and Radin, and Soxhlet. Furthermore, the addition of silica powder was studied to evaluate the introduction of more shear stress to the system as to increase the disruption of cell walls. Among the studied methods, the Bligh and Dyer method assisted by ultrasound resulted in the highest extraction of oil from C. vulgaris (52.5% w/w). Addition of powder silica did not improve the extraction of oil.

Microalgae have the ability to grow rapidly, synthesize and accumulate large amounts (approximately 20-50% of dry weight) of lipids. A successful and economically viable algae based oil industry depends on the selection of appropriate algal strains. In this study ten species of microalgae were prospected to determine their suitability for oil production: Chaetoceros gracilis, Chaetoceros mulleri, Chlorella vulgaris, Dunaliella sp., Isochrysis sp., Nannochloropsis oculata, Tetraselmis sp., Tetraselmis chui, Tetraselmis tetrathele and Thalassiosira weissflogii. The study was carried out in 3 L glass flasks subjected to constant aeration and controlled artificial illumination and temperature at two different salinities. After harvesting, the extraction of oil was carried out using the Bligh and Dyer method assisted by ultrasound. Results showed that C. gracilis presented the highest oil content and that C. vulgaris presented the highest oil production.

The introduction of exotic organisms in marine ecosystems can lead to economic and ecological losses. Globally, seaweeds represent a significant part of these non-indigenous species (NIS), with 407 introduced algal species. Furthermore, the presence of NIS seaweeds has been reported as a major concern worldwide since the patterns of their potential invasion mechanisms and vectors are not yet fully understood. Currently, in the Iberian Peninsula, around 50 NIS seaweeds have been recorded. Some of these are also considered invasive due to their overgrowth characteristic and competition with other species. However, invasive seaweeds are suitable for industrial applications due to their high feedstock. Hence, seaweeds’ historical use in daily food diet, allied to research findings, showed that macroalgae are a source of nutrients and bioactive compounds with nutraceutical properties. The main goal of this review is to evaluate the records of NIS seaweeds in the Iberian Peninsula and critically analyze the potential of invasive seaweeds application in the food industry.

RESUMO.Os glicosaminoglicanos (GAGs) constituem a matriz extracelular de tecidos animais e os resíduos do processamento de peixes comercialmente cultivados podem oferecer novos agentes anticoagulantes em substituição à heparina (HEP) nas ciências médicas. Objetivou-se purificar, caracterizar físico-quimicamente e avaliar a atividade anticoagulante dos GAGs isolados da pele da tilápia do Nilo, Oreochromis niloticus. Os GAGs foram extraídos com papaína em tampão acetato de sódio 100 mM (pH 5,0) contendo cisteína e EDTA (5 mM), seguido por cromatografia de troca iônica em coluna de DEAE-celulose, utilizando um gradiente de NaCl. As frações obtidas foram liofilizadas e submetidas à eletroforese em gel de agarose a 0,5%. A atividade anticoagulante foi avaliada por meio do tempo de tromboplastina parcial ativada (TTPA), usando-se plasma humano normal e HEP padrão (193 UI mg ABSTRACT. Purification, physical and chemical characterization, and anticoagulant activity of glycosaminoglycans isolated from the skin of Nile tilapia (Oreochromis niloticus). Glycosaminoglycans (GAGs) comprise the extracellular matrix of animal tissues, and residues from processing fish commercially harvested may offer new anticoagulant agents to substitute the heparin (HEP) in medical sciences. The aim of this study was to purify, characterize physico-chemically and evaluate the anticoagulant activity of GAGs isolated from the skin of Nile tilapia, Oreochromis niloticus. The GAGs were extracted with papain in 100 mM sodium acetate buffer (pH 5.0) containing cystein and EDTA (5 mM), followed by ion-exchange chromatography on a DEAE-cellulose column using a NaCl gradient. The obtained fractions were lyophilizated and submitted to 0.5% agarose gel electrophoresis. The anticoagulant activity was assessed by the activated partial thromboplastin time (APTT) using normal human plasma and HEP standard ). The chromatographic profile separated into two different GAGs fractions (F I and F II) eluted at 0.50 and 0.75 M of NaCl, respectively, revealing fractions pattern distinct in the charge densities, but both showing GAGs with mobilities similar to standard dermatan sulfate (DS), suggesting the preliminary identification of this GAG. The GAGs modified the APTT, whose activities were, respectively, 4.72 (F I) and 23.80 (F II) IU mg -1 , and expressed themselves dose-dependent. Therefore, the anticoagulant DS from O. niloticus suggests an interesting source for posterior studies of antithrombotic activity.

No abstract

Calliblepharis jubata is an edible red seaweed and a carrageenan primary producer, considered native in Figueira da Foz (Portugal). C. jubata has the particularity of producing only one kind of carrageenan, the iota fraction. However, this seaweed is not yet valuable for the food industry or even for human consumption. In this work, we characterize important biochemical compounds of C. jubata growing up within different cultivation techniques and wild specimens. The aim of this work is to know if there are differences between the biological compounds of interest and identify the advantages for human consumption and the food industry. The results supported the nutritional value of the seaweed, where the ones from inshore cultivation (T) were more identical to the wild specimens (F), than the indoor C. jubata (A, B, C). The parameters analyzed were fatty acids, carbohydrates and carrageenan content.

Marine macroalgae are a vast source of raw materials and biologically active molecules used in the pharmaceutical, cosmetic, food and agricultural industries. The search for a food free of chemical residues by consumers has led producers to use environmentally friendly and economically viable products as they are a source of natural compounds, forming a new and promising area of study. In this context, concentrated marine algae extracts (CMAEs) are an important alternative in this production model. This work aimed to evaluate the effects of CMAEs as biostimulants in plant metabolism, promotion of growth, development and production of pepper (Capsicum annuum L.) cultivated in a greenhouse. This work was carried out from 24 June to 30 October 2019. The number of leaves, plant length, fresh and dry plant mass, root length, root fresh and dry mass, fruit production and the metabolic performance were evaluated. The results of the stomatal conductance of pepper plants, production and biofortification were related with the levels of nutrients absorbed by the plant, which reflected the effect of the applied biostimulant. The dose that showed the most promising results was the 0.5% concentration of CMAEs.

No abstract