Nutritional potential and toxicological evaluation of tetraselmis sp. CTP4 microalgal biomass produced in industrial photobioreactors

Commercial production of microalgal biomass for food and feed is a recent worldwide trend. Although it is common to publish nutritional data for microalgae grown at the lab-scale, data about industrial strains cultivated in an industrial setting are scarce in the literature. Thus, here we present the nutritional composition and a microbiological and toxicological evaluation of Tetraselmis sp. CTP4 biomass, cultivated in 100-m3 photobioreactors at an industrial production facility (AlgaFarm). This microalga contained high amounts of protein (31.2 g/100 g), dietary fibres (24.6 g/100 g), digestible carbohydrates (18.1 g/100 g) and ashes (15.2 g/100 g), but low lipid content (7.04 g/100 g). The biomass displayed a balanced amount of essential amino acids, n-3 polyunsaturated fatty acids, and starch-like polysaccharides. Significant levels of chlorophyll (3.5 g/100 g), carotenoids (0.61 g/100 g), and vitamins (e.g., 79.2 mg ascorbic acid /100 g) were also found in the biomass. Conversely, pathogenic bacteria, heavy metals, cyanotoxins, mycotoxins, polycyclic aromatic hydrocarbons, and pesticides were absent. The biomass showed moderate antioxidant activity in several in vitro assays. Taken together, as the biomass produced has a balanced biochemical composition of macronutrients and (pro-)vitamins, lacking any toxic contaminants, these results suggest that this strain can be used for nutritional applications.Agência financiadora Fundação para a Ciencia e a Tecnologia (FCT) UID/Multi/04326/2019 ALGARED+ 5E - INTERREG V-A Espana-Portugal project 0055 Fundacao para a Ciencia e a Tecnologia (FCT) SFRH/BD/105541/2014 SFRH/BPD/81882/2011 SFRH/BPD/100627/2014 CI-ECO - POCI-01-0145-FEDER-007679 FCT UID/CTM/50011/2013 Q-PNA - FCT UID/QUI/00062/2013info:eu-repo/semantics/publishedVersio

Biological activities and chemical composition of methanolic extracts of selected Autochthonous microalgae strains from the Red Sea

Four lipid-rich microalgal species from the Red Sea belonging to three different genera (Nannochloris, Picochlorum and Desmochloris), previously isolated as novel biodiesel feedstocks, were bioprospected for high-value, bioactive molecules. Methanol extracts were thus prepared from freeze-dried biomass and screened for different biological activities. Nannochloris sp. SBL1 and Desmochloris sp. SBL3 had the highest radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, and the best copper and iron chelating activities. All species had potent butyrylcholinesterase inhibitory activity (>50%) and mildly inhibited tyrosinase. Picochlorum sp. SBL2 and Nannochloris sp. SBL4 extracts significantly reduced the viability of tumoral (HepG2 and HeLa) cells with lower toxicity against the non-tumoral murine stromal (S17) cells. Nannochloris sp. SBL1 significantly reduced the viability of Leishmania infantum down to 62% (250 mu g/mL). Picochlorum sp. SBL2 had the highest total phenolic content, the major phenolic compounds identified being salicylic, coumaric and gallic acids. Neoxanthin, violaxanthin, zeaxanthin, lutein and -carotene were identified in the extracts of all strains, while canthaxanthin was only identified in Picochlorum sp. SBL2. Taken together, these results strongly suggest that the microalgae included in this work could be used as sources of added-value products that could be used to upgrade the final biomass value.National Science, Technology and Innovation Program of King Abdulaziz Medical City for Science and Technology, Riyadh, Saudi Arabia [NPST, 11-ENE 1719-02]; Foundation for Science and Technology (FCT), Portugal [SFRH/BD/78062/2011]; FCT [IF/00049/2012, SFRH/BPD/86071/2012, Pest-OE/QUI/UI0612/2013]info:eu-repo/semantics/publishedVersio

On the development of selective chelators for Cadmium: Synthesis, structure and chelating properties of 3-((5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)amino)benzo[d]isothiazole 1,1-dioxide, a novel Thiadiazolyl Saccharinate

Aquatic contamination by heavy metals is a major concern for the serious negative consequences it has for plants, animals, and humans. Among the most toxic metals, Cd(II) stands out since selective and truly efficient methodologies for its removal are not known. We report a novel multidentate chelating agent comprising the heterocycles thiadiazole and benzisothiazole. 3-((5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl)amino)benzo[d]isothiazole 1,1-dioxide (AL14) was synthesized from cheap saccharin and characterized by different techniques, including single crystal X-ray crystallography. Our studies revealed the efficiency and selectivity of AL14 for the chelation of dissolved Cd(II) (as compared to Cu(II) and Fe(II)). Different spectral changes were observed upon the addition of Cd(II) and Cu(II) during UV-Vis titrations, suggesting different complexation interactions with both metals.UIDB/04326/2020, UIDB/04564/2020, ALG-01-0145-FEDER-022121, SFRH/BD/130407/2017info:eu-repo/semantics/publishedVersio

Improvement of carotenoid extraction from a recently isolated, robust microalga, Tetraselmis sp. CTP4 (chlorophyta)

In recent years, there has been increasing consumer interest in carotenoids, particularly of marine sustainable origin with applications in the food, cosmeceutical, nutritional supplement and pharmaceutical industries. For instance, microalgae belonging to the genus Tetraselmis are known for their biotechnologically relevant carotenoid profile. The recently isolated marine microalgal strain Tetraselmis sp. CTP4 is a fast-growing, robust industrial strain, which has successfully been produced in 100-m3 photobioreactors. However, there are no reports on total carotenoid contents from this strain belonging to T. striata/convolutae clade. Although there are several reports on extraction methods targeting chlorophytes, extraction depends on the strength of cell coverings, solvent polarity and the nature of the targeted carotenoids. Therefore, this article evaluates different extraction methods targeting Tetraselmis sp. CTP4, a strain known to contain a mechanically resistant theca. Here, we propose a factorial experimental design to compare extraction of total carotenoids from wet and freeze-dried microalgal biomass using four different solvents (acetone, ethanol, methanol or tetrahydrofuran) in combination with two types of mechanical cell disruption (glass beads or dispersion). The extraction efficiency of the methods was assessed by pigment contents and profiles present in the extracts. Extraction of wet biomass by means of glass bead-assisted cell disruption using tetrahydrofuran yielded the highest amounts of lutein and β-carotene (622 ± 40 and 618 ± 32 µg g-1 DW, respectively). Although acetone was slightly less efficient than tetrahydrofuran, it is preferable due to its lower costs and toxicity.info:eu-repo/semantics/publishedVersio

Antileishmanial activity of meroditerpenoids from the macroalgae Cystoseira baccata

The development of novel drugs for the treatment of leishmaniases continues to be crucial to overcome the severe impacts of these diseases on human and animal health. Several bioactivities have been described in extracts from macroalgae belonging to the Cystoseira genus. However, none of the studies has reported the chemical compounds responsible for the antileishmanial activity observed upon incubation of the parasite with the aforementioned extracts. Thus, this work aimed to isolate and characterize the molecules present in a hexane extract of Cystoseira baccata that was found to be bioactive against Leishmania infantum in a previous screening effort. A bioactivity-guided fractionation of the C. baccata extract was carried out and the inhibitory potential of the isolated compounds was evaluated via the MIT assay against promastigotes and murine macrophages as well as direct counting against intracellular amastigotes. Moreover, the promastigote ultrastructure, DNA fragmentation and changes in the mitochondrial potential were assessed to unravel their mechanism of action. In this process, two antileishmanial meroditerpenoids, (3R)- and (3S)-tetraprenyltoluquinol (1a/1b) and (3R)- and (3S)-tetraprenyltoluquinone (2a/2b), were isolated. Compounds 1 and 2 inhibited the growth of the L. infantum promastigotes (IC50 = 44.9 +/- 4.3 and 94.4 +/- 10.1 mu M, respectively), inducing cytoplasmic vacuolization and the presence of coiled multilamellar structures in mitochondria as well as an intense disruption of the mitochondrial membrane potential. Compound 1 decreased the intracellular infection index (IC50 = 25.0 +/- 4.1 mu M), while compound 2 eliminated 50% of the intracellular amastigotes at a concentration > 88.0 mu M. This work identified compound 2 as a novel metabolite and compound 1 as a biochemical isolated from Cystoseira algae displaying antileishmanial activity. Compound 1 can thus be an interesting scaffold for the development of novel chemotherapeutic molecules for canine and human visceral leishmaniases studies. This work reinforces the evidence of the marine environment as source of novel molecules. (C) 2017 Elsevier Inc. All rights reserved.Portuguese FCT CCMAR/Multi/04326/2013FAPESP [2013/16297-2, 2015/11936-2]CNPq [470853/2012-3]FCT doctoral grants [ SFRH/BD/105541/2014 ]FCT Investigator Programme [IF/00049/2012]info:eu-repo/semantics/publishedVersio

Light emitting diodes (LEDs) applied to microalgal production.

Light-emitting diodes (LEDs) will become one of the world's most important light sources and their integration in microalgal production systems (photobioreactors) needs to be considered. LEDs can improve the quality and quantity of microalgal biomass when applied during specific growth phases. However, microalgae need a balanced mix of wavelengths for normal growth, and respond to light differently according to the pigments acquired or lost during their evolutionary history. This review highlights recently published results on the effect of LEDs on microalgal physiology and biochemistry and how this knowledge can be applied in selecting different LEDs with specific technical properties for regulating biomass production by microalgae belonging to diverse taxonomic groups

Metodologia para determinação da necrose térmica por furação num modelo 3D de uma mandíbula humana

Neste trabalho apresenta-se o estudo de uma mandibula humana masculina, para avaliação da necrose térmica provocada por furação localizada, aquando da colocação de um implante. As fases de trabalho contemplam o tratamento da imagem médica, a criação do modelo 3D, a localização do processo de furação obtida por corte localizado e a análise térmica obtida por elementos finitos. Os resultados numéricos permitirão identificar a zona de necrose térmica na estrutura óssea

Coupling sea lavender (Limonium algarvense Erben) and green tea (Camellia sinensis (L.) Kuntze) to produce an innovative herbal beverage with enhanced enzymatic inhibitory properties

Herbal beverages containing mixtures of L. algarvense (LA) flowers and C. sinensis (CS) were prepared and their inhibitory properties towards enzymes related with Alzheimer's (acetyl-and butyrylcholinesterase) and Type-2 diabetes mellitus (alpha-amylase and alpha-glucosidase) were evaluated for the first time. Samples were also appraised for antioxidant capacity and phenolic contents by high-performance liquid chromatography with diode-array detection (HPLC-DAD). Both synergistic and antagonistic interactions were observed: LA samples (infusion: IC50 = 0.22 mg/mL; decoction: 0.39 mg/mL) had higher acetylcholinesterase inhibition than CS and mixtures resulted in stronger enzymatic inhibition. CS had the highest rat alpha-glucosidase inhibition (infusion: IC50 = 3.91 mg/mL; decoction: IC50 = 2.50 mg/mL), which decreased when combined with LA. LA and CS samples had strong antioxidant activity, whereas LA and CS mixtures exhibited higher OH center dot radical-scavenging (0.56 <= SE <= 1.07) and anti-lipid peroxidation capacity (0.39 <= SE <= 0.81). CS had higher phenolic contents (infusion: 209 mg/g DW; decoction: 169 mg/g DW) and its combination with LA increased the phenolic diversity of the mixtures. Our results indicate that LA and CS infusions and decoctions and their combinations have relevant in vitro neuroprotective, antidiabetic and antioxidant properties and could be further explored as potential innovative functional beverages able to reduce the progression of neurodegenerative diseases and diabetic complications, and to prevent oxidative stress and lipid oxidation related diseases. (c) 2017 SAAB. Published by Elsevier B.V. All rights reserved.FCT - Foundation for Science and TechnologyPortuguese Foundation for Science and TechnologyPortuguese National Budget funding through the XtremeBio project [PTDC/MAR-EST/4346/2012]Portuguese National Budget funding [CCMAR/Multi/04326/2013]FCT Investigator Programme [IF/00049/2012]FCTPortuguese Foundation for Science and Technology [SFRH/BD/116604/2016, SFRH/BD/94407/2013, SFRH/BD/123658/2016, SFRH/BPD/86071/2012, UID/Multi/00612/2013

A comparative study of the in vitro enzyme inhibitory and antioxidant activities of Butea monosperma (Lam.) Taub. and Sesbania grandiflora (L.) Poiret from Pakistan: New sources of natural products for public health problems

Infusions, decoctions and tinctures were prepared from flowers of Butea monosperma (Lam.) Taub. and Sesbania grandiflora (L.) Poiret and evaluated for in vitro inhibition of enzymes implicated on the onset of neurological diseases (acetylcholinesterase: AChE and butyrylcholinesterase: BuChE), diabetes (alpha-glucosidase and alpha-amylase), obesity (lipase) and skin hyperpigmentation (tyrosinase). Extracts were also appraised for radical scavenging activity (RSA) on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, and for metal chelating activity on copper and iron ions. Samples were evaluated for their total contents in different phenolics groups by spectrophotometric methods, for phenolic profile by high performance liquid chromatography e diode array detection (HPLC-DAD) and for mineral contents by microwave plasma-atomic emission spectrometry (MP-AE). Regarding B. monosperma, the tincture allowed for a moderate inhibition of AChE, the decoction was able to inhibit alpha-glucosidase and no activity was observed towards BuChE, alpha-amylase or lipase. All extracts had a low or moderate inhibition towards tyrosinase, and significant RSA and metal chelating potential. As for S. grandiflora, only the decoction inhibited AChE, none of the extracts was able to inhibit BuChE, all samples inhibited alpha-glucosidase and infusions and decoctions had similar inhibitory properties towards alpha-amylase. None of the extracts was active against lipase, but all were able to inhibit tyrosinase. Extracts had also significant RSA, moderate copper chelation and decoctions had the capacity to chelate iron. The most abundant macroelements in both species were potassium and calcium, while iron was the prevalent microelement, especially in B. monosperma. Both species had significant levels of phenolic compounds, and the main components in decoctions and infusions of B. monosperma were syringic and salicylic acids, while the major compound identified in tinctures was the flavonoid luteolin-7-O-glucoside. In S. grandiflora the most abundant were chlorogenic and neochlorogenic acids and catechin hydrate. Molecular docking studies on the most abundant molecules in S. grandiflora, (+)-catechin, chlorogenic acid and neochlorogenic acid, indicate that these compounds are able to dock to alpha-glucosidase in a similar manner than acarbose. Our results suggest that flowers of both species are a promising source of high value-added compounds with enzyme inhibitory and antioxidant properties. (c) 2018 SAAB. Published by Elsevier B.V. All rights reserved.Foundation for Science and Technology (FCT)Portuguese Foundation for Science and TechnologyPortuguese National Budget [CCMAR/Multi/04326]FCT Investigator Programme [IF/00049/2012]FCTPortuguese Foundation for Science and Technology [SFRH/BD/94407/2013, SFRH/BD/116604/2016

Bursatella leachii from Mar Menor as a source of bioactive molecules: preliminary evaluation of the nutritional profile, In vitro biological activities, and fatty acids contents

Marine invertebrates contain nutritionally important elements that make them suitable to be included in the human diet, and they are considered an outstanding source of secondary metabolites with multiple biotechnological uses. The sea hare Bursatella leachii is an invasive species in Mar Menor that can be managed through the control of its reproduction and/or by massive biomass removal. In this context, this work evaluated the possible use of biomass from B. leachii in the food and cosmetics industries. Biomass was appraised for nutritional properties, and extracts were prepared and evaluated in vitro for antioxidant and anti-inflammatory capacity, cholinesterase and tyrosinase inhibition, and for total contents in different phenolic groups. It had a moderate moisture level, low ash and fat levels, and an adequate protein amount and protein/lipid ratio. The fatty acids (FA) profile was mainly saturated, dominated by palmitic acid. The methanol extract had the highest acetylcholinesterase inhibition. The acetone extract had the strongest capacity to scavenge 1,1-diphenyl-2 picrylhydrazyl (DPPH) radical, reduce iron, inhibit tyrosinase, decrease nitric oxide production in lipopolysaccharide (LPS)-stimulated microglia cells, and the upmost levels of total phenolics, flavonoids, and tannins. Our results suggest multiple biotechnological applications for B. leachii biomass in different economic areas.FCT - Foundation for Science and Technology [CCMAR/Multi/04326/2013]CUMFISH - FCT - Foundation for Science and Technology [PTDC/MAR/119363/2010]CUMARSUR - FCT - Foundation for Science and Technology [PTDC/MAR-BIO/5948/2014]SEABIOMED - FCT - Foundation for Science and Technology [PTDC/MAR/103957/2008]Portuguese National BudgetFCT Investigator Programme [IF/00049/2012, IF/00998/2014][SFRH/BD/105541/2014