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1.
Molecules ; 29(8)2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38675719

RESUMO

Non-communicable diseases (NCDs) represent a global health challenge, constituting a major cause of mortality and disease burden in the 21st century. Addressing the prevention and management of NCDs is crucial for improving global public health, emphasizing the need for comprehensive strategies, early interventions, and innovative therapeutic approaches to mitigate their far-reaching consequences. Marine organisms, mainly algae, produce diverse marine natural products with significant therapeutic potential. Harnessing the largely untapped potential of algae could revolutionize drug development and contribute to combating NCDs, marking a crucial step toward natural and targeted therapeutic approaches. This review examines bioactive extracts, compounds, and commercial products derived from macro- and microalgae, exploring their protective properties against oxidative stress, inflammation, cardiovascular, gastrointestinal, metabolic diseases, and cancer across in vitro, cell-based, in vivo, and clinical studies. Most research focuses on macroalgae, demonstrating antioxidant, anti-inflammatory, cardioprotective, gut health modulation, metabolic health promotion, and anti-cancer effects. Microalgae products also exhibit anti-inflammatory, cardioprotective, and anti-cancer properties. Although studies mainly investigated extracts and fractions, isolated compounds from algae have also been explored. Notably, polysaccharides, phlorotannins, carotenoids, and terpenes emerge as prominent compounds, collectively representing 42.4% of the investigated compounds.


Assuntos
Microalgas , Humanos , Microalgas/química , Organismos Aquáticos/química , Produtos Biológicos/farmacologia , Produtos Biológicos/química , Produtos Biológicos/uso terapêutico , Animais , Alga Marinha/química , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/uso terapêutico , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Antioxidantes/química , Oceanos e Mares , Estresse Oxidativo/efeitos dos fármacos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos/química
2.
Cell Mol Life Sci ; 80(10): 310, 2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37777592

RESUMO

Skeletal disorders are problematic aspects for the aquaculture industry as skeletal deformities, which affect most species of farmed fish, increase production costs and affect fish welfare. Following recent findings that show the presence of osteoactive compounds in marine organisms, we evaluated the osteogenic and mineralogenic potential of commercially available microalgae strains Skeletonema costatum and Tetraselmis striata CTP4 in several fish systems. Ethanolic extracts increased extracellular matrix mineralization in gilthead seabream (Sparus aurata) bone-derived cell cultures and promoted osteoblastic differentiation in zebrafish (Danio rerio) larvae. Long-term dietary exposure to both extracts increased bone mineralization in zebrafish and upregulated the expression of genes involved in bone formation (sp7, col1a1a, oc1, and oc2), bone remodeling (acp5a), and antioxidant defenses (cat, sod1). Extracts also improved the skeletal status of zebrafish juveniles by reducing the incidence of skeletal anomalies. Our results indicate that both strains of microalgae contain osteogenic and mineralogenic compounds, and that ethanolic extracts have the potential for an application in the aquaculture sector as dietary supplements to support fish bone health. Future studies should also identify osteoactive compounds and establish whether they can be used in human health to broaden the therapeutic options for bone erosive disorders such as osteoporosis.


Assuntos
Microalgas , Dourada , Animais , Humanos , Osteogênese , Peixe-Zebra , Suplementos Nutricionais , Dourada/genética , Dourada/metabolismo
3.
Mar Drugs ; 20(7)2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35877733

RESUMO

Microalgae have become a promising novel and sustainable feedstock for meeting the rising demand for food and feed. However, microalgae-based products are currently hindered by high production costs. One major reason for this is that commonly cultivated wildtype strains do not possess the robustness and productivity required for successful industrial production. Several strain improvement technologies have been developed towards creating more stress tolerant and productive strains. While classical methods of forward genetics have been extensively used to determine gene function of randomly generated mutants, reverse genetics has been explored to generate specific mutations and target phenotypes. Site-directed mutagenesis can be accomplished by employing different gene editing tools, which enable the generation of tailor-made genotypes. Nevertheless, strategies promoting the selection of randomly generated mutants avoid the introduction of foreign genetic material. In this paper, we review different microalgal strain improvement approaches and their applications, with a primary focus on random mutagenesis. Current challenges hampering strain improvement, selection, and commercialization will be discussed. The combination of these approaches with high-throughput technologies, such as fluorescence-activated cell sorting, as tools to select the most promising mutants, will also be discussed.


Assuntos
Microalgas , Biocombustíveis , Microalgas/genética , Mutagênese , Mutação
4.
Foods ; 11(13)2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35804687

RESUMO

Microalgae are considered a promising resource of proteins, lipids, carbohydrates, and other functional biomolecules for food and feed markets. Competitive drying solutions are required to meet future demands for high-quality algal biomass while ensuring proper preservation at reduced costs. Since often used drying methods, such as freeze or spray drying, are energy and time consuming, more sustainable processes remain to be developed. This study tested an indirect and hybrid solar dryer as an alternative to conventional freeze drying of industrially produced Tetraselmis chui and Nannochloropsis oceanica wet paste. The effects of the drying method on biomass quality parameters, including biochemical profiles, functional properties, and microbial safety, were assessed. No significant differences were found between the applied drying technologies for total proteins, carbohydrates, lipids, and fatty acid profiles. On the other hand, some pigments showed significant differences, displaying up to 44.5% higher contents in freeze-dried samples. Minor differences were also registered in the mineral profiles (<10%). Analyses of microbial safety and functional properties of the solar-dried biomass appear adequate for food and feed products. In conclusion, industrial solar drying is a sustainable technology with a high potential to preserve high-quality microalgal biomass for various markets at expected lower costs.

5.
Foods ; 11(13)2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35804686

RESUMO

Algae have been consumed for millennia in several parts of the world as food, food supplements, and additives, due to their unique organoleptic properties and nutritional and health benefits. Algae are sustainable sources of proteins, minerals, and fiber, with well-balanced essential amino acids, pigments, and fatty acids, among other relevant metabolites for human nutrition. This review covers the historical consumption of algae in Europe, developments in the current European market, challenges when introducing new species to the market, bottlenecks in production technology, consumer acceptance, and legislation. The current algae species that are consumed and commercialized in Europe were investigated, according to their status under the European Union (EU) Novel Food legislation, along with the market perspectives in terms of the current research and development initiatives, while evaluating the interest and potential in the European market. The regular consumption of more than 150 algae species was identified, of which only 20% are approved under the EU Novel Food legislation, which demonstrates that the current legislation is not broad enough and requires an urgent update. Finally, the potential of the European algae market growth was indicated by the analysis of the trends in research, technological advances, and market initiatives to promote algae commercialization and consumption.

6.
Biology (Basel) ; 11(4)2022 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-35453793

RESUMO

S. costatum and C. calcitrans are two cosmopolitan high-value centric diatoms, with a rich nutritional profile. The following work optimised the culture medium of S. costatum and C. calcitrans cultures, respectively, in a stepwise process as follows: 2.4 mM and 1.2 mM of silicate, 4 mM of nitrate, 100 µM of phosphate, 20 and 80 µM iron, and 0.5 mL L-1 of micronutrients. The results that were obtained revealed an increase in biomass productivity with a 1.8- and 3.2-fold increase in biomass that was produced by S. costatum and C. calcitrans, respectively. The biochemical profile showed an increase in high-value PUFAs such as 2.6-fold and 2.3-fold increase in EPA for S. costatum and C. calcitrans, respectively, whilst a 2.6-fold increase in DHA was detected in S. costatum cultures. The present work provides the basic tools for the industrial cultivation of S. costatum and C. calcitrans with enhanced productivity as well as improved biomass quality, two factors which are highly relevant for a more effective application of these diatoms to aquaculture and nutraceutical production.

7.
J Biotechnol ; 343: 110-119, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34856224

RESUMO

Diatoms are currently considered valuable feedstocks for different biotechnological applications. To deepen the knowledge on the production of these microalgae, the diel pattern of batch growth, photosystem II performance, and accumulation of target metabolites of two commercially relevant diatoms, Phaeodactylum tricornutum and Skeletonema costatum, were followed outdoors in 100-L flat panel photobioreactors. S. costatum presented a higher light-to-biomass conversion resulting in higher growth than P. tricornutum. Both fluorescence data and principal component analysis pointed to temperature as a limiting factor for the growth of P. tricornutum. Higher protein and carbohydrate contents were found in P. tricornutum, whereas S. costatum fatty acids were characterized by a higher unsaturation degree. Higher productivities were found at 1 p.m. for protein, lipid, and ash in the case of S. costatum. Overall, S. costatum showed great potential for outdoor cultivation, revealing a broader temperature tolerance and increased biomass productivity than P. tricornutum.


Assuntos
Diatomáceas , Microalgas , Biomassa , Fotobiorreatores , Fotossíntese
8.
Molecules ; 26(15)2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34361696

RESUMO

The nutritional composition and productivity of halophytes is strongly related to the biotic/abiotic stress to which these extremophile salt tolerant plants are subjected during their cultivation cycle. In this study, two commercial halophyte species (Inula crithmoides and Mesembryanthemum nodiflorum) were cultivated at six levels of salinity using a soilless cultivation system. In this way, it was possible to understand the response mechanisms of these halophytes to salt stress. The relative productivity decreased from the salinities of 110 and 200 mmol L-1 upwards for I. crithmoides and M. nodiflorum, respectively. Nonetheless, the nutritional profile for human consumption remained balanced. In general, I. crithmoides vitamin (B1 and B6) contents were significantly higher than those of M. nodiflorum. For both species, ß-carotene and lutein were induced by salinity, possibly as a response to oxidative stress. Phenolic compounds were more abundant in plants cultivated at lower salinities, while the antioxidant activity increased as a response to salt stress. Sensory characteristics were evaluated by a panel of culinary chefs showing a preference for plants grown at the salt concentration of 350 mmol L-1. In summary, salinity stress was effective in boosting important nutritional components in these species, and the soilless system promotes the sustainable and safe production of halophyte plants for human consumption.


Assuntos
Inula/química , Inula/crescimento & desenvolvimento , Mesembryanthemum/química , Mesembryanthemum/crescimento & desenvolvimento , Valor Nutritivo , Salinidade , Plantas Tolerantes a Sal/química , Plantas Tolerantes a Sal/crescimento & desenvolvimento , Antioxidantes/farmacologia , Dieta Vegetariana , Humanos , Luteína/análise , Minerais/análise , Estresse Oxidativo , Fenóis/análise , Extratos Vegetais/farmacologia , Piridoxina/análise , Estresse Salino , Taninos/análise , Tiamina/análise , beta Caroteno/análise
9.
Biotechnol Bioeng ; 118(11): 4375-4388, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34319592

RESUMO

In situ chlorophyll a fluorescence measurements were applied to monitor changes in the photochemical variables of Nannochloropsis oceanica cultures under nitrogen-deplete and nitrogen-replete (control) conditions. In addition, growth, lipid, fatty acid, and pigment contents were also followed. In the control culture, growth was promoted along with pigment content, electron transport rate (ETR), and polyunsaturated fatty acids, while total lipid content and fatty acid saturation level diminished. Under nitrogen-deplete conditions, the culture showed a higher de-epoxidation state of the xanthophyll cycle pigments. Fast transients revealed a poor processing efficiency for electron transfer beyond QA , which was in line with the low ETR due to nitrogen depletion. Lipid content and the de-epoxidation state were the first biochemical variables triggered by the change in nutrient status, which coincided with a 20% drop in the in situ effective quantum yield of PSII (ΔF'/Fm '), and a raise in the Vj measurements. A good correlation was found between the changes in ΔF'/Fm ' and lipid content (r = -0.96, p < 0.01). The results confirm the reliability and applicability of in situ fluorescence measurements to monitor lipid induction in N. oceanica.


Assuntos
Clorofila A/metabolismo , Ácidos Graxos/biossíntese , Fluorescência , Fotossíntese , Estramenópilas/crescimento & desenvolvimento
10.
Bioresour Technol ; 337: 125385, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34147770

RESUMO

In this study, two carotenoid-rich strains of the euryhaline microalga Tetraselmis striata CTP4 were isolated by random mutagenesis combined with selection via fluorescence activated cell sorting and growth on norflurazon. Both strains, ED5 and B11, showed an up to 1.5-fold increase in carotenoid contents as compared with the wildtype, independent of the growth conditions. More specifically, violaxanthin, ß-carotene and lutein contents reached as high as 1.63, 4.20 and 3.81 mg g-1 DW, respectively. Genes coding for phytoene synthase, phytoene desaturase, lycopene-ß-cyclase and ε-ring hydroxylase involved in carotenoid biosynthesis were found to be upregulated in ED5 and B11 cells as compared to the wildtype. Both strains showed higher contents of eicosapentaenoic acid as compared with those of the wildtype, reaching up to 4.41 and 2.88 mg g-1 DW, respectively. Overall, these results highlight the complexity of changes in carotenoid biosynthesis regulation that are required to improve pigment contents in microalgae.


Assuntos
Ácidos Graxos Ômega-3 , Carotenoides , Expressão Gênica , Regulação da Expressão Gênica de Plantas , Resposta ao Choque Térmico , beta Caroteno
11.
J Biotechnol ; 325: 15-24, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-33245925

RESUMO

As the periodic emission of light pulses by light emitting diodes (LEDs) is known to stimulate growth or induce high value biocompounds in microalgae, this flashing light regime was tested on growth and biochemical composition of the microalgae Nannochloropsis gaditana, Koliella antarctica and Tetraselmis chui. At low flashing light frequencies (e.g., 5 and 50 Hz, Duty cycle = 0.05), a strain-dependent growth inhibition and an accumulation of protein, polyunsaturated fatty acids, chlorophyll or carotenoids (lutein, ß-carotene, violaxanthin and neoxanthin) was observed. In addition, a 4-day application of low-frequency flashing light to concentrated cultures increased productivities of eicosapentaenoic acid (EPA) and specific carotenoids up to three-fold compared to continuous or high frequency flashing light (500 Hz, Duty cycle = 0.05). Therefore, applying low-frequency flashing light as finishing step in industrial production can increase protein, polyunsaturated fatty acids or pigment contents in biomass, leading to high-value algal products.


Assuntos
Clorófitas , Microalgas , Estramenópilas , Biomassa , Ácidos Graxos , Ácidos Graxos Insaturados
12.
Mar Drugs ; 18(11)2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33227960

RESUMO

Tisochrysis lutea is a marine haptophyte rich in omega-3 polyunsaturated fatty acids (e.g., docosahexaenoic acid (DHA)) and carotenoids (e.g., fucoxanthin). Because of the nutraceutical applications of these compounds, this microalga is being used in aquaculture to feed oyster and shrimp larvae. In our earlier report, T. lutea organic crude extracts exhibited in vitro cytotoxic activity against human hepatocarcinoma (HepG2) cells. However, so far, the compound(s) accountable for the observed bioactivity have not been identified. Therefore, the aim of this study was to isolate and identify the chemical component(s) responsible for the bioactivity observed. Bioassay-guided fractionation through a combination of silica-gel column chromatography, followed by preparative thin layer chromatography (PTLC), led to the isolation of two diastereomers of a monoterpenoid lactone, namely, loliolide (1) and epi-loliolide (2), isolated for the first time in this species. The structural elucidation of both compounds was carried out by GC-MS and 1D (1H and 13C APT) and 2D (COSY, HMBC, HSQC-ed, and NOESY) NMR analysis. Both compounds significantly reduced the viability of HepG2 cells and were considerably less toxic towards a non-tumoral murine stromal (S17) cell line, although epi-loliolide was found to be more active than loliolide.


Assuntos
Antineoplásicos/farmacologia , Benzofuranos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Lactonas/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Microalgas/metabolismo , Monoterpenos/farmacologia , Antineoplásicos/isolamento & purificação , Benzofuranos/isolamento & purificação , Carcinoma Hepatocelular/patologia , Sobrevivência Celular/efeitos dos fármacos , Células Hep G2 , Humanos , Lactonas/isolamento & purificação , Neoplasias Hepáticas/patologia , Estrutura Molecular , Monoterpenos/isolamento & purificação
13.
Biology (Basel) ; 9(9)2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32962162

RESUMO

The need to survive in extreme environments has furnished haloarchaea with a series of components specially adapted to work in such conditions. The possible application of these molecules in the pharmaceutical and industrial fields has received increasing attention; however, many potential bioactivities of haloarchaea are still poorly explored. In this paper, we describe the isolation and identification of two new haloarchaeal strains from the saltern ponds located in the marshlands of the Odiel River, in the southwest of Spain, as well as the in vitro assessment of their antioxidant, antimicrobial, and bioactive properties. The acetone extract obtained from the new isolated Haloarcula strain exhibited the highest antioxidant activity, while the acetone extracts from both isolated strains demonstrated a strong antimicrobial activity, especially against other halophilic microorganisms. Moreover, these extracts showed a remarkable ability to inhibit the enzyme cyclooxygenase-2 and to activate the melanogenic enzyme tyrosinase, indicating their potential against chronic inflammation and skin pigmentation disorders. Finally, the aqueous protein-rich extracts obtained from both haloarchaea exhibited an important inhibitory effect on the activity of the acetylcholinesterase enzyme, involved in the hydrolysis of cholinergic neurotransmitters and related to several neurological diseases.

14.
Biosens Bioelectron ; 166: 112442, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32755809

RESUMO

Despite significant progress in diagnostics and disease management during the past decades, human immunodeficiency virus (HIV) infections are still responsible for nearly 1 million deaths every year, mostly in resource-limited settings. Thus, novel, accurate and cost-effective tools for viral load monitoring become crucial to allow specific diagnostics and the effective monitoring of the associated antiviral therapies. Herein, we report an effective combination of a (1) padlock probe (PLP)-mediated rolling circle amplification (RCA) bioassay and an (2) agarose bead-based microfluidic device for the affinity chromatography-based capture and detection of RCA products (RCPs) pre-labelled simultaneously with biotin and an organic fluorophore. This method allowed the efficient capture of ~1 µm-sized RCPs followed by their quantification either as discrete signals or an average fluorescence signal, thus being compatible with both high-resolution imaging for maximum sensitivity as well as simpler optical detection setups. A limit of detection < 30 fM was obtained for HIV-1 synthetic target with just a single round of RCA, comparable to recently reported procedures requiring technically complex amplification strategies such as hyperbranching and/or enzymatic digestion/amplification. Furthermore, targeting a set of five conserved regions in the HIV-1 gag gene, the method could specifically detect HIV-1 in 293T cell culture supernatants, as well as a set of 11 HIV-1 NIH reference samples with four different subtypes. The reported method provides simplicity of operation, unique versatility of signal transduction (i.e. average or discrete signals), and potential coupling with previously reported miniaturized photodetectors. These combined features hold promise for bringing RCA-based molecular diagnostics closer to the point-of-care.


Assuntos
Técnicas Biossensoriais , HIV-1 , Cromatografia de Afinidade , HIV-1/genética , Humanos , Microfluídica , Técnicas de Amplificação de Ácido Nucleico
15.
Food Chem ; 333: 127525, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32683262

RESUMO

The consumption of halophytes as healthy gourmet food has increased considerably in the past few years. However, knowledge on the nutritional profile of domesticated halophytes is scarce and little is known on which cultivation conditions can produce plants with the best nutritional and functional properties. In this context, Salicornia ramosissima J. Woods was cultivated in six different salt concentrations, ranging from 35 to 465 mM of NaCl. Both the nutritional profile, the antioxidant capacity, and microbial quality of the produced plants were evaluated including minerals and vitamins. Salt has a marked effect on growth, which decreases for salinities higher than 110 mM. Nonetheless, plants cultivated with intermediate levels of salinity (110 and 200 mM) revealed better antioxidant status with higher amounts of phenolic compounds. Overall, results from this paper indicated that soilless culture systems using low-intermediate salinities produces S. ramosissima plants fit for commercialization and human consumption.


Assuntos
Antioxidantes/química , Chenopodiaceae/química , Cloreto de Sódio/química , Bactérias/isolamento & purificação , Carotenoides/análise , Chenopodiaceae/crescimento & desenvolvimento , Chenopodiaceae/microbiologia , Cromatografia Líquida de Alta Pressão , Fungos/isolamento & purificação , Valor Nutritivo , Fenóis/química , Vitaminas/análise
16.
Food Chem ; 333: 127536, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32707417

RESUMO

Some halophyte plants are currently used in gourmet cuisine due to their unique organoleptic properties. Moreover, they exhibit excellent nutritional and functional properties, being rich in polyphenolics and vitamins. These compounds are associated to strong antioxidant activity and enhanced health benefits. This work compared the nutritional properties and antioxidant potential of three species (Mesembryanthemum nodiflorum, Suaeda maritima and Sarcocornia fruticosa) collected in saltmarshes from Portugal and Spain with those of cultivated plants. The latter were generally more succulent and had higher contents of minerals than plants obtained from the wild and contained less fibre. All species assayed are a good source of proteins, fibres and minerals. Additionally, they are good sources of carotenoids and vitamins A, C and B6 and showed good antioxidant potential particularly S. maritima. Chromatographic analysis of the phenolic profile revealed that ferulic and caffeic acids as the most relevant phenolic compounds detected in the halophytes tested.


Assuntos
Valor Nutritivo , Plantas Tolerantes a Sal/crescimento & desenvolvimento , Plantas Tolerantes a Sal/metabolismo , Antioxidantes/metabolismo , Chenopodiaceae/crescimento & desenvolvimento , Chenopodiaceae/metabolismo , Fenóis/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-32509750

RESUMO

Microalgae are widely used as food supplements due to their high protein content, essential fatty acids and amino acids as well as carotenoids. The addition of microalgal biomass to food products (e.g., baked confectioneries) is a common strategy to attract novel consumers. However, organoleptic factors such as color, taste and smell can be decisive for the acceptability of foods supplemented with microalgae. The aim of this work was to develop chlorophyll-deficient mutants of Chlorella vulgaris by chemically induced random mutagenesis to obtain biomass with different pigmentations for nutritional applications. Using this strategy, two C. vulgaris mutants with yellow (MT01) and white (MT02) color were successfully isolated, scaled up and characterized. The changes in color of MT01 and MT02 mutant strains were due to an 80 and 99% decrease in their chlorophyll contents, respectively, as compared to the original wild type (WT) strain. Under heterotrophic growth, MT01 showed a growth performance similar to that of the WT, reaching a concentration of 5.84 and 6.06 g L-1, respectively, whereas MT02 displayed slightly lower growth (4.59 g L-1). When grown under a light intensity of 100 µmol m-2 s-1, the pigment content in MT01 increased without compromising growth, while MT02 was not able to grow under this light intensity, a strong indication that it became light-sensitive. The yellow color of MT01 in the dark was mainly due to the presence of the xanthophyll lutein. On the other hand, phytoene was the only carotenoid detected in MT02, which is known to be colorless. Concomitantly, MT02 contained the highest protein content, reaching 48.7% of DW, a 60% increase as compared to the WT. MT01 exhibited a 30% increase when compared to that of the WT, reaching a protein content of 39.5% of DW. Taken together, the results strongly suggest that the partial abrogation of pigment biosynthesis is a factor that might promote higher protein contents in this species. Moreover, because of their higher protein and lower chlorophyll contents, the MT01 and MT02 strains are likely candidates to be feedstocks for the development of novel, innovative food supplements and foods.

18.
Phys Med Biol ; 65(21): 21RM01, 2020 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-32434156

RESUMO

Since the seventies, positron emission tomography (PET) has become an invaluable medical molecular imaging modality with an unprecedented sensitivity at the picomolar level, especially for cancer diagnosis and the monitoring of its response to therapy. More recently, its combination with x-ray computed tomography (CT) or magnetic resonance (MR) has added high precision anatomic information in fused PET/CT and PET/MR images, thus compensating for the modest intrinsic spatial resolution of PET. Nevertheless, a number of medical challenges call for further improvements in PET sensitivity. These concern in particular new treatment opportunities in the context personalized (also called precision) medicine, such as the need to dynamically track a small number of cells in cancer immunotherapy or stem cells for tissue repair procedures. A better signal-to-noise ratio (SNR) in the image would allow detecting smaller size tumours together with a better staging of the patients, thus increasing the chances of putting cancer in complete remission. Moreover, there is an increasing demand for reducing the radioactive doses injected to the patients without impairing image quality. There are three ways to improve PET scanner sensitivity: improving detector efficiency, increasing geometrical acceptance of the imaging device and pushing the timing performance of the detectors. Currently, some pre-localization of the electron-positron annihilation along a line-of-response (LOR) given by the detection of a pair of annihilation photons is provided by the detection of the time difference between the two photons, also known as the time-of-flight (TOF) difference of the photons, whose accuracy is given by the coincidence time resolution (CTR). A CTR of about 10 picoseconds FWHM will ultimately allow to obtain a direct 3D volume representation of the activity distribution of a positron emitting radiopharmaceutical, at the millimetre level, thus introducing a quantum leap in PET imaging and quantification and fostering more frequent use of 11C radiopharmaceuticals. The present roadmap article toward the advent of 10 ps TOF-PET addresses the status and current/future challenges along the development of TOF-PET with the objective to reach this mythic 10 ps frontier that will open the door to real-time volume imaging virtually without tomographic inversion. The medical impact and prospects to achieve this technological revolution from the detection and image reconstruction point-of-views, together with a few perspectives beyond the TOF-PET application are discussed.


Assuntos
Tomografia por Emissão de Pósitrons/métodos , Elétrons , Humanos , Processamento de Imagem Assistida por Computador , Neoplasias/diagnóstico por imagem , Fótons , Razão Sinal-Ruído
19.
Bioprocess Biosyst Eng ; 43(5): 785-796, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31894389

RESUMO

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 ß-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.


Assuntos
Clorófitas/química , Luteína , Microalgas/química , beta Caroteno , Luteína/química , Luteína/isolamento & purificação , Microalgas/isolamento & purificação , beta Caroteno/química , beta Caroteno/isolamento & purificação
20.
Molecules ; 24(17)2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31484299

RESUMO

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.


Assuntos
Vitaminas/metabolismo , Antioxidantes/metabolismo , Biomassa , Reatores Biológicos/microbiologia , Microalgas/fisiologia
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