Browsing by Author "Couto, Daniela"
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- Chrysotila pseudoroscoffensis as a source of high-value polar lipids with antioxidant activity: A lipidomic approachPublication . Moreira, Ana S. P.; Gonçalves, Joana; Conde, Tiago A.; Couto, Daniela; Melo, Tânia; Maia, Inês Beatriz; Pereira, Hugo; Silva, Joana; Domingues, M. Rosário; Nunes, CláudiaMicroalgae are emerging as sustainable sources of a wide range of high-value compounds. However, the knowledge about microalgae polar lipids is still limited, despite their interest due to their chemical diversity and bioactivity. This study shows, for the first time, the polar lipidome of the haptophyte microalga Chrysotila pseudoroscoffensis unveiled by using hydrophilic interaction liquid chromatography-high resolution mass spectrometry (HILIC-HRMS and MS/MS) and gas chromatography-mass spectrometry (GC-MS). Freeze-dried C. pseudoroscoffensis biomass has a lipid content of 6.4 %, containing higher amounts of ash (45.5 %), proteins (11.6 %), and sugars (11.0 %). Uronic acids (53.8 mol%) are the sugars present in higher content, followed by glucose (13.7 mol%) and galactose (12.7 mol%). The polar lipid species identified by HILIC-MS/MS included betaine lipids, glycolipids, and phospholipids, some of them with recognised bioactive properties. Among the lipid classes found from C. pseudoroscoffensis, some are less reported in algae: betaine lipids diacylglycerylcarboxyhydroxymethylcholine (DGCC) and monoacylglycerylcarboxyhydroxymethylcholine (MGCC) (characteristic of haptophyte microalgae); acid glycolipid class glucuronosyldiacylglycerol (GlcADG) (mainly reported in plants with protective effects in phosphate-deprivation conditions); and phospholipid classes monomethylphosphatidylethanolamine (MMPE) and lysomonomethylphosphatidylethanolamine (MMLPE). As estimated by colorimetric assays, glycolipids and phospholipids accounted for 64 and 3 % of the total lipid extracts, respectively. Fatty acid profiling by GC-MS showed that total esterified fatty acids accounted for about 32 % of the total lipid extracts, of which 23 % were omega-3 polyunsaturated fatty acids (PUFA). Four lipid extract concentrations (12.5, 62.5, 125 and 250 mu g mL-1 in ethanol) were tested and displayed antioxidant capacity toward 2,2 & PRIME;-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. A dose-dependent behaviour was observed with IC50 of 111.9 mu g mL(-1) for ABTS and IC35 of 234.8 mu g mL(-1) for DPPH assay. In conclusion, the lipid extracts of C. pseudoroscoffensis may be a source of high-value lipids for the development of novel microalgae-based products, namely nutraceuticals and cosmeceuticals.
- Effects of outdoor and indoor cultivation on the polar lipid composition and antioxidant activity of Nannochloropsis oceanica and Nannochloropsis limnetica: A lipidomics perspectivePublication . Couto, Daniela; Conde, Tiago A.; Melo, Tânia; Neves, Bruna; Costa, Margarida; Cunha, Pedro; Guerra, Inês; Correia, Nádia; Silva, Joana T.; Pereira, Hugo; Varela, João; Silva, Joana; Domingues, Rosário; Domingues, PedroNannochloropsis is a genus of eicosapentaenoic acid-rich microalgae with high levels of value-added polar lipids. However, the polar lipid composition of microalgal biomass is highly dependent on culture conditions (e.g., light or temperature), which are significantly different under indoor and outdoor culture conditions. In this study, we sought to investigate the plasticity of the polar lipid profile of a marine (N. oceanica) and a freshwater (N. limnetica) species of Nannochloropsis grown in indoor and outdoor photobioreactors. To this end, the polar lipidome and fatty acid profiles were characterized by liquid chromatography-mass spectrometry (LC-MS), and gas chromatography-mass spectrometry (GC-MS), respectively. In addition, the antioxidant activity of their lipid extracts was assessed. The highest lipid contents were obtained for the two species grown indoors. LC-MS analysis identified 239 different polar lipid species, of which 220 were shared by all experimental groups. Candidate lipid biomarkers from both culture systems were proposed, including MGDG(34:2), MGDG(34:1) and PG(36:6). For both species, indoor conditions lead to lipid extracts rich in glycolipids and higher in oleic acid content. In contrast, outdoor conditions lead to higher proportions of phospholipids and betaine lipids and a higher relative content of eicosapentaenoic acid (EPA). The polar lipid profile of the two Nannochloropsis species differed primarily in the relative amounts of certain betaine lipids, mainly DGTS (which was increased in N. oceanica) and lysolipids (LPC, and LPE) (increased in N. limnetica), although the majority of lipids were observed in both species. The lipid extracts showed antioxidant activity (IC15) ranging from 30.4 +/- 1.8 to 45.7 +/- 1.6 mu mol Trolox g-1 of lipid extract. Overall, this study provides insight into the lipid metabolic adaptation of two Nannochloropsis species, providing the know-how to obtain a healthy polar lipid-rich biomass useful for novel applications in pharmaceutical, nutraceutical, or novel foods.
- Epidemiological and clinical aspects of Cutaneous and Mucosal Leishmaniases in Portugal: retrospective analysis of cases diagnosed in public hospitals and reported in the literature between 2010 and 2020Publication . Rocha, Rafael; Conceição, Cláudia; Gonçalves, Luzia; Carvalho, Ana Cláudia; Maia, André; Martins, André; Carujo, António; Maio, António; Forra, Catarina; Melita, Catarina; Couto, Daniela; Fernandes, Diana; Pereira, Dulce; Leal, Ema; Sarmento, Helena; Sousa, Inês; Gonçalves, Jean-Pierre; Marinho, Joana; Vasconcelos, Joana; Cunha, João; Rodrigues, João; Silva, José Miguel; Caley, Lídia; Malheiro, Luís; Santos, Luís; Garcia, Margarida; Cunha, Maria; Lima, Maria; Andrade, Maria Margarida; Marques, Marta; Alpalhão, Miguel; Silva, Mónica; Ferraz, Rita; Soares, Rui; Fernandes, Salomão; Llobet, Samuel; Cruz, Sofia; Guimarães, Teresa; Branco, Tiago; Nunes, Tomás Robalo; Almeida, Vasco; Maia, CarlaLeishmania infantum, a zoonotic vector-born parasite, is endemic in the Mediterranean region, presenting mostly as visceral (VL), but also as cutaneous (CL) and mucosal leishmaniasis (ML). This study aimed to describe the epidemiological and clinical aspects of the CL and ML cases diagnosed in mainland Portugal between 2010 and 2020. Collaboration was requested from every hospital of the Portuguese National Health System. Cases were screened through a search of diagnostic discharge codes or positive laboratory results for Leishmania infection. Simultaneously, a comprehensive literature search was performed. Descriptive statistics and hypothesis testing were performed using IBM (R) SPSS (R) Statistics. A total of 43 CL and 7 ML cases were identified, with a predominance of autochthonous cases (86%). In CL, immunosuppressed individuals constituted a significant proportion of patients (48%), and in this group, disseminated CL (22%) and simultaneous VL (54%) were common. In autochthonous cases, lesions, mostly papules/nodules (62%), were frequently observed on the head (48%). The approach to treatment was very heterogeneous. ML cases were all autochthonous, were diagnosed primarily in older immunosuppressed individuals, and were generally treated with liposomal amphotericin B. The findings suggest a need for enhanced surveillance and reporting, clinical awareness, and diagnostic capacity of these forms of leishmaniasis to mitigate underdiagnosis and improve patient outcomes. A holistic One Health approach is advocated to address the multifaceted challenges posed by leishmaniases in Portugal and beyond.
- Optimization of Pavlova gyrans biomass production and the fatty acid profile using a twostep approachPublication . Maciel, Filipe; Couto, Daniela; Geada, Pedro; Pereira, Hugo; Teixeira, José; Domingues, M. Rosário; Silva, Joana; Vicente, AntónioThis work aimed to optimize and characterize the biomass production of Pavlova gyrans through a sequential multivariate approach. Among seventeen cultivation parameters, light intensity, NaNO3, and CuSO45H(2)O were identified as the most significative factors (p < 0.10) for biomass productivity. Together with NaH2PO4H2O, these variables were further studied in order to maximize the biomass production of P. gyrans, with the optimum growth conditions identified as 700 mu mol(photons) m(-2) s(-1) light intensity, 1500 mg L-1 NaNO3, 6 mu g L-1 CuSO45H(2)O and 40 mg L-1 NaH2PO4H2O. These conditions allowed a 3.8-fold increase in biomass production (2.26 g AFDW per L) and improved the biochemical profile (p < 0.05) when compared with the control (Walne's medium). Namely, it was increased the contents of protein (from 10.59 to 30.76% DW), PUFAs (from 37.13 to 47.11% TFA), n - 3 FAs (26.49 to 38.27% TFA), and DHA (from 5.73 to 10.33% TFA). The nutritional value of the microalga (p < 0.05) was also improved, decreasing its atherogenic (AI - from 1.34 to 0.93) and thrombogenic (TI - from 0.45 to 0.24) indices, while the hypocholesterolemic index (HI) increased from 0.96 to 1.63. This work highlights the importance of different growth conditions in P. gyrans, playing a relevant role in the large-scale implementation of this microalga with beneficial nutritional composition for human consumption.