A carregar...
Projeto de investigação
Sem título
Financiador
Autores
Publicações
Improving the heterotrophic media of three Chlorella vulgaris mutants toward optimal color, biomass and protein productivity
Publication . Trovão, Mafalda; Cunha, Miguel; Santo, Gonçalo Espírito; Pedroso, Humberto; Reis, Ana; Barros, Ana; Correia, Nádia; Schüler, Lisa; Costa, Monya; Ferreira, Sara; Cardoso, Helena; Ventura, Márcia; Varela, João; Silva, Joana; Freitas, Filomena; Pereira, Hugo; DQ - Departamento de Química; UCIBIO - Applied Molecular Biosciences Unit; LAQV@REQUIMTE; Nature Publishing Group
The high production costs and unappealing sensory properties still limit the widespread commercialization of microalgae feedstocks. Therefore, this work focused on fine-tuning the heterotrophic medium composition to cultivate novel green, yellow, and white Chlorella vulgaris mutant strains. Screening assays were carried out to select the most significant factors, and different nutrient concentrations were optimized by modelling biomass and protein productivity, specific growth rate, and color, via response surface methodology. The biomass and protein productivities achieved by these strains were improved by up to 70% and 94%, respectively. Additionally, biomass color was correlated with medium composition for the first time, allowing the improvement of the yellow and white mutant colorations by 20%. Overall, the findings of this study are vital to overcoming the challenges of the biobased industry, allowing the enhancement of the cost-effectiveness, attractiveness, and nutritional profiles of microalgae-based products in different markets and applications.
Isolation and Selection of Protein-Rich Mutants of Chlorella vulgaris by Fluorescence-Activated Cell Sorting with Enhanced Biostimulant Activity to Germinate Garden Cress Seeds
Publication . Trovão, Mafalda; Schüler, Lisa; Pedroso, Humberto; Reis, Ana; Santo, Gonçalo Espírito; Barros, Ana; Correia, Nádia; Ribeiro, Joana; Bombo, Gabriel; Gama, Florinda; Viana, Catarina; Costa, Monya M.; Ferreira, Sara; Cardoso, Helena; Varela, João; Silva, Joana; Freitas, Filomena; Pereira, Hugo; UCIBIO - Applied Molecular Biosciences Unit; DQ - Departamento de Química; MDPI - Multidisciplinary Digital Publishing Institute
Microalgae are a promising feedstock with proven biostimulant activity that is enhanced by their biochemical components (e.g., amino acids and phytohormones), which turns them into an appealing feedstock to reduce the use of fertilisers in agriculture and improve crop productivity and resilience. Thus, this work aimed to isolate protein-rich microalgal mutants with increased biostimulant activity. Random mutagenesis was performed with Chlorella vulgaris, and a selection of protein-rich mutants were sorted through fluorescence-activated cell sorting (FACS), resulting in the isolation of 17 protein-rich mutant strains with protein contents 19–34% higher than that of the wildtype (WT). Furthermore, mutant F4 displayed a 38%, 22% and 62% higher biomass productivity, growth rate and chlorophyll content, respectively. This mutant was then scaled up to a 7 L benchtop reactor to produce biomass and evaluate the biostimulant potential of this novel strain towards garden cress seeds. Compared to water (control), the germination index and the relative total growth increased by 7% and 19%, respectively, after the application of 0.1 g L−1 of this bioproduct, which highlights its biostimulant potential.
Shallow water fish display low phenotypic plasticity to ocean warming and extreme weather events regardless of previous thermal history
Publication . Missionário, Madalena; Almeida, Célia; Fernandes, Joana Filipa; Vinagre, Catarina; Madeira, Carolina; Madeira, Diana; DCV - Departamento de Ciências da Vida; Faculdade de Ciências e Tecnologia (FCT); UCIBIO - Applied Molecular Biosciences Unit; Elsevier Science B.V., Amsterdam.
Shallow water environments have long been recognized by scientists as sentinels for climate change. By analysing the impacts of ocean warming and marine heatwaves (MHW) in species from these areas, we can estimate their plasticity and hence vulnerability to thermal challenges. Pomatoschistus microps is a benthic intertidal fish species inhabiting coastal lagoons where temperature fluctuations are common. Here, we tested the effects of “Present” and “Future summer” scenarios (22 °C and 25 °C) and their respective heatwaves (27 °C and 30 °C) versus a “Control” scenario of 19 °C on warm (summer)- and cold (winter)- acclimatized fish. Then, we estimated phenotypic plasticity of critical thermal maximum (CTmax), oxygen consumption and cellular stress responses (CSR). Temperature seasonal variation and body weight (as proxy for body size) effects on fish thermal tolerance were also determined. Fish exposed to higher temperature treatments exhibited higher thermal tolerance, with this pattern being consistent for both warm- and cold-acclimatized fish. However, this difference was subtle (<4.6 %), suggesting a low capacity for acclimation. Nonetheless, warm-acclimatized fish (collected in summer) displayed significantly higher CTmax than cold-acclimatized fish (collected in winter), indicating that CTmax is influenced by seasonal thermal variation. Weight also represents a constraint factor for P. microps thermal tolerance, as heavier animals displayed lower CTmax. No alterations in O2 consumption, neither in CSR biomarkers were detected across temperature treatments, suggesting that fish were otherwise relatively insensitive to thermal fluctuations, independently of thermal history, within the thermal scenarios tested. Overall, the studied population of P. microps seems well adapted to temperature variations in their natural environment, exhibiting a large thermal safety margin (average of 11.02 °C).
Oxyfluorfen
Publication . Trovão, Mafalda; Cardoso, Lucas; Schüler, Lisa; Machado, Adriana; Santo, Gonçalo Espírito; Pedroso, Humberto; Reis, Ana; Barros, Ana; Correia, Nádia; Costa, Monya; Ferreira, Sara; Cardoso, Helena; Mateus, Marília; Silva, Joana; Pereira, Hugo; Freitas, Filomena; Varela, João Carlos Serafim; UCIBIO - Applied Molecular Biosciences Unit; Elsevier
Nowadays, there is an increasing demand for novel feedstocks and alternative protein sources to meet global needs. Because of their rich nutritional profiles and high protein contents, microalgae-based food products and supplements are being developed. Nonetheless, these products present organoleptic characteristics such as taste, smell and colour that are often considered unpleasant by human and animal consumers. To address this constraint, strain improvement approaches such as random mutagenesis have been used, which combined with the right selection strategy, lead to more appealing microalgal biomass. In this work, a novel selection strategy using oxyfluorfen, an inhibitor of the chlorophyll synthesis pathway, was applied for the first time to isolate chlorophyll-deficient strains of Scenedesmus rubescens and Chlorella vulgaris upon treatment with ethyl methanesulfonate (EMS). With this approach, one S. rubescens brownish (37Y01) mutant strain, as well as two C. vulgaris mutant strains, one yellow (31Y15) and one white (31W62), were obtained. S. rubescens 37Y01 displayed a reduced protein content of 19.1% dry weight (DW) compared to that of the wildtype, which presented a protein content of 25.0% DW. C. vulgaris wildtype and mutants exhibited higher protein contents, in the 42.8‐44.3% DW range, compared to Scenedesmus rubescens (p < 0.05). The selective pressure of this inhibitor allowed the selection of S. rubescens and C. vulgaris mutants displaying 55% and 95% decrease in chlorophyll content, respectively. The reduced chlorophyll content greatly improves the sensory properties and consumer acceptance of established mutants, increasing the potential of both strains as feedstocks to develop novel food products.
Projected climate change and limited dispersal potential threaten the seahorse species Hippocampus hippocampus and Hippocampus guttulatus
Publication . Peiffer, Friederike; Assis, Jorge; Lima, André R. A.; Henriques, Sofia; Pardal, Miguel A.; Martinho, Filipe; Gonçalves, Jorge M. S.; Gonçalves, Emanuel J.; Correia, Miguel; Silva, Gonçalo J. F.; MARE - Centro de Ciências do Mar e do Ambiente; Springer Science Business Media
Climate change is predicted to drive species redistribution, altering the composition of marine communities and affecting ecosystem functioning. There is increasing evidence that fish distributions follow a trend of poleward expansion, while realised niches often decrease in range size. This study aimed to assess the influence of oceanographic connectivity and intrinsic dispersal mechanisms on changes in suitable habitats of the European seahorses (Hippocampus hippocampus and Hippocampus guttulatus) from the present (2010–2020) until the end of the century (2090–2100). Habitat suitability was assessed using Ensemble Species Distribution Modelling under two Shared Socio-Economic Pathways (SSP2 and SSP5) coupled with biophysical modelling to estimate oceanographic connectivity. The results show that intrinsic dispersal mechanisms and oceanographic connectivity limit the northward range expansion, while predicted habitat loss remained constant in all dispersal scenarios, with the highest habitat loss forecasted in the Mediterranean and northern Africa. Consequently, considering restricted dispersal, H. guttulatus was projected to experience a negative range change (or habitat contraction [-45% (SSP5)] as opposed to an expansion with unlimited dispersal (standard model) [+ 6% (SSP5)]. On the other hand, for H. hippocampus, a more limited range expansion [+ 8% (SSP5)] was forecasted compared to the standard model [+ 17% (SSP5)]. In addition, the lower emission scenario (SSP2) resulted in half of the habitat losses, while maintaining climate refugia for H. guttulatus populations in the north Mediterranean, Iberian Atlantic Coast, and Black Sea. This study highlights the importance of considering dispersal abilities when assessing climate change impacts on marine species distribution.
Unidades organizacionais
Descrição
Palavras-chave
Contribuidores
Financiadores
Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
Concurso de avaliação no âmbito do Programa Plurianual de Financiamento de Unidades de I&D (2017/2018) - Financiamento Programático
Número da atribuição
UIDP/04326/2020