In-vitro setting and multiplication of Pulicaria microcephala, an endemic species from Berlengas Island

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Effects of different drying conditions on the rehydration ratio and water holding capacity properties in three different species of algae Ulva lactuca, Codium vermilara and Codium tomentosum

Over the last years, algae have been increasingly used in Human food due their rich chemical and nutritional composition, particularly the high supply of essential nutrients to the human body such as protein and dietary fiber. Dietary fiber can be divided into two different types: soluble and insoluble. The characteristics of soluble dietary fiber are related to some physical and chemical properties such as rehydration ratio and water holding capacity and are important in assigning the functional and organoleptic properties and in preventing some human pathologies such as cardiovascular disease and obesity. The present study aimed to investigate the influence of different drying conditions on the rehydration ratio and water holding capacity of three green algae, Codium vermilara, Codium tomentosum and Ulva lactuca. The methods used for the determination of water retention capacity and rehydration ratio were similar to those used in previous studies (Susuki, T. et al., 1996). The algae were processed in a tray dryer and the drying conditions were: Temperature: 30ºC and 40ºC; Relative Humidity: 28%47% ; air velocity 1,9 m/s. In this work, it was concluded that higher drying temperature conditions originate lower rehydration ratio and consequent lower water holding capacity possibly due to a higher physical damage in the algae tissues. It was also observed that both Codium species have higher values for these two parameters than Ulva lactuca, under the same rehydration conditions

Unveiling the Cultivation of Nostoc sp. under Controlled Laboratory Conditions

This work was funded by national funds through FCT—Fundação para a Ciência e a Tecnologia for I.P., within the scope of MARE (https://doi.org/10.54499/UIDP/04292/2020; https://doi.org/10.54499/UIDB/04292/2020) and https://doi.org/10.54499/LA/P/0069/2020, granted to the Associate Laboratory ARNET.Cyanobacteria, photoautotrophic Gram-negative bacteria, play a crucial role in aquatic and terrestrial environments, contributing significantly to fundamental ecological processes and displaying potential for various biotechnological applications. It is, therefore, critical to identify viable strains for aquaculture and establish accurate culture parameters to ensure an extensive biomass supply for biotechnology purposes. This study aims to establish optimal laboratory batch culture conditions for Nostoc 136, sourced from Alga2O, Coimbra, Portugal. Preliminary investigations were conducted to identify the optimal culture parameters and to perform biomass analysis, including protein and pigment content. The highest growth was achieved with an initial inoculum concentration of 1 g.L−1, using modified BG11 supplemented with nitrogen, resulting in a Specific Growth Rate (SGR) of 0.232 ± 0.017 µ.day−1. When exposed to white, red, and blue LED light, the most favourable growth occurred under a combination of white and red LED light exhibiting an SGR of 0.142 ± 0.020 µ.day−1. The protein content was determined to be 10.80 ± 2.09%. Regarding the pigments, phycocyanin reached a concentration of 200.29 ± 30.07 µg.mL−1, phycoerythrin 148.29 ± 26.74 µg.mL−1, and allophycocyanin 10.69 ± 6.07 µg.mL−1. This study underscores the influence of light and nutrient supplementation on the growth of the Nostoc biomass.info:eu-repo/semantics/publishedVersio

The microalga Dunaliella and its applications: a review

This work was funded by national funds through FCT - Fundação para a Ciência e a Tecnologia, I.P., within the scope of the project MARE (UIDB/04292/2020 and UIDP/04292/2020), the project LA/P/0069/2020 granted to the Associate Laboratory ARNET. The authors also wish to acknowledge the Integrated Programme of SR&TD “Smart Valorization of Endogenous Marine Biological Resources Under a Changing Climate” (reference Centro-01-0145-FEDER-000018), co-funded by Centro 2020 program, Portugal 2020, European Union, through the European Regional Development Fund.and industry. The high adaptability of Dunaliella to high salinity, as well as its fast growth and production of several metabolites have triggered interest. The attention of industry relates to its ability to synthesize several high-value compounds, such as β-carotene, lipids, glycerol, vitamins, and proteins. In addition, due to its tolerance to high salinity, contamination is reduced, and it can grow in open systems. Dunaliella salina can accumulate up to 25% dry weight in lipids and is the most efficient natural source of β-carotene. This review highlights the general characteristics of the genus, associated with its history, morphology, reproduction, occurrence, and taxonomy. The metabolic pathways for carotenoid and lipid synthesis are described. Relevant information on the most common strains is provided as well as the most widely used growth systems and conditions, and the expression systems under development. Applications of Dunaliella in several areas of the industry are also highlighted. Thus, this review can serve as a basis for future work and for the development of environmentally friendly, simple, and highly cost-effective production methods.info:eu-repo/semantics/publishedVersio

Extraction of essential oils from native plants and algae from the coast of Peniche (Portugal): antimicrobial and antioxidant activity

Coastal areas are highly complex and dynamic ecosystem of interface between land, sea and atmosphere, which also suffer biotic influences. These areas play several important ecological functions, and here we can find an enormous biodiversity. The coastline of Portugal features a high number of endemic flora and vegetation with the potential to provide functional compounds that may provide physiological benefits at nutritional and therapeutic levels, as sources of bioactive substances with antimicrobial, antioxidant, antifungal, antitumalr and antiinflammatory activity. Among these compounds, we find essential oils, also known as volatile oils, which are a result of secondary metabolism of aromatic plants, containing a large number of substances with varied chemical composition that can be obtained by different methods of extraction. The aim of this study was to extract essential oils of native plants and seaweeds from the coast of Peniche by hydrodistillation in Clevenger apparatus, with optimization of the purification process. Extracted essential oils were tested as to their ability as antibacterial and antifungal agents, and also as antioxidants. The plants studied for this purpose were Inula chritmoides L., Juniperus phoenicea subsp. turbinata (Guss.) Nyman, Daucus carota spp. halophilus and the seaweeds Fucus spiralis L., Codium tomentosum Stackhouse, Stypocaulon scoparium (Linnaeus) Kützing and Plocamium cartilagineum (Linnaeus) P.S.Dixon. The antimicrobial ability was tested in two bacteria species, Bacillus subtilis and Escherichia coli and in the yeast Saccharomyces cerevisiae, using standard procedures. The antioxidant potential was evaluated and from the results obtained, we can conclude that the essential oils extracted by the hydrodistillation method of plants and algae contain bioactive compounds present in its constitution with interesting bioactivity that can offer significant benefits and biotechnological relevance

Growth of Arthrospira platensis under laboratory and outdoor conditions: assessment of the effects of light and different nutrient media

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Environmental limits of low salinity to Gracilaria gracilis development. Where do we draw the line?

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In vitro evaluation of the antibacterial and antioxidant activities of extracts of Gracilaria gracilis with a view into its potential use as an additive in fish feed

Fish in aquaculture systems are subject to several stressors that inhibit the immune response and potentiate the development of disease and increased mortality. The inclusion of additives in the fish diet, namely seaweeds or their extracts, that are natural sources of bioactive compounds can be an important tool for promoting the health and well-being of these animals. The present study aims at the development of sustainable and effective methodologies for the extraction of bioactive compounds of the red seaweed Gracilaria gracilis, exploring its antibacterial and antioxidant potential and considering its potential use as an additive for functional fish feeds. The yield of the extraction methods was evaluated upon the use of sequential solid–liquid extraction techniques with ethanol and water as solvents, different extraction temperatures (room temperature: 40ºC and 70ºC), and extraction time. The results demonstrated that the adoption extraction times of 30 min. at 40ºC provided higher yields. We also evaluated the antioxidant capacity and the antibacterial properties of the obtained extracts against different strains that cause fish diseases by disk diffusion and broth microdilution methods. The antioxidant activity was determined by the DPPH reducing capacity method and quantification of total polyphenols content (TPC).With these results, we can establish extraction procedures that allow the future use of G. gracilis extracts, with antibacterial and antioxidant effects in a safe and effective way.info:eu-repo/semantics/publishedVersio

New insights on the sporulation, germination, and nutritional profile of Gracilaria gracilis (Rhodophyta) grown under controlled conditions

The red seaweed Gracilaria gracilis is a widely cultivated species known for its high agar content. It is also an important source of proteins, minerals, and vitamins. The chemical profile of seaweed depends on the cultivation methods used and the growing conditions to which they are exposed. Thus, two independent methods of sporulation and germination were tested upon Gracilaria gracilis grown in controlled conditions. During the tests, different substrates, culture media and incubation times were tested to induce cystocarp maturation. The results showed that cystocarp maturation and spore release were successful, with a visible volume increase and format change in the protruding cystocarps. Furthermore, the process of maturation to germination was accomplished, fulfilling the complete life cycle. In parallel, the nutritional profile of the biomass obtained was evaluated and compared with the nutritional values of biomass collected from the environment. Results showed no significant differences between wild specimens and cultivated ones in organic matter, ash content, lipid content, carbohydrates, or phycocolloid content. The present work, therefore, presents two simple alternative methods with potential applications in start-ups aimed at the cultivation of seaweed. Through these methods, it is possible to obtain biomass with nutritional characteristics similar to those obtained in the wild.info:eu-repo/semantics/publishedVersio

Faecal indicator bacteria and Pseudomonas aeruginosa in marine coastal waters: is there a relationship?

To estimate the quality of coastal waters, European Union Directive 2006/7/EC provides guidelines to assess levels of faecal bacteria, including Escherichia coli and intestinal enterococci. These microbiological criteria are based on studies that determine the risk of bathers having diseases caused by enteric bacteria, not necessarily measuring the potential danger associated with the presence of nonenteric pathogens. The association between the presence of faecal contaminant indicators and nonenteric pathogenic microorganisms has not been well defined yet. The purpose of this study is to establish a relationship between Pseudomonas aeruginosa and microbiological indicators of faecal contamination. Presence of microbiological contamination in the coastal waters near the sewage treatment plant (STP) of Peniche (Portugal) was confirmed (P. aeruginosa 135.8 Colony Forming Unit/100 mL, Escherichia coli 1100.1 Most Probable Number/100 mL, intestinal enterococci 2685.9 MPN/100 mL) with much lower levels in the areas located south of the STP, along the main water coastal current (beach 1: 0.7 CFU/100 mL, 16.5 MPN/100 mL, 100.5 MPN/100 mL; beach 2: 0.3 CFU/100 mL, 74.0 MPN/100 mL, 145.9 MPN/100 mL, respectively). Analysis of Pearson’s correlation revealed a strong positive correlation between E. coli and P. aeruginosa, suggesting E. coli as an indicator of P. aeruginosa presence.info:eu-repo/semantics/publishedVersio