Efectos de la calidad de luz en la reproducción, crecimiento y contenido pigmentario de Gracilaria birdiae (Rhodophyta: Gracilariales)

Gracilaria species are the main source of agar worldwide. Since laboratory cultivation is an important means of sustaining such production, this study aimed to assess the influence of two fundamental strategies of physiological algae adjustment, photoacclimation and photomorphogenesis, on G. birdiae physiology. Specifically, the effects of different spectral light qualities on reproduction, growth, and pigment content in two distinct photoperiods (8 and 14 hours) were examined. Tetrasporophytes and gametophytes were submitted to different light qualities: white, green, red, and blue over the course of nine weeks. At the end of this period, chlorophyll a, allophycocyanin, phycocyanin, and phycoerythrin contents were analysed. Gametophytes showed reproductive structures only under monochromatic radiation. A stimulatory effect on tetrasporangium differentiation was mainly observed under red light, but this high fertility was negatively correlated with growth rate, i.e. algae cultivated under red light showed the lowest growth rate. However, while growth rates were higher in algae exposed to white light, they were similar to those observed in algae subjected to green light and 14 hours of daylight. PE was the predominant pigment, irrespective of light quality. Phycocyanin and phycoerythrin concentration increased when algae were cultivated under green and blue light. Therefore, considering future management prospects for G. birdiae mariculture, we suggest that red light could be utilized as a reproductive inductor to produce tetraspores. Furthermore, if the aim is to achieve high phycoerythrin content, continuous blue light could be applied during a short photoperiod. Indeed, the combination of different wavelengths could allow better economic resource exploitation.Las especies del género Gracilaria son la principal fuente de agar en el mundo. El desarrollo de técnicas de cultivo en laboratorio es importante para mejorar la producción, y por ello, este estudio tuvo como objetivo la evaluación de la influencia de dos estrategias de ajuste fisiológico de las algas, la fotoaclimatación y la fotomorfogénesis en G. birdiae. De modo más específico, se evaluaron los efectos de diferentes calidades espectrales de luz sobre la reproducción, crecimiento y contenido pigmentario bajo dos fotoperiodos (8 y 14 horas). Tetrasporofitos y gametofitos fueron sometidos a las siguientes calidades de luz: blanca (WH), verde (GR), rojo (RD) y azul (BL) a lo largo de nueve semanas. Al final del periodo, se analizaron los contenidos de clorofila a (Chl a), aloficocianina (APC), ficocianina (PC) y ficoeritrina (PE). Los gametofitos carecieron de estructuras reproductivas exclusivamente en radiación blanca. La diferenciación de tetrasporangios fue obtenida bajo estímulo de luz roja, pero fue negativamente correlacionado con las tasas de crecimiento (GRTs), presentando las tasas más bajas. Por otro lado, mientras las tasas de crecimiento fueron más altas en algas expuestas a luz WH, éstas fueron similares en algas mantenidas bajo luz GR y 14 horas de fotoperiodo. PE fue el pigmento predominante en G. birdiae, independientemente de la calidad de la luz aplicada. La concentración de PC y PE aumentaron cuando las algas recibieron luz GR y BL. De esa manera, considerando las perspectivas de manejo en la maricultura de G. birdiae, se sugiere que la luz roja puede ser utilizada como factor de inducción de la producción de tetrasporas. Por otro lado, las algas cultivadas en fotoperiodos cortos y luz BL alcanzaron altos contenidos de PE. La combinación de diferentes longitudes de onda puede permitir una mayor valorización en la explotación económica de los recursos algales

The use of the invasive allien species Rugulopteryx okamurae (Ochrophyta) as source of cosmeceutical compounds

The brown macroalga Rugulopteryx okamurae (Dictyotales, Ochrophyta) is invading the western coast Mediterranean sea from 2016. In Spain, it is consider exotic invasive species from December, 2020. Recently , it is starting to invade areas in Provence coast (France) and the Azores Islands (Portugal). This risk studies have stablished that it can potentially extend in the whole Mediterranean Sea. This algal species originated from East Asia was identified the first time in the Mediterranean Sea by 2002 in the Thau Lagoon (France) , where its entering was associated to oyster aquaculture. Rugulopteryx can be fixed in hard substrates from the surface to 40 m depth presenting the highest cover (95-100%) about 10-20 m depth. It can be also mantained long time as free floating algae and in addition it can be observed as beach cast algae. Drastic alterations in the biodiversity of the native communities and high impacts in fish and touristic economical sectors are being produced . In addition to the prevention, one strategy to control the invasion in high impacted areas is to harvest specimens for commercial use to obtained natural bioactive compounds . This strategy presents a two-folded opportunity i.e high availability of biological material for the extraction of bioactive compounds for cosmeceutical uses and through specimen collection , mitigating negative effects caused by alien species, contributing to ecosystem integrity and sustainability. In this study seasonal pattern of biomass productivity, photosynthetic capacity and the accumulation of high cosmeceutical compounds as polyphenols and fucoidans and biochemical content (protein, lipids and carbohydrates) are presented. R.okamurae has a high carbon content (35-42%) and broad range of internal N content (1.5-4.5%).Photosynthetic capacity is maintained very high throughout the year with the maximal production and accumulation of high value compounds in summer. Toxicity of extracts was also evaluated.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Las algas rojas como fuente de compuestos bioactivos cosmecéuticos.

Algae present a great molecular diversity with a wide range of bioactivities, among which antioxidant and photoprotective capacity highlighted for their potential cosmeceutical applications. Mycosporine-like amino acids and phenolic compounds present both properties and are synthetize under stress conditions like high UV radiation. These compounds can be use by the cosmetic industry as new active principles, which are natural, biodegradable and non-toxic.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Interactive effects of solar radiation and inorganic nitrogen on biofiltration, biomass production, photosynthetic activity and the accumulation of bioactive compounds i

Interactive effects of solar radiation and inorganic nitrogen and phosphate on biofiltration capacity, biomass production, photosynthetic activity and the accumulation of bio-active compounds were studied in the red alga Gracilaria cornea grown in tanks with a seawater open-flow system during 35 days. Two light conditions were utilized: outdoor (O), full solar natural radiation, and indoor, inside of a greenhouse (G) where UV-B radiation was cut-off and part of the UV-A radiation was filtered. Two inorganic nitrogen and phosphate concentrations were used: High nutrients (HN; 100–200μM of NH4+ and 20μM of KHPO4) and Low nutrients (LN; 10–20μM of NH4+ and 1μM of KHPO4). Growth and biomass productivity were related to the daily integrated electron transport rate determined in situ, as an estimator of daily photosynthetic activity. Nitrogen uptake efficiency (NUE) was close to 100 % under LN, whereas under HN it ranged from 50 to 70 % in the first week of culture, decreasing to 10–15 % in the rest of the experimental period. Nitrogen uptake rate (NUR) ranged from 20 to 45 mmol N m−2 h−1 under HN, and 5 to 18 mmol N m−2 h−1 in LN treatments. Morphological and pigmentation changes were evident through the culture period. The thalli under HN were more reddish under the indoor treatments, than that in LN. The internal compounds increased throughout the experimental period. Mycosporine-like amino acids (MAAs) were accumulated under HN. N plays a photoprotective role due to both the increased photosynthesis and the MAA content. Maximal MAA productivity reached 113–253 mg MAAs m−2 d−1 under the O-HN treatment, the highest level reported until now in the bibliography. G. cornea could be used for bioremediation of high N content waters. In addition, under full solar radiation and high N availability produce high levels of bioactive compounds as MAAs, polyphenols and biliproteins for cosmeceutical applications.This study was financed by resources of the Photobiology and Biotechnology of aquatic organisms (FYBOA-RNM 295) research group and the Project “Photoprotectors of marine algae: compatible cosmeceutics to the ocean” (UMA18-FEDER JA-162) and Nazca Project (P20-00458) of the Andalusian Goverment. Funding for open access charge: Universidad de Málaga / CBUA

Brazilian Beach-Cast Seaweeds: Antioxidant, Photoprotection and Cytotoxicity Properties.

The potential of seaweed extracts in cosmetic applications have increased with novel development and market. Beneficial biological properties include the ability to struggle aging and anticancer agents. This research aimed to evaluate antioxidant, photoprotective and cytotoxic properties of extracts from beach-cast seaweed species from the Brazilian coast in order to propose an appropriate use of this sustainable resource. Analysis of antioxidant capacity, UV/VIS absorption, quantification of UV photoprotectors, total content of C, N and S, development of cosmetic creams and evaluation of the cytotoxicity activity against tumoral cells lines were performed. The highest antioxidant capacity was found in extracts of brown seaweeds, followed by red seaweeds, with the lowest activity detected in the green seaweed. Same pattern was observed for phenolic compounds. The extracts did not show cytotoxicity activity against healthy human cells. Other forms of extraction and incorporation of the extract into the base creams should be evaluated, the isolation and purification of substances could increase the efficiency of the photoprotective capacity. The species were highly promising and proved to be natural sources of antioxidants and substances with cytotoxicity activity against tumoral cells; therefore, they could be exploited as functional ingredients with specific applications for different types of industries. The application of seaweed extracts in combination with other natural ingredients can help in the design of new cosmetics against the negative effects of UV radiation, in addition to having the great advantage of not presenting toxicity to health or the environment because they are biodegradable.Funding for open access publishing: Universidad Málaga/CBUA. // TBH thanks to CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico; 140144/2017-0) for financial support and PhD scholarship and CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior; Code 001) for funding the postgraduate program in Botany at the Institute of Bioscience and PhD sandwich scholarship (88887.368014/2019-00). FC thanks FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo; 2018/18015-8) for financial support and CNPq for research productivity grants (303937/2015-7; 303493/2018-6). This work is part of the international research project BMBF 031B0284 (023/IVV-113816). FLF thanks the financial support by the Ministry of Sciences and Innovation (BlueMaro Project, PID2020-116136RB-I0) and by the Government of Andalusia (Facco Project - UMA18-FEDER JA-162 and NAZCA Project -P20-004589)

Microorganism-Based Larval Diets Affect Mosquito Development, Size and Nutritional Reserves in the Yellow Fever Mosquito Aedes aegypti (Diptera: Culicidae)

BackgroundMosquito larvae feed on organic detritus from the environment, particularly microorganisms comprising bacteria, protozoa, and algae as well as crustaceans, plant debris, and insect exuviae. Little attention has been paid to nutritional studies in Aedes aegypti larvae.ObjectivesWe investigated the effects of yeast, bacteria and microalgae diets on larval development, pupation time, adult size, emergence, survivorship, lifespan, and wing morphology.Materials and MethodsMicroorganisms (or Tetramin® as control) were offered as the only source of food to recently hatched first instar larvae and their development was followed until the adult stage. Protein, carbohydrate, glycogen, and lipid were analyzed in single larvae to correlate energetic reserve accumulation by larva with the developmental rates and nutritional content observed. FITC-labeled microorganisms were offered to fourth instar larvae, and its ingestion was recorded by fluorescence microscopy and quantitation.Results and DiscussionImmature stages developed in all diets, however, larvae fed with bacteria and microalgae showed a severe delay in development rates, pupation time, adult emergence and low survivorship. Adult males emerged earlier as expected and had longer survival than females. Diets with better nutritional quality resulted in adults with bigger wings. Asaia sp. and Escherichia coli resulted in better nutrition and developmental parameters and seemed to be the best bacterial candidates to future studies using symbiont-based control. The diet quality was measured and presented different protein and carbohydrate amounts. Bacteria had the lowest protein and carbohydrate rates, yeasts had the highest carbohydrate amount and microalgae showed the highest protein content. Larvae fed with microalgae seem not to be able to process and store these diets properly. Larvae were shown to be able to process yeast cells and store their energetic components efficiently.ConclusionTogether, our results point that Ae. aegypti larvae show high plasticity to feed, being able to develop under different microorganism-based diets. The important role of Ae. aegypti in the spread of infectious diseases requires further biological studies in order to understand the vector physiology and thus to manage the larval natural breeding sites aiming a better mosquito control

Climate change and Brazil’s coastal zone: socio-environmental vulnerabilities and action strategies

The coastal zone, where most of the Brazilian population lives, plays a central role for discussing vulnerability and adaptation strategies to climate change. Besides saltmarshes, mangroves and coral reefs, this region also presents seagrass beds, macroalgae and rhodolith beds, forming underwater forests, which are key habitats for services such as biodiversity conservation, O2 production, and absorption of part of the CO2 from the atmosphere. Science endorses that ocean warming and acidification, sea level rise, biological invasions and their interactions with pollution, overfishing, and other stressors undermine the structure and functioning of these ecosystems, thus increasing the region's socio-environmental vulnerability. Ecosystem conservation, management and potential bioremediation/restoration using science-based solutions must be prioritized in order to reduce the vulnerability of coastal communities and the ocean.The coastal zone, where most of the Brazilian population lives, plays a central role for discussing vulnerability and adaptation strategies to climate change. Besides saltmarshes, mangroves and coral reefs, this region also presents seagrass beds, macroalgae and rhodolith beds, forming underwater forests, which are key habitats for services such as biodiversity conservation, O2 production, and absorption of part of the CO2 from the atmosphere. Science endorses that ocean warming and acidification, sea level rise, biological invasions and their interactions with pollution, overfishing, and other stressors undermine the structure and functioning of these ecosystems, thus increasing the region's socio-environmental vulnerability. Ecosystem conservation, management and potential bioremediation/restoration using science-based solutions must be prioritized in order to reduce the vulnerability of coastal communities and the ocean

Electron & Biomass Dynamics of Cyanothece Under Interacting Nitrogen & Carbon Limitations

Marine diazotrophs are a diverse group with key roles in biogeochemical fluxes linked to primary productivity. The unicellular, diazotrophic cyanobacterium Cyanothece is widely found in coastal, subtropical oceans. We analyze the consequences of diazotrophy on growth efficiency, compared to NO3–-supported growth in Cyanothece, to understand how cells cope with N2-fixation when they also have to face carbon limitation, which may transiently affect populations in coastal environments or during blooms of phytoplankton communities. When grown in obligate diazotrophy, cells face the double burden of a more ATP-demanding N-acquisition mode and additional metabolic losses imposed by the transient storage of reducing potential as carbohydrate, compared to a hypothetical N2 assimilation directly driven by photosynthetic electron transport. Further, this energetic burden imposed by N2-fixation could not be alleviated, despite the high irradiance level within the cultures, because photosynthesis was limited by the availability of dissolved inorganic carbon (DIC), and possibly by a constrained capacity for carbon storage. DIC limitation exacerbates the costs on growth imposed by nitrogen fixation. Therefore, the competitive efficiency of diazotrophs could be hindered in areas with insufficient renewal of dissolved gases and/or with intense phytoplankton biomass that both decrease available light energy and draw the DIC level down

Effects of salinity on the physiology of Salvinia auriculata Aubl. (Salviniales, Pteridophyta)

Salvinia auriculata Aubl. is reported to occur in different zones of the Capibaribe River, Pernambuco State, Brazil. This river varies in salinity in different areas. This study evaluated the growth, photosynthesis and pigment contents of S. auriculata at different salinity levels. Plant sections were collected in the Cursaí Reservoir, located in the municipality of Paudalho, Pernambuco, and were brought to a greenhouse, where they were put in glass flasks filled with 250 mL of liquid, placed on benches. The plants were exposed for 40 h to salinity levels of 0, 17 and 34, obtained with reservoir freshwater, 1:1 freshwater:seawater and pure seawater, respectively. At the end of the experimental period, the plants in salt water showed color changes, with brownish leaves. In addition, plant growth rates decreased. Salinity and time had a negative influence on photosynthetic responses such as Fv/Fm, ETRmax and ETR, which showed reductions under the highest salinity treatment. Response patterns may help to explain S. auriculata occurrence, and its distribution can be regulated by salinity