Fotorregulación y efecto del nitrógeno inorgánico en la acumulación de aminoácidos tipo micosporina en algas rojas

En este trabajo se analizará el papel de la radiación lumínica y la disponibilidad de nutrientes en la fotosíntesis y en la acumulación de pigmentos fotosintéticos y moléculas fotoprotectoras. La radiación solar es la fuente primaria de energía para la vida sobre la Tierra; ésta puede afectar al crecimiento y al desarrollo de las plantas tanto como fuente de energía mediante la fotosíntesis, como fuente de calor y como fuente de información ambiental. La irradiancia, la composición espectral, la dirección con que incide y su fotoperiodo son aspectos del ambiente lumínico que cambian en condiciones naturales y proporcionan información acerca de las condiciones ambientales. Las plantas poseen fotorreceptores que les permiten emplear dicha información en la modulación de distintos aspectos del crecimiento y desarrollo. Las algas necesitan carbono inorgánico, agua, luz y nutrientes para la fotosíntesis y el crecimiento. El nitrógeno es uno de los elementos químicos más abundantes en la materia viva, todos los aminoácidos contienen nitrógeno y está presente en otras importantes biomoléculas (como son la clorofila, la ficobiliproteína, etc). También es el elemento que con más frecuencia limita el crecimiento algal. La asimilación de nitrógeno es un proceso dependiente de la fotosíntesis y del metabolismo del carbono para el aporte de poder reductor, ATP y esqueletos carbonados. Por ello, no sólo el nitrógeno inorgánico, sino también la luz y los azúcares, actúan como señales que modulan positivamente la síntesis y la actividad de diversas enzimas relacionadas con la asimilación del nitrógeno. En el primer apartado de la introducción se abordarán los efectos biológicos que induce la RUV en los organismos acuáticos y los posibles mecanismos de fotoprotección presentes en los mismos, como la presencia de moléculas pantalla de esta banda de RUV, entre las que se encuentran los aminoácidos tipo micosporina (MAAs, de su abreviatura en inglés mycosporinelike amino acids). Estas moléculas, además de poseer una estructura química que les permite absorber estas longitudes de onda, poseen nitrógeno entre los elementos químicos que la componen. Nos planteamos la posibilidad de que su presencia no sólo se relacione con la cantidad de radiación recibida, sino que también pueda estar relacionada con la disponibilidad relativa de nutrientes (concretamente de nitrógeno) en el medio de cultivo. En el segundo apartado de la introducción se tratará este aspecto

Interactive effects of solar UV radiation and ammonium on the biomass andnutritional compound production in tank cultivated Hydropuntia corne (Rhodophyta)

Figueroa et al. (2016) Acta Aquaculture 16, 331-332Introduction Hydropuntia cornea is a red alga species cultivated in tanks under nitrogen enrichment with high biomass production and content of high value bioactive compounds (Figueroa et al., 2012; Robledo et al, 2014). In this study, the combined effects (2 × 2 factorial design) of solar radiation (in door (I), green house cutting off the UV radiation and out-door (O) with UV radiation) and nitrogen (ammonium) under high (HN) and low (LN) levels on biomass production (g DW m-2 d-1), biofiltration as Nitrogen uptake efficiency (NUE, %) and Nitrogen uptake rate (NUR, mmol N m-2 h-1), photosynthetic activity as maximal electron transport rate (ETRmax), starch content and antioxidant activity were analyzed in H.cornea grown in tanks for 35 days in the above mentioned conditions. Material and methods The red seaweed Hydropuntia cornea was cultivated in cylindrical tanks of 90 L (0.17 m2 superficial area) with open flow-through N and P-enrichment (5 NH4Cl: 1 KHPO4, in a concentration ranges between 50 - 250 µM). Seaweed density assayed in tanks was 9 g FW L-1. Turnover rates were 64 and 6.4 vol d-1 in high and low flow rate, respectively. Photosynthetic activity was measured by using in vivo chlorophyll a fluorescence associated to photosystem II i.e. Electron transport rate (ETR) expressed as μmol electrons m-2 s-1. Starch (%) was determined according to anthrone method (Brooks et al. 1986) and antioxidant activity was evaluated following ABTS method (Ree et al., 1999) and expressed as Trolox equivalent (μM TEAC g-1 DW). Results Maximal photosynthetic production (ETRmax) increased throughout the culture time. (Fig. 1.A). After 35 d culture, ETRmax was higher under HN than that under LN both under in door and out door conditions (Fig.1A). However, biomass production expressed as g DW m-2 d-1 decreased throughout the experimental time (Fig 1.B). After 35d culture the highest biomass production was reached under HN-O and the lowest under LN-O although the differences were not so high (Fig.1B). The maximal efficiency of N assimilation (NUE %) was greater under LN (98%) than that under HN treatment (72%). NUE decreased throughout the time although after 35 d a clear increase was observed (Table 1). In contrast, the maximal nitrogen uptake rate (NUR) was higher under HN (45.5 mmol N m-2 h-1) than that under LN (25.8 mmol N m-2 h-1). The highest values of both NUE and NUR were obtained under solar radiation (outdoor treatments). Starch ranged from 25.1% (LN-I, 21 d) to 49.6 % (LN-O, 28 d) whereas the highest antioxidant activity was reached under LN-O after 21 d culture (68.5 μM TEAC g-1 DW). After 35d the highest level was again under LN-O (65.2 μM TEAC g-1 DW) followed by HN-O treatment (57.3 μM TEAC g-1 DW).Discussion and conclusions Ammonium supply, simulating fishpond effluents, and full solar irradiation (presence of UV radiation) have a positive effect on photosynthetic rate as ETRmax. The decrease in biomass production in spite of the increase of photosynthetic activity and nitrogen uptake rate is explained because the algae through the time could inverse more energy for the accumulation of metabolites (starch and antioxidant compounds) that that for growth. In any case the highest accumulation of starch and antioxidant activity were observed in the treatments associated to the greatest stress conditions i.e LN and outdoor culture due to UVR can negatively affect biological processes related to growth. As expected, under HN supply NUE was lower than that under LN but NUR was the reverse. H. cornea grown in simulated fishpond effluents displays a high biofiltration rate of inorganic N and accumulates commercially N compounds, as the photoprotector-antioxidant substances, mycosporine-like aminoacids (Figueroa et al., 2012) and C-compounds for nutritional uses or bioethanol production. In this study, the antioxidant activity was much higher than that reported in other seaweeds (Matanjun et al., 2008). H. cornea can be cultured and used to remove nutrient-rich fishpond effluents from aquaculture industries and besides, this biomass provides compounds of high added value for the biotechnology industry. References Brooks, J.R., Griffin, V.K., Kattan, M.W. 1986.A modified method for total carbohydrate analysisof glucose syrups, maltodextrins and other starch hydrolysis products. Cereal Chem 63:465-466. Figueroa, F. L., Korbee, N., Abdala, R., Jerez, C. G., López-de la Torre, M., Güenaga, L., Gómez-Pinchetti, J. L. 2012. Biofiltration of fishpond effluents and accumulation of N-compounds (phycobiliproteins and mycosporine-like amino acids) versus C-compounds (polysaccharides) in Hydropuntia cornea (Rhodophyta). Marine Pollution Bulletin, 64(2), 310-318. Matanjun, P., Mohamed, S., Mustapha, N.M., Ming, C.H. 2008. Antioxidant activities and phenolics content of eight species of seaweeds from north Borneo. J Appl Phycol 20:367–373. Re, R., Pellegrini, N., Proteggente, A., Pannala, A.,Yang,M., Rice-Evans, C. 1999. Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radic Biol Med 26:1231–1237. Robledo, D., Navarro‐Angulo, L., Valdes Lozano, D., Freile‐Pelegrín, Y. 2014. Nutrient removal efficiency of Hydropuntia cornea in an integrated closed recirculation system with pink shrimp Farfantepenaeus brasiliensis. Aquaculture Research, 45(10), 1648-1658Universidad de Málaga.Campus de Excelencia Internacional Andalucia Tech

Could secondary flows make possible the cross-strait transport of passive floating organisms in the Strait of Gibraltar?

The Gibraltar Strait suffers an unprecedented invasion of the alien alga Rugulopteryx okamurae of North Pacific origin. Seemingly, algae first settled in the south shore around year 2015, probably following commercial exchanges with French ports, but there is no certainty that algae first colonized the south shore and then spread to the north one. The opposite could well have happened. Whatever the case, it spread with amazing rapidity over the whole area. Human-mediated vectors (algae attached to ship hulls or fishing nets) can be behind the spread from the shore initially settled to the opposite one. But secondary cross-strait flows within frictional Ekman boundary layers associated to the large along-strait velocity typical of this region could also have propitiated the connection without human intervention. Historical currentmeter profiles collected in the Strait show an intermediate layer of north-going cross-strait velocity near the interface of the mean baroclinic exchange, and an overlying surface layer of southward velocity, whose lower part overlaps the interfacial zone. The first one would facilitate south-to-north transport of algal fragments (or any other neutrally buoyant material) able to settle near the interface depth, while the second one would do the opposite. Cross-strait currents at this depth are of few cm/s, which implies crossing times of several days in low-illuminated conditions. Living organisms must be able to overcome these demanding conditions of darkness and maintain good photosynthetic activity after such period for a successful colonization. Rugulopteryx okamurae can do it.Universidad de Málaga. Campus de Excelencia Internacional del Mar CEIMAR

Respuesta ecofisiológica y capacidad de fotoaclimatación de las praderas de Caulerpa prolifera (Forsskal) J.V. Lamouroux y Cymodocea nodosa (Ucria) Ascherson en el Mar Menor (Murcia, España)

Tras el ensanchamiento en 1972 del principal canal de comunicación con el Mediterráneo, la macroalga Caulerpa prolifera colonizó el Mar Menor. Durante más de tres décadas, su expansión gradual ha reducido las praderas de Cymodocea nodosa, existentes en la laguna, a manchas dispersas en zonas arenosas someras. El objetivo principal es describir la respuesta ecofisiológica y la capacidad de aclimatación de ambas especies con el fin de determinar la influencia de estos mecanismos en la distribución actual de las mismas. La fluorescencia de la clorofila a asociada al fotosistema II se empleó para determinar los parámetros fotosintéticos. Se midieron diversos mecanismos fotoprotectores y antioxidantes (concentración de fenoles, actividad antioxidante mediante el método de DPPH), concentración de clorofilas y carotenoides, así como el contenido interno de C y N, para caracterizar la respuesta fisiológica de ambas especies. Asimismo, se llevaron a cabo experimentos de exposición a altas irradiancias y recuperación en oscuridad para valorar su capacidad de aclimatación. Se encontraron valores bajos de los parámetros fotosintéticos (tasa de transporte electrónico máximo, eficiencia fotosintética) en C. prolifera. Sin embargo, se observó una mayor capacidad fotosintética y la ausencia de fotoinhibición en C. nodosa, además de una alta concentración de luteína y un alto grado de de-epoxidación correlacionado con un mayor amortiguamiento no fotoquímico. Los resultados muestran que C. prolifera se comporta como una especie de sombra con una baja capacidad fotoprotectora, siendo la luz uno de los principales factores que determinan su distribución en la laguna. Sin embargo, C. nodosa muestra estar altamente fotoaclimatada a altas irradiancias y su distribución no está directamente relacionada con el ambiente lumínico. Así la regresión de las praderas de Cymodocea, que se observó antes del deterioro de la calidad del agua de la laguna, podría estar relacionada con otros factores ambientales (exceso de materia orgánica, carbonatos en sedimentos, hipoxia…) o con la competencia con C. prolifera. Es necesario realizar experimentos manipulativos para profundizar en el conocimiento de la actual distribución de ambas especies.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The accumulation of UV screen photoprotectors (mycosporine-like amino acids) in red macroalgae is influenced by nitrogen availability

Red macroalgae produce UV screen photoprotectors (Mycosporine like amino acids, MAAs) in response to increased UV radiation. They are low-molecular weight water-soluble nitrogen enriched molecules, absorbing UV radiation in the wavelength range 310-365 nm due to their cyclohexenone or cyclohexenimine chromophores. MAAs were quantified by means of high performance liquid chromatography (HPLC). The photoprotection capacity in the macroalgae has been inferred by their accumulation under increased UV radiation (spatial and temporal changes), by the correlation with reduced photoinhibition and decreased photodamage and by the increase of antioxidant activity in the cells. Despite the fact MAAs are nitrogen compounds, only few studies on nitrogen enrichment have been conducted. In this study, the influence of inorganic nitrogen on the accumulation of MAAs both under artificial and solar UVR in several macroalgae is presented . Both MAAs and biliproteins contents of several species increased in ammonium enriched seawater. Algae with high internal N content presented a higher photoprotection capacity, estimated as in vivo chlorophyll fluorescence parameters, than those growing under N depletion conditions. The relative composition of MAAs changed both under high irradiance and blue light, increasing the content of palythine and asterina-330 in relation to porphyra-334 and shinorine. In bifactorial experiments of UVR and nitrate, a positive synergic response of both variables on the production of MAAs was found. MAA content also increased under ammonium enrichment, obtained from fishpond effluents. The highest MAA-productivity was observed in outdoor-grown algae, indicating a positive effect of increased PAR and UVR on MAA accumulation. In conclusion, the accumulation of MAAs is favoured by inorganic nitrogen enrichment in the presence of UVR. MAAs can protect the algae against increased UV radiation through a double function: (1) UV screen capacity in both UVA and UVB radiation and (2) Antioxidant capacity of both oxo- and imino-MAAs. The use of MAAs as photoprotective sunscreens in cosmetic products is discussed.Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tec

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

Enhancing Bioproducts in Seaweeds via Sustainable Aquaculture: Antioxidant and Sun-Protection Compounds

Marine macroalgae are considered an untapped source of healthy natural metabolites and their market demand is rapidly increasing. Intertidal macroalgae present chemical defense mechanisms that enable them to thrive under changing environmental conditions. These intracellular chemicals include compounds that can be used for human benefit. The aim of this study was to test cultivation protocols that direct seaweed metabolic responses to enhance the production of target antioxidant and photoprotective biomaterials. We present an original integrated multi-trophic aquaculture (IMTA) design, based on a two-phase cultivation plan, in which three seaweed species were initially fed by fish effluents, and subsequently exposed to various abiotic stresses, namely, high irradiance, nutrient starvation, and high salinity. The combined effect of the IMTA’s high nutrient concentrations and/or followed by the abiotic stressors enhanced the seaweeds’ content of mycosporine-like amino acids (MAAs) by 2.3-fold, phenolic compounds by 1.4-fold, and their antioxidant capacity by 1.8-fold. The Sun Protection Factor (SPF) rose by 2.7-fold, and the chlorophyll and phycobiliprotein synthesis was stimulated dramatically by an order of magnitude. Our integrated cultivation system design offers a sustainable approach, with the potential to be adopted by emerging industries for food and health applicationsPartial funding for open access charge: Universidad de Málag

Selection of LED lighting systems for the reduction of the biodeterioration of speleothems induced by photosynthetic biofilms in the Nerja Cave (Malaga, Spain)

Electrical lighting favours the development of photosynthetic biofilms in caves which can induce biodeterioration in the colonized substrates. The use of specific lights as a limiting factor for biofilm growth could be effective in their control and represents an alternative to chemical methods since they can damage the substrate. However, studies about lighting and the photosynthetic activity of organisms in caves are scarce. In order to select the most effective LED light source in reducing photosynthesis and therefore, in reducing the growth rates of microalgae and cyanobacteria, four biofilms in the Nerja Cave were illuminated by several light emitted diodes (LEDs) with different spectral compositions and the photobiological responses were measured both by empirical and theoretical methodologies. The empirical approach was based on the photosynthetic efficiency, by measuring the in vivo chlorophyll a (Chl a) fluorescence and the theoretical approach was based on the photonic assimilation performance related to the proportion of the light quality used for photosynthesis, according to the action spectra for photosynthesis available in the literature. The photobiological responses showed differences between the empirical and theoretical approach mainly in biofilms dominated by cyanobacteria and red algae, probably because the available action spectra were not useful for monitoring these Nerja Cave biofilms. However, the expected spectral responses of photosynthesis were observed in green microalgal biofilms with maximum photosynthetic efficiency in red and blue light although the green light was also unexpectedly high. The high photosynthetic efficiency in green light could be explained by the predictable high chlorophyll content due to a very dark environment. The results were not conclusive enough for all the biofilm types to be able to recommend a specific lighting system for the photocontrol of biofilm expansion. (...)Funding for open access charge: Universidad de Málaga / CBUA. The project is financed by Cueva de Nerja Public Services Foundation and authorized by the Ministry of Culture of the Andalusian Government. This work is also a contribution to the Research Group FYBOA (RNM-295) of the Junta de Andalucía

Seguimiento del alga Rugulopteryx okamurae en la costa del mar de Alborán.

Rugulopteryx okamurae is a macroalgae native to the Pacific Ocean, which has established itself on the northern and southern coasts of the Alborán Sea, becoming a serious problem due to its rapid growth, being included in the list of invasive species in Spain in 2020. The main problems are related to loss of biodiversity, as well as loss of money in fishing and tourism. BLUEMARO project focuses on the monitoring of the brown algae R. okamurae along the Andalusian coastline. The main objective is to increase the knowledge about this species, its ecologic strategies of adaptation to the environment to try to predict its continuous expansion. Within the project, there are different branches of study (oceanographic, ecophysiology, biotechnological), and here, we will focus on the benthic studies of the algae, as well as the chemical and photobiological analysis of the compounds present in it. These marine studies have been carried out during the different seasons of the year 2022-2023, in three different locations (Maro, Estepona and Tarifa). In each of these samplings, we monitored the cover of R. okamurae and other species in different transects. Likewise, specimens of R. okamurae were collected for subsequent analysis in the laboratory, to establish the existence of differences between the different settled populations, as well as their variability throughout the year. Preliminary sampling results show differences for the populations studied, and seasonal changes for the same location. Likewise, biochemical, and photosynthetic preliminary results show differences in the same terms.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Caracterización de la biomasa de distintas especies de algas, enfocadas al consumo incluyéndolas en alimentos funcionales.

Comunicación en formato posterEn un contexto actual que dificulta el abastecimiento de la población de una manera sostenible, encontramos la necesidad de desarrollar nuevos sistemas de producción de alimentos, apostando en este caso por las algas. Éstas son una fuente segura y ambientalmente sostenible de alimentos y compuestos bioactivos con un alto valor nutricional. Este estudio se enmarca en el contexto del Proyecto ALGAHUB (TED2021- 131555B-C22). Dentro de dicho proyecto, la UMA trabaja en coordinación con la UCA en uno de los subproyectos, enfocado a la innovación y desarrollo de alimentos funcionales en un formato atractivo para el consumidor. Concretamente nuestro grupo se dedica a la caracterización de la composición interna de las algas, en busca de las más interesantes a nivel nutricional y funcional. Por su parte, UJA y UAL van a centrar sus esfuerzos en optimizar las tecnologías de producción a gran escala de la biomasa.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech