Marina Aboal

Screening microalgae from extreme environments, including hot springs, is an important research topic that has lately emerged. A thermophilic green alga was isolated from a north-eastern Algerian hot spring at a temperature of 63 °C, and its fatty acid (FA) profile was explored. The strain was cultivated in BBM medium at 35 °C in a 16:8 h light/dark cycle and 75 μM photons m−2 s−1. The morphological studies combined with phylogenetic analysis revealed that the isolate was Coelastrella thermophila var. globulina Q. Wang, H. Song, X. Liu, G. Liu and Z. Hu. The monounsaturated fatty acid (MUFA) content was 51.12%. The saturated fatty acid (SFA) and polyunsaturated fatty acid (PUFA) content, respectively, accounted for 27.01% and 21.87%. The main FA was oleic acid (18:1n–9), whose value was 35.95%, followed in decreasing order by palmitic acid (16:0) with 21.45%, linoleic acid (18:2n–6) with 14.38% and α-linolenic acid (18:3n–3) with 04.22%. The FA profile exhibited high total n–6 and n...

Food supplements with microalgae are becoming increasingly abundant and can be easily found anywhere. The most popular products are based on cyanophytes, such as Aphanizomenon flos-aquae, Arthrospira platensis and Limnospira maxima, or on chlorophytes, such as Chlorella or Haematoccus. Although they are all advertised as being very beneficial for health, these products might be harmful because they may contain cyanotoxins and other contaminants, and no information on production methods or strain origins is usually provided. While legislation on the presence of microcystins in waters for different uses is clear, toxicological analyses are not compulsory for food supplements, nor for analyzing anatoxins. Given the potential risk of eating contaminated food, cyanotoxins, heavy metals and the presence of other contaminant organisms were analyzed in 10 microalgae food supplements. Microcystin-LR and anatoxin-a were detected in three analyzed products, and in both cyanophyte- and chloroph...

Alga in the genus Chroothece have been reported mostly from aquatic or subaerial continental environments, where they grow in extreme conditions. The strain Chroothece mobilis MAESE 20.29 was exposed to different light intensities, red and green monochromatic light, ultraviolet (UV) radiation, high nitrogen concentrations, and high salinity to assess the effect of those environmental parameters on its growth. Confocal laser scanning microscopy (CLSM) was used as an “in vivo” noninvasive single-cell method for the study. The strain seemed to prefer fairly high light intensities and showed a significant increase in allophycocyanin (APC) and chlorophyll a [photosystem I (PSI) and photosystem II (PSII)] fluorescence with 330 and 789 μM/cm2/s intensities. Green monochromatic light promoted a significant increase in the fluorescence of APC and chlorophyll a (PSI and PSII). UV-A significantly decreased phycocyanin and increased APC, while UV-A + B showed a greater decreasing effect on c-Ph...

About the presence of Nostoc commune var. fl agelliforme (Nostocaceae, Cyanophyceae) on clay soils from arid regions of south east Spain Palabras clave. Cyanophyceae,Nostoc, distribución, ecología, morfología, regiones áridas, SE España. Keywords.Cyanophyceae, Nostoc, distribution, ecology, morphology, arid regions, Southeastern Spain. 

Microcystins (MCs) are potent hepatotoxins, and their presence in water bodies poses a threat to wildlife and human populations. Most of the available information refers to plankton, and much less is known about microcystins in other habitats. To broaden our understanding of the presence and environmental distribution of this group of toxins, we conducted extensive sampling throughout Spain, under a range of conditions and in distinct aquatic and terrestrial habitats. More than half of the tested strains were toxic; concentrations of the hepatotoxin were low compared with planktic communities, and the number of toxic variants identified in each sample of the Spanish strains ranged from 1-3. The presence of microcystins LF and LY (MC-LF and MC-LY) in the tested samples was significant, and ranged from 21.4% to 100% of the total microcystins per strain. These strains were only detected in cyanobacteria Oscillatoriales and Nostocales. We can report, for the first time, seven new specie...

Under natural conditions, Chroothece richteriana synthesizes a fairly high proportion of fatty acids. However, nothing is known about how environmental changes affect their production, or about the production of protective compounds, when colonies develop under full sunshine with high levels of UV radiation. In this study wild colonies of C. richteriana were subjected to increasing temperature, conductivity, ammonium concentrations and PAR and UV radiations to assess the potential changes in lipid composition and MAAs concentration. The PERMANOVA analysis detected no differences for the whole fatty acid profile among treatments, but the percentages of α-linolenic acid and total polyunsaturated fatty acids increased at the lowest assayed temperature. The percentages of linoleic and α-linolenic acids increased with lowering temperature. γ-linolenic and arachidonic acids decreased with increasing conductivity, and a high arachidonic acid concentration was related with increased conduct...

... Sergio Marco y Marina Aboal 35 ... cariño también de personas como Alberto Carrato, Alberto Sols, Gertrudis de la Fuente, Sara Borrell, Clemente López Quijada, Manuel Losada, David Vázquez, Gabriela Morreale, Francisco Escobar, Manuel Ruiz Amil, Avelino Pérez Geijo y un ...

ABSTRACT Five species of Licmophora were recorded in the hypersaline Mar Menor coastal lagoon. A detailed electron microscopy study of L. proboscidea, L. debilis, L. tenuis and L. fl abellata is presented as well as data on their relativ e abundance in the epiphytic diatom community. Wide morphological variability was observed in large specimens with a high number of slits in multicissura being assigned to Licmophora sp., three different morphs are described. The ecological range of the species considered must be widened to include their presence in hypersaline waters.

Se presentan un total de 148 táxones de Diatomeas distribuidas por todo tipo de ambientes del SE español. Se aportan datos sobre su ecología y se sumariza por medio de tablas los rangos de variación de los principales factores físico-químicos para la mayoría de las especies.

En una prospección extensiva realizada en 175 fuentes de la provincia de Castellón, se ha recolectado Batrachospermum en un total de 13 localidades. Las especies identificadas son B. moniliforme (Roth.) y B. boryanum (Sirod.),(que no había sido citada con anterioridad para España). Se presentan las principales características físico-químicas de las aguas en las que se desarrollan.

The ecological influence of cyanotoxins on aquatic biota remains unclear despite the numerous published references on toxicological and sanitary problems related with cyanophyte proliferation. The effects of microcystins and cyanophyte extracts on the photosynthesis of the algae that belong to two taxonomic groups, Rhodophyta and Bacillariophyta, were studied in an attempt to elucidate their role in the intraspecific competence and physiognomy of fluvial communities. The data showed that both cyanobacteria extracts and pure microcystin-LR affected the photosynthetic activity of all the tested organisms, diatoms (Fistulifera pelliculosa, Gomphonema parvulum, Nitzschia frustulum and Stephanodiscus minutulus) and red algae (Chroothece richteriana) at environmentally relevant concentrations. Effects varied with strains and time, and promoted or inhibited photosynthesis. The microcystins and the other compounds present in cyanobacteria extracts may explain the competence effects observed in nature, especially in calcareous environments where they predominate, and after disturbing events like heavy rains or floods, which may destroy cyanophyte mats and release toxic or inhibitory compounds in a seasonal scale pattern.

The effects of multiple stressors on marine diatom assemblages are still poorly understood. The interactive effects of metals and nutrients were assessed in two coastal biofilms grown at a reference site and a historically contaminated site. The biofilms were exposed in situ to pulse exposures of metals (Zn and Pb) and nutrients (N and P) individually and in combination to mimic patterns of discharge in the study area. The reference community's structure (composition and abundance of taxa) was modified after metals and/or nutrients exposure, but each stressor acted in different way. Irrespective of the stressors or scenario, the abundance of the dominant species Opephora krumbeinii declined, and it is proposed as sensitive species. Nutrient supply favoured the proliferation of certain species with high nutrient tolerances (Fragilaria famelica, Tabularia ktenoeides), whereas metals promoted the colonisation of metal-tolerant species, e.g., Berkeleya fennica, Opephora marina. Simu...

Benthic algal communities of some sources of the Oliva-Pego marsh, Valencia, Spain The Oliva-Pego marsh is an important rice and citrus growing area in the Spanish Levant. The marsh is situated in the area of maximal rainfall of the Autonomous Community of Valencia and has high temperatures year-round. This marsh presents a conductivity gradient that goes from fresh water to brackish in its main inflowing streams, which gives way to a large variety of macro and microalgae, that form characteristic groups in the different conditions. Several of these species show tropical afnity. The results of two samplings in 1999 are presented, which were carried out in the most contrasting environmental zones –those of minimum and maximum rainfall. In each sampling site (four water bodies: Bullent River, Ullal River close to the Bullent, Bassa Sineu and the Font Sallat) pH, temperature, electrical conductivity, dissolved oxygen, current velocity, depth, and cationic and anionic contents of the water were assessed. The communities studied were constituted by structural species of Cyanophyceae and Chlorophyceae. Diatoms were the most diverse group, while Cyanophyceae and Chlorophyceae formed the visible elements. As structural elements, the presence of Homoeothrix juliana (Meneghini) Kirchner and Schizothrix fasciculata (Nägeli) Gomont was to be noteed in oligohaline waters and Chaetophorales, Phormidium tenue (Meneghini) Gomont, Calothrix pulvinata Kützing and Pleurocapsales in slightly brackish waters. The diatoms Encyonopsis microcephala Grunow Krammer, Cymbella afnis Kützing and Navicula cryptotenella Lange-Bertalot were responsible for their chlorophyll c contribution in two streams (R´AEo Bullent and Ullal), while Hyalodiscus whitneyi Ehrenberg, Nitzschia gracilis Hantzsch, Navicella pusilla (Grunow) Krammer and Cocconeis placentula var. eu-glypta (Ehrenberg) Grunow were responsible in Font Salat, and Rhoicosphenia abbreviata (C. Agardh) Lange-Bertalot was responsible in Bassa Sineu. Characteristic communities of the different degrees of water salinity were observed in the different water bodies, composed of species with afnity for those conditions. The sources in the marsh are fundamental as consistent providers of water, with a constancy in the species within the community , This is why they can be used as equilibrium indicators of the system, in order to understand the combined effects of salinity and water regime on marsh biodiversity. This information is important as an environmental referent for water policies and legislative measures with water quality indicators of the Water Framework Directive (WFD) of the European Community (EC), and offers a precedent for the improvement of ecological quality of both freshwater and marine systems. RESUMEN Comunidades algales bentónicas de algunas fuentes del marjal Oliva-Pego, Comunidad Valenciana, Espã na El marjal Oliva-Pego es una importante zona del Levante Español en el cultivo del arroz y de c´AEtricos. La zona se sitúa en eí area de máxima pluviosidad de la Comunidad Valenciana y posee unas temperaturas elevadas durante todo el año. Este humedal presenta un gradiente de salinidad desde aguas dulces a salobres en sus principales aauentes, que provoca la pre-sencia de una alta diversidad de macro y microalgas, que forman grupos caracter´AEsticos en las diferentes condiciones. Varias de estas especies presentan aanidad tropical.

ABSTRACT The communities of Rivularia in Mediterranean Spanish calcareous streams were surveyed during a year in an attempt to understand the factors promoting or inhibiting their production of microcystins in nature. The hydrological variables seemed to be more important than chemical factors in controlling the synthesis. No relation was found with nitrate or orthophosphate but there was a clear positive correlation of total intracellular microcystin contents and of dominant microcystins with total phosphorus, while the dissolved microcystins were inversely correlated with it. The concentration of microcystins dissolved in water remained most of the time below the legal limits (except in summer), but, due to the carcinogenic character of the toxins in low concentrations and in a scenario of global warming probably leading to an increase of these communities, greater control is recommended especially in areas where water treatment is inadequate.