Evaluación del enriquecimiento en lípidos de valor energético en microalgas

Las microalgas han sido reconocidas en ios últimos años como una de las nuevas fuentes de energías renovables alternativas a los recursos fósiles. Las principales características que avalan a las microalgas para dicha funcionaiidad son su crecimiento rápido y controlado en medio de cultivo líquido, los requerimientos nutricionaies simples para su producción masiva, - C02 atmosférico, agua, luz y sales minerales - y un contenido de acilglicéridos aceptable para obtención de aceites. La producción masiva de aceites para biodiésel requiere, preferiblemente, de microalgas adaptadas a las condiciones ambientales y microbioiógicas propias del lugar de producción y del recurso acuoso utilizado. Esta Tesis Doctoral estudia la acumulación de lípidos de microalgas aisladas de distintos orígenes en la provincia de Hueiva, lugar adecuado para la producción masiva. Una de las microalgas se aisló de las aguas ácidas de la Faja Pirítica de Hueiva y crece a pH muy ácido (inferior a 3). Se aislaron también microalgas de aguas tratadas de la Refinería La Rábida de CEPSA. La microalga de ambiente ácido acumula lípidos antioxidantes, algunos de valor comercial como luteína y algunos ácidos grasos. En esta Tesis Doctoral se estudió la forma de estimular la acumulación ¡ntraceíular de dichas moléculas, a partir de condiciones de estrés nutricional y salino. Los resultados permitieron concluir que C. onubensis crece cuando se incuba en carencia de fósforo o azufre, manteniendo la captura activa de luz. Los resultados sugieren la posible disponibilidad de reservas de azufre en la microalga, que permiten su crecimiento. La carencia del medio de cultivo en nitrógeno, fósforo o azufre favorece temporalmente la acumulación de carotenoides y ácidos grasos, siendo el ácido linolénico (C18:3) el más abundante. Por vez primera en una microalga de ambiente ácido, se ha puesto de manifiesto el vínculo entre carencia de nutrientes y estrés oxidativo. Además, Coccomyxo muestra cierta halotolerancia. Una salinidad moderada, inferior a la del mar, favorece su crecimiento y la acumulación de luteína, p-caroteno y ácidos grasos, particularmente linoléico y linolénico, ambos esenciales en alimentación humana. En dichas condiciones, el aumento en actividades enzimáticas que utilizan glutatión y ascorbato permite relacionar la halotolerancia con el incremento de la respuesta antioxidante. También se aislaron e identificaron microalgas de aguas depuradas de la Refinería La Rábida de CEPSA, de crecimiento robusto y estable y con el máximo contenido posible en lípidos, particularmente acilglicéridos, titiles para la obtención de biodiésel. Se estudiaron condiciones para favorecer la acumulación intracelular de tales lípidos, en cultivos autótrofos y heterótrofos. En particular, se aisló una microalga de rápido crecimiento que se identificó como una nueva cepa del género Chlorella. La microalga acumuló, en forma de lípidos, máximos cercanos al 50 % de su peso seco. Los resultados obtenidos en condiciones limitantes para la fotosíntesis sugieren que la microalga podría utilizar reservas de carbono reducido para incrementar la acumulación de lípidos. En condiciones fotoautotróficas, la producción de FAMEs de la microalga Chlorella sp., se realiza de forma más eficiente si los cultivos se someten a incubación bajo irradiancias saturantes, obteniendo mayor productividad de lípidos que en carencia nutricional como consecuencia de la mayor productividad de biomasa. En las condiciones de máxima acumulación determinadas, la microalga Chlorella sp. objeto de estudio alcanza un contenido promedio de lípidos de un 40 %-45 %, de los cuales un máximo de aproximadamente 30 % son FAMEs. Además, se consiguió estimular la biosíntesis de luteína en la microalga mediante carencia nutricional y alta irradiancia ó en condiciones de heterotrofía con glicerol como fuente de carbono. Estas condiciones, especialmente la heterotrofía, abren una vía de estudio para la producción masiva de luteína a mayor escala. La producción de lípidos en Chlorella sp. resultó similar tanto en condiciones autotróficas como heterotróficas de crecimiento. En condiciones heterotróficas, la mayor producción de lípidos - hasta un 35 % del peso seco de la microalga- y de FAMEs - hasta un 60% del peso total de lípidos- se obtuvo utilizando glicerol como fuente de carbono en oscuridad. La alta productividad de biomasa y los menores costes de producción en heterotrofía sugieren que tales condiciones de cultivo serían de especial valor en la obtención de FAMEs (biodiésel) a partir de la Chlorella sp. estudiadaMicroalgae have recently been recognized as one of the renewable energy alternative sources to fossil fuels. The main features that support the microalgae for such functionality are rapid and controlled growth in liquid culture medium, simple nutritional requirements for mass production - atmospheric C02, water, light and minerals - and acceptable content of acylglycerides for oi! production. Massive algal oil production for biodiesel preferably requires of microalgae adapted to environmental and microbiological conditions of the place and of the water source used. This Doctoral Thesis studies the lipid accumulation of microalgae isolated from different sources in the province of Huelva, which is a suitable place for massive algal production. One of the microalgae was isolated from the acidic waters of the Pyrite Belt of Huelva and grows at very acidic pH (below 3). Microalgae were also isolated from the treated water at CEPSA's La Rabida Refinery. The acid environment microalga accumulated lipid antioxidants, some of them of commercial value, including lutein and some fatty acids. In this Thesis we studied how to stimulate the intracellular accumulation of these molecules, from nutritional and saline stress conditions. The results led us to conclude that C. onubensls grows if incubated in the absence of phosphorus or sulfur, keeping active light capture. The results suggest the microalga might possibly have sulfur reserves which allow it to grow. Lack of nitrogen, phosphorus or sulfur in the culture medium temporarily promotes accumulation of carotenoids and fatty acids, linolenic acid (C18: 3) being the most abundant. For the first time in acid environment microalgae the connection between nutrient deficiency and oxidative stress has been highlighted. In addition, Coccomyxa showed certain haiotolerance. Moderate salinity, below sea salt level, supports Coccomyxa growth and accumulation of lutein, p-carotene and fatty acids, particularly linoleic and linolenic acids, both essential in human nutrition. Under these conditions, the increase in enzyme activities that depend on reduced glutathione and ascorbate allows for relating haiotolerance to increased antioxidant algal response. Microalgae from CEPSA's La Rabida Refinery treated waters were also isolated and identified, looking at strong and stable growth species that accumulated as high as possible lipid content, particularly acylglycerides, which are useful for biodiesel production. Conditions were studied to promote the intracellular accumulation of these lipids in autotrophic and heterotrophic cultures. In particular, a fast-growth microalga was identified as a new strain belonging to Chloreila genus. That microalga accumulated maximum lipid contents of about 50% of biomass dry weight. The results obtained under photosynthesis limiting conditions suggest that the microalga might be making use of reduced carbon stocks in order to increase lipid accumulation. Under photoautotrophic conditions, FAMEs most efficient production of Chloreila sp. performs if cultures are incubated under saturating irradiances. Under such conditions, the increased biomass productivities result in lipid productivities which are higher than in nutrient-deficient cultures. Under conditions of maximum accumulation, the isolated Chloreila sp. reached average lipid content from 40% -45%, of which a maximum of approximately 30% are FAMEs. Further, lutein biosynthesis in the microalga was enhanced through cultivation under nutrient deficiency and high irradiance or under heterotrophy on glycerol as a carbon source. These conditions, especially heterotrophy, open a study line for production of lutein at larger scale. Lipid production of Chlorella sp. was similar in both heterotrophic and autotrophic conditions. In heterotrophic conditions, increased production of lipids -up to 35% of biomass dry weight- and FAMEs -up to 60% of the total weight of lipids- was obtained by using glycerol as a carbon source in the dark. The high biomass productivities and lower production costs in heterotrophy suggest that such culture conditions would be of particular value for FAMEs (biodiesel) production from the isolated Chlorella sp

Computational study of coronoid carbazole based Macrocycles: influence of isomerism.

Carbazole (Cz) units have been recognized as crucial conjugated cores in organic electronics due to their good electro- and photoactive properties, such as high hole-transporting mobilities, when compared to other heterocycles. On the other hand, conjugated macrocycles should be useful building blocks for the construction of 2D porous surface networks or 3D inclusion complexes among other supramolecular structures.2 One of the most interesting features of conjugated cyclic oligomers is that their electronic, structural, and optical properties can be tuned as a function of their interior and exterior domains. Therefore, a systematic study of conjugated macrocycles with well-defined diameters is of crucial importance to establish the structure-property relationships of these materials. For that purpose, we carried out a purely theoretical study of coronoid molecules based on three different indolocarbazoles (ICz) structural isomers (see Figure 1) as indolo[2,3-a]carbazole (23a-4MC), indolo[2,3-b]carbazole (23b-4MC) and indolo[3,2-b]carbazole (32b-4MC), which contain four indolecarbazole units (4MC). This work aims to identify new macrostructures with interesting electronic properties as well as to display the usefulness of the theoretical tools to advance knowledge in the organic electronics field. Overall, this investigation contributes to elucidating the electronic properties of coronoid macrocycles, guiding experimental chemists to produce new molecules with desirable properties.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Sustainability in the University: A Study of Its Presence in Curricula, Teachers and Students of Education

This work forms part of the R + D + i ‘Training project in Spanish universities for professionals as agents of change in order meet the challenges facing society’ (Educación e Innovación Social para la Sostenibilidad (EDINSOST) 2017–2019). The purpose is to analyse the presence of sustainability in terms of curriculum content and training in competence for students, teachers and the curricula of Science of Education degree courses at the University of Seville. In this context, the curricula of the Degree in Early Childhood Education, Primary Education and Pedagogy have been analysed. Two questionnaires have been drawn up, and four reflection groups have been created—in which, a total of 49 teachers and 170 students have participated. The results show that there is a low presence of sustainability in Science of Education degree courses. The teachers express the opinion that they are engaged in sustainable initiatives and have an interest in ethical models. The students express a high degree of interest in receiving sustainability training. Findings provide information for introducing innovation into the university curriculum and the training of teachers and students in order to improve their competency in sustainability

Sport for all education as a proposal for inclusion and social sustainability

INTRODUCCION. El presente artículo analiza un programa denominado Deporte para Todos, que se desarrolla la ciudad francesa de Montpellier. El estudio se realiza en L’Herault Sport. Este es un organismo asociado al Consejo General de l´Hérault y miembro del grupo Hérault, que sustenta todo el movimiento deportivo del departamento francés. MÉTODO. A través de una investigación descriptiva y en base a cinco variables (género, relación de los sectores implicados, desarrollo comunitario, políticas públicas y formación de los monitores y voluntarios), cuestionamos el desarrollo del programa de Deporte para Todos como instrumento de inclusión social. RESULTADOS. Los primeros resultados que se presentan corresponden al análisis en torno a las cinco variables, mostrando las potencialidades del programa y la necesidad de profundizar en las variables de estudio para la construcción de un verdadero programa que favorezca buen vivir a través del deporte. CONCLUSIONES. Las futuras líneas de investigación apuntan a la realización de nuevas investigaciones que posibiliten una mejora en la participación de las niñas y la mujer como profesional en el programa, de creación de redes entre los sectores implicados que favorece un modelo integrado y sistémico de trabajo, una formación personal y profesional del monitor y voluntario, un compromiso sostenido de las políticas públicas y en consecuencia el desarrollo de la comunidad de estudio como espacio educativo que consolida el buen vivir.INTRODUCTION. This article analyzes a program called Deporte para todos (Sport for All), which is developed in the French city of Montpellier. The study is performed in L' Hérault Sport. This is an organization associated with the General Council of l´herault and member of the Héraultgroup, that supports all the sports movement of the French Department. METHOD. Through a descriptive research and based on five variables (gender, relationship of the involved sectors, community development, public policies and training of monitors and volunteers), we question the development of the program of “Sport for All” as a tool for the social inclusion. RESULTS. The first results presented correspond to the analysis around the five variables, showing the potential of the programme and the need to deepen in the variables of study for the construction of a real program that promotes good living through sport. CONCLUSIONS. Future lines of research target new research that make possible an improvement in the participation of girls and women as professional in the program, networking among the involved sectors that favors an integrated and systemic model of work, a personal and professional training for the monitor and the volunteer, a sustained public policy commitment and as a result the development of the community's study as an educational space that consolidates the good live

Supercritical Fluid Extraction of Fucoxanthin from the Diatom Phaeodactylum tricornutum and Biogas Production through Anaerobic Digestion

Phaeodactylum tricornutum is the marine diatom best known for high-value compounds that are useful in aquaculture and food area. In this study, fucoxanthin was first extracted from the diatom using supercritical fluid extraction (SFE) and then using the extracted diatom-like substrate to produce bioenergy through anaerobic digestion (AD) processes. Factors such as temperature (30 °C and 50 °C), pressure (20, 30, and 40 MPa), and ethanol (co-solvent concentration from 10% to 50% v/v) were optimized for improving the yield, purity, and recovery of fucoxanthin extracted using SFE. The highest yield (24.41% w/w) was obtained at 30 MPa, 30 °C, and 30% ethanol but the highest fucoxanthin purity and recovery (85.03mg/g extract and 66.60% w/w, respectively) were obtained at 30 MPa, 30 °C, and 40%ethanol. Furthermore, ethanol as a factor had the most significant effect on the overall process of SFE. Subsequently, P.tricornutum biomass and SFE-extracted diatom were used as substrates for biogas production through AD. The effect of fucoxanthin was studied on the yield of AD, which resulted in 77.15 ± 3.85 LSTP CH4/kg volatile solids (VS) and 56.66 ± 1.90 LSTP CH4/kg VS for the whole diatom and the extracted P.tricornutum, respectively. Therefore, P.tricornutuman can be considered a potential source of fucoxanthin and methane and both productions will contribute to the sustainability of the algae-biorefinery processes

Variability of Omega-3/6 Fatty Acid Obtained Through Extraction-Transesterification Processes from Phaeodactylum tricornutum

The effect of direct transesterification methods on the omega-3/6 composition of extracts from Phaeodactylum tricornutum was studied. The aim of this work was to identify an extraction method which allowed to obtain the most suitable profile of fatty acids in terms of its potential benefits to health, particularly if further used in the food industry. Seven methods using acids, alkalis, and heterogeneous-catalysts, (namely methods from 1 to 7, abbreviated as M1-M7) were performed to determine α-linolenic (ALA), linoleic (LA), docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids. The composition of fatty acids was in all cases characterized by the major abundance of palmitic (23.95–34.08%), palmitoleic (30.94–35.56%), oleic acids (3.00–7.41%), and EPA (0.5–6.45%). Unsaturated fatty acids extraction yield was higher with a two-step transesterification process (M6, 63.65%). The total fatty acid methyl ester content (FAME) obtained with acid-transesterification (M1) reached about 21% wt, and 60% w/w total lipids. ALA higher relative content (ALA/LA ratio) was obtained when a lipid pre-extraction step was performed prior to acid-catalysis (M4). The transesterification method based on alkali-catalyst (M3, KOH catalyst) led to obtain higher DHA relative contents (DHA/EPA ratio up to 0.11), although its FAME content was 3.75-fold lower than that obtained with acid-transesterification (M1). Overall, this study shows that direct transesterification with alkali-catalyst (M3) improves the determination of PUFA content from the diatom through a more efficient transesterification-based extraction process, and thus allow to assess the value of the biomass more accurately for application in the food industry

Neochloris oleoabundans oil production in an outdoor tubular photobioreactor at pilot scale

Oil production was tested with Neochloris oleoabundans in a 6 m3, horizontal soft sleeve tubular reactor from 22 October to 7 November in Matalascañas, southern Spain. Biomass productivity during the nitrogen replete phase was 7.4 g dw m−2 day−1. Maximum lipid content in the biomass was 39% and average lipid productivity during the nitrogen depletion phase was 2.0 g m−2 day−1. Nitrogen depletion of the cultures was carried out in order to enhance fatty acid formation, using the inverse nitrogen quota in the biomass to predict the fatty acid content. TFA concentration at harvest was 14%DW, compared to a value of 17%, predicted by the inverse nitrogen quota. The overall feasibility of the horizontal tubular technology for microalgal oil production, including mixing energy expenditure, was evaluated

Genotypic and Lipid Analyses of Strains From the Archaeal Genus Halorubrum Reveal Insights Into Their Taxonomy, Divergence, and Population Structure

To gain a better understanding of how divergence occurs, and how taxonomy can benefit from studying natural populations, we isolated and examined 25 closely related Halorubrum strains obtained from different hypersaline communities and compared them to validly named species and other reference strains using five taxonomic study approaches: phylogenetic analysis using the 16S rRNA gene and multilocus sequencing analysis (MLSA), polar lipid profiles (PLP), average nucleotide identity (ANI) and DNA-DNA hybridization (DDH). 16S rRNA gene sequence could not differentiate the newly isolated strains from described species, while MLSA grouped strains into three major clusters. Two of those MLSA clusters distinguished candidates for new species. The third cluster with concatenated sequence identity equal to or greater than 97.5% was comprised of strains from Aran-Bidgol Lake (Iran) and solar salterns in Namibia and Spain, and two previously described species isolated from Mexico and Algeria. PLP and DDH analyses showed that Aran-Bidgol strains formed uniform populations, and that strains isolated from other geographic locations were heterogeneous and divergent, indicating that they may constitute different species. Therefore, applying only sequencing approaches and similarity cutoffs for circumscribing species may be too conservative, lumping concealed diversity into a single taxon. Further, our data support the interpretation that local populations experience unique evolutionary homogenization pressures, and once relieved of insular constraints (e.g., through migration) are free to diverge.España, MINECO Projects CGL2013-46941-P and CGL2017-83385-

Ultrasound-Based Recovery of Anti-Inflammatory and Antimicrobial Extracts of the Acidophilic Microalga Coccomyxa onubensis

In the present study, the recovery of valuable molecules of proven anti-inflammatory and antimicrobial activity of the acidophilic microalga Coccomyxa onubensis (C. onubensis) were evaluated using green technologies based on ultrasound-assisted extraction (UAE). Using a factorial design (3 × 2) based on response surface methodology and Pareto charts, two types of ultrasonic equipment (bath and probe) were evaluated to recover valuable compounds, including the major terpenoid of C. onubensis, lutein, and the antimicrobial activity of the microalgal extracts obtained under optimal ultrasound conditions (desirability function) was evaluated versus conventional extraction. Significant differences in lutein recovery were observed between ultrasonic bath and ultrasonic probe and conventional extraction. Furthermore, the antimicrobial activity displayed by C. onubensis UAE-based extracts was greater than that obtained in solvent-based extracts, highlighting the effects of the extracts against pathogens such as Enterococcus hirae and Bacillus subtilis, followed by Staphylococcus aureus and Escherichia coli. In addition, gas chromatography–mass spectrometry was performed to detect valuable anti-inflammatory and antimicrobial biomolecules present in the optimal C. onubensis extracts, which revealed that phytol, sterol-like, terpenoid, and even fatty acid structures could also be responsible for the antibacterial activities of the extracts. Moreover, UAE displayed a positive effect on the recovery of valuable molecules, improving biocidal effects. Our study results facilitate the use of green technology as a good tool in algal bioprocess engineering, improving energy consumption and minimizing environmental impacts and process costs, as well as provide a valuable product for applications in the field of biotechnology.This work was partially supported by the Andalusian Research, Development and Innovation Plan (Junta de Andalucía, Spain) with FEDER funds (Project P20_00930) and by the University of Huelva through a grant obtained in the program “Requalitication of the Spanish Universitary System 2021-2023, María Zambrano” (Real Decreto 289/2021, 20 April and Order UNI/551/2021, 26 May) and “IV Convocatoria de Micro-proyectos-Cátedra de la Provincia UHU 2023”

Role of long non-coding RNAs in adipose tissue metabolism and associated pathologies

The incidence of obesity and its related disorders has increased dramatically in recent years and has become a pandemic. Adipose tissue is a crucial regulator of these diseases due to its endocrine capacity. Thus, understanding adipose tissue metabolism is essential to finding new effective therapeutic approaches. The "omic" revolution has identified new concepts about the complexity of the signaling pathways involved in the pathophysiology of adipose tissue-associated disorders. Specifically, advances in transcriptomics have allowed its application in clinical practice and primary or secondary prevention. Long non-coding RNAs (lncRNAs) have emerged as critical regulators of adipose tissue since they can modulate gene expression at the epigenetic, transcriptional, and post-transcriptional levels. They interact with DNA, RNA, protein complexes, other noncoding RNAs, and microRNAs to regulate a wide range of physiological and pathological processes. Here, we review the emerging field of lncRNAs, including how they regulate adipose tissue biology, and discuss circulating lncRNAs, which may represent a turning point in the diagnosis and treatment of adipose tissue-associated disorders. We also highlight potential biomarkers of obesity and diabetes that could be considered as therapeutic targets.This study was supported by the Spanish Ministry of Science and Innovation (MCIN) (PID2020-114953RB-C21 to LH and DS, co-funded by the European Regional Development Fund [ERDF], PID2020-114343GA-100 to MA, and PID2019-110063RA-I00 to JP and MC), the Biomedical Research Centre in Pathophysiology of Obesity and Nutrition (CIBEROBN) (Grant CB06/03/0001 to LH), and the Merck Health Foundation (to LH). AC is a recipient of the Formación de Personal Investigador (FPI) doctoral fellowship from the MCIN.‬‬‬‬‬‬ We thank MCarmen Soler-Vázquez for her expert assistance in the preparation of Fig. 1