Dataset for proteomic analysis of Chlorella sorokiniana cells under cadmium stress

Cadmium is one of the most hazardous heavy metal for aquatic environments and one of the most toxic contaminants for phytoplankton. This work provides the dataset associated with the research publication “Effect of cadmium in the microalga Chlorella sorokiniana : a proteomic study” [1] . This dataset describes a proteomic approach, based on the sequential window acquisition of all theoretical fragment ion spectra mass spectrometry (SWATH-MS), derived from exposure of Chlorella sorokiniana to 250 μM Cd 2 + for 40 h, showing the proteins that are up- or downregulated. The processing of data included the identification of the Chlamydomonas reinhardtii protein sequences equivalent to the corresponding of Chlorella sorokiniana sequences obtained, which made possible to use KEGG Database. MS and MS/MS information, and quantitative data were deposited PRIDE public repository under accession number PXD015932 .This work was supported in part by research grants from the European governments (IN- TERREG VA-POCTEP- 2014-2020; 0055_ALGARED_PLUS_5_E), the Operative FEDER Program- Andalucía 2014-2020 ( UHU-1257518 ) University of Huelva and by the European Regional De- velopment Fund through the Agencia Estatal de Investigación grants ( PID 2019-110438RB-C22 and PID 2019-109785 GB-100 )

Impact of heavy metals in the microalga Chlorella sorokiniana and assessment of its potential use in cadmium bioremediation

The chlorophyte microalga Chlorella sorokiniana was tested for the bioremediation of heavy metals pollution. It was cultured with different concentrations of Cu2+, Cd2+, As (III) and As (V), showing a significant inhibition on its growth at concentrations of 500 µM Cu2+, 250 µM Cd2+, 750 µM AsO33- and 5 mM AsO43- or higher. Moreover, the consumption of ammonium was also studied, showing significant differences for concentrations higher than 1 mM of Cu2+ and As (III), and 5 mM of As (V). The determination of intracellular heavy metals concentration revealed that Chlorella sorokiniana is an outstanding Cd accumulator organism, able to accumulate 11,232 mg kg−1 of Cd, and removing 65% of initial concentration of this heavy metal. Finally, antioxidant enzymes, such as catalase (CAT) and ascorbate peroxidase (APX), and enzymes involved in the production of glutamate and cysteine, such as glutamine syntethase (GS), glutamate dehydrogenase (GDH), O-acetylserine (thiol) lyase (OASTL) and NAD-isocitrate dehydrogenase (NAD-IDH) were studied both at gene expression and enzymatic activity levels. These enzymes exhibited different grades of upregulation, especially in response to Cd and As stress. However, GS expression was downregulated when Chlorella sorokiniana was cultured in the presence of these heavy metals.This work was supported in part by research grants from the Euro- pean governments (INTERREG VAPOCTEP-2014-2020; 0055_ALGAR- ED_PLUS_5_E), the Operative FEDER Program-Andalucía 2014-2020, the University of Huelva (UHU-1257518), and by the European Regional Development Fund through the Agencia Estatal de Investigaci ́on grant (PID 2019-110438RB-C22

Up-Regulation of the Nrf2/HO-1 Antioxidant Pathway in Macrophages by an Extract from a New Halophilic Archaea Isolated in Odiel Saltworks

The production of reactive oxygen species (ROS) plays an important role in the progression of many inflammatory diseases. The search for antioxidants with the ability for scavenging free radicals from the body cells that reduce oxidative damage is essential to prevent and treat these pathologies. Haloarchaea are extremely halophilic microorganisms that inhabit hypersaline environments, such as saltworks or salt lakes, where they have to tolerate high salinity, and elevated ultraviolet (UV) and infrared radiations. To cope with these extreme conditions, haloarchaea have developed singular mechanisms to maintain an osmotic balance with the medium, and are endowed with unique compounds, not found in other species, with bioactive properties that have not been fully explored. This study aims to assess the potential of haloarchaea as a new source of natural antioxidant and anti-inflammatory agents. A carotenoid-producing haloarchaea was isolated from Odiel Saltworks (OS) and identified on the basis of its 16S rRNA coding gene sequence as a new strain belonging to the genus Haloarcula. The Haloarcula sp. OS acetone extract (HAE) obtained from the biomass contained bacterioruberin and mainly C18 fatty acids, and showed potent antioxidant capacity using ABTS assay. This study further demonstrates, for the first time, that pretreatment with HAE of lipopolysaccharide (LPS)-stimulated macrophages results in a reduction in ROS production, a decrease in the pro-inflammatory cytokines TNF-α and IL-6 levels, and up-regulation of the factor Nrf2 and its target gene heme oxygenase-1 (HO-1), supporting the potential of the HAE as a therapeutic agent in the treatment of oxidative stress-related inflammatory diseases.This research was funded by the Operative FEDER Program-Andalucía 2014-2020 (US-1380844 and UHU-1257518), Spanish Agencia Estatal de Investigación (PID2019-110438RBC22-AEI/FEDER), the Andalusian government (I+D+i-JA-PAIDI-Retos projects 2020-PY20) and the “VII Plan Propio de Investigación y Transferencia” of The University of Seville. The work was partially funded by national funds from Fundação para a Ciência e a Tecnologia (FCT, Portugal) in the scope of the projects UIDB/04565/2020 and UIDP/04565/2020 of the Research Unit iBB-Institute for Bioengineering and Biosciences, and of the project LA/P/0140/2020 of the i4HB-Associate Laboratory Institute for Health and Bioeconomy. P.G.-V acknowledges financial support from the “Margarita Salas” grant for the training of young doctors, University of Huelva

Simultaneous production of carotenoids and chemical building blocks precursors from chlorophyta microalgae

Replacement of fossil fuels has to be accompanied by the incorporation of bio-based procedures for the production of fine chemicals. With this aim, the microalga Chlamydomonas reinhardtii was selected for its ability to accumulate starch, an environmentally-friendly alternative source of chemical building blocks, such as 5′ -hydroxymethylfurfural or levulinic acid. The content of appreciated lipophilic coproducts was assessed in the selected microalga cultured at different nutritional conditions; and the parameters for the acidic hydrolysis of the algal biomass, obtained after pigments extraction, were optimized using a Central Composite Design. Response Surface Methodology predicted that the optimal hydrolysis conditions were elevated temperature, high DMSO % and short hydrolysis time for glucose. LA was favored at long times and high acid % and 5′ -HMF at lower acid % and high DMSO %. Chlamydomonas can therefore be used as a sustainable feedstock for the simultaneous production of high-added value lipophilic compounds and platform chemicals.Funding for open access charge: Universidad de Huelva / CBUA

Amino acids profile of 56 species of microalgae reveals that free amino acids allow to distinguish between phylogenetic groups

Microalgae represent a phototrophic resource with a high protein content, whose nutritional value is very high as a result of its amino acid profile. Although the total amino acid profile has been repeatedly described to change little among phylogenetic groups of microalgae, some variability has occasionally been reported. Part of this uncertainty is associated with the low phylogenetic diversity encompassed in the work to date and the high methodological variability between studies. Among these studies, very few have differentiated between total and free amino acid content for common microalgae samples. Thus, in the present work, the profile of total and free amino acids has been determined in a diverse group composed of 56 species of microalgae belonging to 7 phyla. A multivariate analysis of the total amino acid profile in the studied microalgae group revealed close amino acid patterns throughout microalgae phylogeny and agreed with results obtained from similar analysis performed with published data. Conversely, the free amino acid profile strongly differentiated between phylogenetic groups. On the one hand, species of Cyanobacteria, Plantae, Cryptophyta, and Bacillariophyta showed close free amino acid patterns, characterized by the highest abundance of free glutamic acid. Ochrophyta species were particularly rich in free proline, while the free amino acid profile of Miozoa and Haptophyta species stood out from the rest of the phylogenetic groups for their outstanding levels of the two essential amino acids phenylalanine and lysine. Haptophyta species were also characterized by their much higher free tyrosine content.This work was supported by the European Union Cooperation Program INTERREG VA POCTEP-055 ALGARED PLUS5E Spain-Portugal (2014–2020). The authors are grateful to the Fertinagro Biotech Foundation (C´atedra Fertinagro Biotech Universidad de Huelva). Funding for open access charge: Universidad de Huelva / CBUA is acknowledged

Metabarcoding data of prokaryotes and eukaryotes inhabiting the phosphogypsum stockpiles on the salt marshes of Huelva (SW Spain)

Artículo científico de metadatos bioinformáticosAround 100 Mt of phosphogypsum (PG) of extreme acidity and with high concentrations of heavy metals and radionuclides have been deposited on the salt marshes of the Tinto River estuary in Huelva (SW Spain) for more than forty years. The microbial community able to thrive in these adverse conditions remains totally unknown, despite the fact that it can highly influence the biogeochemical cycle of the phospho- gypsum components and include new species with biotechnological interest. High throughput sequencing of 16S/18S rRNA encoding genes is a potent tool to uncover the microbial diversity of extreme environments. This data article de- scribes for the first time the prokaryotic and eukaryotic diversity of two water samples collected in the Huelva phosphogypsum stacks. The raw amplicons of the 16S/18S rRNA maker genes for the two phosphogypsum samples and two reference samples (seawater and the Tinto River water) obtained after sequencing on MiSeq platform are provided. The operational taxonomic units (OTUs) obtained after the treatment and clustering of the obtained reads with the QIIME2 pipeline and their taxonomic assignation performed by comparison with the SILVA database are also presented to complete the information of the article “Exploring the microbial community inhabiting the phosphogypsum stacks of Huelva (SW, Spain) by a high throughput 16S/18S rDNA Sequencing approach”.Funding for open access charge: Universidad de Huelva / CBUAThe authors thank Fertiberia S.A. for its support in obtaining the water samples used in this study. P. Gómez-Villegas acknowledges the financial support of the University of Huelva (EPIT 2016–17). This research was funded by University of Huelva and the Operative FEDER Program- Andalucía 2014-2020 (UHU-1257518 and UHU-1255876); The SUBV. COOP.ALENTEJO-ALGARVE- ANDALUCIA 2021; The European Regional Development Fund through the Agencia Estatal de In- vestigación (research grant PID 2019–110438RB-C22) and the Andalucian government (I + D + i- JA-PAIDI-Retos project 2020- PY20_00728)Funding for open access charge: Universidad de Huelva / CBU

Using agro-industrial wastes for mixotrophic growth and lipids production by the green microalga Chlorella sorokiniana

There has been growing interest in the use of microalgae for the production of biofuels, but production costs continue to be too high to compete with fossil fuel prices. One of the main limitations for photobioreactor productivity is light shielding, especially at high cell densities. The growth of the green microalga Chlorella sorokiniana, a robust industrial species, has been evaluated under different trophic conditions with traditional carbon sources, such as glucose and sucrose, and alternative low cost carbon sources, such as carob pod extract, industrial glycerol and acetate-rich oxidized wine waste lees. The mixotrophic cultivation of this microalga with wine waste lees alleviated the problems of light shielding observed in photoautotrophic cultures, improving specific growth rate (0.052 h-1) compared with the other organic sources. The fed-batch mixotrophic culture of Chlorella sorokiniana in a 2 L stirred tank reactor, with optimized nutritional conditions, 100 mM of acetate coming from the oxidized wine waste lees and 30 mM of ammonium, produced an algal biomass concentration of 11 g L-1 with a lipid content of 38 % (w/w). This fed-batch strategy has been found to be a very effective means to enhance the biomass and neutral lipid productivity.Research grants from theSpanish (AGL2016-74866-C32R-AEI/FEDER) and European governments(INTERREG VA-POCTEP- 2014-2020; 0055_ALGARED_PLUS_5_E) and the Portuguese Science Foundation (FCT) through the grant UID/MAR/00350/2013 to the CIMA of the University of Algarve. We thank Dr.Molinari from the University of Milan, for kindly providing the Acetobacteracetiistrain. The help of CEIMAR University Excellence Campus is also acknowledged.info:eu-repo/semantics/publishedVersio

Propiedades fisicoquímicas e inmunoquímicas de la ferredoxina-glutamato sintasa y nitrito reductasa del alga eucariótica "Monoraphidium braunii"

El alga eucariótica Monoraphidium braunii muestra actividad glutamato sintasa (GOGAT) con especificidad por ferredoxina (Fd) reducida o por NADH. La actividad NADH-GOGAT incrementa 5,6 veces su nivel de actividad en carencia de fuente nitrogenada. ... 150%; font-family: 'Times New Roman','serif'; font-size: 12pt"> La Fd-GOGAT, monomérica (157 kDa) y localizada en el pirenóide del cloroplasto de este alga, posee máximos de absorción a 280, 375 y 435 NM, indicativos de la presencia de flavinas y una agrupación sulfoférrica, en su molécula. La enzima puede reducirse con un sistema fotoquímico formado por luz, EDTA y 5-DEAZARRIBOFLAVINa. Por su parte, la nitrito reductasa (NIR), también monomérica (63 kDa), muestra máximos de absorción a 280, 385, 573 y 690 NM, indicativos de un Sirohemo y una agrupación sulfoférrica en su molécula. Estudios inmunoquímicos, demuestran la existencia de un dominio común de interacción con Fd, en la Fd-GOGAT y la NIR, e indican la existencia de analogías entre las Fd-GOGATS de algas, cianobacterias y plantas superiores. Complejos covalentes, entre GOGAT y Fd o Flavodoxina (Fld) permiten concluir que la gogat posee dos sitios de interacción con Fd o Fld. La enzima, además, utiliza residuos de lisina y arginina en su interacción con los grupos carboxilos de la Fd o la Fld. Nuestro grupo de trabajo lleva tiempo estudiando la ruta de asimilación de nitrato en algas eucarióticas, y un aspecto ciertamente apasionante son las enzimas dependientes de ferredoxina, como son la nitrato reductasa y la glutamato sintasa. De ahí que el trabajo desarrollado en esta Tesis se haya centrado precisamente en los siguientes puntos:a) Estudio de la actividad glutamato sintasa en extractos crudos de Monoraphidium braunii.b) Purificación y caracterización de la glutamato sintasa dependiente de ferredoxina, así como la nitrato reductasa de

Exploring Nordic microalgae as a potential novel source of antioxidant and bioactive compounds

Nordic microalgae are a group of photosynthetic organisms acclimated to growth at low temperature and in varying light conditions; the subarctic climate offers bright days with moderate temperatures during summer and cold and dark winter months. The robustness to these natural stress conditions makes the species interesting for large-scale cultivation in harsh environments and for the production of high-value compounds. The aim of this study was to explore the ability of nineteen species of Nordic microalgae to produce different bioactive compounds, such as carotenoids or polyphenols. The results showed that some of these strains are able to produce high amounts of carotenoids (over 12 mg·g-1 dry weight) and phenolic compounds (over 20 mg GAE·g-1 dry weight). Based on these profiles, six species were selected for cultivation under high light and cold stress (500 μmol·m-2·s-1 and 10 ˚C). The strains Chlorococcum sp. (MC1) and Scenedesmus sp. (B2–2) exhibited similar values of biomass productivity under standard or stress conditions, but produced higher concentrations of carotenoids (an increase of 40% and 25%, respectively), phenolic compounds (an increase of 40% and 30%, respectively), and showed higher antioxidant capacity (an increase of 15% and 20%, respectively) during stress. The results highlight the ability of these Nordic microalgae as outstanding producers of bioactive compounds, justifying their cultivation at large scale in Nordic environments

Validation of a New Multicistronic Plasmid for the Efficient and Stable Expression of Transgenes in Microalgae

Low stability of transgenes and high variability of their expression levels among the obtained transformants are still pending challenges in the nuclear genetic transformation of microalgae. We have generated a new multicistronic microalgal expression plasmid, called Phyco69, to make easier the large phenotypic screening usually necessary for the selection of high‐expression stable clones. This plasmid contains a polylinker region (PLK) where any gene of interest (GOI) can be inserted and get linked, through a short viral self‐cleaving peptide to the amino terminus of the aminoglycoside 3’‐phosphotransferase (APHVIII) from Streptomyces rimosus, which confers resistance to the antibiotic paromomycin. The plasmid has been validated by expressing a second antibiotic resistance marker, the ShBLE gene, which confers resistance to phleomycin. It has been shown, by RT‐PCR and by phenotypic studies, that the fusion of the GOI to the selective marker gene APHVIII provides a simple method to screen and select the transformants with the highest level of expression of both the APHVIII gene and the GOI among the obtained transformants. Immunodetection studies have shown that the multicistronic transcript generated from Phyco69 is correctly processed, producing independent gene products from a common promoter