CtIP-Specific Roles during Cell Reprogramming Have Long-Term Consequences in the Survival and Fitness of Induced Pluripotent Stem Cells

Acquired genomic instability is one of the major concerns for the clinical use of induced pluripotent stem cells (iPSCs). All reprogramming methods are accompanied by the induction of DNA damage, of which double-strand breaks are the most cytotoxic and mutagenic. Consequently, DNA repair genes seem to be relevant for accurate reprogramming to minimize the impact of such DNA damage. Here, we reveal that reprogramming is associated with high levels of DNA end resection, a critical step in homologous recombination. Moreover, the resection factor CtIP is essential for cell reprogramming and establishment of iPSCs, probably to repair reprogramming-induced DNA damage. Our data reveal a new role for DNA end resection in maintaining genomic stability during cell reprogramming, allowing DNA repair fidelity to be retained in both human and mouse iPSCs. Moreover, we demonstrate that reprogramming in a resection-defective environment has long-term consequences on stem cell self-renewal and differentiation.España, Ministerio de Economía y Competitividad SAF2013-43255-

Sistema de eliminación de metales pesados en aguas mediante microalgas

Publication number: ES2642462 A2 (16.11.2017) Also published as: ES2642462 R1 (29.11.2017) Application number: P201500861 (20.11.2015)La presente invención propone un "sistema de eliminación de metales pesados en aguas mediante microalgas", que utiliza las propiedades de estos microorganismos como material adsorbente y favorecedor de procesos de oxidación y precipitación, y una secuencia de etapas adecuadamente diseñadas para el funcionamiento óptimo del sistema. El proceso propuesto implica dos etapas claramente diferenciadas, la primera de producción en continuo de microalgas y la segunda más novedosa de puesta en contacto del cultivo de microalgas con las aguas de mina mediante sistemas de retención o recirculación de lodos. De esta forma se minimiza la cantidad de microalga necesaria, permitiendo depurar grandes volúmenes de agua contaminada por unidad de volumen de cultivo de microalgas.Universidad de Almerí

Wastewater treatment using microalgae: how realistic a contribution might it be to significant urban wastewater treatment?

Microalgae have been proposed as an option for wastewater treatment since the 1960’s but still this technology has not been expanded to an industrial scale. In this paper, the major factors limiting the performance of these systems are analysed. The composition of the wastewater is highly relevant, and especially the presence of pollutants such as heavy metals and emerging compounds. Biological and engineering aspects are also critical and have to be improved to at least approximate the performance of conventional systems, not just in terms of capacity and efficiency but also in terms of robustness. Finally, the harvesting of the biomass and its processing into valuable products poses a challenge; yet at the same time, an opportunity exists to increase economic profitability. Land requirement is a major bottleneck that can be ameliorated by improving the system’s photosynthetic efficiency. Land requirement has a significant impact on the economic balance but the profits from the biomass produced can enhance these systems’ reliability, especially in small cities

Cadaveric Identification through Macroscopic Analysis of Dental Implants Subjected to High Temperatures-An Experimental Model

The aim of this study was to determine the possibility of identifying a dental implant through the measurement of the apical width and the interspiral distance in a periapical radiograph after being subjected to high temperatures for certain lengths of time. In total, 11 fresh human anatomical models were selected, in which 137 implants were placed. Previous periapical radiographs were performed using parallelizers in each implant. Subsequently, the anatomical models were introduced into a crematory oven at different temperatures and for various durations: 500 °C/15 min, 500 °C/30 min, 700 °C/15 min, 800 °C/15 min, 800 °C/45 min, 500 °C/15 min, 700 °C/15 min, and finally, 1000 °C/120 min. After this, X-rays were taken via a parallel technique, and the apical width and interspiral distance were measured. The implants were disinserted, and the coronal width was used to calculate magnification or possible distortion. All data were analyzed by the Mann–Whitney U test. There were no statistically significant differences for the apical width parameter, except when the temperature was raised to 700 °C/15 min and to 800 °C/45 min. For the interspiral distance parameter, there were no statistically significant differences, except when the implants were subjected to 800 °C/15 min and 1000 °C/120 min. It was determined that there were changes in some groups based on the increase in temperature and exposure time. Neither of the two parameters were completely useful for the identification because some of the groups studied in both variables presented differences, which makes them difficult to identify correctly

Optimisation of Scenedesmus almeriensis production using pig slurry as the sole nutrient source

Pig slurry was used as the sole nutrient source to produce biomass of the microalga Scenedesmus almeriensis using laboratory-scale bubble column photobioreactors. No differences in terms of biomass productivity were observed between fresh and digested pig slurry. The optimum dilution rate to enable the processing of the largest amount of pig slurry per litre was 5%, which led to a biomass productivity rate of 0.68 g·L-1·day-1, comparable to that of the standard growth medium formulated using pure chemicals (0.70 g·L-1·day-1). The inlet N-NH4+ concentration was approximately 180 mg·L-1, with inhibitory effects being observed at concentrations higher than 200 mg·L-1. The N-NH4+, N-NO3-, P-PO43-, and chemical oxygen demand removal rates were 34.1, 0.5, 2.1, and 519.3 mg·L-1·day-1. The observed turbidity of the media did not affect microalgal growth at the studied dilutions. Ozonation effectively reduced the chemical oxygen demand concentration of the media, but no effect on microalgal growth was observed. Overall, pig slurry was an effective nutrient source for the mass production of S. almeriensis, and this strain was shown to be robust with a N-NH4+ tolerance up to 200 mg·L-1 and the potential use in the bioremediation of agro-industrial wastes

Utilization of secondary-treated wastewater for the production of freshwater microalgae

In this work we studied the potential use of secondary-treated wastewater as nutrient source in the production of freshwater microalgae strains. Experiments were performed indoors in semicontinuous mode, at 0.3 day-1, simulating outdoor conditions. We demonstrated that all the tested strains can be produced by using only secondary-treated wastewater as the nutrient source. The utilization of secondary-treated wastewater imposes nutrient-limiting conditions, with maximal biomass productivity dropping to 0.5 g·l-1·day-1and modifies the biochemical composition of the biomass by increasing the amount of lipids and carbohydrates while reducing the biomass protein content. We measured fatty acids content and productivity of up to 25%d.wt. and 110 mg·l-1·day-1, respectively. We demonstrated that all the tested strains were capable of completely removing the nitrogen and phosphorus contained in the secondary-treated wastewater, and while the use of this effluent reduced the cells’ photosynthetic efficiency, the nitrogen and phosphorus coefficient yield increased. Muriellopsis sp. and S. subpicatus were selected as the most promising strains for outdoor production using secondary-treated wastewater as the culture medium; this was not only because of their high productivity but also their photosynthetic efficiency, of up to 2.5%, along with nutrient coefficient yields of up to 96 gbiomass·gN-1 and 166 gbiomass·gP-1. Coupling microalgae production processes to tertiary treatment in wastewater treatment plants makes it possible to recover nutrients contained in the water and to produce valuable biomass, especially where nutrient removal is required prior to wastewater discharge

Effect of microalgae hydrolysate foliar application (Arthrospira platensis and Scenedesmus sp.) on Petunia x hybrida growth

In horticultural practice, accelerated plant development, and particularly earlier flowering, has been reported with microalgae applications. Therefore, the objective of this work was to study the effects of foliar spraying with Scenedesmus sp. and Arthrospira platensis hydrolysates on Petunia x hybrida plant development and leaf nutrient status. Three treatments were tested: T1 (foliar application with water, the control), T2 (foliar application with Arthrospira ) and T3 (foliar application with Scenedesmus). Foliar spraying was applied 5 times (0, 14, 28, 35 and 42 days after transplanting). The concentration of both microalgae was 10 g L-1. At the end of the trial, biometric parameters and nutrient concentration in photosynthetic organs (the leaves) were measured. The results of this assay show that foliar application of Scenedesmus accelerated plant development in terms of higher rates of root growth, leaf and shoot development and earliness of flowering. Arthrospira enhanced the root dry matter, the number of flowers per plant and the water content. Nevertheless, a reduction was found in the conductive tissue (stem+petiole) dry weight with Arthrospira compared with Scenedesmus and the control. The results also show that microalgae hydrolysate supply can improve the plant nutrient status. Based on these results, it is advisable to use Scenedesmus hydrolysates in foliar applications to increase the blooming of Petunia x hybrida

A polyphasic characterisation of Tetradesmus almeriensis sp. nov. (Chlorophyta: Scenedesmaceae)

This article belongs to the Special Issue Extraction, Exploitation and Application of Algae Biomass[EN] The microalga Tetradesmus almeriensis, previously known as Scenedesmus almeriensis, has been isolated and cultivated as a highly productive, fast-growing strain known as a natural source of different products of commercial interest, including bioactive compounds such as lutein. This strain produces up to 40 g·m−2·day−1 of lutein under optimal conditions and is highly recommendable for outdoor production in temperate and warm climates, showing maximal performance at temperatures up to 35 °C with no photo-inhibition taking place with irradiances greater than 1000 μE·m−2·s−1. Morphological and molecular data allow its assignment to the Chlorophycean genus Tetradesmus. The new species can be distinguished from similar Tetradesmus taxa due to its unique combination of features that are seen under light microscopy. We present herein a robust and comprehensive phylogenetic analysis of T. almeriensis, together with several additional Scenedesmaceae species, using a combination of maximum likelihood and Bayesian approaches. Our results confirm T. almeriensis as a distinct species consistently clustering with other ScenedesmaceaeSIThis research is part of the SABANA project founded by the European Union Horizon 2020 Research and Innovation programme under grant agreement No. 72787

Selection of native Tunisian microalgae for simultaneous wastewater treatment and biofuel production

This paper focuses on the selection of native microalgae strains suitable for wastewater treatment and biofuel production. Four Chlorophyceae strains were isolated from North-eastern Tunisia. Their performances were compared in continuous mode at a 0.3 1/day dilution rate. The biomass productivity and nutrient removal capacity of each microalgae strain were studied. The most efficient strain was identified as Scenedesmus sp. and experiments at different dilution rates from 0.2 to 0.8 1/day were carried out. Maximal biomass productivity of 0.92 g/L·day was obtained at 0.6 1/day. The removal of chemical oxygen demand (COD), ammonium and phosphorus was in the range of 92-94%, 61-99% and 93-99%, respectively. Carbohydrates were the major biomass fraction followed by lipids and then proteins. The saponifiable fatty acid content was in the 4.9-13.2% dry biomass range, with more than 50% of total fatty acids being composed of saturated and monosaturated fatty acids