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

Evaluación de la resiliencia forestal al fuego mediante la inversión de modelos de transferencia radiativa a partir de imágenes de satélite

[ES] El objetivo de este estudio fue evaluar la resiliencia ingenieril a corto plazo de diversas comunidades de matorral en función de su estrategia regenerativa y la severidad del fuego, dentro del perímetro de un mega-incendio ocurrido en verano de 2017 en el noroeste de la Península Ibérica. Se dispuso de una serie temporal de imágenes de satélite Sentinel-2 para las que se computó la fracción de cubierta vegetal (FVC) para cada pixel mediante la inversión híbrida del modelo de transferencia radiativa (RTM) PROSAIL-D utilizando el algoritmo random forest. Se obtuvo un elevado ajuste para toda la serie temporal (R2 > 0,75), a partir de la validación con datos de campo. Mediante un muestreo de FVC de puntos aleatorios estratificados por tipo de estrategia regenerativa y nivel de severidad del fuego, se determinó la resiliencia de las comunidades de matorral en términos de recuperación de la cobertura utilizando un índice de resiliencia normalizado por impacto y un modelo de regresión lineal. Severidades altas influyeron negativamente en la resiliencia ingenieril a corto plazo de las comunidades de matorral dominadas por especies germinadoras facultativas. En cambio, las comunidades dominadas por especies rebrotadoras alcanzaron valores de cobertura pre-incendio independientemente de la severidad del fuegoEste estudio ha sido financiado por el Ministerio de Economía y Competitividad de España, y el Fondo Europeo de Desarrollo Regional (FEDER), en el marco de los proyectos GESFIRE (AGL2013- 48189-C2-1-R) y FIRESEVES (AGL2017-86075-C2-1-R); y por la Junta de Castilla y León en el marco de los proyectos FIRECYL (LE033U14), SEFIRECYL (LE001P17) y WUIFIRECYL (LE005P20)

Assessing the influence of the hydraulic retention time and carbon/nitrogen ratio on urban wastewater treatment in a new anoxic-aerobic algal-bacterial photobioreactor configuration

Producción CientíficaThe influence of the hydraulic retention time (HRT) (2 and 4 days) and the carbon/nitrogen ratio (C/N) (7, 8 and 9) of the wastewater on the treatment of synthetic domestic wastewater was evaluated in a new anoxic-aerobic algal-bacterial photobioreactor configuration operated at solids retention time of 10 d by biomass recycling and withdrawal. The removal of chemical oxygen demand remained between 84% and 89% regardless of the operational conditions. However, the decrease in the HRT from 4 to 2 d entailed reductions in the removal of total nitrogen (TN) and P-PO43− from 87 ± 2% to 62 ± 2% and from 22 ± 5% to 11 ± 1%, respectively. On the other hand, the decrease in the C/N ratio of the wastewater from 9 to 8 and 7 at a HRT of 2 d induced TN removals of 62 ± 4% and 48 ± 4%, respectively. In contrast, P-PO43- removals unexpectedly increased from 11 ± 1% at a C/N ratio of 9 to 53 ± 3% and 47 ± 5% at C/N ratios of 8 and 7, respectively. Finally, biomass settling and recycling supported the enrichment of an algal-bacterial population with good settleability characteristics (suspended solids removals in the settler ∼98%), being Chlorella vulgaris the dominant microalga specie at a C/N ratio of 9 which was gradually replaced by Phormidium sp., as a result of the reduction in the C/N ratio of the wastewater.Junta de Castilla y León - Fondo Europeo de Desarrollo Regional (projects CLU-2017-09 and UIC 71)CEMIE-Bio (project 247006

A systematic comparison of the potential of microalgae-bacteria and purple phototrophic bacteria consortia for the treatment of piggery wastewater

Producción CientíficaThis study evaluated the performance of two open-photobioreactors operated with microalgae-bacteria (PBR-AB) and purple photosynthetic bacteria (PBR-PPB) consortia during the treatment of diluted (5%) piggery wastewater (PWW) at multiple hydraulic retention times (HRT). At a HRT of 10.6 days, PBR-AB provided the highest removal efficiencies of nitrogen, phosphorus and zinc (87 ± 2, 91 ± 3 and 98 ± 1%), while the highest organic carbon removals were achieved in PBR-PPB (87 ± 4%). The decrease in HRT from 10.6, to 7.6 and 4.1 day caused a gradual deterioration in organic carbon and nitrogen removal, but did not influence the removal of phosphorus and Zn in both photobioreactors. The decrease in HRT caused a severe wash-out of microalgae in PBR-AB and played a key role in the structure of bacterial population in both photobioreactors. In addition, batch biodegradation tests at multiple PWW dilutions (5, 10 and 15%) confirmed the slightly better performance of algal-bacterial systems regardless of PWW dilution.Ministerio de Ciencia, Innovación y Universidades - FEDER (CTQ2017-84006-C3-1-R)Gobierno regional de Castilla y León (UIC 71)EURICA program (Erasmus Mundus Action 2, Strand 1, Lot 15, Grant 2013-2587