Environmental assessment of a new building envelope material derived from urban agriculture wastes: the case of the tomato plants stems

Purpose: Decarbonizing cities is one of today biggest challenges. In this regard, particular attention has been paid on improving the environmental performance of buildings. In this framework, this work consists in assessing the environmental impact of an innovative building envelope component derived from urban agriculture (UA) wastes. In fact, rooftop UA seems to be a possible solution to the rising food demand due to increasing urban demographic growth. Consequently, rooftop UA wastes need to be treated in sustainable ways. Methods: This study aims to determine the carbon footprint and embodied energy of a new infill wall material, derived from UA wastes produced by a building rooftop greenhouse tomato crop, and evaluate the potential biogenic carbon that such by-product could fix temporally until its end of life. After an initial description of the manufacturing process of the new material, its carbon footprint and embodied energy have been calculated by means of the life cycle assessment (LCA) methodology according to the ISO 14044 and the ISO 14067 guidelines adapted to the analyzed context. In particular, the inventory analysis is based on data collected from the production of samples of the new material at the laboratory scale. Results and discussion: The results of the LCA indicate that, when the biogenic carbon fixed in the UA wastes is considered, a negative carbon footprint of -0.2 kg CO2 eq. per kg of material can be obtained. Hence, it can be assumed that from a life cycle perspective the material is able to fix carbon emissions instead of emitting them. Specifically, for the considered scenario, approximately 0.42 kg CO2 eq./m2 per year could be sequestered. However, the crop area required to produce enough waste to manufacture a unit of material is quite high. Therefore, future studies should focus on individuate solutions to reduce the density of the new component, and also different urban crops with higher waste production rates. Conclusions: The outcomes of the study put in evidence the potential of the new proposed infill wall component in fixing carbon emissions from UA, allowing to also compensate those relating to the production and transportation stages of the component life cycle. Moreover, producing by-products with UA wastes, hence temporally storing the carbon fixed by crops, may contribute to reduce the carbon cycles speed conversely to traditional waste management solutions, other than lower new raw materials depletion

Molecular diversity and distribution of marine fungi across 130 European environmental samples.

Journal ArticleEnvironmental DNA and culture-based analyses have suggested that fungi are present in low diversity and in low abundance in many marine environments, especially in the upper water column. Here, we use a dual approach involving high-throughput diversity tag sequencing from both DNA and RNA templates and fluorescent cell counts to evaluate the diversity and relative abundance of fungi across marine samples taken from six European near-shore sites. We removed very rare fungal operational taxonomic units (OTUs) selecting only OTUs recovered from multiple samples for a detailed analysis. This approach identified a set of 71 fungal 'OTU clusters' that account for 66% of all the sequences assigned to the Fungi. Phylogenetic analyses demonstrated that this diversity includes a significant number of chytrid-like lineages that had not been previously described, indicating that the marine environment encompasses a number of zoosporic fungi that are new to taxonomic inventories. Using the sequence datasets, we identified cases where fungal OTUs were sampled across multiple geographical sites and between different sampling depths. This was especially clear in one relatively abundant and diverse phylogroup tentatively named Novel Chytrid-Like-Clade 1 (NCLC1). For comparison, a subset of the water column samples was also investigated using fluorescent microscopy to examine the abundance of eukaryotes with chitin cell walls. Comparisons of relative abundance of RNA-derived fungal tag sequences and chitin cell-wall counts demonstrate that fungi constitute a low fraction of the eukaryotic community in these water column samples. Taken together, these results demonstrate the phylogenetic position and environmental distribution of 71 lineages, improving our understanding of the diversity and abundance of fungi in marine environments.Gordon and Betty Moore FoundationDeutsche ForschungsgemeinschaftMarie Curie International Outgoing FellowshipMarie Curie Intra-European FellowshipEMBO Long-Term fellowshi

Gene expression during bacterivorous growth of a widespread marine heterotrophic flagellate

Phagocytosis is a fundamental process in marine ecosystems by which prey organisms are consumed and their biomass incorporated in food webs or remineralized. However, studies searching for the genes underlying this key ecological process in free-living phagocytizing protists are still scarce, in part due to the lack of appropriate ecological models. Our reanalysis of recent molecular datasets revealed that the cultured heterotrophic flagellate Cafeteria burkhardae is widespread in the global oceans, which prompted us to design a transcriptomics study with this species, grown with the cultured flavobacterium Dokdonia sp. We compared the gene expression between exponential and stationary phases, which were complemented with three starvation by dilution phases that appeared as intermediate states. We found distinct expression profiles in each condition and identified 2056 differentially expressed genes between exponential and stationary samples. Upregulated genes at the exponential phase were related to DNA duplication, transcription and translational machinery, protein remodeling, respiration and phagocytosis, whereas upregulated genes in the stationary phase were involved in signal transduction, cell adhesion, and lipid metabolism. We identified a few highly expressed phagocytosis genes, like peptidases and proton pumps, which could be used to target this ecologically relevant process in marine ecosystems

New Insights into the Diversity of Marine Picoeukaryotes

Over the last decade, culture-independent surveys of marine picoeukaryotic diversity based on 18S ribosomal DNA clone libraries have unveiled numerous sequences of novel high-rank taxa. This newfound diversity has significantly altered our understanding of marine microbial food webs and the evolution of eukaryotes. However, the current picture of marine eukaryotic biodiversity may be significantly skewed by PCR amplification biases, occurrence of rDNA genes in multiple copies within a single cell, and the capacity of DNA to persist as extracellular material. In this study we performed an analysis of the metagenomic dataset from the Global Ocean Survey (GOS) expedition, seeking eukaryotic ribosomal signatures. This PCR-free approach revealed similar phylogenetic patterns to clone library surveys, suggesting that PCR steps do not impose major biases in the exploration of environmental DNA. The different cell size fractions within the GOS dataset, however, displayed a distinct picture. High protistan diversity in the <0.8 µm size fraction, in particular sequences from radiolarians and ciliates (and their absence in the 0.8–3 µm fraction), suggest that most of the DNA in this fraction comes from extracellular material from larger cells. In addition, we compared the phylogenetic patterns from rDNA and reverse transcribed rRNA 18S clone libraries from the same sample harvested in the Mediterranean Sea. The libraries revealed major differences, with taxa such as pelagophytes or picobiliphytes only detected in the 18S rRNA library. MAST (Marine Stramenopiles) appeared as potentially prominent grazers and we observed a significant decrease in the contribution of alveolate and radiolarian sequences, which overwhelmingly dominated rDNA libraries. The rRNA approach appears to be less affected by taxon-specific rDNA copy number and likely better depicts the biogeochemical significance of marine protists

Regularidades estacionales en la producción primaria y los parámetros fotosintéticos en una estación costera del NO Mediterráneo

We carried out monthly photosynthesis-irradiance (P-E) experiments with the 14C-method for 12 years (2003–2014) to determine the photosynthetic parameters and primary production of surface phytoplankton in the Blanes Bay Microbial Observatory, a coastal sampling station in the NW Mediterranean Sea. Our goal was to obtain seasonal trends and to establish the basis for detecting future changes of primary production in this oligotrophic area. The maximal photosynthetic rate PBmax ranged 30-fold (0.5-15 mg C mg Chl a–1 h–1), averaged 3.7 mg C mg Chl a–1 h–1 (±0.25 SE) and was highest in August and lowest in April and December. We only observed photoinhibition twice. The initial or light-limited slope of the P-E relationship, αB, was low, averaging 0.007 mg C mg Chl a–1 h–1 (μmol photons m–2 s–1)–1 (±0.001 SE, range 0.001-0.045) and showed the lowest values in spring (April-June). The light saturation parameter or saturation irradiance, EK, averaged 711 μmol photons m–2 s–1 (± 58.4 SE) and tended to be higher in spring and lower in winter. Phytoplankton assemblages were typically dominated by picoeukaryotes in early winter, diatoms in late autumn and late winter, dinoflagellates in spring and cyanobacteria in summer. Total particulate primary production averaged 1.45 mg C m-3 h–1 (±0.13 SE) with highest values in winter (up to 8.50 mg C m-3 h–1) and lowest values in summer (summer average, 0.30 mg C m-3 h–1), while chlorophyll-specific primary production averaged 2.49 mg C mg Chl a–1 h–1 (±0.19, SE) and peaked in summer (up to 12.0 mg C mg Chl a–1 h–1 in August). 14C-determined phytoplankton growth rates varied between ca. 0.3 d–1 in winter and 0.5 d–1 in summer and were within 60-80% of the maximal rates of growth, based on PBmax. Chlorophyll a was a good predictor of primary production only in the winter and autumn. Seasonality appeared to explain most of the variability in the studied variables, while phytoplankton composition played a minor role. Daily integrated primary production was fairly constant throughout the year: similar to previous oxygen-based estimates in winter but considerably lower than these in summer. The difference between 14C- and oxygen-based estimates of primary production could be explained by community respiration. Annually integrated primary production amounted to a rather modest 48 g C m–2 yr–1 (equivalent to 130 mg C m–2 d–1). Although no interannual patterns were detected, our work soundly establishes the seasonal trends for the coastal NW Mediterranean, therefore setting the basis for future detection of change.Hemos llevado a cabo mediciones mensuales de la relación entre fotosíntesis e irradiancia (curvas P-E) con el método del 14C durante 12 años (2003-2014), para obtener los parámetros fotosintéticos y la producción primaria del fitoplancton superficial en el Observatorio Microbiano de la Bahía de Blanes, una estación de muestreo costera en el noroeste del Mediterráneo. Nuestro objetivo era determinar las tendencias estacionales y establecer la línea de base para detectar cambios futuros de la producción primaria en esta área oligotrófica. La tasa fotosintética máxima PBmaxosciló 30 veces (0.5 a 15 mg C mg Chl a–1 h–1), con un promedio de 3.7 mg C mg Chl a–1 h–1 (±0.25, error estándar), y fue máxima en agosto y mínima en abril y diciembre. Sólo se observó fotoinhibicion dos veces. La pendiente inicial de la curva P-E, αB, fue baja, con un promedio de 0.007 mg C mg Chl a–1 h–1 (µmol fotones m–2 s–1)–1 (error estándar ±0.001, rango de 0.001-0.045) y presentó los valores más bajos en primavera (abril-junio). El parámetro de saturación de irradiancia, EK, presentó un promedio de 711 µmol fotones m–2 s–1 (±58.4, error estándar) y tendió a ser mayor en primavera y menor en invierno. El fitoplancton estuvo típicamente dominado por picoeucariotas a principios de invierno, diatomeas a finales de otoño y en el invierno avanzado, dinoflagelados en primavera, y cianobacterias en verano. La producción primaria particulada total promedió 1.45 m–3 h–1 (±0.13 error estándar) con máximos en invierno (hasta 8.50 mg C m–3 h–1) y mínimos en verano (media en verano, 0.30 mg C m–3 h–1), mientras que la producción primaria por unidad de clorofila promedió 2.49 mg C mg Chl a–1 h–1 (±0.19, error estándar) y alcanzó su punto máximo en verano (hasta 12.0 mg C mg Chl a–1 h–1 en agosto). Las tasas de crecimiento del fitoplancton determinadas por 14C oscilaron entre ca. 0.3 d–1 en invierno y 0.5 d–1 en verano, siendo 60-80% de las tasas máximas de crecimiento basadas en los valores de PBmax. La clorofila a resultó ser un buen predictor de la producción primaria sólo en el invierno y el otoño. La estacionalidad explica la mayor parte de la variabilidad en las variables estudiadas, mientras que la composición del fitoplancton juega un papel menor. La producción primaria integrada diaria fue bastante constante durante todo el año, similar a estimaciones anteriores con mediciones de oxígeno en invierno, pero considerablemente más bajas en verano. La diferencia entre las estimaciones de la producción primaria por 14C y las estimaciones en base al oxígeno podrían explicarse por la respiración de la comunidad. Anualmente la producción primaria integrada ascendió a valores más bien modestos de 48 g C m–2 año–1 (equivalentes a 130 mg C m–2 d–1). Aunque no se detectaron patrones interanuales, nuestro trabajo establece las tendencias estacionales para la producción primaria en el litoral Mediterráneo noroccidental, y supone la línea de base para la detección de cambios futuros

Large-scale ocean connectivity and planktonic body size

Villarino, Ernesto ... et al.-- 13 pages, 5 figures, 5 tables, supplementary material https://dx.doi.org/10.1038/s41467-017-02535-8Global patterns of planktonic diversity are mainly determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size play in determining spatial patterns of diversity remains unclear. Here we analyse spatial community structure - β-diversity - for several planktonic and nektonic organisms from prokaryotes to small mesopelagic fishes collected during the Malaspina 2010 Expedition. β-diversity was compared to surface ocean transit times derived from a global circulation model, revealing a significant negative relationship that is stronger than environmental differences. Estimated dispersal scales for different groups show a negative correlation with body size, where less abundant large-bodied communities have significantly shorter dispersal scales and larger species spatial turnover rates than more abundant small-bodied plankton. Our results confirm that the dispersal scale of planktonic and micro-nektonic organisms is determined by local abundance, which scales with body size, ultimately setting global spatial patterns of diversityThis research was funded by the project Malaspina 2010 Circumnavigation Expedition (Consolider-Ingenio 2010, CSD2008-00077) and cofounded by the Basque Government (Department Deputy of Agriculture, Fishing and Food Policy). [...] E.V. was supported by a PhD Scholarship granted by the Iñaki Goenaga−Technology Centres FoundationPeer Reviewe

Disentangling the mechanisms shaping the surface ocean microbiota

BACKGROUND: The ocean microbiota modulates global biogeochemical cycles and changes in its configuration may have large-scale consequences. Yet, the underlying ecological mechanisms structuring it are unclear. Here, we investigate how fundamental ecological mechanisms (selection, dispersal and ecological drift) shape the smallest members of the tropical and subtropical surface-ocean microbiota: prokaryotes and minute eukaryotes (picoeukaryotes). Furthermore, we investigate the agents exerting abiotic selection on this assemblage as well as the spatial patterns emerging from the action of ecological mechanisms. To explore this, we analysed the composition of surface-ocean prokaryotic and picoeukaryotic communities using DNA-sequence data (16S- and 18S-rRNA genes) collected during the circumglobal expeditions Malaspina-2010 and TARA-Oceans. RESULTS: We found that the two main components of the tropical and subtropical surface-ocean microbiota, prokaryotes and picoeukaryotes, appear to be structured by different ecological mechanisms. Picoeukaryotic communities were predominantly structured by dispersal-limitation, while prokaryotic counterparts appeared to be shaped by the combined action of dispersal-limitation, selection and drift. Temperature-driven selection appeared as a major factor, out of a few selected factors, influencing species co-occurrence networks in prokaryotes but not in picoeukaryotes, indicating that association patterns may contribute to understand ocean microbiota structure and response to selection. Other measured abiotic variables seemed to have limited selective effects on community structure in the tropical and subtropical ocean. Picoeukaryotes displayed a higher spatial differentiation between communities and a higher distance decay when compared to prokaryotes, consistent with a scenario of higher dispersal limitation in the former after considering environmental heterogeneity. Lastly, random dynamics or drift seemed to have a more important role in structuring prokaryotic communities than picoeukaryotic counterparts. CONCLUSIONS: The differential action of ecological mechanisms seems to cause contrasting biogeography, in the tropical and subtropical ocean, among the smallest surface plankton, prokaryotes and picoeukaryotes. This suggests that the idiosyncrasy of the main constituents of the ocean microbiota should be considered in order to understand its current and future configuration, which is especially relevant in a context of global change, where the reaction of surface ocean plankton to temperature increase is still unclear. Video Abstract

The Large Magellanic Cloud stellar content with SMASH I. Assessing the stability of the Magellanic spiral arms

The Large Magellanic Cloud (LMC) is the closest and most studied example of an irregular galaxy. Among its principal defining morphological features, its off-centred bar and single spiral arm stand out, defining a whole family of galaxies known as the Magellanic spirals (Sm). These structures are thought to be triggered by tidal interactions and possibly maintained via gas accretion. However, it is still unknown whether they are long-lived stable structures. In this work, by combining photometry that reaches down to the oldest main sequence turn-off in the colour-magnitude diagrams (CMD, up to a distance of ∼4.4 kpc from the LMC centre) from the SMASH survey and CMD fitting techniques, we find compelling evidence supporting the long-term stability of the LMC spiral arm, dating the origin of this structure to more than 2 Gyr ago. The evidence suggests that the close encounter between the LMC and the Small Magellanic Cloud (SMC) that produced the gaseous Magellanic Stream and its Leading Arm also triggered the formation of the LMC’s spiral arm. Given the mass difference between the Clouds and the notable consequences of this interaction, we can speculate that this should have been one of their closest encounters. These results set important constraints on the timing of LMC-SMC collisions, as well as on the physics behind star formation induced by tidal encounters.AEI/FEDER, UE AYA201789076-P AYA2016-77237-C3-1-P AYA2015-63810-PMinisterio de Ciencia, Innovacion y Universidades (MCIU), through Juan de la Cierva - Formacion grant FJCI-2016-30342Consejeria de Economia, Industria, Comercio y Conocimiento of the Canary Islands Autonomous Community, through Regional BudgetSpanish Public State Employment Service (SEPE)National Science Foundation (NSF) AST 1655677 AST-1909497Premiale INAF "MITIC"Ministry of Economy and Competitiveness of Spain AYA201342781PINFN (Iniziativa specifica TAsP)European Research Council (ERC) 682115"Centre of Excellence Severo Ochoa" award SEV-2017-0709Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1181797Max Planck Society through a Partner Group grantComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT PIA/BASAL AFB-170002Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1170364AYA2016-81065-C2-2PGC2018-095049-B-C2

Sample richness and genetic diversity as drivers of chimera formation in nSSU metagenetic analyses

Eukaryotic diversity in environmental samples is often assessed via PCR-based amplification of nSSU genes. However, estimates of diversity derived from pyrosequencing environmental data sets are often inflated, mainly because of the formation of chimeric sequences during PCR amplification. Chimeras are hybrid products composed of distinct parental sequences that can lead to the misinterpretation of diversity estimates. We have analyzed the effect of sample richness, evenness and phylogenetic diversity on the formation of chimeras using a nSSU data set derived from 454 Roche pyrosequencing of replicated, large control pools of closely and distantly related nematode mock communities, of known intragenomic identity and richness. To further investigate how chimeric molecules are formed, the nSSU gene secondary structure was analyzed in several individuals. For the first time in eukaryotes, chimera formation proved to be higher in both richer and more genetically diverse samples, thus providing a novel perspective of chimera formation in pyrosequenced environmental data sets. Findings contribute to a better understanding of the nature and mechanisms involved in chimera formation during PCR amplification of environmentally derived DNA. Moreover, given the similarities between biodiversity analyses using amplicon sequencing and those used to assess genomic variation, our findings have potential broad application for identifying genetic variation in homologous loci or multigene families in general