Departamento de Biología Animal, Biología Vegetal y Ecología

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A multi-proxy framework to detect insect defoliations in tree rings: a case study on pine processionary
(Frontiers, 2023) Camarero, Jesús J.; Colangelo, M.; Rita, A.; Hevia, Andrea; Pizarro, M.; Voltas, Jordi
Assessing and reconstructing the impacts of defoliation caused by insect herbivores on tree growth, carbon budget and water use, and differentiating these impacts from other stresses and disturbances such as droughts requires multi-proxy approaches. Here we present a methodological framework to pinpoint the impacts of pine processionary moth (Thaumetopoea pityocampa), a major winter-feeding defoliator, on tree cover (remote-sensing indices), radial growth and wood features (anatomy, density, lignin/carbohydrate ratio of cell walls, d13C and d18O of wood cellulose) of drought-prone pine (Pinus nigra) forests in north-eastern Spain. We compared host defoliated (D) and coexisting non-defoliated (ND) pines along with non-host oaks (Quercus faginea) following a strong insect outbreak occurring in 2016 at two climatically contrasting sites (cool-wet Huesca and warm-dry Teruel). Changes in tree-ring width and wood density were analyzed and their responses to climate variables (including a drought index) were compared between D and ND trees. The Normalized Difference Infrared Index showed reductions due to the outbreak of –47.3% and –55.6% in Huesca and Teruel, respectively. The D pines showed: a strong drop in growth (–96.3% on average), a reduction in tracheid lumen diameter (–35.0%) and lower lignin/carbohydrate ratios of tracheid cell-walls. Both pines and oaks showed synchronous growth reductions during dry years. In the wet Huesca site, lower wood d13C values and a stronger coupling between d13C and d18O were observed in D as compared with ND pines. In the dry Teruel site, the minimum wood density of ND pines responded more negatively to spring drought than that of D pines. We argue that multi-proxy assessments that combine several variables have the potential to improve our ability to pinpoint and reconstruct insect outbreaks using tree-ring data.
A Novel Expansin Protein from the White-Rot Fungus Schizophyllum commune
(PLOS, 2015) Batista-García, Ramón; Tovar-Herrera, Omar; Sánchez-Carbente, María; Iracheta, María Magdalena; Arévalo-Niño, Katiushka; Folch, Jorge Luis
A novel expansin protein (ScExlx1) was found, cloned and expressed from the Basidiomycete fungus Schizophylum commune. This protein showed the canonical features of plant expansins. ScExlx1 showed the ability to form “bubbles” in cotton fibers, reduce the size of avicel particles and enhance reducing sugar liberation from cotton fibers pretreated with the protein and then treated with cellulases. ScExlx1 was able to bind cellulose, birchwood xylan and chitin and this property was not affected by different sodium chloride concentrations. A novel property of ScExlx1 is its capacity to enhance reducing sugars (N-acetyl glucosamine) liberation from pretreated chitin and further added with chitinase, which has not been reported for any expansin or expansin-like protein. To the best of our knowledge, this is the first report of a bona fide fungal expansin found in a basidiomycete and we could express the bioactive protein in Pichia pastoris.
A novel TctA citrate transporter from an activated sludge metagenome: Structural and mechanistic predictions for the TTT family
(2014) Batista-García, Ramón; Sánchez-Reyes, Ayixon; Millán, César; González-Zuñiga, Víctor Manuel; Folch, Jorge Luis; Juárez-Ramírez, Soledad
We isolated a putative citrate transporter of the tripartite tricarboxylate transporter (TTT) class from a metagenomic library of activated sludge from a sewage treatment plant. The transporter, dubbed TctA_ar, shares ~50% sequence identity with TctA of Comamonas testosteroni (TctA_ct) and other b-Proteobacteria, and contains two 20-amino acid repeat signature sequences, considered a hallmark of this particular transporter class. The structures for both TctA_ar and TctA_ct were modeled with I-TASSER and two possible structures for this transporter family were proposed. Docking assays with citrate resulted in the corresponding sets of proposed critical residues for function. These models suggest functions for the 20-amino acid repeats in the context of the two different architectures. This constitutes the first attempt at structure modeling of the TTT family, to the best of our knowledge, and could aid functional understanding of this little-studied family.
Biology and management of sarcoptic mange in wild Caprinae populations.
(John Wiley & Sons Ltd., 2121-01) Pérez-Jiménez, Jesús María; Granados, José Enrique; Espinosa-Cerrato, José; Ráez-Bravo, Arián; López-Olvera, Jorge Ramón; Rossi, Luca; Meneguz, Pier Giuseppe; Angelone, Samer; Fandos, Paulino; Casimiro-Soriguer-Escofet, Ramón
Sarcoptic mange is a cosmopolitan disease affecting the skin of domestic and wild mammalian species and humans as well. In Eurasia, sarcoptidosis (also known as sarcoptic mange or scabies) affects mountain ungulates (Caprinae) among other wild hosts, and epizootic outbreaks induce variable mortality rates. This fact, coupled with the important ecological and socio-economic values of such mammalian hosts, resulted in many research projects being focused on addressing ecological, physiological, behavioural, genetic, and pathological effects of the disease. Nevertheless, information about management of sarcoptic mange in free-ranging populations is scarce and scattered, with contradictory results and a lack of consensus on basic aspects of the disease. In this review, we summarise knowledge on the effects of sarcoptic mange in wild Caprinae, at individual, pathological and population epidemiological levels, as well as on the current tools and management strategies for its detection, diagnosis, prevention, and control. Disease spread in naïve populations is ca. 6 km year−1, and the mortality rate can be >95%. Tools for monitoring the disease include visual diagnosis, photographic traps, trained dogs, thermography, immunodiagnostics, molecular tools, radiocollars, and epidemiological modelling. Options for management include eradication, control, and prevention of the disease; biosecurity and prevention of spread to humans can be achieved by careful hygiene methods. Sarcoptic mange is a natural, biological factor controlling host population numbers and dynamics in Caprinae, so goals and strategies for its management in wild populations must be set accordingly. Specific management programmes for preventing and controlling sarcoptic mange in wild Caprinae populations must be based on reliable epidemiological data. More research is needed to provide evidence-based policies. The efficacy and safety of various management approaches remain to be tested experimentally.
Characterization of Lignocellulolytic Activities from a Moderate Halophile Strain of Aspergillus caesiellus Isolated from a Sugarcane Bagasse Fermentation
(PLOS ONE, 2014-08-27) Batista-García, Ramón; Balcázar, Edgar; Miranda, Estefan; Sánchez-Reyes, Ayixon; Cuervo, Laura; Aceves, Denise; Atriztán, Karina; Morales-Herrera, Catalina; Rodríguez-Hernández, Rocío; Folch, Jorge Luis
A moderate halophile and thermotolerant fungal strain was isolated from a sugarcane bagasse fermentation in the presence of 2 M NaCl that was set in the laboratory. This strain was identified by polyphasic criteria as Aspergillus caesiellus. The fungus showed an optimal growth rate in media containing 1 M NaCl at 28°C and could grow in media added with up to 2 M NaCl. This strain was able to grow at 37 and 42°C, with or without NaCl. A. caesiellus H1 produced cellulases, xylanases, manganese peroxidase (MnP) and esterases. No laccase activity was detected in the conditions we tested. The cellulase activity was thermostable, halostable, and no differential expression of cellulases was observed in media with different salt concentrations. However, differential band patterns for cellulase and xylanase activities were detected in zymograms when the fungus was grown in different lignocellulosic substrates such as wheat straw, maize stover, agave fibres, sugarcane bagasse and sawdust. Optimal temperature and pH were similar to other cellulases previously described. These results support the potential of this fungus to degrade lignocellulosic materials and its possible use in biotechnological applications.
Climate variability of the southern Amazon inferred by a multi-proxy tree-ring approach using Cedrela fissilis Vell.
(Elsevier, 2023-05-01) Ortega-Rodríguez, Daigard Ricardo; Sánchez-Salguero, Raúl; Hevia, Andrea; Granato-Souza, Daniela; Cintra, Bruno B.L.; Hornink, Bruna; Andreu-Hayles, Laia; Assis-Pereira, Gabriel; Roig, Fidel Alejandro; Tomazello-Filho, Mario
The analysis of climate variability and development of reconstructions based on tree-ring records in tropical forests have been increasing in recent decades. In the Amazon region, ring width and stable isotope long-term chronologies have been used for climatic studies, however little is known about the potential of wood traits such as density and chemical concentrations. In this study, we used well-dated rings of Cedrela fissilis Vell. from the drought-prone southern Amazon basin to assess the potential of using inter-annual variations of annually-resolved ring width, wood density, stable oxygen isotope (δ18OTR) measured in tree-ring cellulose and concentration of Sulfur (STR) and Calcium (CaTR) in xylem cells to study climate variability. During wet years, Cedrela fissilis produced wider and denser rings with higher CaTR and lower STR, as well as depleted δ18OTR values. During dry years, a wider range of responses was observed in growth, density and STR, while lower CaTR and enriched δ18OTR values were found. The annual centennial chronologies spanning from 1835 to 2018 showed good calibration skills for reconstructing local precipitation, evapotranspiration (P-PET), Amazon-wide rainfall, as well as climate modes related to sea surface temperature (SST) anomalies such as El Niño South Oscillation (ENSO), Tropical Northern Atlantic (TNA), and the Western Hemisphere Warm Pool (WHWP) oscillations. CaTR explained 42 % of the variance of local precipitation (1975–2018), RW explained 30 % of the P-PET variance (1975–2018), while δ18OTR explained 60 % and 57 % of the variance of Amazon rainfall (1960–2018) and El Niño 3.4 (1920–2018), respectively. Our results show that a multi-proxy tropical tree-ring approach can be used for high-reliable reconstructions of climate variability over Amazon basin at inter-annual and multidecadal time scales.
Coinfection patterns in the ectoparasitic community affecting the Iberian ibex Capra pyrenaica
(BMC (Springer-Nature), 2023-05) Fernández-Muñoz, María J.; Castillo-Contreras, Raquel; Pérez, Jesús M.; Granados, José E.; Márquez, Francisco J.; López-Montoya, Antonio J.
Background: Sarcoptic mange is one of the main parasitic diseases affecting Iberian ibex Capra pyrenaica. Scabietic animals suffer a decline in body condition and reproductive fitness and in severe cases may die. Although several previous studies of the pathology of this disease and the physiological changes it produces in ibex have been carried out in recent years, our knowledge of the relationship between Sarcoptes scabiei and other ectoparasites of this host is still limited. Methods: We analysed 430 Iberian ibex skin samples. Ectoparasites were removed, counted and identified. Mite (Sarcoptes scabiei) numbers were obtained after digesting the skin samples in a 5% KOH solution. We modelled mite numbers in terms of host sex and age, site, year, season and the presence of other ectoparasites such as ticks and lice using generalized linear mixed models (GLMMs) and ectoparasite co-occurrence patterns using two different models: the probabilistic model species co-occurrence and general linear latent variable model (GLLVM). Results: The ectoparasite community was mainly composed of S. scabiei, six ticks (Haemaphysalis sulcata, H. punctata, Rhipicephalus bursa, R. turanicus, Dermacentor marginatus and Ixodes ricinus) and two lice (Bovicola crassipes and Linognathus stenopsis). Adult male ibex harboured more mites than females. Mite numbers varied greatly spatially and seasonally and increased with the presence of other parasites. Some positive co-occurrence relationships between pairs of different ectoparasites were observed, particularly between ticks. The presence of S. scabiei negatively affected lice and H. sulcata numbers. Conclusions: Sarcoptic mange has spread above all in ibex populations in and around the Mediterranean Basin, where it is now found in almost a third of its host’s range. Mite numbers varied seasonally and spatially and were higher in male hosts. The presence of S. scabiei had a negative effect on lice numbers but favoured the presence of ticks.
Daphne, la Naturaleza al Rescate: las SbN contra los contaminantes
(2024-09-27) Jiménez-Melero, Raquel; López-Valcárcel, María Eugenia; Parra-Anguita, Gema
Daphne, una niña interesada en el medioambiente y en la Ciencia, nos explica qué son las Soluciones Basadas en la Naturaleza y cómo estas nos pueden ayudar a retirar los fármacos de las aguas residuales. De una forma amena y sencilla, este cómic nos acerca el trabajo de los científicos y las científicas en la búsqueda de soluciones ante una de las principales crisis ambientales: la contaminación de las aguas. Esta pequeña pieza de divulgación científica se enmarca dentro del proyecto "Soluciones basadas en la Naturaleza frente a contaminantes emergentes: Protegiendo las aguas para la Transición Ecológica (NbSPRO-TE)" financiado por el Ministerio de Ciencia e Innovación en su convocatoria 2021 de «Proyectos de Transición Ecológica y Transición Digital» .
Depósito captador de lluvia para riego con efecto protector tipo planta nodriza
(OEMP, 2011-11-29) Muñoz-Rodríguez, Juan José; García-Fuentes, Antonio
Depósito captador de lluvia para riego con efecto protector tipo nodriza, que comprende una estructura cilíndrica con malla de sombreado y un depósito de agua (D), con una tapadera cóncava (T), con una válvula antirretorno que permite la entrada por gravedad del agua de lluvia, conectado dicho depósito a un tubo de riego por goteo, que puede estar controlado por un temporizador o un dispositivo de descarga retardada, con posibilidad de instalación de un mecanismo fotosensible. El depósito puede tener una prolongación a modo de visera hecha de material microperforado, y puede estar conectado en serie con otros depósitos análogos. El dispositivo planteado se compone de dos componentes. El primer componente es un depósito capaz de almacenar agua, recoger agua procedente de la precipitación evitando su pérdida y suministrarla a una planta. El suministro de agua se realiza paulatinamente, mediante un mecanismo retardado tras las precipitaciones, de tal forma que además de aumentar la cantidad de agua suministrada a la planta, aumenta el periodo de tiempo en el que el agua está disponible para la planta, manteniendo el suelo húmedo y aumentando el balance de número de días de lluvia/días secos. Así la planta recibe un aporte hídrico no sólo en los días de lluvia, sino también en los días posteriores, procedente del agua recogida en el depósito. El segundo componente es una estructura capaz de suministrar sombra y protección mecánica a una planta y, de este modo, reducir el exceso de radiación solar, la acción perjudicial de inclemencias meteorológicas y/o animales herbívoros. Esta estructura está diseñada para no reducir el aporte hídrico natural que recibiría la planta.
Development of resistance to sarcoptic mange in ibex.
(John Wiley & Sons, Inc, 2022-07) Pérez, Jesús M.; López-Montoya, Antonio J.; Cano_Manuel, Francisco J.; Soriguer, Ramón C.; Fandos, Paulino; Granados, José E.
Sarcoptic mange affects mammal host species worldwide and, particularly, wild Caprinae throughout much of Eurasia. In the Iberian Peninsula, several outbreaks of sarcoptic mange in Iberian ibex (Capra pyrenaica) have been reported since the 1980s. Using data from a period of long-term monitoring and a seasonal autoregressive integrated moving average (SARIMA)-generalized autoregressive conditional heteroscedasticity (GARCH) model approach, we performed a time-series analysis of the monthly prevalence of sarcoptic mange in the Iberian ibex population in Sierra Nevada Natural Space (S Spain). In January 2003–March 2021, we documented a significant negative trend in sarcoptic mange prevalence, albeit with some interannual peaks. These findings can only be explained if a certain level of resistance to sarcoptic mange exists in hosts that, along with other factors, could provoke this reduced prevalence. Prevalence values varied seasonally, with maximum values in spring and minimum values at the end of summer, which may be due to factors linked to climate, host behavior, and endocrine activity. Our model predicts that the prevalence of sarcoptic mange in the Iberian ibex will continue to decrease over the next 2 years. Despite the inherent challenges involved, the diagnosing and monitoring of wildlife diseases remain a pivotal part of obtaining reliable epidemiological data and designing appropriate management strategies.
Ecotoxicological assessment of the effects of fluoxetine on Daphnia magna based on acute toxicity, multigenerational reproduction effects, and attraction-repellence responses.
(2023-01) Stremmel, Helmut; Weiss, Linda; Ramos-Rodríguez, Eloísa; Araújo, Cristiano; Parra-Anguita, Gema
Fluoxetine, a common pharmaceutical used as an antidepressant, is already considered potentially hazardous to biota due to its increasing use and detection in European, North American, and Asian rivers. We studied the effects of fluoxetine on Daphnia magna, as we hypothesized that fluoxetine might have harmful effects, short and long-term, at different levels: survival, behaviour, and reproduction (offspring production). We applied two different approaches: (i) a scenario at environmentally relevant concentrations (0.1–1.0 μg/L) and (ii) a scenario simulating a future worsening of contamination (1–800 μg/L) until the reach of lethal concentrations. In the former, we examined whether there are multigenerational effects on reproduction and on the avoidance/colonisation behaviour in previously exposed populations. In the latter, three responses were assessed: survival, avoidance behaviour and reproduction. We did not detect differences in the reproduction output of D. magna among the treatments over the three generations examined. Irrespective of the multigenerational treatment, D. magna colonised the environments with fluoxetine in a similar way. In the second scenario, we determined the lethal concentration for 50% of the population (96 h-LC50 = 365 μg/L), which, in spite of the toxic effect, was attractive to organisms during the avoidance tests (24 h); in fact, D. magna were attracted (no repellence) even to the highest concentrations of fluoxetine tested (800 μg/L). Lastly, in a 21-day chronic toxicity test the reproduction output of D. magna increased with higher concentrations of fluoxetine. This effect might be related to the fact that the organisms in the contaminated treatment began their first reproduction earlier, when compared to that in the control treatments. In conclusion, this study discusses an identified hazard for aquatic biota due to the fluoxetine attraction effect and a predictive assessment of the consequences expected if its indiscriminate use increases.
Environmental forensics evaluation of residual soybean sludge using trees of Brazilian savannah
(Elsevier B.V., 2023-12-20) Roquette, J.G.; Ortega-Rodriguez, D. R.; Portal-Cahuana, L.A.; de Almeida Lobo, F.; Hevia, Andrea; Sánchez-Salguero, Raúl; Wallace Pereira de Carvalho, H.; Tomazello-Filho, M.
Truck and train are the primary transport means for soybean shipments to national or international markets from Brazil. Substantial amounts of grain residues are dispersed throughout the transport and may accumulate in various places by the runoff. The objective of this study was to evaluate the contamination and mortality of Brazilian savannah trees due to the accumulation of soybean runoff that comes from a grain storage yard. Xylem samples were collected from 28 dead trees in a forest where residues severely polluted the natural environment. Increment cores at breast height were also taken from 25 living trees for control procedure. All samples were analyzed by X-ray densitometry and microfluorescence (XRF) techniques. No differences were observed in the xylem densitometry profile from bark to pith between dead and living trees, indicating that the stagnation in cell production and tree growth occurred drastically after the accumulation of soybean residual sludge, which was confirmed by temporal analysis of satellite images. Significantly higher S, P, Ca and Fe concentrations were observed close to the bark in dead trees. The roots of dead trees accumulated higher amounts of Al, Si, S, Ca and Mn. Higher K, Ca and Si concentrations and lower Mn concentrations were observed in trees closer to the polluted area, and it indicates the need for soil remediation. However, As, Pb and Cd, markers of fertilizers and pesticides in soybean production, were not detected by the analyses performed. It is likely that the residual soybean sludge and its fermentation process during the rainy season (tree - growing season) have generated toxic concentrations of inorganic constituents, that together with warmer soil conditions caused the death of many trees. This study provides tools for the assessment of the environmental impact of soybean production through a novel protocol for monitoring the physical and chemical patterns of tree growth using rapid microscopic scale Xray techniques.
Epidemiology of Trichinella infection in wild boar from Spain and its impact on human health during the period 2006-2019.
(Elsevier, 2022-12) Moral-Moral, Sheila; Azorit, Concepción; López-Montoya, Antonio Jesús; Pérez-Jiménez, Jesús María
Trichinellosis is a notifiable zoonotic disease caused by parasitic nematode larvae belonging to genus Trichinella. Domestic pig and wild boar are important hosts within the natural cycle of T. spiralis, being the last one an animal whose populations have experienced an important growth. Therefore, this paper studies the prevalence of Trichinella infection in wild boar in Spain, as well as its relation with hunting bag and its impact on public health during the period 2006-2019. For this purpose, different sources of information were consulted and analyzed depending on autonomous communities of Spain and years. During the fourteen years of study, the number of wild boars hunted and the number of cases of Trichinella infection in them increased (from 172 cases in 2006 to 421 in 2019), although prevalence values remained low as the number of animals analyzed also increased. On the other hand, trichinellosis in humans tends to decrease (from a peak of 107 cases in 2007 to 11 cases in 2019). Nevertheless, both the number of wild boars and humans infected with Trichinella in Spain are among the highest in Europe, and this emphasizes the importance of food safety, sanitary controls of game meat and citizen awareness campaigns, which prevent Trichinella spreads through the human population.
First demonstration that ascomycetous halophilic fungi (Aspergillus sydowii and Aspergillus destruens) are useful in xenobiotic mycoremediation under high salinity conditions
(Elsevier, 2019-02-02) Perez-Llano, Yordanis
First demonstration that ascomycetous halophilic fungi (Aspergillus sydowii T and Aspergillus destruens) are useful in xenobiotic mycoremediation under high salinity conditions
(Elsevier, 2019) Batista-García, Ramón; González-Abradeloa, Deborah; Pérez-Llano, Yordanis; Peidro-Guzmán, Heidy; Sánchez-Carbente, María; Folch, Jorge Luis; Aranda-Ballesteros, Elizabet; Vaidyanathan, Vinoth Kumar; Cabana, Hubert; Gunde-Cimerman, Nina
Polycyclic aromatic hydrocarbons (PAH) and pharmaceutical compounds (PhC) are xenobiotics present in many saline wastewaters. Although fungi are known for their ability to remove xenobiotics, the potential of halophilic fungi to degrade highly persistent pollutants was not yet investigated. The use of two halophilic fungi, Aspergillus sydowii and Aspergillus destruens, for the elimination of PAH and PhC at saline conditions was studied. In saline synthetic medium both fungi used benzo-α-pyrene and phenanthrene as sole carbon source and removed over 90% of both PAH, A. sydowii due to biodegradation and A. destruens to bioadsorption. They removed 100% of a mixture of fifteen PAH in saline biorefinery wastewater. Test using Cucumis sativus demonstrated that wastewater treated with the two fungi lowered considerably the phytotoxicity. This study is the first demonstration that ascomycetous halophilic fungi, in contrast to other fungi (and in particular basidiomycetes) can be used for mycotreatments under salinity conditions.
From lignocellulosic metagenomes to lignocellulolytic genes: trends, challenges and future prospects
(Wiley, 2016) Batista-García, Ramón; Sánchez-Carbente, María; Talia, Paola; Jackson, Stephen A.; O'Leary, Niall D.; Dobson, Alan D.W.; Folch, Jorge Luis
Lignocellulose is the most abundant biomass on Earth with immense potential to act as a primary resource for the production of a range of compounds currently obtained from fossil fuel sources. However, lignocellulosic feedstocks remain largely underexploited due to the complex mixture of recalcitrant polymers present, whose structural features hinder access to the utilizable monosaccharide reservoir within cellulose. Various fungi and bacteria have been identifi ed that can enzymatically decompose lignocellulose to its monomeric compounds for use as carbon sources. The investigation of such lignocellulolytic organisms has proven very useful in gaining primary insights into degradation processes and key microbial enzymes, but the established limitations of culture-based approaches suggest that we have yet to understand the full range of lignocellulolytic mechanisms, likely expressed within natural systems. In this review, we focus on metagenomic approaches to study lignocellulose degradation from structural and functional perspectives, which may provide novel insights into this process in order to rationally design methods for the extraction of compounds from biomass that could enhance biorefinery efficiencies.
Haloadaptative responses of Aspergillus sydowii to extreme water deprivation: morphology, compatible solutes, and oxidative stress at NaCl saturation
(MDPI, 2020-11) Perez-Llano, Yordanis
Haloadaptative Responses of Aspergillus sydowii to Extreme Water Deprivation: Morphology, Compatible Solutes, and Oxidative Stress at NaCl Saturation
(MDPI, 2020) Batista-García, Ramón; Jiménez-Gómez, Irina; Valdés-Muñoz, Gisell; Moreno-Perlin, Tonatiuh; Mouriño-Pérez, Rosa Reyna; Sánchez-Carbente, María; Folch, Jorge Luis; Pérez-Llano, Yordanis; Gunde-Cimerman, Nina; Sánchez-Castellanos, Nilda
Water activity (aw) is critical for microbial growth, as it is severely restricted at aw < 0.90. Saturating NaCl concentrations (~5.0 M) induce extreme water deprivation (aw 0.75) and cellular stress responses. Halophilic fungi have cellular adaptations that enable osmotic balance and ionic/oxidative stress prevention to grow at high salinity. Here we studied the morphology, osmolyte synthesis, and oxidative stress defenses of the halophile Aspergillus sydowii EXF-12860 at 1.0 M and 5.13 M NaCl. Colony growth, pigmentation, exudate, and spore production were inhibited at NaCl-saturated media. Additionally, hyphae showed unpolarized growth, lower diameter, and increased septation, multicellularity and branching compared to optimal NaCl concentration. Trehalose, mannitol, arabitol, erythritol, and glycerol were produced in the presence of both 1.0 M and 5.13 M NaCl. Exposing A. sydowii cells to 5.13 M NaCl resulted in oxidative stress evidenced by an increase in antioxidant enzymes and lipid peroxidation biomarkers. Also, genes involved in cellular antioxidant defense systems were upregulated. This is the most comprehensive study that investigates the micromorphology and the adaptative cellular response of different non-enzymatic and enzymatic oxidative stress biomarkers in halophilic filamentous fungi.
How many threatened lice are there? An approximation to the red list of the Spanish Phthiraptera.
(Elsevier, 2024-04) Pérez, Jesús M.
Although the idea of conserving parasites as part of biodiversity is not new, these in general and lice in particular, are not included in the threatened list of invertebrate fauna. Assuming that the conservation status of a lice species is similar to that of its host, the number of threatened lice within the Spanish entomofauna was estimated based on the known host-lice assemblages. The lice parasitizing many of the Spanish birds and mammals are unknown. Overall, I found 6 extinct (EX) species; 4 critically endangered (CR); 15 endangered (EN), 7 vulnerable (VU) and 1 species near threatened (NT), at regional level. Since the status of hosts varies through time and space, it, (together with those of their lice, must be periodically updated. In addition to a number of reasons that justify the conservation of parasites, lice deserve being conserved, particularly, because of their scientific value.
Identification of a novel carbohydrate esterase from Bjerkandera adusta: Structural and function predictions through bioinformatics analysis and molecular modeling
(Wiley, 2015-01) Batista-García, Ramón; Valdés, Gilberto; Cuervo, Laura; Sánchez-Carbente, María; Balcázar, Edgar; Lira, Verónica; Folch, Jorge Luis
A new gene from Bjerkandera adusta strain UAMH 8258 encoding a carbohydrate esterase (designated as BacesI) was isolated and expressed in Pichia pastoris. The gene had an open reading frame of 1410 bp encoding a polypeptide of 470 amino acid residues, the first 18 serving as a secretion signal peptide. Homology and phylogenetic analyses showed that BaCesI belongs to carbohydrate esterases family 4. Three-dimensional modeling of the protein and normal mode analysis revealed a breathing mode of the active site that could be relevant for esterase activity. Furthermore, the overall negative electrostatic potential of this enzyme suggests that it degrades neutral substrates and will not act on negative substrates such as peptidoglycan or p-nitrophenol derivatives. The enzyme shows a specific activity of 1.118 U mg21 protein on 2-naphthyl acetate. No activity was detected on p-nitrophenol derivatives as proposed from the electrostatic potential data. The deacetylation activity of the recombinant BaCesI was confirmed by measuring the release of acetic acid from several substrates, including oat xylan, shrimp shell chitin, N-acetylglucosamine, and natural substrates such as sugar cane bagasse and grass. This makes the protein very interesting for the biofuels production industry from lignocellulosic materials and for the production of chitosan from chitin.

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