Search

As the association of denitrification with global warming and nitrogen removal from ecosystems has gained attention in recent decades, numerous studies have examined denitrification rates and the distribution of denitrifiers across different environments. In this minireview, reported studies focused on coastal saline environments, including estuaries, mangroves, and hypersaline ecosystems, have been analysed to identify the relationship between denitrification and saline gradients. The analyses of the literature and databases stated the direct effect of salinity on the distribution patterns of denitrifiers. However, few works do not support this hypothesis thus making this topic controversial. The specific mechanisms by which salinity influences denitrifier distribution are not fully understood. Nevertheless, several physical and chemical environmental parameters, in addition to salinity, have been shown to play a role in structuring the denitrifying microbial communities. The prevalence of nirS or nirK denitrifiers in ecosystems is a subject of debate in this work. In general terms, in mesohaline environments, the predominant nitrite reductase is NirS type and, NirK is found predominantly in hypersaline environments. Moreover, the approaches used by different researchers are quite different, resulting in a huge amount of unrelated information, making it difficult to establish comparative analysis. The main techniques used to analyse the distribution of denitrifying populations along salt gradients have been also discussed.

Home hemodialysis (HHD) with low-flow dialysate devices has gained popularity in recent years due to its simple design, portability, and ability to provide greater freedom of movement for our patients. However, there are doubts about the adequacy that this technology offers, since it uses monitors with low-flow bath and lactate. The aim of this study was to demonstrate the clinical benefits of low-flow HHD with the NxStage System One® recently introduced in Spain. We present the results of an observational, retrospective cohort study that included the first patients who started short daily HHD with this device in 12 Spanish centers. We analyzed the evolution of 86 patients at 0, 6 and 12 months, including data related to prescription, and evolution of biochemical parameters related to dialysis dose, anemia, mineral-bone metabolism; evolution of residual renal function, medication usage, and causes of withdrawal during the followup. We were able to demonstrate that this NxStage System One® monitor, in patients with HHD, have provided an adequate dialysis dose, with optimal ultrafiltration rate, with improvement of main biochemical markers of dialysis adequacy. The usage of this technique was associated to a decrease of antihypertensive drugs, phosphate binders and erythropoietin agents, with very good results both patient and technique survival. The simplicity of the technique, together with its good clinical outcomes, should facilitate the growth and utilization of HHD, both in incident and prevalent patients. La hemodiálisis domiciliaria (HDD) con monitores de bajo flujo de líquido de diálisis ha ganado popularidad en los últimos años gracias a su sencillez de diseño, portabilidad y capacidad de desplazamiento. No obstante, existen dudas respecto a la adecuación que este tipo de técnica ofrece, pues utiliza monitores con baño a flujos bajos y lactato. El objetivo de este estudio fue demostrar los beneficios clínicos de la HDD con el monitor NxStage System One® introducido recientemente en España. Presentamos los resultados de un estudio observacional, retrospectivo que incluyó de manera no seleccionada a los primeros pacientes con HDD corta mediante este monitor en 12 centros en España. Se analizó la evolución clínica de 86 pacientes a 0, 6 y 12 meses, incluyendo datos relacionados con la prescripción, evolución de parámetros analíticos de dosis de diálisis, anemia, metabolismo óseo-mineral, evolución de la diuresis residual, utilización de fármacos y datos relacionados con permanencia en la técnica, y causas de salida a lo largo del seguimiento. Pudimos demostrar que este monitor proporcionó una adecuada dosis de diálisis, con tasa óptima de ultrafiltración, con mejoría de los principales marcadores bioquímicos de adecuación en diálisis. El uso de esta técnica se asoció con una disminución de antihipertensivos, captores del fósforo y agentes eritropoyéticos, observándose, además, muy buenos resultados de supervivencia tanto del paciente como de la técnica. La sencillez de este monitor unida a sus buenos resultados clínicos debería facilitar el crecimiento y utilización de la HDD, tanto en pacientes incidentes como prevalentes.

Editorial on the Research Topic Nitrogen dynamics and load in soils.

Salivary glands concentrate plasma nitrate into saliva, leading to high nitrate concentrations that can reach the millimolar range after a nitrate-rich vegetable meal. Whereas human cells cannot reduce nitrate to nitrite effectively, certain oral bacteria can. This leads to an increase in systemic nitrite that can improve conditions such as hypertension and diabetes through nitric oxide availability. Apart from systemic benefits, it has been proposed that microbial nitrate reduction can also promote oral health. In this review, we discuss evidence associating dietary nitrate with oral health. Oral bacteria can reduce nitrite to nitric oxide, a free radical with antimicrobial properties capable of inhibiting sensitive species such as anaerobes involved in periodontal diseases. Nitrate has also been shown to increase resilience against salivary acidification in vivo and in vitro, thus preventing caries development. One potential mechanism is proton consumption during denitrification and/or bacterial reduction of nitrite to ammonium. Additionally, lactic acid (organic acid involved in oral acidification) and hydrogen sulfide (volatile compound involved in halitosis) can act as electron donors for these processes. The nitrate-reducing bacteria Rothia and Neisseria are consistently found at higher levels in individuals free of oral disease (vs. individuals with caries, periodontitis, and/or halitosis) and increase when nitrate is consumed in clinical studies. Preliminary in vitro and clinical evidence show that bacteria normally associated with disease, such as Veillonella (caries) and Prevotella (periodontal diseases and halitosis), decrease in the presence of nitrate. We propose nitrate as an ecologic factor stimulating eubiosis (i.e., an increase in health-associated species and functions). Finally, we discuss the preventive and therapeutic potential, as well as safety issues, related to the use of nitrate. In vivo evidence is limited; therefore, robust clinical studies are required to confirm the potential benefits of nitrate reduction on oral health. A. Mira was supported by a grant from the European Regional Development Fund and Spanish Ministry of Science, Innovation and Universities (RTI2018-102032-B-I00), as well as a grant from the Valencian Innovation Agency (INNVA2/2021/3). B.T. Rosier was supported by an FPI fellowship from the Spanish Ministry of Science, Innovation and Universities (Bio2015-68711-R).

Marine environments and salty inland ecosystems encompass various environmental conditions, such as extremes of temperature, salinity, pH, pressure, altitude, dry conditions, and nutrient scarcity. The extremely halophilic archaea (also called haloarchaea) are a group of microorganisms requiring high salt concentrations (2–6 M NaCl) for optimal growth. Haloarchaea have different metabolic adaptations to withstand these extreme conditions. Among the adaptations, several vesicles, granules, primary and secondary metabolites are produced that are highly significant in biotechnology, such as carotenoids, halocins, enzymes, and granules of polyhydroxyalkanoates (PHAs). Among halophilic enzymes, reductases play a significant role in the textile industry and the degradation of hydrocarbon compounds. Enzymes like dehydrogenases, glycosyl hydrolases, lipases, esterases, and proteases can also be used in several industrial procedures. More recently, several studies stated that carotenoids, gas vacuoles, and liposomes produced by haloarchaea have specific applications in medicine and pharmacy. Additionally, the production of biodegradable and biocompatible polymers by haloarchaea to store carbon makes them potent candidates to be used as cell factories in the industrial production of bioplastics. Furthermore, some haloarchaeal species can synthesize nanoparticles during heavy metal detoxification, thus shedding light on a new approach to producing nanoparticles on a large scale. Recent studies also highlight that exopolysaccharides from haloarchaea can bind the SARS-CoV-2 spike protein. This review explores the potential of haloarchaea in the industry and biotechnology as cellular factories to upscale the production of diverse bioactive compounds. This study was supported by the Science and Engineering Research Board (SERB) Government of India funds through the EEQ (EEQ/2018/001085) scheme. This study was also supported by Generalitat Valenciana, Spain (PROMETEO/2021/055), and VIGROB-309 (University of Alicante) to RM-E.

12 páginas.- 3 figuras.- 56 referencias.- Supplementary information The online version contains supplementary material available at https://doi.org/10.1038/s41467-023-37428-6, Soil contamination is one of the main threats to ecosystem health and sustainability. Yet little is known about the extent to which soil contaminants differ between urban greenspaces and natural ecosystems. Here we show that urban greenspaces and adjacent natural areas (i.e., natural/semi-natural ecosystems) shared similar levels of multiple soil contaminants (metal(loid)s, pesticides, microplastics, and antibiotic resistance genes) across the globe. We reveal that human influence explained many forms of soil contamination worldwide. Socio-economic factors were integral to explaining the occurrence of soil contaminants worldwide. We further show that increased levels of multiple soil contaminants were linked with changes in microbial traits including genes associated with environmental stress resistance, nutrient cycling, and pathogenesis. Taken together, our work demonstrates that human-driven soil contamination in nearby natural areas mirrors that in urban greenspaces globally, and highlights that soil contaminants have the potential to cause dire consequences for ecosystem sustainability and human wellbeing., This study was supported by a 2019 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation (URBANFUN), and by the BES grant agreement No LRB17\1019 (MUSGONET). We are grateful for the assistance of Yunyun Hao and Xuemei Han during soil sampling. We also thank Drs. Shuai Du and Xiuli Hao for their help in data analyses. M. D-B. is supported by the projects from the Spanish Ministry of Science and Innovation (PID2020-115813RA-I00) (SOIL4GROWTH) and TED2021-130908B-C41 (URBANCHANGE) funded by MCIN/AEI/10.13039/501100011033, and a project of the Fondo Europeo de Desarrollo Regional (FEDER) and the Consejería de Transformación Económica, Industria, Conocimiento y Universidades of the Junta de Andalucía (FEDER Andalucía 2014-2020 Objetivo temático “01 - Refuerzo de la investigación, el desarrollo tecnológico y la innovación”) associated with the research project P20_00879 (ANDABIOMA). Y-R. L. is supported by the National Natural Science Foundation of China (42177022). M.G.A.H is supported by the Swiss National Science Foundation (310030_188799). D.J.E. is supported by the Hermon Slade Foundation. F.B. and J.L.M. acknowledge support from the Spanish Ministry and FEDER funds for the project AGL2017-85755-R, the I+D+i project PID2020-114942RB-I00 funded by MCIN/AEI/10.13039/ 501100011033, the i-LINK+2018 (LINKA20069) from CSIC, as well as funds from “Fundación Séneca” from Murcia Province (19896/GERM/15). E.M.-J. was supported by an Experienced Researcher Fellowship of the Humboldt Foundation. E.M-J. and C.P. acknowledge support from the Spanish Ministry of Science and Innovation (PID2020-116578RB-I00). F.A. is supported by ANID FONDECYT 1220358. H-W.H. and J-Z.H. are supported by the project (DP210100332) from Australian Research Council. S.A. is funded by ANID FONDECYT 1170995 and ANID ANILLO ACT192027. MB is supported by a Ramón y Cajal grant from Spanish Ministry of Science (RYC2021-031797-I). The contribution of TG and TUN was supported by the Research Program in Forest Biology, Ecology and Technology (P4-0107) and project V4-3098 of the Slovenian Research Agency. T.P.M. would like to acknowledge contributions from the National Research Foundation of South Africa and cities involved in the South African survey. J.D. and A. Rey acknowledge support from the FCT (IF/00950/2014 and SFRH/BDP/108913/2015, respectively). JPV is thankful to SERB (EEQ/2021/001083) and DST (DST/INT/SL/P-31/2021) and BHU-IoE (6031)-incentive grant for research and development. MCR acknowledges support from an ERC Advanced Grant (694368). AM acknowledged financial support from the PMRF, Ministry of Education - Government of India, India.

Haloferax mediterranei is the model microorganism for the study of the nitrogen cycle in haloarchaea. This archaeon not only assimilate N-species such as nitrate, nitrite, or ammonia, but also it can perform denitrification under low oxygen conditions, using nitrate or nitrite as alternative electron acceptors. However, the information currently available on the regulation of this alternative respiration in this kind of microorganism is scarce. Therefore, in this research, the study of haloarchaeal denitrification using H. mediterranei has been addressed by analyzing the promoter regions of the four main genes of denitrification (narGH, nirK, nor, and nosZ) through bioinformatics, reporter gene assays under oxic and anoxic conditions and by site-directed mutagenesis of the promoter regions. The results have shown that these four promoter regions share a common semi-palindromic motif that plays a role in the control of the expression levels of nor and nosZ (and probably nirK) genes. Regarding the regulation of the genes under study, it has been concluded that nirK, nor, and nosZ genes share some expression patterns, and therefore their transcription could be under the control of the same regulator whereas nar operon expression displays differences, such as the activation by dimethyl sulfoxide with respect to the expression in the absence of an electron acceptor, which is almost null under anoxic conditions. Finally, the study with different electron acceptors demonstrated that this haloarchaea does not need complete anoxia to perform denitrification. Oxygen concentrations around 100 μM trigger the activation of the four promoters. However, a low oxygen concentration per se is not a strong signal to activate the promoters of the main genes involved in this pathway; high activation also requires the presence of nitrate or nitrite as final electron acceptors.

9 páginas.- 4 figuras.- 38 referemcias.- Supplementary information The online version contains supplementary material available at https://doi.org/10.1038/s41558-023-01627-2, Increasing the number of environmental stressors could decrease ecosystem functioning in soils. Yet this relationship has not been globally assessed outside laboratory experiments. Here, using two independent global standardized field surveys, and a range of natural and human factors, we test the relationship between the number of environmental stressors exceeding different critical thresholds and the maintenance of multiple ecosystem services across biomes. Our analysis shows that having multiple stressors, from medium levels (>50%), negatively and significantly correlates with impacts on ecosystem services and that having multiple stressors crossing a high-level critical threshold (over 75% of maximum observed levels) reduces soil biodiversity and functioning globally. The number of environmental stressors exceeding the >75% threshold was consistently seen as an important predictor of multiple ecosystem services, therefore improving prediction of ecosystem functioning. Our findings highlight the need to reduce the dimensionality of the human footprint on ecosystems to conserve biodiversity and function., This project received funding from the British Ecological Society (agreement no. LRA17\1193; MUSGONET). M.D.-B. acknowledges support from the Spanish Ministry of Science and Innovation for the I+D+i project PID2020-115813RA-I00 funded by MCIN/AEI/10.13039/501100011033. M.D.-B. is also supported by a project of the Fondo Europeo de Desarrollo Regional (FEDER) and the Consejería de Transformación Económica, Industria, Conocimiento y Universidades of the Junta de Andalucía (FEDER Andalucía 2014-2020 Objetivo temático ‘01 - Refuerzo de la investigación, el desarrollo tecnológico y la innovación’) associated with the research project P20_00879 (ANDABIOMA). E.M.-J. thanks the Alexander von Humboldt Foundation for supporting his research stay in Germany (Fellowship for Experienced Researchers). M.C.R. acknowledges support from an ERC Advanced Grant (694368). M.G.A.H. acknowledges funding from the Swiss National Science Foundation (grant 310030_188799). M.B. is supported by Spanish Ministry of Science and Innovation through a Ramón y Cajal Fellowship (# RYC2021-031797-I)

Editorial on the Research Topic Environmental omics and their biotechnological applications. JA was indebted to the French National Agency for Research (Agence Nationale de la Recherche, grant ANR-20-CE34-0012) and the Région Occitanie (grant 21023526-DeepMicro) for their support for the development of omics within the ProGénoMix platform.

Filter-feeder organisms such as oyster and mussels are exposed to particles like microplastics (MPs). Although widely used to monitor MPs contamination, little is known about their performance as sentinels, which are biological monitors accumulating contaminants without significant adverse effects. This study comparatively evaluated the quantitative and qualitative accumulation of MPs by oysters (Crassostrea brasiliana) and mussels (Perna perna) along a gradient of contamination in a highly urbanized estuarine system of Brazil. In the most contaminated site, both species presented the worst status of nutrition and health, and also one of the highest MPs levels reported for molluscs to date (up to 44.1 particles·g−1). Despite some inter-specific differences, oysters and mussels were suitable and showed an equivalent performance as sentinels, reflecting the gradient condition demonstrated for other contaminants in the region. The similarity in MPs accumulation was also observed for qualitative aspects (polymer composition, sizes, shapes and colors). Particles were mostly

Haloferax mediterranei has revealed a high bioremediation potential for several inorganic anions (e.g., nitrates and nitrites) and metals from hypersaline waters and brines. However, it is unclear, to date, whether this microorganism allows Cd (II) bioremediation. Consequently, the main objective of this work was to assess the Cd (II) bioremediation potential of Hfx. mediterranei R4. To this end, Hfx. mediterranei cell growth rate and metal bioaccumulation were investigated using different culture media (complex, CM, and defined medium, DM) containing Cd (II) up to 1 mM. In addition, the elemental profile of the biomass (i.e., Al, Ba, Ca, Co, Cu, Fe, K, Mg, Mn, Na, Ni, Sr and Zn) has also been monitored to gain insight into the metabolic processes that may be taking place at the intracellular level for Cd (II) removal. Because of the formation of CdS precipitate, CM is not a suitable culture media for evaluating Cd bioremediation since metal concentration could not be appropriately controlled. When operating in DM, it was observed that the cell doubling time increases three times in the presence of Cd (II). Hfx. mediterranei can bioaccumulate Cd, showing the highest significant accumulation at concentrations of 0.4 mM (108 ± 12 mg Cd/g dry tissue). Finally, the presence of Cd (II) affects the content of K, Mg, Mn and Zn in the biomass, by increasing K levels up to 27 ± 18% and Mn up to 310 ± 140% and reducing Mg levels up to 55 ± 36% and Zn up to 30 ± 4%. These results suggest that different mechanisms are involved in Cd (II) tolerance by Hfx. mediterranei, resulting in increasing the cell concentration of stress-tolerant elements in the biomass (K and Mn), while lowering the concentration of elements which Cd (II) competes with (Mg and Zn), and that all affects the physiological response of the organism by decreasing its growth rate. This study has been funded by Generalitat Valencia (PROMETEO/2021/055), and Universidad de Alicante (VIGROB-309 and VIGROB-050).

Microplastics are an emerging global threat to freshwater ecosystems. There is a growing number of microplastic studies in wetlands and floodplains such as the Pantanal. Microplastics in the Pantanal’s water courses, lakes, and floodplains were sampled with a plankton net in 16 locations in the Pantanal lowlands at varying distances from their potential urban sources over 2 years. Microplastics from the water samples were separated from sediments and organic matter and examined under a stereomicroscope to be identified and counted. Visual determination was then confirmed by RAMAN spectrometry. We found 730 microplastics. The average ± std microplastic concentration was 38 ± 16 x/m3, ranging between 10 and 100 x/m3. Fibres, fragments, and films represented 68%, 28%, and 4%, respectively, of the total microplastics. Surprisingly, a synthetic blue fibre of non-identified composition accounted for 51.0% of the microplastics. Other identified polymers included PP (18.2%), PET (16.9%), PVC (5.1%), PVA (4.4%) and LDPE (4.4%). The blue fibres, PP, and PET were found at all sampling locations. Microplastic concentrations varied from 27 ± 12 x/m3 to 48 ± 21 x/m3 across the sampling sites. Microplastics’ average size was 0.51 ± 0.21 mm, ranging from 0.06 to 0.97 mm. In the study area, the average seasonal concentrations varied from 34 ± 11 to 43 ± 18 x/m3 during the 2 years study period (2018–2019). In lentic environments, the median concentrations (30 x/m3) were significantly lower than in the lotic ones (40 x/m3). Urban human activities are a potential source of microplastics as the concentration of these increased significantly with the population of the nearest human agglomeration. These results indicate widespread contamination of the Pantanal waters by microplastics. Furthermore, a microsynthetic of indeterminate composition is found everywhere in the Pantanal, and more research is urgently needed to determine its composition and sources. The contamination by micropolymers and other microsynthetics will likely impact the Pantanal biota and, eventually, humans living in these floodplains.

This work aims to characterize the haloarchaeal diversity of unexplored environmental salty samples from a hypersaline environment on the southern coast of Jeddah, Saudi Arabia, looking for new isolates able to produce polyhydroxyalkanoates (PHAs). Thus, the list of PHA producers has been extended by describing two species of Halolamina; Halolamina sediminis sp. strain NRS_35 and unclassified Halolamina sp. strain NRS_38. The growth and PHA-production were investigated in the presence of different carbon sources, (glucose, sucrose, starch, carboxymethyl cellulose (CMC), and glycerol), pH values, (5–9), temperature ranges (4–65 °C), and NaCl concentrations (100–350 g L−1). Fourier-transform infra-red analysis (FT-IR) and Liquid chromatography–mass spectrometry (LC-MS) were used for qualitative identification of the biopolymer. The highest yield of PHB was 33.4% and 27.29% by NRS_35 and NRS_38, respectively, using starch as a carbon source at 37 °C, pH 7, and 25% NaCl (w/v). The FT-IR pattern indicated sharp peaks formed around 1628.98 and 1629.28 cm−1, which confirmed the presence of the carbonyl group (C=O) on amides and related to proteins, which is typical of PHB. LC-MS/MS analysis displayed peaks at retention times of 5.2, 7.3, and 8.1. This peak range indicates the occurrence of PHB and its synthetic products: Acetoacetyl-CoA and PHB synthase (PhaC). In summary, the two newly isolated Halolamina species showed a high capacity to produce PHB using different sources of carbon. Further research using other low-cost feedstocks is needed to improve both the quality and quantity of PHB production. With these results, the use of haloarchaea as cell factories to produce PHAs is reinforced, and light is shed on the global concern about replacing plastics with biodegradable polymers. This work was funded by the Deanship of Scientific Research, University of Jeddah, Jeddah, Saudi Arabia, under Grant no. (UJ-02-015-ICGR).

Haloarchaeal carotenoids have attracted attention lately due to their potential antioxidant activity. This work studies the effect of different concentrations of carbon sources on cell growth and carotenoid production. Carotenoid extract composition was characterized by HPLC-MS. Antioxidant activity of carotenoid extracts obtained from cell cultures grown under different nutritional conditions was determined by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH), Ferric Reducing Ability Power (FRAP) and β-carotene bleaching assays. The ability of these carotenoid extracts to inhibit α-glucosidase, α-amylase, and lipase enzymes was also assessed to determine if they could be used to reduce blood glucose and lipid absorption. The maximum production of carotenoids (92.2 µg/mL) was observed combining 12.5% inorganic salts and 2.5% of glucose/starch. Antioxidant, hypoglycemic, and antilipidemic studies showed that higher carbon availability in the culture media leads to changes in the extract composition, resulting in more active haloarchaeal carotenoid extracts. Carotenoid extracts obtained from high-carbon-availability cell cultures presented higher proportions of all-trans-bacterioruberin, 5-cis-bacterioruberin, and a double isomeric bacterioruberin, whereas the presence 9-cis-bacterioruberin and 13-cis-bacterioruberin decreased. The production of haloarchaeal carotenoids can be successfully optimized by changing nutritional conditions. Furthermore, carotenoid composition can be altered by modifying carbon source concentration. These natural compounds are very promising in food and nutraceutical industries. This study was funded by Generalitat Valencia (PROMETEO/2021/055), Ministerio de Economía y Competitividad (RTI2018-099860-B-316 I00), and Universidad de Alicante (VIGROB-309). Generalitat Valenciana Predoctoral fellowship grant (G.N.ACIF/2019/043) and EMBO Short-Term Fellowship (8977) for M.G.

Microplastics (−2), size and the variables related to the distribution of microplastics in fluvial sediments of the Cuiabá River, a tributary of the Pantanal, the world largest flooded Savanna and a UNESCO World Heritage were investigated. The mean microplastic level was 576.8 ± 577.8 items/m−2 of sediments which were mainly fragments (309.0 ± 319.6 items/m−2) and fibers (267.8 ± 339.9 items/m−2). The maximum level was 1938.8 items/m−2 found in the urban stretch of the sister cities of Cuiabá and Várzea Grande, the largest urban agglomeration in the study area. Unexpectedly, the composition of the microplastic with highest average level (240.7 ± 310.4 items/m−2), a blue synthetic fiber, could not be unequivocally determined by RAMAN spectrometry. Its complex composition includes Pb, Li and Nb, suggesting it may derive from electronic waste. Polypropylene (159.2 ± 133.4 items/m−2) and Polyvinyl Chloride (104.6 ± 217.2 items/m−2) were the second and third polymers with higher average levels. The average size of microplastics particles in sampling sites ranged from 0.18 mm to 1.74 mm. Microplastic concentration was positively related to urban areas. Similarly, microplastics particles size decreased with distance from urban areas. These results suggest that urban areas along the Cuiabá River, with poor waste management, are a major source of microplastic pollution in the Pantanal floodplain and that electronic waste might contribute significantly to this contamination. This study highlights the importance of adequate waste management in cities to limit microplastic contamination in areas of ecological importance, such as the Pantanal.

The biosynthesis of nanoparticles (NPs) has gained an overwhelming interest due to their biological applications. However, NPs synthesis by pigmented extreme halophiles remains underexplored. The NPs synthesis using pigmented halophiles is inexpensive and less toxic than other processes. In this study, pigmented halophilic microorganisms (n = 77) were screened to synthesize silver chloride nanoparticles (AgCl-NPs) with silver nitrate as metal precursors, and their biological applications were assessed. The synthesis of AgCl-NPs was possible using the crude extract from cellular lysis (CECL) of six extreme halophiles. Two of the AgCl-NPs viz. AK2-NPs and MY6-NPs synthesized by the CECL of Haloferax alexandrinus RK_AK2 and Haloferax lucentense RK_MY6, respectively, exhibited antimicrobial, antioxidative, and anti-inflammatory activities. The surface plasmon resonance of the AgCl-NPs was determined with UV spectroscopy. XRD analysis of AK2-NPs and MY6-NPs confirmed the presence of silver in the form of chlorargyrite (silver chloride) having a cubic structure. The crystallite size of AK2-NPs and MY6-NPs, estimated with the Scherrer formula, was 115.81 nm and 137.50 nm. FTIR analysis verified the presence of diverse functional groups. Dynamic light-scattering analysis confirmed that the average size distribution of NPs was 71.02 nm and 117.36 nm for AK2-NPs and MY6-NPs, respectively, with monodisperse nature. The functional group in 1623–1641 cm−1 indicated the presence of protein β-sheet structure and shifting of amino and hydroxyl groups from the pigmented CECL, which helps in capping and stabilizing nanoparticles. The study provides evidence that CECL of Haloferax species can rapidly synthesize NPs with unique characteristics and biological applications. This work was the partial financial support from DST-EMR (2016/003715/BBM), SERB-EMEQ/051/2014, and EEQ/2018/001085.

Plastic pollution is a global environmental threat. Remote and pristine islands are not safe from this threat. Here, we estimated beach macro- (>25 mm), meso- (5–25 mm) and microdebris (

Climate change, global pollution due to plastics, greenhouse gasses, or heavy metals among other pollutants, as well as limited natural sources due to unsustainable lifestyles and consumption patterns, are revealing the need for more research to understand ecosystems, biodiversity, and global concerns from the microscale to the macroscale [...]

[Motivation]: Batch effects in omics datasets are usually a source of technical noise that masks the biological signal and hampers data analysis. Batch effect removal has been widely addressed for individual omics technologies. However, multi-omic datasets may combine data obtained in different batches where omics type and batch are often confounded. Moreover, systematic biases may be introduced without notice during data acquisition, which creates a hidden batch effect. Current methods fail to address batch effect correction in these cases., [Results]: In this paper we introduce the MultiBaC R package, a tool for batch effect removal in multi-omics and hidden batch effect scenarios. The package includes a diversity of graphical outputs for model validation and assessment of the batch effect correction.oinformatics online., [Availability and implementation]: MultiBaC package is available on Bioconductor (https://www.bioconductor.org/packages/release/bioc/html/MultiBaC.html) and GitHub (https://github.com/ConesaLab/MultiBaC.git). The data underlying this article are available in Gene Expression Omnibus repository (accession numbers GSE11521, GSE1002, GSE56622 and GSE43747)., This work was funded by the Generalitat Valenciana through PROMETEO grants program for excellence research groups [PROMETEO 2016/093] and by the Spanish MICINN [PID2020-119537RB-I00]., Funding for open access charge: Universitat Politècnica de València.

Climate change is not only changing the mean values of environmental parameters that modulate ecosystems, but also the regime of disturbances. Among them, extreme events have a key role in structuring biological communities. Ecosystems are frequently suffering multiple anthropogenic pressures which can cause effects that are not additive. Thus, the effects of extreme events need to be studied in combination with other pressures to adequately evaluate their consequences. We performed a manipulative approach in two rocky shores in the Mediterranean with contrasting levels of anthropogenic pressure (mainly eutrophication) simulating storms with different disturbance regimes in the intertidal and subtidal zones. In the short-term, an extreme storm had a greater impact on the species assemblage than other disturbance regimes, being especially notable in the area suffering from a high anthropogenic pressure. In this area, the species assemblages that suffered from an extreme storm took a longer time to recover than the ones affected by other disturbance regimes and were generally more affected after the disturbance. The intertidal zone, having more variable environmental conditions than the subtidal zone, was more resistant and able to recover from extreme storms. Our results suggest that the effects of extreme events on biological communities could be strengthened when co-occurring with anthropogenic pressures, especially ecosystems adapted to less variable environmental conditions. Thus, limiting other anthropogenic pressures that ecosystems are suffering is crucial to maintain the natural resistance and recovery capacity of ecosystems towards extreme events such as storms. This work was supported by the Biodiversity Foundation of the Ministry for the Ecological Transition and Demographic Challenge from Spain (FBIOMARINA20-01). C. S. was funded by the University of Alicante (Ref. UATALENTO 17-11).

Los grupos de alto rendimiento académico (ARA) son una opción que ya existe en muchos de los grados de la Universidad de Alicante. Su principal objetivo consiste en aumentar y mejorar las aptitudes del alumnado desde el comienzo de sus estudios, ofreciendo parte de la docencia en inglés. Por este motivo, el alumnado matriculado en estas clases tiene una serie de ventajas con respecto al resto del alumnado. Entre los beneficios que aporta pertenecer al grupo ARA se encuentran la mención de esta pertenencia en el Suplemento Europeo en el título, así como la preferencia tanto para obtener ayudas de viaje para el aprendizaje de idiomas, como para la obtención de ayudas para la formación del personal investigador en las distintas modalidades y para bolsas Erasmus. Respecto de los beneficios para el profesorado, se le reconocerá el mérito preferente para ser tomado en consideración como tutor/a para la asignación de ayudas de formación de personal investigador. Con el objetivo de mejorar la calidad del proceso de enseñanza-aprendizaje, se ha realizado un estudio que abarca los últimos seis años consecutivos, acerca del nivel de satisfacción y la opinión general sobre los grupos ARA, tanto del alumnado como del personal docente e investigador (PDI) de grados de Ciencias e Ingeniería Química de la Universidad de Alicante. El estudio se ha basado en una serie de encuestas formativas que pretendían evaluar las diferencias entre ambos grupos (ARA y no ARA), además de recopilar ideas para poder impulsar al alumnado en el futuro a participar en un grupo ARA. Este curso académico, además, se ha introducido como novedad, preguntas acerca de la repercusión y/o posible interés por parte de alumnado con una adaptación curricular. En conjunto los datos obtenidos se basan en la participación de todos los colectivos implicados, con una mayor colaboración del alumnado frente a la participación del profesorado. En cambio, del conjunto de alumnos y alumnas que participaron en la encuesta, solo un pequeño porcentaje pertenecían al grupo ARA. La mayoría del profesorado que ha participado en este estudio no imparte docencia en grupos ARA. Sobre los docentes de grupos ARA, podemos destacar que un gran porcentaje considera que la docencia en inglés aporta beneficios a los y las estudiantes. Entre el profesorado en general, ya sea de grupos ARA o no, existe un pensamiento generalizado de un beneficio de los grupos ARA para alumnado con adaptaciones curriculares. En general se observa en los datos obtenidos un grado de satisfacción bueno con respecto a los grupos ARA, aunque se han obtenido propuestas dirigidas a mejorar su funcionamiento y percepción, entre las que cabe destacar dar a conocer más los beneficios que ofrece pertenecer a un grupo ARA. Este tipo de estudios contribuye a conocer el grado de satisfacción de los diferentes colectivos universitarios con respecto de los grupos ARA, así como a proponer medidas orientadas a optimizar su implementación.

The search of separation hyperplanes is an efficient way to find rules with classification purposes. This paper presents an alternative mathematical programming formulation to existing methods to find a discriminant hyperplane. The hyperplane H is found by minimizing the sum of all the distances to the area assigned to the group each individual belongs to. It results in a convex optimization problem for which we find an equivalent linear programming problem. We demonstrate that H exists when the centroids of the two groups are not equal. The method is effective dealing with low and high dimensional data where reduction of the dimension is proposed to avoid overfitting problems. We show the performance of this approach with different data sets and comparisons with other classifications methods. The method is called LPDA and it is implemented in a R package available in https://github.com/mjnueda/lpda.

The author is thankful to Generalitat Valenciana, Spain (PROMETEO/2021/055) and the University of Alicante, Spain (VIGROB-309).

Extremophilic microbes show a unique metabolism due to the adaptations they display to deal with extreme environmental parameters characterizing the extreme ecosystems that they inhabit (high salt concentration, high temperatures, and extreme pH values, high exposure to solar radiation etc.). Halophilic microorganisms characterised and isolated from saltmarshes, brines, salted ponds, salty lagoons etc. have recently attracted attention due to their potential biotechnological applications (as whole cells used for different purposes like wastewater treatments, or their biomolecules: enzymes, antibiotics, carotenoids, bioplastics). Alicante county (southeast of Spain) accounts for a significant number of salty environments like coastal or inland salty ponds from where sodium chloride (NaCl)is obtained, marshes, salty lagoons, etc. The best system characterised so far from a microbiological point of view is “Salinas de Santa Pola”, also termed “Salinas Bras del Port”. However, there are many other salty environments to be explored, like the natural park of Torrevieja and la Mata lagoons, salty lagoon located in Calpe city or inland salted ponds like those located in the northwest of the county. This review summarises the most relevant biotechnological applications of halophilic microbes described up to now. In addition, special attention is focused on ecosystems such as the lagoons of Torrevieja or inland salt marshes as natural environments whose microbial biodiversity is worthy of being studied in search of new strains and species with the aim to analyze their potential biotechnological applications (pharmaceutical, food industry, biomedicine, etc.). This work was funded by Torrevieja Town Hall and by a research grant from VIGROB-309 (University of Alicante)

Plastic debris is becoming a growing environmental concern and microplastics (size

Editorial on the Research Topic Nitrogen in the Environment

Heavy metals are essential micronutrients at low concentrations, serving as cofactors for relevant microbial enzymes (i.e., respiratory nitrate and nitrite reductases NADH dehydrogenase-2, amine oxidase, etc.), but they become harmful cellular intoxicants at significant low concentrations compared to other chemical compounds. The increasing need to incorporate bioremediation in the removal of heavy metals and other contaminants from wastewaters has led extremophiles to the spotlight of research. The haloarchaeon Haloferax mediterranei has promising physiological characteristics regarding bioremediation. However, little is known about how haloarchaea manage to resist high concentrations of heavy metals in the environment. The aim of this work is to develop bioinformatics research as the first step for further omics-based studies to shed light on copper metabolism in haloarchaea by analyzing H. mediterranei genome (strain ATCC 33500). To reach this aim, genome and protein databases have been consulted, and copper-related genes have been identified. BLAST analysis has been carried out to find similarities between copper resistance genes described from other microorganisms and H. mediterranei genes. Plausible copper importer genes, genes coding for siderophores, and copper exporters belonging to P1B-type ATPase group have been found apart from genes encoding copper chaperones, metal-responsive transcriptional regulators, and several proteins belonging to the cupredoxin superfamily: nitrite reductase, nitrous oxide reductases, cytochrome c oxidases, multicopper oxidases, and small blue copper proteins from the amicyanin/pseudoazurin families as halocyanins. As the presence of heavy metals causes oxidative stress, genes coding for proteins involved in antioxidant mechanisms have been also explored: thioredoxin, glutaredoxin, peroxiredoxin, catalase, and γ-glutamylcysteine as an analog of glutathione. Bioinformatic-based analysis of H. mediterranei genome has revealed a set of genes involved in copper metabolism that could be of interest for bioremediation purposes. The analysis of genes involved in antioxidative mechanisms against heavy metals makes it possible to infer the capability of H. mediterranei to synthesize inorganic polyphosphate granules against oxidative stress. The authors thank the following institutions for funding this research: MICINN Spain (RTI2018-099860-B-I00), Generalitat Valenciana, Spain (PROMETEO/2021/055), and University of Alicante, Spain (VIGROB-309).

Breast cancer is the leading cause of death among women worldwide. Over the years, oxidative stress has been linked to the onset and progression of cancer. In addition to the classical histological classification, breast carcinomas are classified into phenotypes according to hormone receptors (estrogen receptor—RE—/progesterone receptor—PR) and growth factor receptor (human epidermal growth factor receptor—HER2) expression. Luminal tumors (ER/PR-positive/HER2-negative) are present in older patients with a better outcome. However, patients with HER2-positive or triple-negative breast cancer (TNBC) (ER/PR/HER2-negative) subtypes still represent highly aggressive behavior, metastasis, poor prognosis, and drug resistance. Therefore, new alternative therapies have become an urgent clinical need. In recent years, anticancer agents based on natural products have been receiving huge interest. In particular, carotenoids are natural compounds present in fruits and vegetables, but algae, bacteria, and archaea also produce them. The antioxidant properties of carotenoids have been studied during the last years due to their potential in preventing and treating multiple diseases, including cancer. Although the effect of carotenoids on breast cancer during in vitro and in vivo studies is promising, clinical trials are still inconclusive. The haloarchaeal carotenoid bacterioruberin holds great promise to the future of biomedicine due to its particular structure, and antioxidant activity. However, much work remains to be performed to draw firm conclusions. This review summarizes the current knowledge on pre-clinical and clinical analysis on the use of carotenoids as chemopreventive and chemotherapeutic agents in breast cancer, highlighting the most recent results regarding the use of bacterioruberin from haloarchaea. This work was funded by a research grant from MINECO Spain (RTI2018-099860-B-I00), Generalitat Valenciana (PROMETEO/2021/055;A) and VIGROB-309 (University of Alicante).

Deep eutectic solvents (DES) are promising reaction media where interesting catalytic processes can be carried out. In theory, most of these mixtures are environmentally friendly, being an alternative to traditionally pollutant organic solvents used in several processes related to organic chemistry and biotechnology. However, recent studies show contradictory results regarding their toxicity. The method selected to perform toxicity studies could be significantly conditioned by some of the physical properties displayed by the DESs. Also, the metabolic capabilities of the organisms/cells used to monitor their toxicity are influenced by their physical properties. In this review, relevant physical-chemical properties for toxicity studies are summarized. The advantages/disadvantages of the used tests to monitor their toxicity and biodegradability in connection with the chosen organisms/cells are discussed, shedding light on their limitations. These findings could be taken as a starting point for designing more accurate DESs toxicity studies covering a wider spectrum of organisms and cells to be used as biomodels to monitor environmental pollution caused by DESs. This work was funded by research grants from Generalitat Valenciana, Spain (PROMETEO/2021/055), the Spanish Ministerio de Economia, Industria y Competitividad (PGC2018-096616-B-100 and PID2021-123765NB-I00) and University of Alicante (VIGROB-309, VIGROB-316FI and VIGROB-173FI).

Resumen La hemodialisis domiciliaria (HDD) con monitores de bajo flujo de liquido de dialisis ha ganado popularidad en los ultimos anos gracias a su sencillez de diseno, portabilidad y capacidad de desplazamiento. No obstante, existen dudas respecto a la adecuacion que este tipo de tecnica ofrece, pues utiliza monitores con bano a flujos bajos y lactato. El objetivo de este estudio fue demostrar los beneficios clinicos de la HDD con el monitor NxStage System One® introducido recientemente en Espana. Presentamos los resultados de un estudio observacional, retrospectivo que incluyo de manera no seleccionada a los primeros pacientes con HDD corta mediante este monitor en 12 centros en Espana. Se analizo la evolucion clinica de 86 pacientes a 0, 6 y 12 meses, incluyendo datos relacionados con la prescripcion, evolucion de parametros analiticos de dosis de dialisis, anemia, metabolismo oseo-mineral, evolucion de la diuresis residual, utilizacion de farmacos y datos relacionados con permanencia en la tecnica, y causas de salida a lo largo del seguimiento. Pudimos demostrar que este monitor proporciono una adecuada dosis de dialisis, con tasa optima de ultrafiltracion, con mejoria de los principales marcadores bioquimicos de adecuacion en dialisis. El uso de esta tecnica se asocio con una disminucion de antihipertensivos, captores del fosforo y agentes eritropoyeticos, observandose, ademas, muy buenos resultados de supervivencia tanto del paciente como de la tecnica. La sencillez de este monitor unida a sus buenos resultados clinicos deberia facilitar el crecimiento y utilizacion de la HDD, tanto en pacientes incidentes como prevalentes.

Microorganisms from the Halobacteria class, also known as haloarchaea, inhabit a wide range of ecosystems of which the main characteristic is the presence of high salt concentration. These environments together with their microbial communities are not well characterized, but some of the common features that they share are high sun radiation and low availability of oxygen. To overcome these stressful conditions, and more particularly to deal with oxygen limitation, some microorganisms drive alternative respiratory pathways such as denitrification. In this paper, denitrification in haloarchaea has been studied from a phylogenetic point of view. It has been demonstrated that the presence of denitrification enzymes is a quite common characteristic in Halobacteria class, being nitrite reductase and nitric oxide reductase the enzymes with higher co-occurrence, maybe due to their possible role not only in denitrification, but also in detoxification. Moreover, copper-nitrite reductase (NirK) is the only class of respiratory nitrite reductase detected in these microorganisms up to date. The distribution of this alternative respiratory pathway and their enzymes among the families of haloarchaea has also been discussed and related with the environment in which they constitute the major populations. Complete denitrification phenotype is more common in some families like Haloarculaceae and Haloferacaceae, whilst less common in families such as Natrialbaceae and Halorubraceae. This work was funded by a research grant from MINECO Spain (RTI2018-099860-B-I00) and VIGROB-309 (University of Alicante).

This study presents a comparative analysis of halophiles from the global open sea and coastal biosystems through shotgun metagenomes (n = 209) retrieved from public repositories. The open sea was significantly enriched with Prochlorococcus and Candidatus pelagibacter. Meanwhile, coastal biosystems were dominated by Marinobacter and Alcanivorax. Halophilic archaea Haloarcula and Haloquandratum, predominant in the coastal biosystem, were significantly (p &lt, 0.05) enriched in coastal biosystems compared to the open sea. Analysis of whole genomes (n = 23,540), retrieved from EzBioCloud, detected crtI in 64.66% of genomes, while cruF was observed in 1.69% Bacteria and 40.75% Archaea. We further confirmed the viability and carotenoid pigment production by pure culture isolation (n = 1351) of extreme halophiles from sediments (n = 410 × 3) sampling at the Arabian coastline of India. All red-pigmented isolates were represented exclusively by Haloferax, resistant to saturated NaCl (6 M), and had &gt, 60% G + C content. Multidrug resistance to tetracycline, gentamicin, ampicillin, and chloramphenicol were also observed. Our study showed that coastal biosystems could be more suited for bioprospection of halophiles rather than the open sea.

During the last century, anthropogenic activities such as fertilization have led to an increase in pollution in many ecosystems by nitrogen compounds. Consequently, researchers aim to reduce nitrogen pollutants following different strategies. Some haloarchaea, owing to their denitrifier metabolism, have been proposed as good model organisms for the removal of not only nitrate, nitrite, and ammonium, but also (per)chlorates and bromate in brines and saline wastewater. Bacterial denitrification has been extensively described at the physiological, biochemical, and genetic levels. However, their haloarchaea counterparts remain poorly described. In previous work the model structure of nitric oxide reductase was analysed. In this study, a bioinformatic analysis of the sequences and the structural models of the nitrate, nitrite and nitrous oxide reductases has been described for the first time in the haloarchaeon model Haloferax mediterranei. The main residues involved in the catalytic mechanism and in the coordination of the metal centres have been explored to shed light on their structural characterization and classification. These results set the basis for understanding the molecular mechanism for haloarchaeal denitrification, necessary for the use and optimization of these microorganisms in bioremediation of saline environments among other potential applications including bioremediation of industrial waters. Research was funded by research grants from the MINECO Spain (RTI2018-099860-B-I00) and VIGROB-309 (University of Alicante).

Despite the large research effort on reporting quantities of coastal litter, the dynamics of this litter is not yet sufficiently understood. Litter inputs in five cobble beaches located in the Mediterranean (Spain) were studied over three months during winter by biweekly litter tagging. Plastic represented the dominant material that reached the beaches (77%). In remote and narrow beaches, storms constituted the main driver in litter dynamics, favouring the accumulation of floating items such as plastic bottles and wood fragments as well as the largest but contrasting effects, increasing litter inputs and outputs from the beach, respectively. In rural beaches, beach users, mainly fisher people, but also tourists, contributed to a notable input of litter to the beach. Burial and exhumation of litter were reported as common occurring processes. Better management actions are required to improve beach environmental quality., This research is a contribution to the Andalusia PAI Research Group "RNM-328" and to the Ibero-American Beach Management and Certification Network -PROPLAYAS. This work was supported by the Biodiversity Foundation of the Ministry for the Ecological Transition and Demographic Challenge from Spain [FBIOMARINA19-01]. Special thanks go to David Saez, Natalia Sanchez, Laura Valero and Alba Amat for their help during the sampling periods and thanks to "Puertos del Estado" for oceanographic data. Thanks are also given to the municipalities involved in this research for answering to enquires about beach cleaning modalities. Finally, special thanks to two anonymous reviewers for their useful comments and suggestions, which have been very helpful in improving the manuscript.

A sustainable synthesis of sulfonamides using a copper-catalysed process starting from triarylbismuthines, Na2S2O5 and nitro compounds in a Deep Eutectic Solvent (DES) as a reaction medium is described. Thus, triarylbismuthines are used as reagents for the incorporation of SO2 into organic motifs. The bismuth salts formed as by-products can be easily removed from the crude reaction mixture by precipitation with water, while the use of volatile organic compounds (VOCs) as solvents can be avoided in the entire process. The eutectic mixture employed as the solvent is fully characterised, with the preliminary results proving its low toxicity. The designed DES also allows for a novel multicomponent reaction which saves time and reduces purification steps, energy and cost. This work was supported by the University of Alicante (VIGROB-173 and VIGROB-309) and the Spanish Ministerio de Economía, Industria y Competitividad (CTQ2015-66624-P and PGC2018-096616-B-I00). X. M. and J. T. C. thank Generalitat Valenciana (ACIF/2016/057 and ACIF/2016/077) for their fellowships.

Marine aquaculture is expanding offshore, where the environmental interactions are not yet fully understood. We performed a benthic environmental assessment of an offshore fish farm on unconsolidated sediment. The physicochemical variables showed marked changes just under the fish farm, although the structure of the community and its bioturbation potential were not influenced. Under no or minimum influence from the fish farm, the physicochemical variables, including acid-volatile sulphides and redox, were notably different to those found in unaffected coastal areas. For this reason, classifications of the environmental status based on physicochemical variables should be adapted to offshore areas. Despite the low degree of impact detected, the organic matter carrying capacity should be carefully determined to avoid environmental drawbacks in terms of fine-grained offshore sediments. Offshore aquaculture could have a lower environmental impact than other types of aquaculture located closer to the coast, but further research is needed to obtain conclusive results. This work was funded by the Office for University Cooperation for Development of the University of Alicante (CUD-05/16). C.S. is funded by the University of Alicante (Ref. UATALENTO 17–11).

Haloferax mediterranei is a haloarchaeon of high interest in biotechnology because it produces and mobilizes intracellular polyhydroxyalkanoate (PHA) granules during growth under stress conditions (limitation of phosphorous in the culture media), among other interesting metabolites (enzymes, carotenoids, etc.). The capability of PHA production by microbes can be monitored with the use of staining-based methods. However, the staining of haloarchaea cells is a challenging task, firstly, due to the high ionic strength of the medium, which is inappropriate for most of dyes, and secondly, due to the low permeability of the haloarchaea S-layer to macromolecules. In this work, Haloferax mediterranei is used as a halophilic archaeon model to describe an optimized protocol for the visualization and analysis of intracellular PHA granules in living cells. The method is based on double-fluorescence staining using Nile red and SYBR Green by confocal fluorescence microscopy. Thanks to this method, the capability of PHA production by new haloarchaea isolates could be easily monitored.

Plastics are essential materials, but their extensive production poses a threat to the environment. Biobased plastics provide an alternative, that reduce, in many cases, their perdurability. The degradation of conventional (polyethylene (PE) / polyethylene terephthalate (PET) and polyamide (PA) / polypropylene (PP)- ethylene vinyl alcohol (EVOH)-PP) and polylactic acid (PLA)-based materials was evaluated through an in situ manipulative experiment for one year simulating different soil scenarios. The degradation of the materials was evaluated by means of weight loss, differential scanning calorimetry and infrared spectroscopy. Conventional materials showed values less than 2% of weight loss for all treatments after one year. The weight loss in PLA-based materials was notably enhanced at temperatures above 20°C and with high water availability, while soil texture showed a minor influence. The carbonyl and crystallization indices, as well as the enthalpy of fusion, detected early signs of degradation of biobased materials and confirmed the degradation detected by weight loss. This study highlights that the degradation of materials can be markedly different depending on the environmental conditions in terrestrial environmental compartments such as soil, where water availability and temperature can be more variable than in marine environments. Thus, the certification of material degradability needs to be linked to the specific environmental compartment and conditions in which the material has been tested. C. S. was funded by the University of Alicante (Ref. UATALENTO 17-11). This work has been funded by the Spanish Foundation for Science and Technology (FECYT2-19I; PR238).

While the use of biodegradable polymers is recognized as a global strategy to minimize plastic pollution, the technical standards (TS) used to attest their biodegradability may not be in compliance with most environmental parameters observed aquatic ecosystems. Indeed, through a careful assessment of the TS currently in use, this study evidenced that these guidelines cover only a fraction of the biogeochemical parameters seen in nature and largely disregard those that occur in the deep-sea. Thus, these TS may not be able to ensure the degradation of such polymers in natural environments, where microbial activity, pH, temperature, salinity, UV radiation and pressure are highly variable. This raises environmental concern, since relevant parcel of plastic ends up in the oceans reaching deep zones. Therefore, there is an urgent need to revise these TS, which must consider the actual fate of most plastic debris and include assessments under the challenging conditions found at these types of environment, alongside microplastic formation and ecotoxicology effects. Moreover, the next generation of biodegradability tests must be designed to enable a cost-effective implementation and incorporate accurate analytical techniques to assess polymer transformation. Furthermore, certification should provide information on time scale and degradation rates and, preferably, be globally harmonized. This research was support by São Paulo Research Foundation (FAPESP n. 2019/13750-4). I.B. Castro (PQ 302713/2018-2) and M.R.C. Marques (PQ 304295/2018-3) were recipient of research productivity fellowship from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). M.C. Nazareth was sponsored by Coordenação Aperfeiçoamento de Pessoal de Nível Superior (CAPES / Finance code: 001).

Some seabirds or coastal birds such as flamingos or pelicans display elegant pink or reddish colours. These colours are due to pigments that birds cannot synthesize de novo. Thus, this coloration is mainly originated from carotenoids ingested trough carotenoid rich food sources like microalgae (Dunaliella) or small shrimps (Artemia), which are microorganisms inhabiting the salty environments where the mentioned birds live. New advances in this field of knowledge have revealed that extreme microorganisms belonging to the haloarchaea group (Archaea Domain) may contribute significantly to the characteristic pink- red colour of flamingos’ feathers for instance. Alive haloarchaea cells have been found on the surface of the feathers. Besides, the major carotenoid produced by haloarchaea (bacterioruberin) has also been identify within the feathers structure. This work summarizes the main contributions recently reported about this topic as well as general aspects regarding bacterioruberin as a powerful colour carotenoid. Discussions about potential role of these microorganisms in the life of seaside birds are also included. This work was funded by research grant from the University of Alicante (VIGROB-309).

Haloarchaea produce C50 carotenoids such as bacterioruberin, which are of biotechnological in-terest. This study aimed to analyze the effect of different environmental and nutritional conditions on the cellular growth and dynamics of carotenoids accumulation in Haloferax mediterranei. The maximum production of carotenoids (40 µg·mL−1) was obtained during the stationary phase of growth, probably due to nutrient-limiting conditions (one-step culture). By seven days of culture, 1 mL culture produced 22.4 mg of dry weight biomass containing 0.18 % (w/w) of carotenoids. On the other hand, carbon-deficient cultures (low C/N ratio) were observed to be optimum for C50 bacterioruberin production by Hfx. mediterranei, but negatively affected the growth of cells. Thus, a two-steps process was evaluated for optimum carotenoids yield. In the first step, a nutri-ent-repleted culture medium enabled the haloarchaea to produce biomass, while in the second step, the biomass was incubated under osmotic stress and in a carbon-deficient medium. Under the conditions used, the obtained biomass contained 0.27% (w/w) of carotenoids after seven days, which accounts for 58.49 µg·mL−1 of carotenoids for a culture with turbidity 14.0. This work was funded by a research grant from MINECO Spain (RTI2018-099860-B-I00) and the University of Alicante (VIGROB-309). We are also indebted to the Andalusian Government (research project BIO-214). ZM was assisted by a pre-doctoral grant from “Plan Propio de Investigación” of the University of Huelva, Spain. MG was awarded with a pre-doctoral fellowship from the Valencian Community Government (ACIF/2019/043).

Although there is a rich body of literature about the implementation of ICTs in foreign language learning, none has investigated the technological attitudes and digital skills of pre-service teachers thanks to the adoption of a Project-Based Learning (PBL) methodology. This study analyses the attitudes and digital skills of pre-service teachers through the implementation of ICT-based projects in the EFL classroom. For this purpose, 120 teacher candidates at the University of Alicante (Spain) participated in this experiment. First, all students were administered a pretest to measure the degree of technological affinity and digital skills. Then, they were divided into smaller groups (cooperative learning) in order to design and create several ICT-based projects aimed at teaching English as a foreign language to children and young learners. All the participants later presented their projects and evaluated the results (peer-evaluation) from a technical and pedagogical perspective. Finally, they completed a post-test based on their self-perceived learning outcomes in relation to ICT integration. The results revealed significant learning gains in digital and higher-order thinking skills (create, analyse, evaluate). Teaching candidates show a positive attitude towards the integration of ICTs in the EFL classroom but demand better training as regards the adoption of new technologies, particularly given the current situation and the need for increased on-line teaching.

Los grupos de Alto Rendimiento Académico (ARA) se caracterizan por una docencia impartida en inglés y un número reducido de estudiantes en sus aulas. El presente trabajo se integra dentro de un proyecto plurianual que tiene como objetivo conocer la evolución en el nivel de satisfacción y la opinión general respecto a los grupos ARA, tanto del alumnado como del personal docente de la Facultad de Ciencias. Adicionalmente, este año el estudio incluye la perspectiva de género. Las series temporales se analizaron mediante modelos lineales generalizados y los datos de género se analizaron mediante un test de Student. En los 5 años de estudio, las tendencias no son significativas ya que los p-valores son > 0.05. Los resultados en perspectiva de género han ayudado a entender las diferencias en la percepción del alumnado y profesorado en base al género, y las diferencias en el nivel de inglés. Este estudio muestra que son necesarias nuevas propuestas para dar a conocer y mejorar el funcionamiento de estos grupos y hay alumnos de otros grados interesados en pertenecer a grupos ARA.

Although heavy metals are naturally found in the environment as components of the earth’s crust, environmental pollution by these toxic elements has increased since the industrial revolution. Some of them can be considered essential, since they play regulatory roles in different biological processes; but the role of other heavy metals in living tissues is not clear, and once ingested they can accumulate in the organism for long periods of time causing adverse health effects. To mitigate this problem, different methods have been used to remove heavy metals from water and soil, such as chelation-based processes. However, techniques like bioremediation are leaving these conventional methodologies in the background for being more effective and eco-friendlier. Recently, different research lines have been promoted, in which several organisms have been used for bioremediation approaches. Within this context, the extremophilic microorganisms represent one of the best tools for the treatment of contaminated sites due to the biochemical and molecular properties they show. Furthermore, since it is estimated that 5% of industrial effluents are saline and hypersaline, halophilic microorganisms have been suggested as good candidates for bioremediation and treatment of this kind of samples. These microorganisms, and specifically the haloarchaea group, are of interest to design strategies aiming the removal of polluting compounds due to the efficiency of their metabolism under extreme conditions and their significant tolerance to highly toxic compounds such as heavy metals, bromate, nitrite, chlorate, or perchlorate ions. However, there are still few trials that have proven the bioremediation of environments contaminated with heavy metals using these microorganisms. This review analyses scientific literature focused on metabolic capabilities of haloarchaea that may allow these microbes to tolerate and eliminate heavy metals from the media, paying special attention to cadmium. Thus, this work will shed light on potential uses of haloarchaea in bioremediation of soils and waters negatively affected by heavy metals, and more specifically by cadmium. This work was funded by research grant from the MINECO Spain (RTI2018-099860-B-I00) and University of Alicante (VIGROB-309).

Los grupos de Alto Rendimiento Académico (ARA) se caracterizan por una docencia impartida en inglés y un número reducido de estudiantes en sus aulas. El presente trabajo se centra en el grupo ARA de Biología, el único de este tipo presente en la Facultad de Ciencias de la Universidad de Alicante. Se integra dentro de un proyecto plurianual que tiene como objetivo conocer la evolución en el nivel de satisfacción y la opinión general respecto a los grupos ARA, tanto del alumnado como del personal docente de la Facultad de Ciencias. Además, se analiza si existen diferencias significativas en función del género con el que se identifican los participantes. Para ello se realizaron encuestas a 350 personas. Las series temporales se analizaron mediante modelos lineales generalizados y los datos de género se analizaron mediante un test de Student. En los 5 años de estudio, las tendencias no son significativas ya que los p-valores son > 0.05. Los resultados en perspectiva de género han ayudado a entender las diferencias en la percepción del alumnado y profesorado en base al género, y las diferencias en el nivel de inglés. Como conclusión, son necesarias nuevas propuestas para dar a conocer y mejorar el funcionamiento de estos grupos y hay alumnos de otros grados interesados en pertenecer a grupos ARA.

Background Abnormalities of bone mineral parameters are associated with increased mortality in patients on dialysis, but their effects and the optimal range of these biomarkers are less well characterized in non-dialysis chronic kidney disease (CKD). Methods PECERA (Collaborative Study Project in Patients with Advanced CKD) is a 3-year, prospective multicenter, open-cohort study of 966 adult patients with non-dialyzed CKD stages 4-5 enrolled from 12 centers in Spain. Associations between levels of serum calcium (Ca) (corrected for albumin), phosphate (P), and intact parathyroid hormone (iPTH) with all-cause mortality (primary outcome) and cardiovascular mortality (secondary outcome) were examined using time-dependent Cox proportional hazards models and penalized splines analysis adjusted by demographics and comorbidities, treatments and biochemical values collected every 6 months for 3 years. Results After a median follow-up of 29 months (IQR: 13-36 months) there were 181 deaths (19%). The association of calcium with all-cause mortality was J-shaped, with an increased risk for all-cause mortality at levels > 10.5 mg/dL. For phosphate and iPTH levels, the association was U-shaped. The serum values associated with the minimum risk of mortality were 3.8 mg/dL for phosphate and 70 pg/mL for iPTH, being the lowest risk ranges between 2.8 and 5.0 mg/dL, and between 38 and 112 pg/mL for phosphate and iPTH, respectively. Conclusions Our study provides evidence on the non-linear association of serum calcium, phosphate and iPTH levels with mortality in stage 4 and 5 CKD patients, and suggests potential survival benefits for controlling bone mineral parameters in this population, as previously reported for dialysis patients.

El Grado de Gastronomía y Artes Culinarias pretende dotar al alumno de conocimiento sobre la industria gastronómica, y su relación con el entorno. El plan de estudios contempla asignaturas de diferentes ramas del conocimiento, gestión de empresas, marketing, turismo, habilidades sociales, recursos humanos, salud y nutrición humana. La presente investigación se contextualiza en la asignatura Bromatología. El objetivo de la presente actividad es detectar carencias formativas en el alumnado para diseñar, implementar y evaluar las acciones educativas necesarias. Para ello, se diseñó e implementó la actividad, se analizaron y difundieron los resultados y se desarrollaron nuevos materiales. Se confirmó que más del 60% del alumnado afirma tener ningún o muy escaso conocimiento sobre química, biología, etc. Además, se detectaron carencias en el alumnado en informática, lectura y comprensión de idioma extranjero y en la redacción de trabajos académicos. Se desarrollaron diferentes materiales docentes incluyendo la visualización de videos cortos con explicaciones sencillas, presentaciones con audio breves, aula invertida, cálculos matemáticos, así como juegos. Se llevó a cabo la evaluación de los resultados obtenidos a partir de cuestionarios al alumnado y se revisaron las calificaciones obtenidas observando una mejora significativa en la calificación final.

Climate change makes plant‐parasitic nematodes (PPN) an increasing threat to commercial crops. PPN can be managed sustainably by the biocontrol fungus Pochonia chlamydosporia (Pc). Chitosan generated from chitin deacetylation enhances PPN parasitism by Pc. In this work, we investigate the molecular mechanisms of Pc for chitosan resistance and root‐knot nematode (RKN) parasitism, using transcriptomics. Chitosan and RKN modify the expression of Pc genes, mainly those involved in oxidation–reduction processes. Both agents significantly modify the expression of genes associated to 113 GO terms and 180 Pc genes. Genes encoding putative glycoproteins (Pc adhesives) to nematode eggshell, as well as genes involved in redox, carbohydrate and lipid metabolism trigger the response to chitosan. We identify genes expressed in both the parasitic and endophytic phases of the Pc lifecycle; these include proteases, chitosanases and transcription factors. Using the Pathogen—Host Interaction database (PHI‐base), our previous RNA‐seq data and RT‐PCR of Pc colonizing banana we have investigated genes expressed both in the parasitic and endophytic phases of Pc lifecycle. This work was supported by H2020 MUSA 727624 European Project.

Marine aquaculture releases mollusc shell debris which can accumulate on the seabed. Due to its low degradability, mollusc shell debris becomes integrated into the sediment, modifying both its structure and associated biogeochemical processes. These changes are expected to influence the biological assemblages within the sediment, which play a key role in the biogeochemical processes due to bioturbation. We performed an in-situ experiment to test the effects of mollusc shell-hash on the bioturbation capacity of the macrofaunal assemblages within the sediments affected by marine aquaculture. The aquaculture facilities chosen were a fish farm in an oligotrophic area of the Mediterranean over a sandy sediment, and a mussel farm in the Atlantic located in an estuary over silty sediment. Mollusc shell-hash promoted macrofaunal assemblages with a high bioturbation potential, regardless of the influence of aquaculture. Nevertheless, in the sediment from the mussel-farm, the shell-hash did not have a marked effect on the macrofaunal assemblages. The effect of shell-hash on promoting macrofaunal communities with a high bioturbation potential capacity is therefore dependent on the existing environmental conditions in the area, including the natural organic matter input and grain size of the sediment. Shell-hash could be used a strategy to improve the ecosystem function of sediments as a circular economy-oriented management practice. This research was funded by the project CGL2015-70136-R from the Spanish National Agency for Research (MINECO/FEDER). CS was funded by the University of Alicante (Ref. UATALENTO 17-11).

La asignatura de Estadística en el grado en Óptica y Optometría de la Universidad de Alicante cuenta con apenas seis horas de prácticas con ordenador, en las que se introduce al alumnado en el manejo básico del popular software estadístico de código abierto R. Para poner en valor esas horas y favorecer el aprendizaje de este programa mediante la interfaz conocida por RStudio, hemos decidido crear videotutoriales de corta duración que se han publicado en la plataforma Youtube, mostrando cómo se realizan con R distintas actividades como la obtención de gráficas y medidas descriptivas, y el cálculo de probabilidades. Tras evaluar la experiencia con dos cuestionarios, uno anterior y otro posterior a la misma, concluimos que la acogida global ha sido positiva, que R les parece difícil pero adecuado, y que desconocen en gran medida la importancia de la estadística en su plan de estudios.