DigitalUM :: Browsing by Subject "Bacteria"

Browsing by Subject "Bacteria"

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Open Access
An Interactive Tool for Simulation of Biological Models Into the Wastewater Treatment With Microalgae
(Frontiers Media, 2021-07-28) Guzmán Sánchez, José Luis; Fernández Sevilla, José María; Acién Fernández, Francisco Gabriel; Sánchez Zurano, Ana; Ingeniería Química
Este trabajo presenta una novedosa herramienta de simulación para comprender y analizar modelos biológicos para procesos de tratamiento de aguas residuales utilizando microalgas. Los modelos para este tipo de procesos son muy complejos de analizar debido a los muy diferentes fenómenos, variables y parámetros involucrados. El modelo ya incluido en la herramienta ha sido validado en condiciones controladas que simulan las condiciones exteriores, resultando útil para simular cultivos reales al aire libre. La principal contribución de la herramienta propuesta es que estos modelos pueden simularse y compararse de manera fácil e interactiva. La herramienta permite simular modelos biológicos considerando solo microalgas o incluyendo el consorcio microalgas-bacterias. Además, las simulaciones se pueden realizar utilizando únicamente la contribución de la radiación solar o agregando los efectos ambientales y bacterianos como términos cardinales. Asimismo, se pueden evaluar los efectos de las propiedades de las aguas residuales o de diferentes cepas de microalgas. Las simulaciones interactivas se pueden realizar para días seleccionados como representativos de las diferentes estaciones del año que ya están precargadas en la herramienta. Sin embargo, el usuario también puede cargar datos de otras ubicaciones para simular los modelos en condiciones particulares.
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Artemisia pollen is the main vector for airborne endotoxin
(Elsevier, 2018-08-09) Oteros, José; Bartusel, Elke; Alessandrini, Francesca; Núñez, Andrés; Moreno, Diego A.; Behrendt, Heidrun; Schmidt-Weber, Carsten; Traidl-Hoffmann, Claudia; Buters, Jeroen; Genética y Microbiología
Background: Endotoxin (LPS) released from gram-negative bacteria causes strong immunologic and inflammatory effects and, when airborne, can contribute to respiratory conditions, such as allergic asthma. Objectives: We sought to identify the source of airborne endotoxin and the effect of this endotoxin on allergic sensitization. Methods: We determined LPS levels in outdoor air on a daily basis for 4 consecutive years in Munich (Germany) and Davos (Switzerland). Air was sampled as particulate matter (PM) greater than 10 μm (PM > 10) and PM between 2.5 and 10 μm. LPS levels were determined by using the recombinant Factor C assay. Results: More than 60% of the annual endotoxin exposure was detected in the PM > 10 fraction, showing that bacteria do not aerosolize as independent units or aggregates but adhered to large particles. In Munich 70% of annual exposure was detected between June 12th and August 28th. Multivariate modeling showed that endotoxin levels could be explained by phenological parameters (ie, plant growth). Indeed, days with high airborne endotoxin levels correlated well with the amount of Artemisia pollen in the air. Pollen collected from plants across Europe (100 locations) showed that the highest levels of endotoxin were detected on Artemisia vulgaris (mugwort) pollen, with little on other pollen. Microbiome analysis showed that LPS concentrations on mugwort pollen were related to the presence of Pseudomonas species and Pantoea species communities. In a mouse model of allergic disease, the presence of LPS on mugwort pollen was needed for allergic sensitization. Conclusions: The majority of airborne endotoxin stems from bacteria dispersed with pollen of only one plant: mugwort. This LPS was essential for inducing inflammation of the lung and allergic sensitization.
Open Access
Assessment and statistical modelling of airborne microorganisms in Madrid
(Elsevier, 2020-11-21) Cordero, José María; Núñez, Andrés; García, Ana M.; Borge, Rafael; Genética y Microbiología
The limited evidence available suggests that the interaction between chemical pollutants and biological particles may intensify respiratory diseases caused by air pollution in urban areas. Unlike air pollutants, which are routinely measured, records of biotic component are scarce. While pollen concentrations are daily surveyed in most cities, data related to airborne bacteria or fungi are not usually available. This work presents the first effort to understand atmospheric pollution integrating both biotic and abiotic agents, trying to identify relationships among the Proteobacteria, Actinobacteria and Ascomycota phyla with palynological, meteorological and air quality variables using all biological historical records available in the Madrid Greater Region. The tools employed involve statistical hypothesis contrast tests such as Kruskal-Wallis and machine learning algorithms. A cluster analysis was performed to analyse which abiotic variables were able to separate the biotic variables into groups. Significant relationships were found for temperature and relative humidity. In addition, the relative abundance of the biological phyla studied was affected by PM10 and O3 ambient concentration. Preliminary Generalized Additive Models (GAMs) to predict the biotic relative abundances based on these atmospheric variables were developed. The results (rÂ =Â 0.70) were acceptable taking into account the scarcity of the available data. These models can be used as an indication of the biotic composition when no measurements are available. They are also a good starting point to continue working in the development of more accurate models and to investigate causal relationships.
Open Access
Bacterial community of reindeer lichens differs between northern and southern lichen woodlands
(Canadian Science Publishing, 2022-01-18) Villarreal A., Juan Carlos; Alonso García, Marta; Biología Vegetal
Lichens cover nearly 7% of the earth’s surface, and in eastern Canada, lichen woodlands occupy over 300 000 km2. Reindeer lichens (genus Cladonia) are the main component of lichen woodlands and they play a crucial role in boreal forest ecology. We study, for the first time, the bacterial community of four species of reindeer lichens from eastern North America’s boreal forests. Using the 16S rRNA gene, we characterize the bacterial community of 189 lichen samples. We aim to analyse the effect of geography and host identity in the bacterial community composition and structure, verify the presence of a common core bacteria, and identify the most abundant core taxa. Our results suggest that host-lichen identity does not determine bacterial community composition and structure in reindeer lichens, but we confirm the influence of geography in shaping the diversity and abundance of bacteria associated with Cladonia stellaris. We also reveal that reindeer lichens share a reduced common core bacteria composed exclusively by Alphaproteobacteria. Northern lichen woodlands exhibit a significantly higher diversity and abundance of bacteria associated with C. stellaris than southern lichen woodlands do. The presence of the species Methylorosula polaris in the core bacteria is evident and may have a particular importance for reindeer lichens.
Open Access
Bacterial sirtuins overview: an open niche to explore
(Frontiers, 2021-10-26) Lozano Terol, Gema; Cánovas Díaz, Manuel; Diego Puente, Teresa de; Gallego Jara, Julia; Ortega Retuerta, Álvaro; Sola Martínez, Rosa Alba; Bioquímica y Biología Molecular B e Inmunología
Open Access
Bacterial sirtuins overview: an open niche to explore
(Frontiers Media, 2021-10-26) Lozano Terol, Gema; Cánovas Díaz, Manuel; Diego Puente, Teresa de; Gallego Jara, Julia; Ortega Retuerta, Álvaro; Sola Martínez, Rosa Alba; Bioquímica y Biología Molecular B e Inmunología
Sirtuins are deacetylase enzymes widely distributed in all domains of life. Although for decades they have been related only to histones deacetylation in eukaryotic organisms, today they are considered global regulators in both prokaryotes and eukaryotes. Despite the important role of sirtuins in humans, the knowledge about bacterial sirtuins is still limited. Several proteomics studies have shown that bacterial sirtuins deacetylate a large number of lysines in vivo, although the effect that this deacetylation causes in most of them remains unknown. To date, only the regulation of a few bacterial sirtuin substrates has been characterized, being their metabolic roles widely distributed: carbon and nitrogen metabolism, DNA transcription, protein translation, or virulence. One of the most current topics on acetylation and deacetylation focuses on studying stoichiometry using quantitative LC-MS/MS. The results suggest that prokaryotic sirtuins deacetylate at low stoichiometry sites, although more studies are needed to know if it is a common characteristic of bacterial sirtuins and its biological significance. Unlike eukaryotic organisms, bacteria usually have one or few sirtuins, which have been reported to have closer common ancestors with the human Sirt5 than with any other class. In this work, in addition to carrying out an in-depth review of the role of bacterial sirtuins in their physiology, a phylogenetic study has been performed that reveals the evolutionary differences between sirtuins of different bacterial species and even between homologous sirtuins.
Open Access
Bacterial Sirtuins Overview: An Open Niche to Explore
(Frontiers, 2021-09-26) Lozano Terol, Gema; Cánovas Díaz, Manuel; Diego Puente, Teresa de; Gallego Jara, Julia; Ortega Retuerta, Álvaro; Sola Martínez, Rosa Alba; Bioquímica y Biología Molecular B e Inmunología
Sirtuins are deacetylase enzymes widely distributed in all domains of life. Although for decades they have been related only to histones deacetylation in eukaryotic organisms, today they are considered global regulators in both prokaryotes and eukaryotes. Despite the important role of sirtuins in humans, the knowledge about bacterial sirtuins is still limited. Several proteomics studies have shown that bacterial sirtuins deacetylate a large number of lysines in vivo, although the effect that this deacetylation causes in most of them remains unknown. To date, only the regulation of a few bacterial sirtuin substrates has been characterized, being their metabolic roles widely distributed: carbon and nitrogen metabolism, DNA transcription, protein translation, or virulence. One of the most current topics on acetylation and deacetylation focuses on studying stoichiometry using quantitative LC-MS/MS. The results suggest that prokaryotic sirtuins deacetylate at low stoichiometry sites, although more studies are needed to know if it is a common characteristic of bacterial sirtuins and its biological significance. Unlike eukaryotic organisms, bacteria usually have one or few sirtuins, which have been reported to have closer phylogenetic similarity with the human Sirt5 than with any other human sirtuin. In this work, in addition to carrying out an in-depth review of the role of bacterial sirtuins in their physiology, a phylogenetic study has been performed that reveals the evolutionary differences between sirtuins of different bacterial species and even between homologous sirtuins.
Open Access
Bovine oviduct epithelial cells suppress the phagocytic activity of neutrophils towards sperm but not for bacteria in vitro: Immunofluorescence and electron microscopic observations
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Marey, Mohamed Ali; Matsukawa, Haruhisa; Sasaki, Motoki; Ezz, Mohamed Aboul; Yousef, Mohamed Samy; Takahashi, Ken-ichi; Miyamoto, Akio
Previously, we reported that polymorpho- nuclear neutrophils (PMNs) are constantly existent in the bovine oviduct fluid during the pre-ovulatory stage under physiological conditions. Moreover, incubation of PMNs with bovine oviduct epithelial cells-conditioned medium (BOEC-CM) resulted in suppression of their phagocytic activity for sperm. During pathophysiological conditions, cows may be inseminated by infected semen which exposes oviductal PMNs to allogenic sperm simultaneously with pathogens. This study aimed to visually investigate the role of oviduct epithelium in regulating the phagocytic behavior of PMNs toward sperm as a physiological stimulus, with Escherichia coli (E. coli) as a pathological stimulus. In our experiment, PMNs were incubated for 2 h in BOEC-CM. Phagocytosis was then assayed by co-incubation of these PMNs either with sperm, E. coli, or latex beads. BOEC- CM significantly suppressed the direct phagocytosis of PMNs for sperm, but did not affect their phagocytic activity for E. coli or latex beads. Additionally, an investigation with scanning electron microscopy revealed that BOEC-CM suppressed the formation of DNA-based neutrophil extracellular traps (NETs) for sperm entanglement. BOEC-CM did not alter NETs formation towards E. coli. A quantification of NETs formation using an immunofluorescence microscopy showed that the areas of NETs formation for E. coli were significantly larger than those formed for sperm. Our data clearly show that the bovine oviduct, through secretions, protects sperm from phagocytosis by PMNs and eliminates bacterial dissemination through maintaining the phagocytic activity of PMNs towards bacteria
Open Access
Byproducts from cassava industry: alternative substrates for cyclodextrin glycosyltransferase production by alkalophilic Bacillus trypoxylicola SM-02
(Murcia: Servicio de Publicaciones de la Universidad de Murcia, 2020) Peixoto, Carine Mascena; Coelho, Sheila Lorena de Araújo; Cazetta, Marcia Luciana
In the present work was studied the use of cassava peel flour (CPF), corn steep liquor (CSL), and cassava wastewater as substrates to produce cyclodextrin glycosyltransferase (CGTase) from a new alkalophilic isolate of Bacillus trypoxylicola SM-02 by submerged fermentation. The experiments were performed as a Central Composite Design 22 , totalizing 11 assays. An enzymatic activity of 352.53 U/mL was obtained using 1.5 g of CPF and 0.6 g of CSL. The optimum temperature and pH of CGTase was 55 °C and 8.0, respectively. The CGTase depicted a relative activity of more than 50% for 120 min at the optimum temperature. The only salt that positively influenced the CGTase activity was CaCl2. The results are indicative of a potential role of B. trypoxylicola SM-02 in the production of CGTase using residual substrates.
Embargo
Chapter 2: Bacterial Laccases: Some Recent Advances and Applications
(Springer Nature Switzerland AG 2020, 2020) Martins, Ligia O.; Pinho Melo, Eduardo; Sanchez-Amat, Antonio; Robalo, Maria Paula; Genética y Microbiología
Laccases belong to the large family of multi-copper oxidases (MCOs) that couple the one-electron oxidation of substrates with the four-electron reduction of molecular oxygen to water. Because of their high relative non-specific oxidation capacity particularly on phenols and aromatic amines as well as the lack of requirement for expensive organic cofactors, they have found application in a large number of biotechnological fields. The vast majority of studies and applications were performed using fungal laccases, but bacterial laccases show interesting properties such as optimal temperature above 50 ºC, optimal pH at the neutral to alkaline range, thermal and chemical stability and increased salt tolerance. Additionally, bacterial systems benefit from a wide range of molecular biology tools that facilitates their engineering and achievement of high yields of protein production and set-up of costeffective bioprocesses. In this review we will provide up-to-date information on the distribution and putative physiological role of bacterial laccases and highlight their distinctive structural and biochemical properties, discuss the key role of copper in the biochemical properties, discuss thermostability determinants and, finally, review biotechnological applications with a focus on catalytic mechanisms on phenolics and aromatic amines.
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Effects of living cyanobacteria, cyanobacterial extracts and pure microcystins on growth and ultrastructure of microalgae and bacteria
(Elsevier, 2006-12-02) Aboal Sanjurjo, Marina; Valdor Alonso, Rut; Bioquímica y Biología Molecular B e Inmunología
In this study, we demonstrate the inhibitory effect of both cyanobacterial extracts and pure microcystins on the growth of microalgae and bacteria. This inhibitory effect was more persistent in pure microcystins than in the extracts, which lost their properties eight days after exposure. In addition, the effects on bacteria were longerlasting than those on microalgae. The microalgae exposed to both extracts and cultures of microcystin producing species showed morphological and ultrastructural alterations, even in cases where there was no clear effect on growth. The implications for colonisation and benthic communities structure and development are discussed in the context of biomonitoring.
Open Access
Evolution of the gasdermin family and pyroptosis
(Elsevier, 2023-09-19) Angosto-Bazarra, Diego; Guijarro, Adriana; Pelegrín Vivancos, Pablo; Bioquímica y Biología Molecular B e Inmunología
Gasdermins have been identified as playing a prominent role in the innate immune response as the executors of a specific type of cell death called pyroptosis. Specific proteolytic cleavage of gasdermins generates an N-terminal that oligomerizes and forms pores in the cell membrane. Although pyroptosis has been widely described in mammals, the importance of gasdermins and gasdermin-like proteins in inducing cell death in other vertebrates, in invertebrates and in other taxa including fungi and bacteria is still being determined. Mammalian, fungal and bacterial gasdermins have in common the fact that they go through the same stages (such as proteolytic activation) when inducing membrane rupture, which suggests that pyroptosis is as an ancient mechanism. In this review, we summarize the evolution and function of the gasdermin and gasdermin-like proteins in animals, fungi and bacteria.
Open Access
Flora microbiana en mieles de la región de Murcia, España
(Murcia: Universidad de Murcia, Servicio de Publicaciones, 1997) Pérez Sánchez, María Consuelo; Baño Breis, Francisco del; Candela Castillo, María Emilia; Egea Gilabert, Catalina; Facultad de Biología
Se han analizado, desde el punto de vista microbiológico, dieciocho muestras de miel de la Región de Murcia (España), y en ningúna de ellas se encontraron mieles fermentadas o alteradas. Todas las muestras contienen esporas fúngicas, procedentes de hongos del suelo y también de hongos parásitos de insectos o de plantas. Los géneros más abundantes fueron: Aspergillus, presente en trece muestras, Alternaria en once, Pullularia en diez, Penicillium en siete y Cladosporium en cinco. Las levaduras, representadas por el género Candida, solamente se detectaron en dos muestras. El análisis bacteriano fue cualitativo y cuantitativo. Once muestras dieron positivo para anaerobias termófilas. En medio PCA se identificaron Micrococcus roseus y Bacillus subtilis que no producen alteraciones e, incluso, pueden ser importantes en la elaboración del pan de abejas. En ninguna muestra de miel se encontraron coliformes o Salmonella.
Open Access
Histopathology, microbiology and the inflammatory process associated with Sarcoptes scabiei infection in the Iberian ibex, Capra pyrenaica
(Springer Nature, 2017-12-04) Espinosa, José; Ráez-Bravo, Arián; López-Olvera, Jorge R.; Pérez, Jesús M.; Lavín, Santiago; Tvarijonaviciute, Asta; Cano-Manuel, Francisco J.; Fandos, Paulino; Soriguer, Ramón C.; Granados, José Enrique; Romero García, Diego; Velarde, Roser; Ciencias Sociosanitarias
Background: Sarcoptic mange has been identified as the most significant infectious disease affecting the Iberian ibex (Capra pyrenaica). Despite several studies on the effects of mange on ibex, the pathological and clinical picture derived from sarcoptic mange infestation is still poorly understood. To further knowledge of sarcoptic mange pathology, samples from ibex were evaluated from histological, microbiological and serological perspectives. Methods: Samples of skin, non-dermal tissues and blood were collected from 54 ibex (25 experimentally infected, 15 naturally infected and 14 healthy). Skin biopsies were examined at different stages of the disease for quantitative cellular, structural and vascular changes. Sixteen different non-dermal tissues of each ibex were taken for histological study. Acetylcholinesterase and serum amyloid A protein levels were evaluated from blood samples from ibex with different lesional grade. Samples of mangy skin, suppurative lesions and internal organs were characterized microbiologically by culture. Bacterial colonies were identified by a desorption/ionization time-of-flight mass spectrometry system (MALDI TOF/TOF). Results: The histological study of the skin lesions revealed serious acanthosis, hyperkeratosis, rete ridges, spongiotic oedema, serocellular and eosinophilic crusts, exocytosis foci, apoptotic cells and sebaceous gland hyperplasia. The cellular response in the dermis was consistent with type I and type IV hypersensitivity responses. The most prominent histological findings in non-dermal tissues were lymphoid hyperplasia, leukocytosis, congestion and the presence of amyloid deposits. The increase in serum concentrations of acetylcholinesterase and amyloid A protein correlated positively with the establishment of the inflammatory response in mangy skin and the presence of systemic amyloidosis. A wide variety of bacterial agents were isolated and the simultaneous presence of these in mangy skin, lymph nodes and internal organs such as lungs, liver, spleen and kidney was compatible with a septicaemic pattern of infection. Conclusions: The alteration of biomarkers of inflammation and its implication in the pathogenesis of the disease and development of lesions in non-dermal tissues and septicaemic processes are serious conditioners for the survival of the mangy ibex. This severe clinical picture could be an important factor when considering the decision to eliminate animals that exceed a certain disease threshold from a population.
Embargo
In vitro study of the antibacterial properties and microbial colonization susceptibility of four self-etching adhesives used in orthodontics
(Oxford University Press, 2013-05-29) Jacobo, Carmen; Torrella, Francisco; Bravo González, Luis Alberto; Ortiz Ruiz, Antonio José; Vicente, Ascensión; Dermatología, Estomatología, Radiología y Medicina Física
OBJECTIVES: 1. To determine the in vitro antibacterial effectiveness of the orthodontic bonding Transbond XT (3M Unitek) and four self-etching adhesives with possible use in orthodontic bonding (Clearfil Protect Bond, CPB; Clearfil Self-etching Bond, CSB; Transbond Plus Self-Etching Primer, TSEP; iBond) against Streptococcus mutans and Lactobacillus gasseri in order to compare that capacity among the adhesives and with respect to Transbond XT; 2. To determine the bacterial adhesion capacity of the above mentioned microorganisms to the tested adhesives. MATERIALS AND METHODS: The inhibitory effects of the adhesives against S. mutans and L. gasseri were examined using the agar diffusion method with Whatman No.1 5mm disks loaded with 15 μl of adhesive, UV polymerized, layered on previously inoculated BHI and MRS plates incubated microaerobically for 48 hours at 37 degree C. Data were analysed with Kruskal–Wallis (P < 0.05) and Mann–Whitney tests, applying the Bonferroni correction (P < 0.003). Bacterial adhesion was studied with scanning electron microscopy. RESULTS: Only CPB and iBond produced a clear growth inhibition halo against S. mutans and L. gasseri (P < 0.0001). iBond was the only tested product to which the bacteria adhere profusely, particularly S. mutans. CONCLUSIONS: CPB has shown antimicrobial properties in vitro, and, provided the limitations of an in vitro study, the use of this self-etching adhesive may contribute to reduce microbial decalcification, making the use of this self-etching adhesive an attractive option for bracket bonding.
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Microbiologically influenced corrosion on naval carbon steel inside the hull of tugboats: a case study of prevention and control
(Taylor & Francis Group, 2023-05-11) Núñez, Andrés; García, Ana M.; Ranninger, Carlos; Moreno, Diego A.; Genética y Microbiología
Microbiologically influenced corrosion (MIC) has a significant cost to many industries, including naval engineering. In this case-of-study, three tugboats developed pitting corrosion in the carbon steel of the inner hulls. Grade A naval steel was used for the hull sheets but the inner side (corroded) showed only two protective layers of paint. The maintenance employed seawater, which ended up in the bilge and made MIC possible. Bilge’s waters were submitted to physicochemical, biological and molecular tests. DNA analyses confirmed the presence of Pseudomonas spp. and Desulfovibrio spp. in water samples and, consequently, a MIC mechanism was proposed to explain the corrosion process. In addition, a biocide treatment was evaluated and a new maintenance protocol was recommended. This work highlights the importance of the engineering design to prevent MIC in marine transports and provides some guidelines to treat it.
Open Access
Saharan dust storms affecting the center of the Iberian Peninsula: effect on the urban aerobiome
(Elsevier, 2024-04-16) Núñez, Andrés; Moreno, Diego A.; García, Ana M.; Genética y Microbiología
Dust storms are known to be atmospheric phenomena that transport mineral dust but also airborne biological particles (bioaerosols) from desert areas to distant regions. These bioaerosols can influence atmospheric processes and they have the potential of changing the composition of the local aerobiome in urban areas, which, in recent years, have been associated with allergies and the exacerbation of respiratory syndromes. Here, we studied four dust events initiated in the Sahara Desert affecting the center of the Iberian Peninsula. The biological particles before and during the phenomena were analyzed by high-throughput DNA sequencing. The global composition of bioaerosols showed a marked seasonality. The relative abundances of the most predominant groups of bacteria and fungi were not significantly altered compared to the days prior the corresponding event. Nonetheless, we detected specific bacterial and fungal taxa associated with these events, whose composition and abundance were also related to the period of the year. Although a variety of plant and animal pathogens were identified both before and throughout the days influenced by dust storms, some were only detected during the latter, suggesting a long-range transport for these species. This work highlights the importance of analyzing the storm dust events separately, especially when they occur at different seasons, and the particular effect on an urban environment in the Iberian Peninsula as a model case, providing some recommendations for future studies.
Open Access
Seasonal changes dominate long-term variability of the urban air microbiome across space and time
(Elsevier, 2021-02-09) Núñez, Andrés; García, Ana M.; Moreno, Diego A.; Guantes, Raúl; Genética y Microbiología
Compared to soil or aquatic ecosystems, the atmosphere is still an underexplored environment for microbial diversity. In this study, we surveyed the composition, variability and sources of microbes (bacteria and fungi) in the near surface atmosphere of a highly populated area, spanning ~ 4,000 Km2 around the city center of Madrid (Spain), in different seasonal periods along two years. We found a core of abundant bacterial genera robust across space and time, most of soil origin, while fungi were more sensitive to environmental conditions. Microbial communities showed clear seasonal patterns driven by variability of environmental factors, mainly temperature and accumulated rain, while local sources played a minor role. We also identified taxa in both groups characteristic of seasonal periods, but not of specific sampling sites or plant coverage. The present study suggests that the near surface atmosphere of urban environments contains an ecosystem stable across relatively large spatial and temporal scales, with a rather homogenous composition, modulated by climatic variations. As such, it contributes to our understanding of the long-term changes associated to the human exposome in the air of highly populated areas.
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Temporal patterns of variability for prokaryotic and eukaryotic diversity in the urban air of Madrid (Spain)
(Elsevier, 2019-09-10) Núñez, Andrés; Amo de Paz, Guillermo; Rastrojo, Alberto; Ferencova, Zuzana; Gutiérrez-Bustillo, A. Montserrat; Alcamí, Antonio; Moreno, Diego A.; Guantes, Raúl; Genética y Microbiología
Although many microorganisms are ubiquitously present in the air, airborne microbial communities have been much less characterized than those in soil or aquatic environments. Besides its ecological importance, detection and monitoring of the wide diversity of these aerosolized microorganisms (bacteria, viruses, fungi and pollen) is relevant for understanding allergy and disease outbreaks, especially in highly populated cities. In this study, we describe the simultaneous biodiversity of bacteria, fungi and plants present in the urban atmosphere of Madrid (Spain) along different seasonal periods, using DNA sequencing. Sampling in two different locations (downtown and peri-urban) we found that changes in the composition of each community are mainly driven by environmental factors, rather than by the features of the specific sampling microenvironments. While pollen particles are dominated by a few taxa characteristic of each season, bacteria and fungi show a high diversity but stable core communities along the year. The prokaryotic core is governed by soil and leaf surface bacteria, with predominance of Actinobacteria (Frankiales and Micrococcales) and Alphaproteobacteria (Sphingomonadales, Rhodobacterales, Rhizobiales and Acetobacterales). Fungal diversity is characterized by the steady presence of members of Capnodiales and Pleosporales. Pathogenic bacterial and fungal taxa were also detected across the year. We also correlated the airborne biodiversity with environmental variables. Air temperature has a strong influence on the community composition of bacteria, while pollen and fungi seasonal variations are mainly correlated with precipitation. Our results contribute to the characterization of airborne prokaryotic and eukaryotic communities in urban areas and show the suitability of this method for biosurveillance strategies.
Open Access
The differential vertical distribution of the airborne biological particles reveals an atmospheric reservoir of microbial pathogens and aeroallergens
(Springer, 2020-03-27) Núñez, Andrés; Moreno, Diego A.; Genética y Microbiología
The most abundant biological particles present in the air are bacteria, fungal propagules and pollen grains. Many of them are proved allergens or even responsible for airborne infectious diseases, which supports the increase of studies in recent years on their composition, diversity, and factors involved in their variability. However, most studies in urban areas are conducted close to ground level and a factor such as height is rarely taken into account. Thus, the information about how the composition of biological particles changes with this variable is scarce. Here, we examined the differential distribution of bacteria, fungi, and plants at four altitudes (up to ∼ 250 m) in a metropolitan area using high-throughput DNA sequencing. Most taxa were present at all levels (common taxa). However, a transitional layer between 80 and 150 m seemed to affect the scattering of these bioaerosols. Taxa not present at all altitudes (non-common) showed an upward tendency of diversity for bacteria and plants with height, while the opposite trend was observed for fungi. Certain patterns were observed for fungi and specific plant genera, while bacterial taxa showed a more arbitrary distribution and no patterns were found. We detected a wide variety of aeroallergens and potential pathogens at all heights, which summed a substantial portion of the total abundance for fungi and plants. We also identified potential connections between the biological particles based on their abundances across the vertical section.

Browsing by Subject "Bacteria"

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