RESUMO
Since prophages can play a multifaceted role in bacterial evolution, this study aims to characterize the virome of Rummeliibacillus stabekisii, a bacterium isolated from different environments, including Antarctic soil and NASA spacecraft floors. From the analyses, it was found that the Antarctic strain, PP9, had the largest number of prophages, including intact ones, indicating potential benefits for survival in adverse conditions. In contrast, other strains harbored predominantly degenerate prophages, suggesting a dynamic process of gene gain and loss during evolution. Furthermore, strain PP9 exhibited polylysogeny, a strategy capable of increasing its competitive advantage by providing a broader spectrum of defensive mechanisms. In addition, evidence demonstrates that prophage regions in PP9 act as hotspots for recombination events, favoring the insertion of different phages and possible antimicrobial resistance genes. Finally, lytic cycle induction experiments revealed at least two intact prophages active in PP9. In this way, understanding the interaction between viruses and bacteria can provide valuable information about microbial evolution and adaptation in extreme environments, such as Antarctica.
Assuntos
Ambientes Extremos , Prófagos , Microbiologia do Solo , Regiões Antárticas , Prófagos/genética , Astronave , Evolução Molecular , Lisogenia , Bacillaceae/genética , Bacillaceae/virologia , Bacillaceae/isolamento & purificaçãoRESUMO
Drylands' poly-extreme conditions limit edaphic microbial diversity and functionality. Furthermore, climate change exacerbates soil desiccation and salinity in most drylands. To better understand the potential effects of these changes on dryland microbial communities, we evaluated their taxonomic and functional diversities in two Southern African dryland soils with contrasting aridity and salinity. Fungal community structure was significantly influenced by aridity and salinity, while Bacteria and Archaea only by salinity. Deterministic homogeneous selection was significantly more important for bacterial and archaeal communities' assembly in hyperarid and saline soils when compared to those from arid soils. This suggests that niche partitioning drives bacterial and archaeal communities' assembly under the most extreme conditions. Conversely, stochastic dispersal limitations drove the assembly of fungal communities. Hyperarid and saline soil communities exhibited similar potential functional capacities, demonstrating a disconnect between microbial structure and function. Structure variations could be functionally compensated by different taxa with similar functions, as implied by the high levels of functional redundancy. Consequently, while environmental selective pressures shape the dryland microbial community assembly and structures, they do not influence their potential functionality. This suggests that they are functionally stable and that they could be functional even under harsher conditions, such as those expected with climate change.
Assuntos
Archaea , Bactérias , Fungos , Microbiota , Salinidade , Microbiologia do Solo , Bactérias/genética , Bactérias/classificação , Archaea/genética , Archaea/classificação , Fungos/genética , Fungos/classificação , Mudança Climática , Clima Desértico , Solo/química , Ambientes Extremos , África Austral , BiodiversidadeRESUMO
The Atacama Desert in Chile is one of the driest and most inhospitable places on Earth. To analyze the diversity and distribution of microbial communities in such an environment, one of the most important and challenging steps is DNA extraction. Using commercial environmental DNA extraction protocols, a mixture of living, dormant, and dead cells of microorganisms is extracted, but separation of the different DNA pools is almost impossible. To overcome this problem, we applied a novel method on soils across a west-east moisture transect in the Atacama Desert to distinguish between extracellular DNA (eDNA) and intracellular DNA (iDNA) at the cell extraction level. Here, we show that a large number of living and potentially active microorganisms, such as Acidimicrobiia, Geodermatophilaceae, Frankiales, and Burkholderiaceae, occur in the hyperarid areas. We observed viable microorganisms involved as pioneers in initial soil formation processes, such as carbon and nitrogen fixation, as well as mineral-weathering processes. In response to various environmental stressors, microbes coexist as generalists or specialists in the desert soil environment. Our results show that specialists compete in a limited range of niches, while generalists tolerate a wider range of environmental conditions. Use of the DNA separation approach can provide new insights into different roles within viable microbial communities, especially in low-biomass environments where RNA-based analyses often fail.IMPORTANCEThe novel e- and iDNA separation technique offers insights into the living community at the cell extraction level in the hyperarid Atacama Desert. This approach provides a new framework for analyzing the composition and structure of the potentially active part of the microbial communities as well as their specialization, ecological network and community assembly process. Our findings underscore the significance of utilizing alternative genomic techniques in low-biomass environments where traditional DNA- and RNA-based analyses may not be feasible. The results demonstrate the viability of the proposed study framework and show that specialized microorganisms are important in initial soil formation processes, including microbial-driven mineral weathering, as well as the fixation of carbon and nitrogen.
Assuntos
Bactérias , Clima Desértico , Ambientes Extremos , Microbiota , Microbiologia do Solo , Chile , Bactérias/genética , Bactérias/classificação , Bactérias/isolamento & purificação , DNA Bacteriano/genética , Solo/químicaRESUMO
We surveyed the presence of perchlorate-reducing microorganisms in available metagenomic data of halite environments from the Atacama Desert, an extreme environment characterized by high perchlorate concentrations, intense ultraviolet radiation, saline and oxidizing soils, and severe desiccation. While the presence of perchlorate might suggest a broad community of perchlorate reducers or a high abundance of a dominant taxa, our search reveals a scarce presence. In fact, we identified only one halophilic species, Salinibacter sp003022435, carrying the pcrA and pcrC genes, represented in low abundance. Moreover, we also discovered some napA genes and organisms carrying the nitrate reductase nasB gene, which hints at the possibility of cryptic perchlorate reduction occurring in these ecosystems. Our findings contribute with the knowledge of perchlorate reduction metabolism potentially occurring in halites from Atacama Desert and point towards promising future research into the perchlorate-reducing mechanism in Salinibacter, a common halophilic bacterium found in hypersaline ecosystems, whose metabolic potential remains largely unknown.
Assuntos
Clima Desértico , Ambientes Extremos , Oxirredução , Percloratos , Percloratos/metabolismo , Metagenoma , MicrobiotaRESUMO
Chile is unique because of its diverse extreme environment, ranging from arid climates in the north to polar climates in Patagonia. Microorganisms that live in these environments are called extremophiles, and these habitats experience intense ecosystem changes owing to climate warming. Most studies of extremophiles have focused on their biotechnological potential; however, no study has examined how students describe extremophiles. Therefore, we were interested in answering the following question: How do schoolchildren living in extreme environments describe their environments and extremophiles? We performed an ethnographic study and analyzed the results of 347 representative drawings of participants aged 12-16 years from three schools located in the extreme environments of Chile San Pedro de Atacama (hyper-arid, 2,400 m), Lonquimay (forest, 925 m), and Punta Arenas (sub-Antarctic, 34 m). The social representation approach was used to collect data, and systemic networks were used to organize and systematize the drawings. The study found that, despite differences between extreme environments, certain natural elements, such as trees and the sun, are consistently represented by schoolchildren. The analysis revealed that the urban and rural categories were the two main categories identified. The main systemic networks were rural-sun (21,1%) for hyper-arid areas, urban-tree (14,1%) for forest areas, and urban-furniture (23,4%) for sub-Antarctic areas. When the results were analyzed by sex, we found a statistically significant difference for the rural category in the 7th grade, where girls mentioned being more rural than boys. Students living in hyper-arid areas represented higher extremophile drawings, with 57 extremophiles versus 20 and 39 for students living in sub-Antarctic and forest areas, respectively. Bacteria were extremophiles that were more represented. The results provide evidence that natural variables and semantic features that allow an environment to be categorized as extreme are not represented by children when they are focused on and inspired by the environment in which they live, suggesting that school literacy processes impact representations of their environment because they replicate school textbooks and not necessarily their environment.
Assuntos
Extremófilos , Masculino , Criança , Feminino , Humanos , Chile , Ecossistema , Ambientes Extremos , Biotecnologia , ÁrvoresRESUMO
Extreme environmental conditions have profound impacts on shaping the evolutionary trajectory of organisms. Exposure to these conditions elicits stress responses, that can trigger phenotypic changes in novel directions. The Mexican Tetra, Astyanax mexicanus, is an excellent model for understanding evolutionary mechanisms in response to extreme or new environments. This fish species consists of two morphs; the classical surface-dwelling fish and the blind cave-dwellers that inhabit dark and biodiversity-reduced ecosystems. In this review, we explore the specific stressors present in cave environments and examine the diverse adaptive strategies employed by cave populations to not only survive but thrive as successful colonizers. By analyzing the evolutionary responses of A. mexicanus, we gain valuable insights into the genetic, physiological, and behavioral adaptations that enable organisms to flourish under challenging environmental conditions.
Assuntos
Adaptação Fisiológica , Evolução Biológica , Cavernas , Characidae , Ambientes Extremos , Estresse Fisiológico , Animais , Characidae/fisiologia , Estresse Fisiológico/fisiologiaRESUMO
Oxic methane production (OMP) has been reported to significantly contribute to methane emissions from oxic surface waters. Demethylation of organic compounds, photosynthesis-associated methane production, and (bacterio)chlorophyll reduction activity are some of the investigated mechanisms as potential OMP sources related to photosynthetic organisms. Recently, cyanobacteria have often been correlated with methane accumulation and emission in freshwater, marine, and saline systems. The Brazilian Pantanal is the world's largest wetland system, with approximately 10,000 shallow lakes, most of which are highly alkaline and saline extreme environments. We initiated this study with an overall investigation using genetic markers, from which we explored metagenomic and limnological data from the Pantanal soda for five potential OMP pathways. Our results showed a strong positive correlation between dissolved methane concentrations and bloom events. Metagenomic data and nutrients, mainly orthophosphate, nitrogen, iron, and methane concentrations, suggest that the organic phosphorous demethylation pathway has the most potential to drive OMP in lakes with blooms. A specialized bacterial community was identified, including the Cyanobacteria Raphidiopsis, although the bloom does not contain the genes to carry out this process. These data showed enough evidence to infer the occurrence of an OMP pathway at Pantanal soda lakes, including the microbial sources and their relation to the cyanobacterial blooms.
Assuntos
Lagos , Organofosfonatos , Brasil , Ambientes Extremos , MetanoRESUMO
A thermophilic, chemolithoautotrophic, and aerobic microbial consortium (termed carbonitroflex) growing in a nutrient-poor medium and an atmosphere containing N2, O2, CO2, and CO is investigated as a model to expand our understanding of extreme biological systems. Here we show that the consortium is dominated by Carbonactinospora thermoautotrophica (strain StC), followed by Sphaerobacter thermophilus, Chelatococcus spp., and Geobacillus spp. Metagenomic analysis of the consortium reveals a mutual relationship among bacteria, with C. thermoautotrophica StC exhibiting carboxydotrophy and carbon-dioxide storage capacity. C. thermoautotrophica StC, Chelatococcus spp., and S. thermophilus harbor genes encoding CO dehydrogenase and formate oxidase. No pure cultures were obtained under the original growth conditions, indicating that a tightly regulated interactive metabolism might be required for group survival and growth in this extreme oligotrophic system. The breadwinner hypothesis is proposed to explain the metabolic flux model and highlight the vital role of C. thermoautotrophica StC (the sole keystone species and primary carbon producer) in the survival of all consortium members. Our data may contribute to the investigation of complex interactions in extreme environments, exemplifying the interconnections and dependency within microbial communities.
Assuntos
Actinobacteria , Alphaproteobacteria , Bacillaceae , Ambientes Extremos , CarbonoRESUMO
BACKGROUND AND AIMS: Trait-based frameworks assess plant survival strategies using different approaches. Some frameworks use functional traits to assign species to a priori defined ecological strategies. Others use functional traits as the central element of a species ecophysiological strategy. We compared these two approaches by asking: (1) what is the primary ecological strategy of three dominant co-occurring shrub species from inselbergs based on the CSR scheme, and (2) what main functional traits characterize the ecophysiological strategy of the species based on their use of carbon, water and light? METHODS: We conducted our study on a Colombian inselberg. In this extreme environment with multiple stressors (high temperatures and low resource availability), we expected all species to be stress tolerant (S in the CSR scheme) and have similar ecophysiological strategies. We measured 22 anatomical, morphological and physiological leaf traits. KEY RESULTS: The three species have convergent ecological strategies as measured by CSR (S, Acanthella sprucei; and S/CS, Mandevilla lancifolia and Tabebuia orinocensis) yet divergent resource-use strategies as measured by their functional traits. A. sprucei has the most conservative carbon use, risky water use and a shade-tolerant strategy. M. lancifolia has acquisitive carbon use, safe water use and a shade-tolerant strategy. T. orinocensis has intermediate carbon use, safe water use and a light-demanding strategy. Additionally, stomatal traits that are easy to measure are valuable to describe resource-use strategies because they are highly correlated with two physiological functions that are hard to measure: stomatal conductance and maximum photosynthesis per unit mass. CONCLUSIONS: The two approaches provide complementary information on species strategies. Plant species can co-occur in extreme environments, such as inselbergs, because they exhibit convergent primary ecological strategies but divergent ecophysiological strategies, allowing them to use limiting resources differently.
Assuntos
Fotossíntese , Folhas de Planta , Folhas de Planta/fisiologia , Carbono , Ambientes Extremos , ÁguaRESUMO
Free-living amoebas (FLAs) are microorganisms, unicellular protozoa widely distributed in nature and present in different environments, such as water or soil; they are maintained in ecosystems and play a fundamental role in the biological control of bacteria, other protozoa, and mushrooms. In particular circumstances, some can reach humans or animals, promoting several health complications. Notably, FLAs are characterized by a robust capacity to survive in extreme environments. However, currently, there is no updated information on the existence and distribution of this protozoan in inhospitable places. Undoubtedly, the cellular physiology of these protozoan microorganisms is very particular. They can resist and live in extreme environments due to their encysting capacity and tolerance to different osmolarities, temperatures, and other environmental factors, which give them excellent adaptative resistance. In this review, we summarized the most relevant evidence related to FLAs and the possible mechanism, which could explain their adaptative capacity to several extreme environments.
Assuntos
Amoeba , Animais , Humanos , Ecossistema , Planetas , Ambientes Extremos , BactériasRESUMO
In Antarctica, human access and presence are complex and require detailed planning and preparation in advance. The personnel of National Antarctic Programs (NAPs, i.e., scientists and support personnel, including military, civilians, and mountaineers) stay in different isolation, confinement, and extreme (ICE) environments such as ships, research stations, and scientific summer camps. Antarctica imposes harsh conditions that influence physiological and psychological responses impacting health, mood, and physical and cognitive performances. In this context, we argue why people should prepare in advance for staying in Antarctica and what to expect in ICE environments. We also spotlighted recommendations shared by different NAPs participant guides, including predeployment training. Next, we present a case study of the Brazilian Pre-Antarctic Training (PAT), a theoretical-practical training that provides technical and logistical information and assesses the adaptability and physical capacity of researchers and military personnel to perform fundamental activities in a polar environment. We evaluated and compared the individual's mood at the beginning and the end of the PAT week and observed group-specific mood changes depending on the sex, functions, and the facilities that participants accessed. Finally, we proposed that conducting training before staying in Antarctica, besides promoting conditions to better plan the voyage and knowledge of the region, can contribute to dealing with the possible mood swings during expeditions and even promote positive affect. Therefore, the psychophysiological effects of PAT are topics for further investigations.
Assuntos
Expedições , Afeto/fisiologia , Regiões Antárticas , Brasil , Ambientes Extremos , HumanosRESUMO
We summarize and elaborate on the challenges of researching in the field of human health in Antarctica based on the conceptual and methodological specificities of a line of investigation that aims to study the human presence in Antarctica in all of its dimensions (biological, psychological, and socio-anthropological). Herein, we discuss the principal results and limitations of the research carried out by researchers of MEDIANTAR (Antarctic medicine, physiology, and anthropology) group of Programa Antártico Brasileiro in isolated, confined, and extreme environments over the last six years. Fieldwork has been carried out in remote research camps, Brazilian navy ships (Almirante Maximiano/H-41 and Ary Rongel/H-44), and Comandante Ferraz Antarctic Station. Adaptative responses to isolated, confined, and extreme environments were studied based on questionnaires, interviews, participative observation, biological samples, anthropometric, and physiological parameters. Our researchers face the unique situation of concomitantly working under the stressful living conditions that are the object of their investigation. A critical examination of the socio-methodological characteristics and challenges of this research niche indicates the need for exchanging the lessons learned and limitations of these practices with researchers in the humanities field, with attention to the human resources needs in multidisciplinary human-related studies.
Assuntos
Adaptação Fisiológica , Ambientes Extremos , Regiões Antárticas , Brasil , Humanos , PesquisadoresRESUMO
The Rio Pearlfish, Nematolebias whitei, is a bi-annual killifish species inhabiting seasonal pools in the Rio de Janeiro region of Brazil that dry twice per year. Embryos enter dormant diapause stages in the soil, waiting for the inundation of the habitat which triggers hatching and commencement of a new life cycle. Rio Pearlfish represents a convergent, independent origin of annualism from other emerging killifish model species. While some transcriptomic datasets are available for Rio Pearlfish, thus far, a sequenced genome has been unavailable. Here, we present a high quality, 1.2 Gb chromosome-level genome assembly, genome annotations, and a comparative genomic investigation of the Rio Pearlfish as representative of a vertebrate clade that evolved environmentally cued hatching. We show conservation of 3D genome structure across teleost fish evolution, developmental stages, tissues, and cell types. Our analysis of mobile DNA shows that Rio Pearlfish, like other annual killifishes, possesses an expanded transposable element profile with implications for rapid aging and adaptation to harsh conditions. We use the Rio Pearlfish genome to identify its hatching enzyme gene repertoire and the location of the hatching gland, a key first step in understanding the developmental genetic control of hatching. The Rio Pearlfish genome expands the comparative genomic toolkit available to study convergent origins of seasonal life histories, diapause, and rapid aging phenotypes. We present the first set of genomic resources for this emerging model organism, critical for future functional genetic, and multiomic explorations of "Eco-Evo-Devo" phenotypes of resilience and adaptation to extreme environments.
Assuntos
Ciprinodontiformes , Fundulidae , Animais , Evolução Biológica , Brasil , Ambientes Extremos , GenomaRESUMO
The photoautotrophic poly(3-hydroxybutyrate) (PHB) production by cyanobacteria is an attractive option as it only requires CO2 and light. In this work, a new wild-type strain producing PHB, Synechococcus elongatus UAM-C/S03, was identified using a polyphasic approach. The strain was cultured in a photobioreactor operated under N-sufficiency conditions at different pH values (7 to 11) and fed with CO2 on demand. We also evaluated the production of PHB under N-starving conditions. Highest biomass productivity, 324 mg L-1 d-1, and CO2 capture, 674 mg L-1 d-1, were obtained at pH 7 and under N-sufficiency conditions. The strain accumulated 29.42% of PHB in dry cell weight (DCW) under N-starvation conditions without pH control, and highest PHB productivity was 58.10 mg L-1 d-1. The highest carbohydrate content registered at pH 8, 50.84% in DCW, along with a release of carbon-based organic compounds, suggested the presence of exopolysaccharides in the culture medium.
Assuntos
Hidroxibutiratos , Synechococcus , Ácido 3-Hidroxibutírico , Ambientes Extremos , PoliésteresRESUMO
The prevalence of mites of the genus Demodex and their associations with host age, gender, workplace, and comorbid skin and ocular conditions were studied in participants in Antofagasta, Chile, which is in a region with an extreme environment. We examined 680 participants aged 18-88 yr using standardized surface skin biopsies. Among them, Demodex had a prevalence of 13.5 % (95% confidence interval, 10.88-16.17). A slightly higher prevalence was observed in males (51.1%; 95% confidence interval, 40.9-61.3; nonsignificant) and participants in the 69-88 yr age group (50.0%; 95% confidence interval, 23.8-76.2; P < 0.05). Regarding the species involved, Demodex folliculorum was found in 89.1% (CI 82.7-95.5) of cases, while D. brevis was found in the remaining 10.9% of cases. A higher prevalence (25.0% CI 16.1-33.91) was observed in participants who worked indoors in generally enclosed and dust-rich environments (such as theaters, libraries, and administrative offices). There was also a strong association between Demodex prevalence and conjunctival hyperemia, with 35.9% (95% confidence interval, 9.1-35; OR 17.9) of the Demodex positive participants having this pathology compared to 10.3% of the noninfested participants. In summary, the prevalence of Demodex in Antofagasta, Chile (13.5%) was toward the lower end of the range reported among other regions around the world. Environmental factors such as exposure to the sun (including ultraviolet rays) or environmental pollution may affect the mites. In addition, Demodex genetics (related to virulence) and the ocular or skin microbiota may positively or negatively influence infestation and pathology.
Assuntos
Distribuição Animal , Clima Desértico , Ambientes Extremos , Infestações por Ácaros/epidemiologia , Ácaros/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Chile/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infestações por Ácaros/parasitologia , Dinâmica Populacional , Prevalência , Especificidade da Espécie , Adulto JovemRESUMO
Antarctica is a space-analog ICE (isolated, cold, and extreme) environment. Cardiovascular and heart autonomic adjustments are key-adaptive physiological responses to Antarctica, both in summer camps and in research stations winter-over. Research fieldwork in ICE environments imposes limitations such as energy restriction, the need for portable and easy-to-handle resources, and resistance of materials to cold and snow/water. Herein, we present the methods we use for cardiac monitoring in the Antarctic field, the limitations of the equipment currently available, and the specific demands for smart wearables to physiological and health tracking in ICE environments, including the increased remote monitoring demand due to COVID-19 restrictions.
Assuntos
Ambientes Extremos , Dispositivos Eletrônicos Vestíveis , Regiões Antárticas , HumanosRESUMO
Os pequenos ruminantes são espécies pouco exigentes e altamente adaptáveis a várias condições ambientais. Por isso, sua distribuição mundial é ampla, encontrando rebanhos desde o nível do mar até 5.000 metros de altitude, em climas quentes e frios, como também em regiões semidesérticas ou chuvosas. Apesar de sua capacidade adaptativa, a exposição a ambientes extremos, como altitudes elevadas e o clima frio subantártico, influenciam negativamente sua eficiência reprodutiva. Neste artigo revisamos os efeitos mais importantes dessas condições extremas sobre várias variáveis reprodutivas em pequenos ruminantes domésticos, analisando alguns mecanismos que medeiam esses efeitos, bem como uma abordagem alternativa que visa melhorar a eficiência reprodutiva nesses ambientes.
Small ruminants are undemanding species and highly adaptable to various environmental conditions. For this reason, they are widely distributed around the world, finding herds from sea level to 5000 meters of altitude, in hot and cold climates, as well as in semi-desert or rainy regions. Despite its adaptive capacity, exposure to extreme environments such as high altitudes and the sub-Antarctic cold climate, negatively influence its reproductive efficiency. In this article we review the most important effects of these extreme conditions on various reproductive variables in small domestic ruminants, analyzing some mechanisms that mediate these effects, as well as an alternative approach aimed to improving reproductive efficiency under these environments.
Assuntos
Animais , Comportamento Reprodutivo , Fenômenos Reprodutivos Fisiológicos , Ruminantes/fisiologia , Ambientes ExtremosRESUMO
The hypersaline lagoons located in evaporation basins or salars (salt flats) in the Atacama Desert are extreme environments harbouring a specialised biota able to survive harsh conditions for life. The knowledge of the parasitic biodiversity of these extreme habitats is still scarce despite their functional importance in regulating relevant non-economic services like habitats of waterbirds. The present study is the first report on the cestode infection of Artemia franciscana Kellogg in Salar de Atacama lagoons in northern Chile. A total of 23 parasite larvae were isolated and identified as belonging to five cestode taxa of the order Cyclophyllidea: two species of the family Hymenolepididae, i.e. Flamingolepis sp. 1 and Flamingolepis sp. 2 (adults parasitic in flamingos); two species of Dilepididae, i.e. Fuhrmannolepis averini (adults parasitic in phalaropes) and Eurycestus avoceti (adult parasitic in charadriforms birds); and one species of Progynotaeniidae, i.e. Gynandrotaenia (?) stammeri (adult parasitic in flamingos). The cysticercoids of each species are described and figured. The study represents the first geographical record of the genera Eurycestus, Gynandrotaenia and Fuhrmannolepis in South America and the first report of Gynandrotaenia and Flamingolepis in A. franciscana in its native range. This survey also contributes to the knowledge of cestodes of Phoenicopteriformes and Charadriiformes and their life cycles in the Neotropical Region. A review of cestodes recorded in brine shrimps of the genus Artemia in the world is provided. Further studies on cestode fauna of aquatic birds and their intermediate hosts in hypersaline habitats of the Neotropical Region are needed to understand their functional role in such extreme and unique ecosystems.
Assuntos
Artemia/parasitologia , Aves/parasitologia , Cestoides/crescimento & desenvolvimento , Infecções por Cestoides/veterinária , Ambientes Extremos , Animais , Aves/classificação , Cestoides/classificação , Cestoides/isolamento & purificação , Infecções por Cestoides/parasitologia , Chile , Ecossistema , Larva/classificação , Larva/crescimento & desenvolvimento , Estágios do Ciclo de VidaRESUMO
Interval timing measures time estimation in the seconds-to-minutes range. Antarctica provides a real-world context to study the effect of extreme photoperiods and isolation on time perception. The aim of this study was to explore interval timing as a cognitive measure in the crew of Belgrano II Argentine Antarctic Station. A total of 13 subjects were assessed for interval timing in short (3 s), intermediate (6 s) and long (12 s) duration stimuli. Measures were taken during the morning and evening, five times along the year. Significant variations were found for 3 s and 6 s during the morning and 6 s during the evening. Results suggest an impact of isolation on morning performances and an effect of the polar night on evening measures. These findings shed some light on the use of interval timing as a cognitive test to assess performance in extreme environments.
Assuntos
Ritmo Circadiano/fisiologia , Ambientes Extremos , Fotoperíodo , Estações do Ano , Isolamento Social/psicologia , Percepção do Tempo/fisiologia , Adulto , Regiões Antárticas/epidemiologia , Humanos , Estudos Longitudinais , Masculino , Militares/psicologia , Testes NeuropsicológicosRESUMO
The surfactant industry moves billions of dollars a year and consists of chemically synthesized molecules usually derived from petroleum. Surfactant is a versatile molecule that is widely used in different industrial areas, with an emphasis on the petroleum, biomedical and detergent industries. Recently, interest in environmentally friendly surfactants that are resistant to extreme conditions has increased because of consumers' appeal for sustainable products and industrial processes that often require these characteristics. With this context, the need arises to search for surfactants produced by microorganisms coming from extreme environments and to mine their unique biotechnological potential. The production of biosurfactants is still incipient and presents challenges regarding economic viability due to the high costs of cultivation, production, recovery and purification. Advances can be made by exploring the extreme biosphere and bioinformatics tools. This review focuses on biosurfactants produced by microorganisms from different extreme environments, presenting a complete overview of what information is available in the literature, including the advances, challenges and future perspectives, as well as showing the possible applications of extreme biosurfactants.