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AIMS: This study aimed to evaluate the efficiency of two phages [VB_VaC_TDDLMA (phage TDD) and VB_VaC_SRILMA (phage SRI)] alone and in a cocktail to control Vibrio alginolyticus in brine shrimp before their administration in larviculture. METHODS AND RESULTS: Phages were isolated from seawater samples and characterized by host spectrum, growth parameters, adsorption rate, genomic analysis, and inactivation efficiency. Both phages belong to the Caudoviricetes class and lack known virulence or antibiotic-resistance genes. They exhibit specificity, infecting only their host, V. alginolyticus CECT 521. Preliminary experiments in a culture medium showed that phage TDD (reduction of 5.8 log CFU ml-1 after 10 h) outperformed phage SRI (reduction of 4.6 log CFU ml-1 after 6 h) and the cocktail TDD/SRI (reduction of 5.2 log CFU ml-1 after 8 h). In artificial marine water experiments with Artemia franciscana, both single phage suspensions and the phage cocktail, effectively inactivated V. alginolyticus in culture water (reduction of 4.3, 2.1, and 1.9 log CFU ml-1 for phages TDD, SRI, and the phage cocktail, respectively, after 12 h) and in A. franciscana (reduction of 51.6%, 87.3%, and 85.3% for phages TDD, SRI, and the phage cocktail, respectively, after 24 h). The two phages and the phage cocktail did not affect A. franciscana natural microbiota or other Vibrio species in the brine shrimp. CONCLUSIONS: The results suggest that phages can safely and effectively control V. alginolyticus in A. franciscana prior to its administration in larviculture.
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Acuicultura , Artemia , Bacteriófagos , Vibrio alginolyticus , Vibrio alginolyticus/virología , Animales , Artemia/microbiología , Artemia/virología , Alimentación Animal , Agua de Mar/microbiología , Larva/microbiologíaRESUMEN
AIMS: We aim at understanding the effect of domestication on the endophytic microbiome and metabolome of Salicornia europaea and collecting evidence on the potential role of microbial populations and metabolites in the adaptation of plants to different ecological contexts (wild vs crops). METHODS AND RESULTS: Samples were collected from a natural salt marsh (wild) and an intensive crop field (crop). High-throughput sequencing of the 16S rRNA gene, gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) were used to analyze the endophytic bacterial communities and the metabolite profiles of S. europaea roots, respectively. The elemental analysis of the plant shoots was performed by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS).Overall, significant differences were found between the microbiome of wild and cultivated plants. The later showed a higher relative abundance of the genera Erythrobacter, Rhodomicrobium, and Ilumatobacter than wild plants. The microbiome of wild plants was enriched in Marinobacter, Marixanthomonas, and Thalassospira. The metabolite profile of crop plants revealed higher amounts of saturated and non-saturated fatty acids and acylglycerols. In contrast, wild plants contained comparatively more carbohydrates and most macroelements (i.e. Na, K, Mg, and Ca). CONCLUSIONS: There is a strong correlation between plant metabolites and the endosphere microbiome of S. europaea. In wild populations, plants were enriched in carbohydrates and the associated bacterial community was enriched in genes related to primary metabolic pathways such as nitrogen metabolism and carbon fixation. The endosphere microbiome of crop plants was predicted to have higher gene counts related to pathogenesis. Crop plants also exhibited higher amounts of azelaic acid, an indicator of exposure to phytopathogens.
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Chenopodiaceae , Domesticación , Cromatografía Liquida , ARN Ribosómico 16S/genética , Espectrometría de Masas en Tándem , MetabolomaRESUMEN
In the present study, we compared mucus and gut-associated prokaryotic communities from seven nudibranch species with sediment and seawater from Thai coral reefs using high-throughput 16S rRNA gene sequencing. The nudibranch species were identified as Doriprismatica atromarginata (family Chromodorididae), Jorunna funebris (family Discodorididae), Phyllidiella nigra, Phyllidiella pustulosa, Phyllidia carlsonhoffi, Phyllidia elegans, and Phyllidia picta (all family Phyllidiidae). The most abundant bacterial phyla in the dataset were Proteobacteria, Tenericutes, Chloroflexi, Thaumarchaeota, and Cyanobacteria. Mucus and gut-associated communities differed from one another and from sediment and seawater communities. Host phylogeny was, furthermore, a significant predictor of differences in mucus and gut-associated prokaryotic community composition. With respect to higher taxon abundance, the order Rhizobiales (Proteobacteria) was more abundant in Phyllidia species (mucus and gut), whereas the order Mycoplasmatales (Tenericutes) was more abundant in D. atromarginata and J. funebris. Mucus samples were, furthermore, associated with greater abundances of certain phyla including Chloroflexi, Poribacteria, and Gemmatimonadetes, taxa considered to be indicators for high microbial abundance (HMA) sponge species. Overall, our results indicated that nudibranch microbiomes consisted of a number of abundant prokaryotic members with high sequence similarities to organisms previously detected in sponges.
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Chloroflexi , Gastrópodos , Microbiota , Animales , ARN Ribosómico 16S/genética , Células Procariotas , Proteobacteria , Moco , Microbiota/genética , Agua de MarRESUMEN
Understanding the maintenance and origin of beta diversity is a central topic in ecology. However, the factors that drive diversity patterns and underlying processes remain unclear, particularly for host-prokaryotic associations. Here, beta diversity patterns were studied in five prokaryotic biotopes, namely, two high microbial abundance (HMA) sponge taxa (Xestospongia spp. and Hyrtios erectus), one low microbial abundance (LMA) sponge taxon (Stylissa carteri), sediment and seawater sampled across thousands of kilometres. Using multiple regression on distance matrices (MRM), spatial (geographic distance) and environmental (sea surface temperature and chlorophyll α concentrations) variables proved significant predictors of beta diversity in all five biotopes and together explained from 54% to 82% of variation in dissimilarity of both HMA species, 27% to 43% of variation in sediment and seawater, but only 20% of variation of the LMA S. carteri. Variance partitioning was subsequently used to partition the variation into purely spatial, purely environmental and spatially-structured environmental components. The amount of variation in dissimilarity explained by the purely spatial component was lowest for S. carteri at 11% and highest for H. erectus at 55%. The purely environmental component, in turn, only explained from 0.15% to 2.83% of variation in all biotopes. In addition to spatial and environmental variables, a matrix of genetic differences between pairs of sponge individuals also proved a significant predictor of variation in prokaryotic dissimilarity of the Xestospongia species complex. We discuss the implications of these results for the HMA-LMA dichotomy and compare the MRM results with results obtained using constrained ordination and zeta diversity.
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Biodiversidad , Poríferos , Animales , Bacterias/genética , Clorofila , Humanos , Filogenia , Poríferos/genética , ARN Ribosómico 16S/genética , Agua de MarRESUMEN
Marine microbiomes are prolific sources of bioactive natural products of potential pharmaceutical value. This study inspected two culture collections comprising 919 host-associated marine bacteria belonging to 55 genera and several thus-far unclassified lineages to identify isolates with potentially rich secondary metabolism and antimicrobial activities. Seventy representative isolates had their genomes mined for secondary metabolite biosynthetic gene clusters (SM-BGCs) and were screened for antimicrobial activities against four pathogenic bacteria and five pathogenic Candida strains. In total, 466 SM-BGCs were identified, with antimicrobial peptide- and polyketide synthase-related SM-BGCs being frequently detected. Only 38 SM-BGCs had similarities greater than 70% to SM-BGCs encoding known compounds, highlighting the potential biosynthetic novelty encoded by these genomes. Cross-streak assays showed that 33 of the 70 genome-sequenced isolates were active against at least one Candida species, while 44 isolates showed activity against at least one bacterial pathogen. Taxon-specific differences in antimicrobial activity among isolates suggested distinct molecules involved in antagonism against bacterial versus Candida pathogens. The here reported culture collections and genome-sequenced isolates constitute a valuable resource of understudied marine bacteria displaying antimicrobial activities and potential for the biosynthesis of novel secondary metabolites, holding promise for a future sustainable production of marine drug leads.
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Antozoos , Antiinfecciosos , Poríferos , Animales , Humanos , Metabolismo Secundario/genética , Bacterias/metabolismo , Poríferos/genética , Familia de Multigenes , Candida , Antiinfecciosos/farmacología , Antiinfecciosos/metabolismo , Antozoos/genética , FilogeniaRESUMEN
Campomanesia xanthocarpa (Mart.) O. Berg is a South American fruit tree species with important ecological and medicinal properties, which remnants are currently found mainly in isolated forest fragments. In this study, SSR markers from three different genomic origins (gene-linked, nuclear neutral, and organellar) were used to evaluate the patterns of genetic diversity, fine-scale spatial genetic structure and historical gene flow in fragmented forest formations of C. xanthocarpa from the Atlantic Forest in southern Brazil. Our results show that the forest fragments present moderate to high levels of genetic diversity in comparison to species presenting similar life traits, although a trend opposite to expected was observed concerning gene-linked and neutral SSR markers. The fine-scale spatial genetic structure revealed different patterns in short and large distance classes, with a distinct influence of gene-linked and neutral markers in driving the genetic structure in each distance class. The presence of an isolation-by-adaptation pattern implies the need for maintenance of the current remnants to assure the conservation of the private alleles. Finally, as the genetic diversity is found predominantly within forest fragments, programs of seed collection and/or genetic rescue should prioritize a larger number of individuals within each fragment, to increase the sampled diversity.
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Flujo Génico , Variación Genética , Alelos , Flujo Génico/genética , Variación Genética/genética , Genómica , Humanos , Árboles/genéticaRESUMEN
Despite the several novel features arising from the dissipative optomechanical coupling, such effect remains vastly unexplored due to the lack of a simple formalism that captures non-Hermiticity in the engineering of optomechanical systems. In this Letter, we show that quasinormal-mode-based perturbation theory is capable of correctly predicting both dispersive and dissipative optomechanical couplings. We validate our model through simulations and also by comparison with experimental results reported in the literature. Finally, we apply this formalism to plasmonic systems, used for molecular optomechanics, where strong dissipative coupling signatures in the amplification of vibrational modes could be observed.
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BACKGROUND: Antenatal maternal psychological distress is common in low and middle-income countries (LMIC), but there is a dearth of research on its effect on birth and developmental outcomes in these settings, particularly in Sub-Saharan Africa. This study set out to identify risk factors for antenatal maternal psychological distress and determine whether antenatal maternal psychological distress was associated with infant birth and developmental outcomes, using data from the Drakenstein Child Health Study (DCHS), a birth cohort study in South Africa. METHODS: Pregnant women were enrolled in the DCHS from primary care antenatal clinics. Antenatal maternal psychological distress was measured using the Self-Reporting Questionnaire 20-item (SRQ-20). A range of psychosocial measures, including maternal childhood trauma, depression, and posttraumatic stress disorder (PTSD) were administered. Birth outcomes, including premature birth, weight-for-age z-score and head circumference-for-age z-score, were measured using revised Fenton growth charts. The Bayley III Scales of Infant and Toddler Development was administered at 6 months of age to assess infant development outcomes, including cognitive, language, and motor domains in a subset of n=231. Associations of maternal antenatal psychological distress with psychosocial measures, and with infant birth and developmental outcomes were examined using linear regression models. RESULTS: 961 women were included in this analysis, with 197 (21%) reporting scores indicating the presence of psychological distress. Antenatal psychological distress was associated with maternal childhood trauma, antenatal depression, and PTSD, and inversely associated with partner support. No association was observed between antenatal maternal psychological distress and preterm birth or early developmental outcomes, but antenatal maternal psychological distress was associated with a smaller head circumference at birth (coefficient=-0.30, 95% CI: -0.49; -0.10). CONCLUSION: Antenatal maternal psychological distress is common in LMIC settings and was found to be associated with key psychosocial measures during pregnancy, as well as with adverse birth outcomes, in our study population. These associations highlight the potential value of screening for antenatal maternal psychological distress as well as of developing targeted interventions.
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Desarrollo Infantil/fisiología , Complicaciones del Embarazo/psicología , Efectos Tardíos de la Exposición Prenatal/psicología , Distrés Psicológico , Adulto , Estudios de Cohortes , Familia , Femenino , Humanos , Lactante , Recién Nacido , Embarazo , Complicaciones del Embarazo/diagnóstico , Factores de Riesgo , Sudáfrica , Trastornos por Estrés Postraumático/diagnóstico , Trastornos por Estrés Postraumático/psicología , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Research thrusts in silicon photonics are developing control operations using higher order waveguide modes for next generation high-bandwidth communication systems. In this context, devices allowing optical processing of multiple waveguide modes can reduce architecture complexity and enable flexible on-chip networks. We propose and demonstrate a hybrid resonator dually resonant at the 1st and 2nd order modes of a silicon waveguide. We observe 8 dB extinction ratio and modal conversion range of 20 nm for the 1st order quasi-TE mode input.
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The aim of this study is to evaluate the effects of the inoculation of the saltmarsh plant (Halimione portulacoides) with Pseudomonas sp. SPN31 nah+ combined with exposure to 2-methylnaphthalene (2-MtN) on the plant rhizosphere and endosphere bacterial communities as well as on plant health. To achieve this goal, microcosm experiments were set up. Denaturing gradient gel electrophoresis (DGGE) profiles and statistical analysis showed that rhizosphere and endosphere bacterial communities had distinct responses to plant inoculation and/or exposure to 2-MtN. PCR-sequencing analysis of nah genes encoding for 2-MtN degrading enzymes suggested the presence of Pseudomonas sp. SPN31 nah+ in the endosphere of H. portulacoides with 2-MtN contamination. Moreover, a significant effect in the photosynthetic performance of inoculated plants was detected. To conclude, despite the potential beneficial effect of plant inoculation with Pseudomonas sp. SPN31 nah+ endophytic bacteria may have on plant health, no significant effect on the removal of MtN was detected for the level of contamination used in the study.
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Bacterias , Chenopodiaceae/efectos de los fármacos , Chenopodiaceae/microbiología , Naftalenos/efectos adversos , Pseudomonas/fisiología , Rizosfera , Contaminantes del Suelo/efectos adversos , Bacterias/clasificación , Bacterias/genética , Biodegradación Ambiental , Chenopodiaceae/fisiología , Regulación Bacteriana de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Genes Bacterianos , Naftalenos/metabolismo , Fotosíntesis , Filogenia , Raíces de Plantas/microbiología , ARN Ribosómico 16S/genética , Microbiología del Suelo , Contaminantes del Suelo/metabolismo , Compuestos Orgánicos VolátilesRESUMEN
PURPOSE: There are few data available on the experience of minority surgeons in the field of oral and maxillofacial surgery (OMS). Therefore, the purpose of this study was to 1) explore factors that contribute to African Americans choosing OMS as a career, 2) examine satisfaction among minority oral and maxillofacial surgeons with the residency application and training process, 3) report on practice patterns among minority oral and maxillofacial surgeons, and 4) identify perceived bias for or against minority oral and maxillofacial surgeons in an attempt to aid the efforts of OMS residency organizations to foster diversity. MATERIALS AND METHODS: A 19-item survey was sent to 80 OMS practitioners by use of information from the mailing list of the National Society of Oral and Maxillofacial Surgeons, an American Association of Oral and Maxillofacial Surgeons-affiliated organization. All surveys were sent by mail and were followed by a reminder mailing after 8 weeks. Responses returned within 16 weeks were accepted for analysis. RESULTS: Of the 80 mailed surveys, 41 were returned within the 16-week parameter, representing a return rate of 51%. Most of the minority surgeon respondents were married men with a mean age of 60 years who worked as private practitioners. Most respondents practiced on the eastern and western coasts of the United States. Exposure in dental school was the most important factor in selecting OMS as a specialty. Location and prestige were the most important factors in selecting a residency program. Most respondents reported that race did not affect the success of their application to a residency program and did not currently affect the success of their practice. However, 25 to 46% of participants experienced race-related harassment, and 48 to 55% of participants believed there was a bias against African Americans in OMS. CONCLUSIONS: Our data suggest that a substantial number of minority oral and maxillofacial surgeons subjectively perceive race-based bias in their career, although it does not appear to affect professional success.
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Negro o Afroamericano , Selección de Profesión , Satisfacción en el Trabajo , Cirujanos Oromaxilofaciales , Pautas de la Práctica en Medicina/estadística & datos numéricos , Cirugía Bucal , Adulto , Negro o Afroamericano/educación , Negro o Afroamericano/psicología , Negro o Afroamericano/estadística & datos numéricos , Actitud del Personal de Salud/etnología , Femenino , Humanos , Internado y Residencia/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Cirujanos Oromaxilofaciales/educación , Cirujanos Oromaxilofaciales/psicología , Cirujanos Oromaxilofaciales/estadística & datos numéricos , Cirujanos Oromaxilofaciales/provisión & distribución , Racismo/etnología , Racismo/psicología , Racismo/estadística & datos numéricos , Cirugía Bucal/educación , Cirugía Bucal/estadística & datos numéricos , Encuestas y Cuestionarios , Estados UnidosRESUMEN
There is growing concern that predicted changes to global ocean chemistry will interact with anthropogenic pollution to significantly alter marine microbial composition and function. However, knowledge of the compounding effects of climate change stressors and anthropogenic pollution is limited. Here, we used 16S and 18S rRNA (cDNA)-based activity profiling to investigate the differential responses of selected microbial taxa to ocean acidification and oil hydrocarbon contamination under controlled laboratory conditions. Our results revealed that a lower relative abundance of sulphate-reducing bacteria (Desulfosarcina/Desulfococcus clade) due to an adverse effect of seawater acidification and oil hydrocarbon contamination (reduced pH-oil treatment) may be coupled to changes in sediment archaeal communities. In particular, we observed a pronounced compositional shift and marked reduction in the prevalence of otherwise abundant operational taxonomic units (OTUs) belonging to the archaeal Marine Benthic Group B and Marine Hydrothermal Vent Group (MHVG) in the reduced pH-oil treatment. Conversely, the abundance of several putative hydrocarbonoclastic fungal OTUs was higher in the reduced pH-oil treatment. Sediment hydrocarbon profiling, furthermore, revealed higher concentrations of several alkanes in the reduced pH-oil treatment, corroborating the functional implications of the structural changes to microbial community composition. Collectively, our results advance the understanding of the response of a complex microbial community to the interaction between reduced pH and anthropogenic pollution. In future acidified marine environments, oil hydrocarbon contamination may alter the typical mixotrophic and k-/r-strategist composition of surface sediment microbiomes towards a more heterotrophic state with lower doubling rates, thereby impairing the ability of the ecosystem to recover from acute oil contamination events.
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Archaea/clasificación , Contaminación por Petróleo , Agua de Mar/química , Bacterias Reductoras del Azufre/clasificación , Contaminantes Químicos del Agua/efectos adversos , Cambio Climático , Concentración de Iones de HidrógenoRESUMEN
Coupled resonators are commonly used to achieve tailored spectral responses and allow novel functionalities in a broad range of applications. The Temporal Coupled-Mode Theory (TCMT) provides a simple and general tool that is widely used to model these devices. Relying on TCMT to model coupled resonators might however be misleading in some circumstances due to the lumped-element nature of the model. In this article, we report an important limitation of TCMT related to the prediction of dark states. Studying a coupled system composed of three microring resonators, we demonstrate that TCMT predicts the existence of a dark state that is in disagreement with experimental observations and with the more general results obtained with the Transfer Matrix Method (TMM) and the Finite-Difference Time-Domain (FDTD) simulations. We identify the limitation in the TCMT model to be related to the mechanism of excitation/decay of the supermodes and we propose a correction that effectively reconciles the model with expected results. Our discussion based on coupled microring resonators can be useful for other electromagnetic resonant systems due to the generality and far-reach of the TCMT formalism.
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Archaea play crucial roles in a number of key ecological processes including nitrification and methanogenesis. Although several studies have been conducted on these organisms, the roles and dynamics of coral reef archaeal communities are still poorly understood, particularly in host and nonhost biotopes and in high (HMA) and low microbial abundance (LMA) sponges. Here, archaeal communities detected in six distinct biotopes, namely, sediment, seawater and four different sponge species Stylissa carteri, Stylissa massa, Xestospongia testudinaria and Hyrtios erectus from the Spermonde Archipelago, SW Sulawesi, Indonesia were investigated using 454-pyrosequencing of 16S rRNA genes (OTU cut-off 97%). Archaeal communities from sediment and sponges were dominated by Crenarchaeota, while the seawater community was dominated by Euryarchaeota. The biotope explained almost 75% of the variation in archaeal composition, with clear separation between microbial assemblages from sediment, X. testudinaria and H. erectus (HMA). In contrast, samples from seawater and both Stylissa species (LMA) showed considerable overlap in the ordination and, furthermore, shared most abundant OTUs with the exception of a single dominant OTU specifically enriched in both Stylissa species. Predicted functional gene content in archaeal assemblages also revealed significant differences among biotopes. Different ammonia assimilation strategies were exhibited by the archaeal communities: X. testudinaria, H. erectus and sediment archaeal communities were enriched for glutamate dehydrogenase with mixed specificity (NAD(P)(+) ) pathways, while archaeal planktonic communities were enriched for specific glutamate dehydrogenase (NADP(+) ) and glutamate synthase pathways. Archaeal communities in Stylissa had intermediate levels of enrichment. Our results indicate that archaeal communities in different biotopes have distinct ecophysiological roles.
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Archaea/clasificación , Sedimentos Geológicos/microbiología , Poríferos/microbiología , Agua de Mar/microbiología , Animales , Archaea/genética , Biodiversidad , Arrecifes de Coral , ADN de Archaea/genética , Indonesia , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
There is growing concern that modifications to the global environment such as ocean acidification and increased ultraviolet radiation may interact with anthropogenic pollutants to adversely affect the future marine environment. Despite this, little is known about the nature of the potential risks posed by such interactions. Here, we performed a multifactorial microcosm experiment to assess the impact of ocean acidification, ultraviolet B (UV-B) radiation and oil hydrocarbon contamination on sediment chemistry, the microbial community (composition and function) and biochemical marker response of selected indicator species. We found that increased ocean acidification and oil contamination in the absence of UV-B will significantly alter bacterial composition by, among other things, greatly reducing the relative abundance of Desulfobacterales, known to be important oil hydrocarbon degraders. Along with changes in bacterial composition, we identified concomitant shifts in the composition of oil hydrocarbons in the sediment and an increase in oxidative stress effects on our indicator species. Interestingly, our study identifies UV-B as a critical component in the interaction between these factors, as its presence alleviates harmful effects caused by the combination of reduced pH and oil pollution. The model system used here shows that the interactive effect of reduced pH and oil contamination can adversely affect the structure and functioning of sediment benthic communities, with the potential to exacerbate the toxicity of oil hydrocarbons in marine ecosystems.
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Cambio Climático , Estuarios , Sedimentos Geológicos/microbiología , Microbiota/fisiología , Modelos Biológicos , Contaminación por Petróleo/efectos adversos , Secuencia de Bases , Cartilla de ADN/genética , Deltaproteobacteria/metabolismo , Deltaproteobacteria/efectos de la radiación , Hidrocarburos/análisis , Concentración de Iones de Hidrógeno , Microbiota/efectos de los fármacos , Datos de Secuencia Molecular , Portugal , Análisis de Secuencia de ADN , Rayos UltravioletaRESUMEN
Optical mode-splitting is an efficient tool to shape and fine-tune the spectral response of resonant nanophotonic devices. The active control of mode-splitting, however, is either small or accompanied by undesired resonance-shifts, often much larger than the resonance splitting. We report a control mechanism that enables reconfigurable and widely tunable mode splitting while efficiently mitigating undesired resonance shifts. This is achieved by actively controlling the excitation of counter-traveling modes in coupled resonators. The transition from a large splitting (80 GHz) to a single-notch resonance is demonstrated using low-power microheaters (35 mW). We show that the spurious resonance shift in our device is only limited by thermal crosstalk, and resonance-shift-free splitting control may be achieved.
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In this study, we used a 16S rRNA gene barcoded pyrosequencing approach to sample bacterial communities from six biotopes, namely, seawater, sediment and four sponge species (Stylissa carteri, Stylissa massa, Xestospongia testudinaria and Hyrtios erectus) inhabiting coral reefs of the Spermonde Archipelago, South Sulawesi, Indonesia. Samples were collected along a pronounced onshore to offshore environmental gradient. Our goals were to (1) compare higher taxon abundance among biotopes, (2) test to what extent variation in bacterial composition can be explained by the biotope versus environment, (3) identify dominant (>300 sequences) bacterial operational taxonomic units (OTUs) and their closest known relatives and (4) assign putative functions to the sponge bacterial communities using a recently developed predictive metagenomic approach. We observed marked differences in bacterial composition and the relative abundance of the most abundant phyla, classes and orders among sponge species, seawater and sediment. Although all biotopes housed compositionally distinct bacterial communities, there were three prominent clusters. These included (1) both Stylissa species and seawater, (2) X. testudinaria and H. erectus and (3) sediment. Bacterial communities sampled from the same biotope, but different environments (based on proximity to the coast) were much more similar than bacterial communities from different biotopes in the same environment. The biotope thus appears to be a much more important structuring force than the surrounding environment. There were concomitant differences in the predicted counts of KEGG orthologs (KOs) suggesting that bacterial communities housed in different sponge species, sediment and seawater perform distinct functions. In particular, the bacterial communities of both Stylissa species were predicted to be enriched for KOs related to chemotaxis, nitrification and denitrification whereas bacterial communities in X. testudinaria and H. erectus were predicted to be enriched for KOs related to the toxin-antitoxin (TA) system, nutrient starvation and heavy metal export.
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Sedimentos Geológicos/microbiología , Poríferos/microbiología , Agua de Mar/microbiología , Animales , Bacterias/genética , Biodiversidad , Arrecifes de Coral , Código de Barras del ADN Taxonómico , ADN Bacteriano/genética , Ecosistema , Indonesia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Especificidad de la Especie , Xestospongia/microbiologíaRESUMEN
Estuaries are sinks for various anthropogenic contaminants, such as petroleum hydrocarbons, giving rise to significant environmental concern. The demand for organisms and processes capable of degrading pollutants in a clean, effective, and less expensive process is of great importance. Phytoremedition approaches involving plant/bacteria interactions have been explored as an alternative, and halophyte vegetation has potential for use in phytoremedition of hydrocarbon contamination. Studies with plant species potentially suitable for microbe-assisted phytoremediation are widely represented in scientific literature. However, the in-depth understanding of the biological processes associated with the re-introduction of indigenous bacteria and plants and their performance in the degradation of hydrocarbons is still the limiting step for the application of these bioremediation solutions in a field context. The intent of the present review is to summarize the sources and effects of hydrocarbon contamination in estuarine environments, the strategies currently available for bioremediation (potential and limitations), and the perspectives of the use of halophyte plants in microbe-assisted phytoremediation approaches.
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Biodegradación Ambiental , Estuarios , Hidrocarburos/metabolismoRESUMEN
In the present study, we sampled bacterial communities associated with mussels inhabiting two distinct coastal marine ecosystems in Kalimantan, Indonesia, namely, marine lakes and coastal mangroves. We used 16S rRNA gene pyrosequencing and predicted metagenomic analysis to compare microbial composition and function. Marine lakes are small landlocked bodies of seawater isolated to varying degrees from the open sea environment. They contain numerous endemic taxa and represent natural laboratories of speciation. Our primary goals were to (1) use BLAST search to identify closely related organisms to dominant bacterial OTUs in our mussel dataset and (2) to compare bacterial communities and enrichment in the predicted bacterial metagenome among lakes. Our sequencing effort yielded 3553 OTUs belonging to 44 phyla, 99 classes and 121 orders. Mussels in the largest marine lake (Kakaban) and the coastal mangrove habitat were dominated by bacteria belonging to the phylum Proteobacteria whereas smaller lakes, located on the island of Maratua, were dominated by bacteria belonging to the phyla Firmicutes and Tenericutes. The single most abundant OTU overall was assigned to the genus Mycoplasma. There were several significant differences among locations with respect to metabolic pathways. These included enrichment of xenobiotic biodegradation pathways in the largest marine lake and coastal mangrove. These locations were also the most enriched with respect to nitrogen metabolism. The presence of genes related to isoquinoline alkaloids, polyketides, hydrolases, mono and dioxygenases in the predicted analysis of functional pathways is an indication that the bacterial communities of Brachidontes mussels may be potentially important sources of new marine medicines and enzymes of industrial interest. Future work should focus on measuring how mussel microbial communities influence nutrient dynamics within the marine lake environment and isolating microbes with potential biotechnological applications.
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Bacterias/clasificación , Bacterias/genética , Biota , Bivalvos/microbiología , Metagenoma , Animales , Organismos Acuáticos/microbiología , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Indonesia , Lagos , Datos de Secuencia Molecular , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Communicative Development Inventories (CDIs, parent-completed language development checklists) are a helpful tool to assess language in children who are unused to interaction with unfamiliar adults. Generally, CDIs are completed in written form, but in developing country settings parents may have insufficient literacy to complete them alone. We designed CDIs to assess language development in children aged 0;8 to 2;4 in two languages used in Coastal communities in Kenya. Measures of vocabulary, gestures, and grammatical constructions were developed using both interviews with parents from varying backgrounds, and vocabulary as well as grammatical constructions from recordings of children's spontaneous speech. The CDIs were then administered in interview format to over 300 families. Reliability and validity ranged from acceptable to excellent, supporting the use of CDIs when direct language testing is impractical, even when children have multiple caregivers and where respondents have low literacy levels.