RESUMO
Long-distance host-independent virus dispersal is poorly understood, especially for viruses found in isolated ecosystems. To demonstrate a possible dispersal mechanism, we show that bacteriophage T4, archaeal virus Sulfolobus spindle-shaped virus Kamchatka, and vaccinia virus are reversibly inactivated by mineralization in silica under conditions similar to volcanic hot springs. In contrast, bacteriophage PRD1 is not silicified. Moreover, silicification provides viruses with remarkable desiccation resistance, which could allow extensive aerial dispersal.
Assuntos
Vírus de Archaea/química , Vírus de Archaea/fisiologia , Bacteriófago T4/química , Bacteriófago T4/fisiologia , Dióxido de Silício/química , Vaccinia virus/química , Vaccinia virus/fisiologia , Inativação de Vírus , Vírus de Archaea/efeitos dos fármacos , Bacteriófago T4/efeitos dos fármacos , Dessecação , Dióxido de Silício/farmacologia , Vaccinia virus/efeitos dos fármacos , Inativação de Vírus/efeitos dos fármacosRESUMO
Silicification of organisms in silica-depositing environments can impact both their ecology and their presence in the fossil record. Although microbes have been silicified under laboratory and environmental conditions, viruses have not. Bacteriophage T4 was successfully silicified under laboratory conditions that closely simulated those found in silica-depositing hot springs. Virus morphology was maintained, and a clear elemental signature of phosphorus was detected by energy-dispersive X-ray spectrophotometry (EDS).
Assuntos
Bacteriófago T4/química , Bacteriófago T4/ultraestrutura , Fenômenos Químicos , Fontes Termais/química , Fósforo/análise , Dióxido de Silício , Fósseis , Microscopia Eletrônica de Transmissão , Espectrofotometria , Microbiologia da ÁguaRESUMO
Microbially mediated anaerobic oxidation of methane (AOM) moderates the input of methane, an important greenhouse gas, to the atmosphere by consuming methane produced in various marine, terrestrial, and subsurface environments. AOM coupled to sulfate reduction has been most extensively studied because of the abundance of sulfate in marine systems, but electron acceptors otherthan sulfate are more energetically favorable. Phylogenetic trees based on 16S rRNA gene clone libraries derived from microbial communities where AOM occurs show evidence of diverse, methanotrophic archaea (ANME) closely associated with sulfate-reducing bacteria, but these organisms have not yet been isolated as pure cultures. Several biochemical pathways for AOM have been proposed, including reverse methanogenesis, acetogenesis, and methylogenesis, and both culture-dependent and independent techniques have provided some clues to howthese communities function. Still, questions remain regarding the diversity, physiology, and metabolic restrictions of AOM-related organisms.
Assuntos
Bactérias/metabolismo , Ecologia , Metabolismo Energético , Metano/metabolismo , Anaerobiose , OxirreduçãoRESUMO
Many autism advocacy groups use the data collected by the US Department of Education (USDE) to show a rapidly increasing prevalence of autism. Closer examination of these data to follow each birth-year cohort reveals anomalies within the USDE data on autism. The USDE data show not only a rise in overall autism prevalence with time but also a significant and nearly linear rise in autism prevalence within a birth-year cohort as it ages, with significant numbers of new cases as late as 17 years of age. In addition, an unexpected reduction in the rise of autism prevalence occurs in most cohorts at 12 years of age, the age when most children would be entering middle school. These anomalies point to internal problems in the USDE data that make them unsuitable for tracking autism prevalence.