Podcasts about geobacter

Learn about a bacterial electric grid; traits females have evolved to avoid harassment; and why tea leaves sink.  There's a bacterial electric grid beneath our feet by Grant Currin  Hidden bacterial hairs power nature's “electric grid.” (2021, September). EurekAlert! https://www.eurekalert.org/news-releases/927031  Gu, Y., Srikanth, V., Salazar-Morales, A. I., Jain, R., O'Brien, J. P., Yi, S. M., Soni, R. K., Samatey, F. A., Yalcin, S. E., & Malvankar, N. S. (2021). Structure of Geobacter pili reveals secretory rather than nanowire behaviour. Nature, 597(7876), 430–434. https://doi.org/10.1038/s41586-021-03857-w  Specktor, B. (2020, September 18). Scientists find “secret molecule” that allows bacteria to exhale electricity. Livescience.com; Live Science. https://www.livescience.com/electron-breathing-geobacter-microbes.html  ‌Basic Biology of Oral Microbes. (2015). Atlas of Oral Microbiology, 1–14. https://doi.org/10.1016/b978-0-12-802234-4.00001-x  Many females have evolved traits to avoid harassment by Cameron Duke Berlin, S. (2021, August 30). Female Octopuses Throw Debris at Unwanted Mates Who Pester Them, Study Shows. Newsweek; Newsweek. https://www.newsweek.com/female-octopuses-throw-debris-unwanted-mates-who-pester-them-study-shows-1624345 Feldblum, Joseph T., Wroblewski, Emily E., Rudicell, Rebecca S., Hahn, Beatrice H., Paiva, T., Cetinkaya-Rundel, M., Pusey, Anne E., & Gilby, Ian C. (2014). Sexually Coercive Male Chimpanzees Sire More Offspring. Current Biology, 24(23), 2855–2860. https://doi.org/10.1016/j.cub.2014.10.039 Female hummingbirds avoid harassment by looking as flashy as males. (2021). Female hummingbirds avoid harassment by looking as flashy as males. Phys.org. https://phys.org/news/2021-08-female-hummingbirds-flashy-males.html  Godfrey-Smith, P., Scheel, D., Chancellor, S., Linquist, S., & Lawrence, M. (2021). In the Line of Fire: Debris Throwing by Wild Octopuses. https://doi.org/10.1101/2021.08.18.456805  Hosken, D. J., Alonzo, S., & Wedell, N. (2016). Why aren't signals of female quality more common? Exeter.ac.uk. https://doi.org/http://hdl.handle.net/10871/19606 Male-like ornamentation in female hummingbirds results from social harassment rather than sexual selection. (2021). Current Biology. https://doi.org/10.1016/j.cub.2021.07.043 Power Play. (2018). National Wildlife Federation. https://www.nwf.org/Magazines/National-Wildlife/2018/Oct-Nov/Animals/Animal-Aggression Wielgus, R. B., & Bunnell, F. L. (1994). Sexual Segregation and Female Grizzly Bear Avoidance of Males. The Journal of Wildlife Management, 58(3), 405. https://doi.org/10.2307/3809310 Why do tea leaves sink? by Ashley Hamer originally aired June 10, 2018 https://omny.fm/shows/curiosity-daily/the-cutest-kind-of-puppy-rural-happiness-and-the-s  James Norwood Pratt. (2010, August 16). The Ancient and Best Way to Brew Loose-Leaf Tea. The Atlantic. https://www.theatlantic.com/health/archive/2010/08/the-ancient-and-best-way-to-brew-loose-leaf-tea/61479/  Inglis-Arkell, E. (2014, May 6). Why Do Your Tea Leaves Move To The Middle Of The Cup? Gizmodo. https://gizmodo.com/why-do-your-tea-leaves-move-to-the-middle-of-the-cup-1572125743  Ouellette, J. (2016). The Strange Physics of Tea Leaves Floating Upstream. Nautilus. https://nautil.us/blog/the-strange-physics-of-tea-leaves-floating-upstream  Follow Curiosity Daily on your favorite podcast app to learn something new every day withCody Gough andAshley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers. See omnystudio.com/listener for privacy information.

En el capítulo de esta semana os hablamos sobre el bólido que atravesó el noroeste de la Península Ibérica hace unos días. Hablamos con Óscar Blanco, astrofotógrafo y miembro de la Asociación Astronómica Coruñesa Ío, que estaba esa noche de observación y fue testigo de los fogonazos que iluminaron el cielo durante unos segundos. Hablamos sobre la frecuencia de estos eventos y cómo podemos averiguar su origen y su velocidad. Después Marta García Aller nos habla de la historia de la cremallera, y cómo fue un invento que tardó décadas en ganar popularidad, y Javier Cancho nos habla de la ciudad de China donde se fabrican el 80% de las cremalleras del mundo. Finalmente, dedicamos unos minutos a hablar sobre los microorganismos y su increíble capacidad de inventiva. Organizamos un pequeño concurso para elegir al microbio más interesante de la Tierra, y para ello presentamos cuatro candidatos: - Warnowia, el alga con ojos - Geobacter, la bacteria que respira hierro - GSB1, que hace la fotosíntesis en el fondo del mar - Magnetospirillium, la bacteria-brújula En este concurso nos acompaña Ignacio Crespo, médico, director de la sección de ciencia del diario La Razón y autor del libro de divulgación de la neurociencia "Una selva de sinapsis". Si queréis aprender más sobre bólidos y cuán frecuente es que se encuentren con la Tierra os recomiendo que escuchéis el episodio s02e16 de nuestro pódcast hermano, La Brújula de la Ciencia. En él contamos el estallido en la atmósfera de otro bólido, más grande que el del Bierzo, sobre la ciudad rusa de Cheliabinsk a principios del año 2013. Si queréis conocer otros microorganismos con propiedades sorprendentes escuchad, también en La Brújula de la Ciencia, los capítulos s05e24, s05e18 y s09e01. O repasad el episodio s03e04 de esta misma temporada de Aparici en Órbita, en el que hablamos de cómo los ecosistemas de las chimeneas hidrotermales dependen de las bacterias que convierten el material que sale de las chimeneas en comida. Este programa se emitió originalmente el 21 de enero de 2021. Podéis escuchar el resto de audios de Más de Uno en su canal de iVoox y en la web de Onda Cero, ondacero.es

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.03.367284v1?rss=1 Authors: Brittain, T. J., O'Malley, M. C., Swaim, C. M., Fink, R. A., Kokhan, O. Abstract: C-type cytochromes play an important role in respiration of dissimilatory metal-reducing bacteria. They form extended conduits for charge transfer between the cellular metabolism and external electron acceptors such as particles of iron oxide, metal ions, and humic substances. Out of more than a hundred c-type cytochromes in Geobacter sulfurreducens, only a small fraction has been previously characterized. Here we present our results on expression and biophysical characterization of GSU0105, a novel 3-heme cytochrome, important for Fe(III) respiration in G. sulfurreducens. We successfully cloned the gene and achieved ~3 mg/L of culture GSU0105 expression in E.coli. Despite a similar size (71 amino acids) and the same number of c-type hemes to the members of the cytochrome (cyt) c7 family, multiple sequence alignment suggests that GSU0105 does not belong to the cyt c7 family. UV-Vis spectroscopy revealed typical c-type cytochrome spectral features, including a weak iron-sulfur charge transfer band suggesting that at least one heme is ligated with a methionine residue. Far UV circular dichroism studies demonstrate approximately 35% content of -helices and {beta}-sheets, each, as well as thermal aggregation occurring above 60C. A combination of SAXS and analytical size exclusion chromatography data shows that GSU0105 is monomeric in solution. Finally, affinity pull-down assays demonstrate high binding affinity to PpcD and weaker binding to the other members of the cyt c7 family. Copy rights belong to original authors. Visit the link for more info

Gemma Reguera discusses her studies of Geobacter pili, which transfers electrons to iron oxide and other minerals, and can be used for new biotech applications. Host: Julie Wolf  Subscribe (free) on Apple Podcasts, Google Podcasts, Android, RSS, or by email. Also available on the ASM Podcast Network app. Julie’s Biggest Takeaways: Geobacter sulferreducans, a bacterium that “breathes” rust, is the lab representative of the genus Geobacter that dump electrons onto rust. These specialized microbes use minerals like manganese oxide and iron oxide (also known as rust) for respiration in both terrestrial and aquatic sediments. Although many species are strict anaerobes, a few species can grow under microaerophilic conditions, in which the bacteria will respire the oxygen to eliminate its toxic effects on the cell. Iron oxide respiration relies on the Geobacter pili, a simple structure composed of a single peptide repeat. The pili concentrate on one side of the bacterial cell, where they connect the cell with the iron oxide to release the electrons that have been accumulating. The pili immediately depolymerize and retract, shedding the mineral before returning into the cell. Mass-producing pilin subunits in E. coli took a bit of trouble shooting, but now Reguera and her colleagues can make them on a much larger scale, which bodes well for expanding tests into electronic applications. Commercialization grants address the “valley of death,” the chasm between the technologies developed at the bench and the scale of production necessary for industrialization. Geobacter can bind and reduce many minerals using their pili, including uranium and other toxic heavy metals like lead and cobalt. Using Geobacter pili in agricultural soils or aquaculture waters may help remove these contaminants and improve the health of these ecosystems. Featured Quotes: “I remember when I started as a microbiology student, I think I underappreciated the role that electrons and the movement of electrons play in microbiology.” “There is absolutely not a single process in living organisms that is not energized by the movement of electrons.” “The Earth didn’t have oxygen for the first 2 billion years, if not longer - and there was life! On Earth! Those early organisms were really great at finding minerals, metals, just about anything other than oxygen to dump their electrons, continue to grow, and to colonize the Earth.” “When you start comparing the structure and the amino acid composition of this subunit to any other known bacterial pilins, you really see 2 remarkable changes: one of them is the pilin of Geobacter is very small. the second is that little stick has aromatic amino acids. When the sticks come together to make the filament, they cluster very close to each other and create like a staircase for the electrons to move fast. It’s like a magic combination in which you have the right structural reduction and the right amino acids to really fit like a puzzle to create paths for electrons.” “What has always motivated me is learning something new.” Links for This Episode: Gemma Reguera lab website Gemma Reguera interview on “People Behind the Science” HOM: Thirty-Second Annual Meeting of the Society of American Bacteriologists HOM: Barney Cohen: An Appreciation (Bacteriological Reviews memorial)

Host: Jeff Fox with special guests, Gemma Reguera and Geoffrey Gadd. Gemma Reguera of Michigan State University in East Lansing and Geoffrey Gadd of the University of Dundee in Scotland talk with Jeff Fox about their efforts, to probe some of the electrical properties of materials produced naturally by specific microorganisms. Thus, Geobacter bacteria make protein filaments, called pili, that act as nanowires, transporting 1 billion electrons per second, according to Reguera and her collaborators. Analytic evidence suggests that the electrons move along these proteins by a thermally activated, multistep hopping mechanism, enabling these bacteria to draw electrons from the extracellular milieu. Meanwhile, the fungus Neurospora crassa can transform manganese into a mineral composite with favorable electrochemical properties. The fungal cells produce filaments that take up manganese, which after heat treatment forms structures that have electrochemical properties that are suitable for use in supercapacitors or lithium-ion batteries. The carbonized fungal biomass-mineral composite has excellent cycling stability and retains more than 90% capacity after 200 cycles, according to Gadd and his collaborators. This story was featured in the June 2016 issue of Microbe Magazine. Subscribe to MMP (free) on iTunes, Stitcher, Android, RSS, or by email. You can also listen on your mobile device with the Microbeworld app. Send your microbiology questions and comments (email or audio file) to jfox@asmusa.org Tweet me your questions about this episode or just say hi!

On episode #14 of the podcast This Week in Microbiology, Stanley, Margaret, Michael and Elio review how the fungus Cryptococcus escapes from macrophages, and electrical conductivity in nanowires formed by the bacterium Geobacter.

Virus humanos presentes en el océanoLas aguas marinas se encuentran contaminadas con virus provenientes del tracto digestivo de los seres humanos, que llegan a estas a través de las plantas de tratamiento de aguas residuales y que pueden infectar a otras personas.  Se han descubierto bacterias muy comunes en las playas, llamadas Marinomonas, que son enemigos naturales de estos virus y que podrían utilizarse en un futuro para controlar la contaminación por virus en los océanos. Detectores de ListeriaLa listeria es una bacteria causante de infecciones alimentarias que en muchos casos llegan a ser mortales.  Para detectarla en los alimentos se está probando un método a base de sondas de ADN específicas para las cepas especialmente peligrosas. Este método permitirá una detección más rápida de esta bacteria en los alimentos y estos podrán ser rastreados para detectar el origen de la contaminación. Así, se logrará retirar del mercado los alimentos contaminados rápidamente y reducir el número de personas afectadas por estos.Muerte celular programadaLa muerte celular programada es un mecanismo utilizado por las plantas para protegerse de las infecciones por virus, hongos y bacterias. Cuando una planta es infectada activa este mecanismo, en el que las células que rodean al invasor se “suicidan” para limitarlo. Cuando esto sucede aparecen manchas marrones en la superficie de las hojas. Se están tratando de modificar estos genes para proteger las cosechas de una gama más amplia de plagas.Nanocables electrificados de GeobacterLas bacterias del género Geobacter sp. son capaces de generar electricidad y de conducirla a través de sus pili, estructuras superficiales extrafinas que se extienden desde la célula. Por su tamaño, los pili pueden ser utilizados para producir biológicamente nanocables. Estos serían mucho menos costosos que los nanocables actuales, que son fabricados con sílice o carbono. Los dispositivos fabricados podrían ser tan pequeños, que incluso podrían viajar por los capilares sanguíneos para detectar enfermedades.Bacterias que trabajan en equipoLa endosimbiosis es un proceso de cooperación entre células que ha permitido que surjan evolutivamente, nuevos microorganismos. Un ejemplo de esto aparentan ser  los mitocondrios y los cloroplastos, estructuras que se encuentran dentro de las células y que producen energía y convierten la luz del sol en alimento, respectivamente. Se cree que estas estructuras fueron inicialmente bacterias simples que se adaptaron a vivir dentro de otras bacterias, formando un organismo más complejo.