Stay ConnectedMicrobe Magazine Podcast is a monthly science podcast hosted by Jeff Fox, features editor for Microbe Magazine, published by the American Society for Microbiology.
Each podcast episode coincides with an article in the current issue of Microbe, which is available online at www.microbemagazine.org.
Please contact Patrick Lacey, Managing Editor for Microbe, with any questions, feedback or show ideas at placey@asmusa.org.
Copyright: © American Society for Microbiology
Warren C. Ruder of Virginia Polytechnic Institute and State University (Virginia Tech) in Blacksburg, Virginia talks with Jeff Fox about efforts to develop an electronic model system that incorporates a robot for a host and two slightly different kinds of simulated bacteria for its microbiome. The model carries an engineered bacterial population onboard to stand in for the microbiome, while the robot serves as a proxy for an animal host. When conditions are changed a bit, and the robot is made to send signals to its virtual microbiome, the robot's behavior changes rather dramatically, making it look very much like the microbiome is pulling the robot's "strings," dictating to the host what to do next. This model system carries implications for fields ranging from synthetic biology and ecology to mobile robotics, according to Ruder and his collaborators. Details appeared in the July 2015 Scientific Reports (DOI: 10.1038/srep11988.) This story was featured in the November 2015 issue of Microbe magazine.
Alexander Mankin –called Shura --of the University of Illinois, Chicago, and Michael Jewett at Northwestern University talk with Jeff Fox about their recent success in joining the 30S and 50S bacterial ribosomal subunits into a single, functioning entity and the implications of that work in terms of making specialized proteins and for studying antibiotics that target the ribosome. This story was featured in the October 2015 issue of Microbe magazine.
Visit microbeworld.org/mmp for more.
Jeremy Brownlie of Griffıth University in Brisbane, Australia, talks with Jeff Fox about how bacteria influence aggressive behavior in an animal. Fruit flies infected with the wMelPop strain of Wolbachia were less aggressive than their uninfected peers. The neurotransmitter octopamine regulates fruit fly aggression, and Brownlie and his collaborators found that the infected flies produce less of the compound than their uninfected peers, and expression of two genes that encode enzymes responsible for producing octopamine are present at lower levels in infected flies. "That suggested that Wolbachia directly affects fruit fly gene function," he says.
This story was featured in the September 2015 issue of Microbe magazine.
Visit http://microbeworld.org/mmp for complete show notes.
Thijs Ettema of Uppsala University in Sweden talks with Jeff Fox about a deep-sea archaeon, named Lokiarchaeum for the underwater volcano between Greenland and Norway near where it was found, that might be related to the last common ancestor of eukaryotes.
"The shape-shifting deity 'Loki' is described as complex and confusing; thus, 'Lokiarchaeum' seems a very appropriate name for our typical prokaryote with a whole bunch of eukaryotic genes," he says. "Importantly, the genes we found in Lokiarchaeum could have provided the archaeal ancestor of eukaryotes with a 'starter kit' for the cellular complexity typical in the eukaryotes we see today." Genes usually associated with eukaryotes are found in Lokiarchaeota, including those enabling membrane remodeling and vesicular traffıcking, indicating that the onset of "cellular complexity was already underway before the acquisition of a mitochondrial endosymbiont." The fındings favor a two-domain Tree of Life, in which eukaryotes are placed together with a diverse group of archaea known as the "TACK" superphylum because it includes Thaumarchaeota, Aigarchaeota, Crenarchaeota, and Korarchaeota, which share several signature proteins with eukaryotes. This story was featured in the August 2015 issue of Microbe magazine.
Paul Kelton of the University of Kansas, Lawrence, talks with Jeff Fox about the introduction of infectious diseases among Native American populations. Kelton's book Cherokee Medicine, Colonial Germs: an Indigenous Nation's Fight against Smallpox, 1518–1824, published in April 2015 by the University of Oklahoma Press, looks at how Native American communities responded to new diseases, including establishing quarantines, to protect themselves against smallpox and other diseases. He offers evidence that the high mortality rate ascribed to smallpox in native populations had as much to do with cultural factors and the ferment of trade and warfare during the colonial period, as to any lack of immunity to the new disease. Kelton also discusses the question of whether Europeans may have means to deliberately infect Native Americans.
This story was featured in the July 2015 issue of Microbe Magazine.
Birgit Luef of Trondheim University in Norway and Chris Brown of the University of California, Berkeley, talk with Jeff Fox about ultrasmall bacteria.
Birgit Luef and Chris Brown of Jill Banfield's lab at UC Berkeley went looking for bacteria with small genomes. They found large numbers of organisms that not only had small genomes but also were extremely small in size—small enough to pass through a 0.2-micrometer filter, with many in the 250-nanometer range. Such ultrasmall bacteria are ubiquitous and diverse, and half of their genes are unique. Most are missing basic synthetic pathways, and they seem to be dependent on other organisms for metabolic products. Though it has not been possible to culture the organisms, genomic analyses reveal close similarities among large groups of them.
This research was featured in the June 2015 issue of Microbe.
Although virologists long assumed that lone viruses independently infect target cells, in the case of poliovirus and other enteroviruses, several viral particles can cluster within lipid vesicles—from which they collectively enter target cells, improving overall infectivity and yields, the NIH researchers report. Nihal Altan-Bonnet at the National Heart Lung and Blood Institute at the National Institutes of Health (NIH) in Bethesda, Md., and her collaborators focused on poliovirus, a particular type of enterovirus.
This group also includes rhinovirus, Coxsackie viruses, and enterovirus 68, which is linked to a recent outbreak leading to paralysis among some infected children. In HeLa cells after replication and assembly, poliovirus congregates in clusters that are surrounded by double-membrane phosphatidylserine vesicles, ranging from 250 to 350 nm in diameter. Both rhinovirus and Coxsackie virus also form similar vesicles after infecting cells. The vesicles fuse with the plasma membrane of the host cell, and the viruses are released into the extracellular environment within this package, rather than as separate particles.
Details appeared 12 February 2015 in Cell (doi:10.1016/j.cell.2015.01.032), and the research was featured in the May 2015 issue of Microbe.
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