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Category Archives: Microbiology

The Secret Language of Bacteria – An ASM “Microbes After Hours” Event – Video

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The Secret Language of Bacteria - An ASM "Microbes After Hours" Event
No bacterium lives alone -- it is constantly encountering members of its own species as well as other kinds of bacteria and diverse organisms like viruses, fungi, plants and animals. To navigate a complex world, microbes use chemical signals to sense and communicate with one another. Live streamed on Monday, January 28th, 2013, from 6-7:30 pm at ASM #39;s headquarters, 1752 N St., NW, Washington, DC Dr. Bonnie Bassler, Princeton University Bonnie Bassler Ph.D. is a Howard Hughes Medical Institute Investigator and the Squibb Professor of Molecular Biology at Princeton University. The research in her laboratory focuses on the molecular mechanisms that bacteria use for intercellular communication. This process is called quorum sensing. Bassler #39;s research is paving the way to the development of novel therapies for combating bacteria by disrupting quorum-sensing-mediated communication. Dr. Bassler was awarded a MacArthur Foundation Fellowship in 2002. She was elected to the American Academy of Microbiology in 2002 and made a fellow of the American Association for the Advancement of Science in 2004. Dr. Bassler was the President of the American Society for Microbiology in 2010-2011; she is currently the Chair of the American Academy of Microbiology Board of Governors. She is also a member of the National Science Board and was nominated to that position by President Barak Obama. The Board oversees the NSF and prioritizes the nation #39;s research and educational priorities in science ...

By: MicrobeWorld

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The Secret Language of Bacteria - An ASM "Microbes After Hours" Event - Video

Scientists trick iron-eating bacteria into breathing electrons instead

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Public release date: 29-Jan-2013 [ | E-mail | Share ]

Contact: Jim Sliwa jsliwa@asmusa.org 202-942-9297 American Society for Microbiology

Scientists have developed a way to grow iron-oxidizing bacteria using electricity instead of iron, an advance that will allow them to better study the organisms and could one day be used to turn electricity into fuel. The study will be published on January 29 in mBio, the online open-access journal of the American Society for Microbiology.

The method, called electrochemical cultivation, supplies these bacteria with a steady supply of electrons that the bacteria use to respire, or "breathe". It opens the possibility that one day electricity generated from renewable sources like wind or solar could be funneled to iron oxidizing bacteria that combine it with carbon dioxide to create biofuels, capturing the energy as a useful, storable substance.

"It's a new way to cultivate a microorganism that's been very difficult to study. But the fact that these organisms can synthesize everything they need using only electricity makes us very interested in their abilities," says Daniel Bond of the BioTechnology Institute at the University of Minnesota Twin Cities, who co-authored the paper with Zarath Summers and Jeffrey Gralnick.

To "breathe", iron oxidizers take electrons off of dissolved iron, called Fe(II) a process that produces copious amounts of rust, called Fe(III). Iron-oxidizing bacteria are found around the world, almost anywhere an aerobic environment (with plenty of oxygen) meets an anaerobic environment (which lacks oxygen). They play a big role in the global cycling of iron and contribute to the corrosion of steel pipelines, bridges, piers, and ships, but their lifestyle at the interface of two very different habitats and the accumulation of cell-trapping Fe(III) makes iron oxidizers difficult to grow and study in the lab.

Scientists think these bacteria must carry out the iron oxidation step on their surfaces. If that's true, Bond reasoned, the outsides of the organisms should be covered with proteins that interact with Fe(II), so you should be able to provide a stream of pure electrons to the outsides of the bacteria and get them to grow.

Bond and his colleagues added the marine iron oxidizer Mariprofundus ferrooxydans PV-1, along with some nutrient medium, to an electrode carefully tuned to provide electrons at the same energy level, or potential, as Fe(II) would provide. The idea, says Bond, was to "fool the bacteria into thinking they're at the world's best buffet of Fe(II) atoms."

It worked. The bacteria multiplied and formed a film on the electrode, Bond says, and eventually they were able to grow M. ferrooxydans with no iron in the medium, proof that the bacteria were living off the electrons they absorbed from the electrode to capture carbon dioxide and replicate. And since the electron donor is a solid surface, say the authors, it's pretty likely that the bacterial electron-harvesting machinery is exposed on the outer membrane of the cell.

It's this capture of carbon dioxide that could enable electrochemical cultivation to create biofuels or other useful products one day, Bond says.

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Scientists trick iron-eating bacteria into breathing electrons instead

Allan Jacobson, PhD, Chair

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Allan Jacobson, PhD, Chair Professor of Microbiology Physiological Systems
"Serendipity matters a lot in biology. You just happen to be talking to somebody about what they #39;re doing, or in this case now, you #39;ll just be moseying over to somebody #39;s bench and they #39;ll be doing an experiment that you were otherwise clueless about or be working on a machine that you were otherwise clueless about."

By: UMassMedicalSchool

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Allan Jacobson, PhD, Chair

Mechanism of competence generation – Video

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Mechanism of competence generation
For more information, log on to- shomusbiology.weebly.com Download the study materials here- shomusbiology.weebly.com In microbiology, genetics, cell biology and molecular biology, competence is the ability of a cell to take up extracellular ("naked") DNA from its environment. Competence may be differentiated between natural competence, a genetically specified ability of bacteria which is thought to occur under natural conditions as well as in the laboratory, and induced or artificial competence, which arises when cells in laboratory cultures are treated to make them transiently permeable to DNA. This article primarily deals with natural competence in bacteria. Information about artificial competence is provided in the article Transformation (genetics). In the natural world DNA usually becomes available by death and lysis of other cells, but in the laboratory it is provided by the researcher, often as a genetically engineered fragment or plasmid. During uptake, DNA is transported across the cell membrane(s), and the cell wall if one is present. Once the DNA is inside the cell it may be degraded to nucleotides, which are reused for DNA replication and other metabolic functions. Alternatively it may be recombined into the cell #39;s genome by its DNA repair enzymes. If this recombination changes the cell #39;s genotype the cell is said to have been transformed. Artificial competence and transformation are used as research tools in many organisms (see Transformation (genetics)).[1 ...

By: Suman Bhattacharjee

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Mechanism of competence generation - Video

organic waste converter – Video

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organic waste converter
mam = Machinery (shredder/chipper/pulveriser) Assisted Microbiology OWC = Organic Waste Converter Organic Waste Converter is a composting machine that does mechanical reduction in size (homogenisation) to make it easy for the microbial digestion and quick turning in to manure compost. The homogenised waste undergoes composting process breakdown in the composting bins, this process can take 10 to 15 days, if things are done correctly.

By: riteways enviro

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organic waste converter - Video

Some carbon nanotubes deplete beneficial microbes in certain soils

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Ron Turco found that raw, non-functionalized, single-wall carbon nanotubes damage active microbiology in low-organic soils. Credit: Purdue Agricultural Communication photo/Tom Campbell

(Phys.org)Some types of carbon nanotubes used for strengthening plastics and other materials may have an adverse effect on soil microbiology and soil microbial processes, a Purdue University study shows.

Specifically, these raw, non-functionalized single-walled carbon nanotubes were shown to damage the active microbiology in low-organic soil. Ron Turco, a professor of agronomy, said many of the bacteria affected could be involved in carbon and nitrogen cycling, which are critical processes to ensure a fully functional soil.

"There appears to be more negative potential on the active microbial population than we thought," said Turco, whose findings were published in the journal Environmental Science & Technology. "The as-produced materials could be a negative environmental situation if they are released into low-organic soils that could not absorb them."

Functionalized carbon nanotubes have modifications that create chemical or biological changes to the nanotubes. They're often used in medicines, and Turco's research showed they had no effect in high-organic or low-organic soils.

Non-functionalized single-walled nanotubes - those lacking intentional surface alterations - are being added to a variety of products during manufacturing because they can strengthen the material without adding much weight. Nanotubes contained in manufacturing waste products may find their way into wastewater treatment plants and bio-solids that result from water purification. Those bio-solids cannot be released into water, so they are often discarded by spreading on land, adding critically needed plant nutrients to soil.

"Land application of biosolids is standard procedure now," Turco said. "If any of that contains nanotubes, that could be a problem."

Single-walled nanotubes also didn't affect microbes in high-organic soils, Turco said, likely because organic materials are highly reactive. Organic materials may have reacted with the nanotubes, leaving them unable to affect microbes.

"We want to alert people to the fact that if you're going to apply these as part of a land-treatment program, you may want to focus on high-organic matter soils," he said.

It's also possible, though much less likely, that nanotubes could contaminate soil through accidental spills during a delivery, Turco said.

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Some carbon nanotubes deplete beneficial microbes in certain soils

Ohio State student named 2013 Marshall Scholar

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South Yorkshire, England, apparently bares some striking resemblances to Solon, Ohio.

At least according to Alex Chaitoff, who recently became the sixth Marshall Scholar in Ohio States history.

Chaitoff, a fourth-year in microbiology and political science, became one of 34 students to be named a 2013 Marshall Scholar. He is the first Marshall Scholar that OSU has seen since 2007.

Hes very unusual in the sense that he has a lot of initiative and just loves to learn about new things, said Thomas Wickizer, a professor within the OSU College of Public Health who has worked with Chaitoff for the past two years. He really came to appreciate learning about public health sciences. He came to figure out how he could take that new found understanding and combine it with the want to go to medical school. And I think thats how he came to win the Marshall Scholarship.

The Marshall Scholarship was founded in honor of U.S. Secretary of State George C. Marshall by a 1953 Act of Parliament in order to pay tribute to the Marshall Plan, a World War II-era program where the U.S. provided monetary aid to Europe. The scholarships fund opportunities for American students to do one to three years of graduate study at any institution in the United Kingdom. Between 30 and 40 scholars are chosen each year with the aim of fostering mutual understanding between Great Britain and America through the advancement of any field of study a Marshall Scholar wishes to pursue, according to the scholarship website.

Chaitoff, who was also awarded the competitive national Truman Scholarship in 2012, has done research with Wickizer in the College of Public Health and with Tina Henkinin the Department of Microbiology. He is also involved with Global Health Initiative, the Undergraduate Research Office's Student Advisory Committee and Alpha Epsilon Pi fraternity. He co-founded and directs research for the Pure Water Access Project, a nonprofit organization that helps people in developing countries access clean water. Chaitoff acknowledges several people for his successful record, including Wickizer and Henkin. But he said without the guidance of Dana Kuchem, an adviser in the Undergraduate Fellowship Office, he never would have been able to successfully maneuver each scholarship application.

Without the Undergraduate Fellowship Office, I would have been completely lost, Chaitoff said. Without them, I guarantee I never would have been awarded any of these fellowships.

Kuchem said working with students like Chaitoff is why the UFO was established.

The fellowship office has only been around for a handful of years, and the whole reason the university created it was because of these types of national competitions, Kuchem said. The university really wants to invest in OSU students, and they know that that means somebody has to help them.

Chaitoff has chosen to pursue a masters degree in public health at the University of Sheffield in South Yorkshire, England. I chose Sheffield because Im really interested in the social-cultural components of health care, Chaitoff said. Sheffield has an MPH program, and they have people that work with government institutions and have connections to the British health care system, which Im very interested in learning about.

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Ohio State student named 2013 Marshall Scholar


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