Monday, October 14, 2019

BacterioFiles 399 - Conductor Creating Carbon Canvases

Scanning probe microscope
image of graphene
By U.S. Army Material Command
CC BY 2.0
This episode: Bacteria can aide the production of the useful material graphene, using their ability to add electrons to external surfaces!

Download Episode (7.7 MB, 11.3 minutes)

Show notes:
Microbe of the episode: Brevibacterium frigoritolerans

News item

Takeaways
Advanced materials often take advanced techniques to create, but they offer numerous benefits: increased strength and flexibility, smaller size, more options. One such material is graphene, which is basically a sheet of carbon atoms linked together like chainmail. It is only a single atom thick but is amazingly strong, mostly transparent, and good at conducting heat and electricity.

The trick is, it's hard to make in large quantities cheaply and easily. Sheets of carbons can be obtained from blocks of graphite, but these sheets are graphene oxide, which lack the desirable properties of graphene. Chemical methods can be used to remove the oxidation, but they are harsh and difficult. Luckily, bacteria are great at microscopic remodeling. In this study, electron-transferring bacteria are able to reduce the graphene oxide to graphene with properties almost as good as are achieved by chemical reduction.

Journal Paper:
Lehner BAE, Janssen VAEC, Spiesz EM, Benz D, Brouns SJJ, Meyer AS, van der Zant HSJ. 2019. Creation of Conductive Graphene Materials by Bacterial Reduction Using Shewanella oneidensis. ChemistryOpen 8:888–895.

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Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

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Monday, October 7, 2019

BacterioFiles 398 - Marathon Microbes Maximize Mileage

Veillonella parvula
Stand Genomic Sci 2(1): 57-65
This episode: Bacteria found in the guts of serious athletes help mice exercise longer by transforming their metabolic waste!

Download Episode (7.3 MB, 10.6 minutes)

Show notes:
Microbe of the episode: Aggregatibacter (Actinobacillus) actinomycetemcomitans

News item

Takeaways
Our gut microbes affect many aspects of health, and many aspects of how we live affect our microbes. One such aspect is physical exertion, which has been associated with enrichment of various microbes in the guts of athletes. This observation led to the question: are these microbes just benefiting from the high levels of exertion, or are they able to contribute also?

This study found that certain such bacteria, when given to mice, enabled the mice to run for a longer period on a treadmill. These microbes break down lactic acid, which is generated in our bodies when we push our physical limits, but the study provided evidence that the longer run times were due not to removal of this waste product, but to the propionate compound produced by its degradation.

Journal Paper:
Scheiman J, Luber JM, Chavkin TA, MacDonald T, Tung A, Pham L-D, Wibowo MC, Wurth RC, Punthambaker S, Tierney BT, Yang Z, Hattab MW, Avila-Pacheco J, Clish CB, Lessard S, Church GM, Kostic AD. 2019. Meta-omics analysis of elite athletes identifies a performance-enhancing microbe that functions via lactate metabolism. Nat Med 25:1104–1109.

Other interesting stories:

Post questions or comments here or email to bacteriofiles@gmail.com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.