BacterioFiles

This episode: Phages eavesdrop on bacterial communications to attack at the perfect moment!

Thanks to Justin Silpe and Dr. Bonnie Bassler for their contributions!

Download Episode (11.1 MB, 12.2 minutes)

Show notes:
Microbe of the episode: Artichoke Aegean ringspot virus

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Takeaways
Even organisms as small as bacteria can, and often do, communicate with each other through a process called quorum sensing, in which each cell releases a small amount of a certain chemical into their surroundings. When the population is large enough that the concentration of this chemical builds up to a certain level, the cells in the population change their behavior. The specifics of this change depend on the species and the situation.

But since this chemical signal is released into the environment, anything around that can sense it can listen in on the communications of a bacterial population. In this study, Justin Silpe and Dr. Bonnie Bassler find a type of virus that uses such a chemical communication as a signal to come out of stasis and hijack a whole population of bacteria at once!

Journal Paper:
Silpe JE, Bassler BL. 2019. A Host-Produced Quorum-Sensing Autoinducer Controls a Phage Lysis-Lysogeny Decision. Cell 176:268-280.E13.

Other interesting stories:

• Bacteria around plant roots can affect when they flower (paper)
• Certain respiratory microbe communities seem to protect against flu
• New process for finding better electric bacteria

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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This episode: Enhancing a virus with magnetic nanoparticles and CRISPR-Cas gene editing abilities makes it a good vector for genetic therapies!

Download Episode (11.2 MB, 12.25 minutes)

Show notes:
Microbe of the episode: Staphylococcus virus S253

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Takeaways
Gene delivery, getting genetic content for gene therapy to the correct tissues in an organism, has long been a very tricky problem. And genetic modification, making specific changes at a specific place in a genome, is also difficult.

Viruses can help with both delivery and modification, but they're often not specific and targeted enough to be effective, or even safe. Off-target effects could be harmful or even deadly, potentially resulting in cancer.

In this study, a virus is modified with nanotechnology in the form of tiny magnets to allow humans to target it to specific tissues, and given the ability to modify specific genes using the bacterial CRISPR-Cas system. These modifications potentially make this gene delivery system much more safe and effective.

Journal Paper:
Zhu H, Zhang L, Tong S, Lee CM, Deshmukh H, Bao G. 2018. Spatial control of in vivo CRISPR–Cas9 genome editing via nanomagnets. Nat Biomed Eng.

Other interesting stories:

• Bacteria found in hot, dry areas could have potentially useful industrial enzymes (paper)
• Gut bacteria help regulate vitamin A activity in gut
• Confined swimming bacteria form shifting vortex like clothes washer (paper)

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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This episode: Purple phototrophic bacteria could use certain kinds of wastewater, along with electric current, to produce valuable products like hydrogen without much waste!

Thanks to Dr. Ioanna Vasiliadou for her contribution!

Download Episode (12.7 MB, 13.9 minutes)

Show notes:
Microbe of the episode: Streptomyces tendae

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Takeaways
Purple phototrophic bacteria can take light energy and use it to help power their metabolism. They're not dependent on it like plants, but can use light or other energy sources for their versatile metabolism.

This versatility makes them very interesting candidates for industrial biotechnology applications. These bacteria can take in various combinations of nutrients and produce a number of different valuable products, including protein-rich feed, bioplastics, and biofuels such as hydrogen gas.

Today's study shows they can also take up electrons directly to help make their biofuel production process even more environmentally sustainable.

Journal Paper:
Vasiliadou IA, Berná A, Manchon C, Melero JA, Martinez F, Esteve-Nuñez A, Puyol D. 2018. Biological and Bioelectrochemical Systems for Hydrogen Production and Carbon Fixation Using Purple Phototrophic Bacteria. Front Energy Res 6:107.

Other interesting stories:

• Looking at which microbes degrade classic paintings, and how
• Neurotransmitter-consuming gut microbes correlated with fewer signs of depression (paper)
• Phages don't always transfer the same way in fecal microbe transplants (paper)

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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This episode: Fruit fly gut microbes can mediate non-genetic traits passed from parents to offspring!

Thanks to Dr. Per Stenberg for his contribution!

Download Episode (10.0 MB, 10.9 minutes)

Show notes:
Microbe of the episode: Bifidobacterium breve

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Takeaways
Heritability of traits is essential for evolution; if an ability can't be passed on from generation to generation, then natural selection can't act on it on a population-wide level.

An organism's genome is the source of most heritable traits, as DNA gets passed on to offspring, but a number of other ways of passing on traits have been discovered, in the field of epigenetics.

In this study, the gut microbes from fruit flies raised in one temperature could affect the gene expression of their offspring raised in a different temperature, compared to flies that had been kept at the latter temperature over both generations. While the effects on fly fitness or behavior are not yet known, these results suggest that gut microbes, transmitted from parents to offspring, could be another mechanism of heritability.

Journal Paper:
Zare A, Johansson A-M, Karlsson E, Delhomme N, Stenberg P. 2018. The gut microbiome participates in transgenerational inheritance of low-temperature responses in Drosophila melanogaster. FEBS Lett 592:4078–4086.

Other interesting stories:

• Bacteria living in alfalfa plants seem to extend roundworm lifespans (paper)
• Whole fruit fly microbe community affects whether flies live longer or reproduce more
• Hot spring archaea have unusual membranes that help tolerate the heat

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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This episode: Women who immigrated to the US from southeast Asia lost much of their gut microbiota diversity, resulting in a microbe community similar to the typical American!

Download Episode (9.3 MB, 10.2 minutes)

Show notes:
Microbe of the episode: Pseudomonas anguilliseptica

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Journal Paper:
Vangay P, Johnson AJ, Ward TL, Al-Ghalith GA, Shields-Cutler RR, Hillmann BM, Lucas SK, Beura LK, Thompson EA, Till LM, Batres R, Paw B, Pergament SL, Saenyakul P, Xiong M, Kim AD, Kim G, Masopust D, Martens EC, Angkurawaranon C, McGready R, Kashyap PC, Culhane-Pera KA, Knights D. 2018. US Immigration Westernizes the Human Gut Microbiome. Cell 175:962-972.e10.

Other interesting stories:

• Soil archaea help plants resist pathogenic microbes (paper)
• Engineering bacteria to evolve more heat-stable proteins with unusual amino acids
• Anemones and clown fish live together and also share microbes

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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

This episode: Bacteria rid themselves of burdensome waste by ejecting it inside little pieces of their own cell, called minicells!

Download Episode (10.8 MB, 11.9 minutes)

Show notes:
Microbe of the episode: Cacao yellow mosaic virus

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Journal Papers:
Rang CU, Proenca A, Buetz C, Shi C, Chao L. 2018. Minicells as a Damage Disposal Mechanism in Escherichia coli. mSphere 3:e00428-18.

Other interesting stories:

• Gut microbe can help protect mice from colon cancer (paper)
• Microbes living in super-dry desert couldn't survive excess rains

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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

This episode: Dr. Klara Junker joins me to discuss her work on the predatory yeast Saccharomycopsis schoenii that can kill the serious pathogenic yeast Candida auris!

Download Episode (11.0 MB, 12.0 minutes)

Show notes:
Microbe of the episode: Lambdapapillomavirus 5

Movies of Saccharomycopsis attacking other yeasts

Journal Papers:
Junker K, Bravo Ruiz G, Lorenz A, Walker L, Gow NAR, Wendland J. 2018. The mycoparasitic yeast Saccharomycopsis schoenii predates and kills multi-drug resistant Candida auris. Sci Rep 8:14959.

Other interesting stories:

• Studying which microbes grow well on different gravestones
• Certain fiber-digesting bacteria in mouse gut correlate with less artery disease

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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

This episode: Engineering other organisms to fix nitrogen by combining the required enzyme components into giant proteins that then get cut into the regular-sized subunit components!

Download Episode (10.5 MB, 11.5 minutes)

Show notes:
Microbe of the episode: Blastochloris sulfoviridis

Journal commentary (paywall)

Journal Papers:
Yang J, Xie X, Xiang N, Tian Z-X, Dixon R, Wang Y-P. 2018. Polyprotein strategy for stoichiometric assembly of nitrogen fixation components for synthetic biology. Proc Natl Acad Sci 115:E8509–E8517.

Other interesting stories:

• How the human microbiota recovers after antibiotic treatment

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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

This episode: Intricate networks of tunnels in garnet gemstones seem to have come from tunneling microorganisms!

Thanks to Magnus Ivarsson for his contribution!

Download Episode (5.4 MB, 5.9 minutes)

Show notes:
Microbe of the episode: Streptomyces griseosporeus

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Journal Papers:
Ivarsson M, Skogby H, Phichaikamjornwut B, Bengtson S, Siljeström S, Ounchanum P, Boonsoong A, Kruachanta M, Marone F, Belivanova V, Holmström S. 2018. Intricate tunnels in garnets from soils and river sediments in Thailand – Possible endolithic microborings. PLOS ONE 13:e0200351.

Other interesting stories:

• Swimming algae can move through bloodstream to deliver drugs
• Mosquito microbes engineered to inhibit spread of malaria (paper)
• A probiotic inhibits a pathogen by interfering with its signaling between cells
• Healthy microbiota seems important for mice recovering from heart attack

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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

This episode: Combining all 16 of yeast's chromosomes into one or two only impairs their growth slightly in the lab, but it prevents them from successful mating with wild yeasts!

Download Episode (12.4 MB, 13.6 minutes)

Show notes:
Microbe of the episode: Vibrio succinogenes

News item 1/News item 2

Journal Papers:
Luo J, Sun X, Cormack BP, Boeke JD. 2018. Karyotype engineering by chromosome fusion leads to reproductive isolation in yeast. Nature 560:392–396.
Shao Y, Lu N, Wu Z, Cai C, Wang S, Zhang L-L, Zhou F, Xiao S, Liu L, Zeng X, Zheng H, Yang C, Zhao Z, Zhao G, Zhou J-Q, Xue X, Qin Z. 2018. Creating a functional single-chromosome yeast. Nature 560:331–335.

Other interesting stories:

• Treating Salmonella infection with phages plus gut microbiota works better together (paper)
• Bioreactor fermentation strategy allows efficient vitamin K production

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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