BacterioFiles 397 - Plant Promotes Pathogen-Prohibiting Partner

Bacillus subtilis

By Y tambe, CCBY-SA 3.0

This episode: Plants stimulate their root bacteria to compete better, and these bacteria help the plants resist disease!

Download Episode (7.3 MB, 10.6 minutes)

Show notes:
Microbe of the episode: Bacillus circulans

Takeaways
In some ways, plants' roots are like our gut. They both absorb nutrients, and they both have complex communities of microbes living alongside the host cells. These microbes can assist their hosts in various ways, and get fed in return.

In this study, one species of root bacterium is able to compete against others by producing an antimicrobial compound. The plant stimulates this production with chemical signals, and benefits from its symbionts' increased competitiveness because the bacterium helps the plant resist infection.

Journal Paper:
Ogran A, Yardeni EH, Keren-Paz A, Bucher T, Jain R, Gilhar O, Kolodkin-Gal I. 2019. The Plant Host Induces Antibiotic Production To Select the Most-Beneficial Colonizers. Appl Environ Microbiol 85:e00512-19.

Other interesting stories:

• Plant virus influences aphid viral infection, which possibly increases spread of both
• Producing bioplastics from low-cost carbon sources (paper)

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

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BacterioFiles 396 - Bacteria Boost Blood Bank Budgets

Red blood cells

This episode: Bacterial enzymes could convert donated blood to be compatible with more people in need!

Download Episode (8.0 MB, 11.7 minutes)

Show notes:
Microbe of the episode: Cucumber leaf spot virus

News item

Takeaways
Blood transfusions using donated blood save many lives. Unfortunately, most donations can't be given to just anyone that needs blood; there must be a match in blood type between donor and recipient, or else a life-threatening reaction could occur in the recipient's body. So type A can't donate to type B, or vice versa, but type O is compatible with the other types.

In this study, bacterial enzymes found in human gut microbes have the ability to cleave off the unique type A and B sugars on the surface of red blood cells. This could allow the conversion of all donated blood to type O, greatly increasing the blood bank supply, but more testing is needed to develop the process.

Journal Paper:
Rahfeld P, Sim L, Moon H, Constantinescu I, Morgan-Lang C, Hallam SJ, Kizhakkedathu JN, Withers SG. 2019. An enzymatic pathway in the human gut microbiome that converts A to universal O type blood. Nat Microbiol 4:1475–1485.

Other interesting stories:

• Interesting new protist has novel swimming stroke
• Quantum dot-microbe hybrids power conversion of carbon dioxide to useful stuff

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

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BacterioFiles 395 - Many Microbiome Mindsets

This episode: Five different ways of thinking about our relationship with our microbes!

Download Episode (20.4 MB, 29.8 minutes)

Show notes:
Microbe of the episode: Tuhoko rubulavirus 3

News item

Takeaways
The microbiome by itself is an amazingly complicated community of many different species, with different lifestyles and metabolisms, all living together in competition and cooperation. On top of that, interactions between the microbiome and our body and our lifestyle multiply the complexity even more.

This article explores five different views of the microbiome and how it fits into our body (or how the body fits in with the microbiome). From the organ view to the ecosystem view, each is a different way of looking at the different functions, dynamic patterns, and integration of the microbiome in its host, and each provides guidance for how to approach treatment of disease and maintenance of health.

Journal Paper:
Morar N, Bohannan BJM. 2019. The Conceptual Ecology of the Human Microbiome. The Quarterly Review of Biology 94:149–175.

Other interesting stories:

• New resource connecting drugs, foods, and microbiota enzymes for potential interactions (paper)
• Building cancer-killing viruses that are controlled with light (paper)

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

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Special episode, hurricanes, and more

Hey all, I've been working on a somewhat special episode that is taking me longer than usual, so I don't have anything for this week. It may be up next week, but it is unlikely due to Hurricane Dorian and/or family events. Look forward to it!

BacterioFiles 394 - Skinny Cell Structure Supports

Bacillus subtilisBy Y tambe, CC BY-SA 3.0

This episode: Not as simple as it sounds—how rod-shaped bacteria maintain their shape!

Thanks to Dr. Ethan Garner for his contribution!

Download Episode (6.3 MB, 9.2 minutes)

Show notes:
Microbe of the episode: Erwinia virus M7

News item

Takeaways
Microbes seem like they should be a lot simpler than large multicellular organisms, but even what seems like it should be a simple system in microbes can be surprisingly complex. In this case, the system bacteria maintaining their particular cell shape.

Spherical cells have it easier: just add more cell material at every point. But for rods, they must make the cell longer without making it wider. How do they accomplish this? Two groups of proteins work together to help rod-shaped species grow, but how they work wasn't specifically known.

In this study, it was found that one group of proteins adds more cell material as it moves around the circumference, while the other adds structure to the cell that allows it to maintain shape. The more of these structural proteins present, the thinner the cell can stay.

Journal Paper:
Dion MF, Kapoor M, Sun Y, Wilson S, Ryan J, Vigouroux A, van Teeffelen S, Oldenbourg R, Garner EC. 2019. Bacillus subtilis cell diameter is determined by the opposing actions of two distinct cell wall synthetic systems. Nat Microbiol 4:1294–1305.

Other interesting stories:

• Giant viruses have genes encoding interesting chemical-metabolizing enzymes
• Tiny marine animal with two intriguing bacterial symbionts

Check out BacterioFiles featured in Top 10 Microbiology Podcasts

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

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BacterioFiles 393 - Prokaryote Partner Prevents Pathogen Potency

Acanthamoeba
By J Lorenzo-Morales et al. (2015).
Parasite 22: 10, CC BY 4.0

This episode: Bacterial symbionts of amoebas help them survive bacterial infection, and prevent pathogens from spreading to others as much!

Download Episode (7.5 MB, 8.1 minutes)

Show notes:
Microbe of the episode: Eubacterium dolichum

News item

Takeaways
Amoebas are free-living, single-celled organisms, but they have some things in common with some cells of our immune system (macrophages). For example, certain bacterial pathogens can infect both in similar ways. So it can be useful to study the interactions of amoebas and bacteria to learn about our own immune defenses.

In this study, the amoeba Acanthamoeba castellanii has another bacterial symbiont that helps it resist killing by the bacterial pathogen Legionella pneumophila. Once the amoebas recovered from the infection, they were more resistant to future challenges. Even better, the symbiont prevented the pathogen from transforming into a more spreadable form like it does when infecting amoebas alone.

Journal Paper:
König L, Wentrup C, Schulz F, Wascher F, Escola S, Swanson MS, Buchrieser C, Horn M. 2019. Symbiont-Mediated Defense against Legionella pneumophila in Amoebae. mBio 10:e00333-19.

Other interesting stories:

• RNA-cutting CRISPR/Cas system induces bacterial dormancy to prevent phage replication
• Gut bacteria degrade/modify many different kinds of drugs (paper)

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

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BacterioFiles 392 - Magnetic Microbes Maneuver Marine Manager

Calkinsia aureus
By djpmapleferryman
Uploaded by Shureg, CC BY 2.0

This episode: A marine protist can orient itself along magnetic fields thanks to bacterial symbionts on its surface that make magnetic nanoparticles!

Download Episode (7.2 MB, 7.9 minutes)

Show notes:
Microbe of the episode: Chlorocebus pygerythrus polyomavirus 3

Takeaways
Various kinds of bacteria can orient their movement along a magnetic field. These are called magnetotactic, and they use this ability to swim toward or away from the surface of their aquatic habitat, to adjust their oxygen exposure according to their preference.

No eukaryotic microbes have yet been discovered that can sense and react to magnetic fields like these prokaryotes. In this study, however, a protist was discovered that can do it via its partnership with ectosymbionts, or bacteria attached to its surface, that sense magnetism and orient their host's movement. In return, factors of the host's metabolism may feed its symbionts.

Journal Paper:
Monteil CL, Vallenet D, Menguy N, Benzerara K, Barbe V, Fouteau S, Cruaud C, Floriani M, Viollier E, Adryanczyk G, Leonhardt N, Faivre D, Pignol D, López-García P, Weld RJ, Lefevre CT. 2019. Ectosymbiotic bacteria at the origin of magnetoreception in a marine protist. Nat Microbiol 4:1088–1095.

Other interesting stories:

• Fungus infects mosquitoes and quickly kills them with engineered toxin
• Nose microbe helps mediate immune response to flu virus, in mouse study (paper)

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

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