447 - Big Bacteria Bank Behaviors

Achromatium
By Ionescu et al. Mol Biol Evol
DOI: 10.1093/molbev/msaa273
CC BY-NC 4.0

This episode: Giant bacteria with many chromosomes in each cell carry extra genes to help them live in many different environments!

Thanks to Dr. Danny Ionescu for his contribution!

Download Episode (8.7 MB, 12.7 minutes)

Show notes:
Microbe of the episode: Propionibacterium virus SKKY

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Takeaways

We think of bacteria a certain way: too small to see and having mostly just a single large chromosome with all the genes they need for their lifestyle and not much more. And most bacteria are like that. But not all! Giant bacteria exist, some of which can be so large that individual cells can be seen without a microscope.

Achromatium species are one such kind of bacteria. They form clumps of minerals that take up most of their internal volume, but their cells are big enough to see and handle. In order to supply all parts of their vast innards with proteins, they have many copies of their chromosome distributed throughout their cytoplasm.

In this study, a survey of Achromatium genomes from all different kinds of ecosystem revealed that even different species in very different environments all seem to share one set of genetic functions, but only use the ones they need for their particular lifestyle while archiving the rest.

Journal Paper:
Ionescu D, Zoccarato L, Zaduryan A, Schorn S, Bizic M, Pinnow S, Cypionka H, Grossart H-P. Heterozygous, Polyploid, Giant Bacterium, Achromatium, Possesses an Identical Functional Inventory Worldwide across Drastically Different Ecosystems. Mol Biol Evol https://doi.org/10.1093/molbev/msaa273.

Other interesting stories:

• As with other infections, gut microbiota correlates with severity of COVID-19
• Fungi help plants defend against aphids

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.

446 - Biofilm Benefits Bone Braces

Biofilm-coated implant
By Tan et al. 2020,
Sci Adv 6:eaba5723
CC BY-NC 4.0

This episode: The biofilm that probiotic bacteria can leave behind on a titanium implant seems to help it integrate better with the existing skeleton, with less inflammation and risk of infection!

Download Episode (5.5 MB, 7.9 minutes)

Show notes:
Microbe of the episode: Methylobacterium organophilum

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Takeaways

Skeletal implants make it a lot easier for many people to stay mobile as they age, but the surgical procedure of implanting is risky. Its invasive nature puts stress on the immune system, which puts stress on other systems, and the spread of antibiotic resistance is increasing the risk of a hard-to-treat infection.

In this study, probiotic bacteria grow in a biofilm on titanium implants before being inactivated, leaving only the biofilm behind on the implant. This biofilm-coated implant showed improved bone integration, antimicrobial resistance that was not toxic to the body's own tissues, and reduced inflammation when implanted into rats.

Journal Paper:
Tan L, Fu J, Feng F, Liu X, Cui Z, Li B, Han Y, Zheng Y, Yeung KWK, Li Z, Zhu S, Liang Y, Feng X, Wang X, Wu S. 2020. Engineered probiotics biofilm enhances osseointegration via immunoregulation and anti-infection. Sci Adv 6:eaba5723.

Other interesting stories:

• Certain gut microbes correlate with lower risk from norovirus (paper)
• Mixture of microbes similar to kombucha engineered to produce living functional materials

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.