449 - Paralyzed Poisons Push Power

Hydrothermal vent

This episode: Deep-sea bacteria can detoxify cadmium and convert it to light-capturing particles!

Download Episode (5.8 MB, 8.4 minutes)

Show notes:
Microbe of the episode: Arthrobacter virus Sonny

Takeaways

Hydrothermal vents can have thriving communities, despite being too deep for much light to penetrate. Microbes can derive energy from chemicals coming out of the vent, and form the foundation of the food chain. But toxic heavy metals also come out of the vent, including lead, mercury, and cadmium.

The microbes in this study were found to be resistant to cadmium, which they can detoxify by combining it with the sulfur found in the amino acid cysteine. This forms cadmium-sulfur nanoparticles, which can function as light-absorbing semiconductors, allowing the bacteria to harvest light energy.

Journal Paper:
Ma N, Sha Z, Sun C. 2021. Formation of cadmium sulfide nanoparticles mediates cadmium resistance and light utilization of the deep-sea bacterium Idiomarina sp. OT37-5b. Environ Microbiol 23:934–948.

Other interesting stories:

• Different fungi behave differently in growing through a tiny maze
• Bacteriophages could be used as disinfectants in some situations (paper)

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.

448 - Myxomycete Makes Mycelial Memories

Slime mold on a log
By frankenstoen, CC BY 2.5

Finally found some good stories, so we're back! This episode: How slime molds encode and use memories built into their own bodies!

Download Episode (4.6 MB, 6.7 minutes)

Show notes:
Microbe of the episode: Aeromonas salmoncida

News item

Takeaways

Despite being single-celled organisms, slime molds have fairly complex behavior, including a basic form of memory. They often grow as a network of tubes of cytoplasm branching out from one place to find and exploit new sources of food in their environment. When these tubes connect to new food, other less productive branches of its body shrink away.

As it turns out, this body form serves a role in memory also. This study determined that the slime mold's tubes undergo constant squeezing, which moves cell contents around and also shrinks them. When tubes are connecting to a food source though, they secrete a softening agent that allows the pressure to expand the tubes instead of shrinking them. These larger tubes consequently are capable of transporting more softening agent farther away to newer food sources, so the history of food discoveries is recorded in the slime mold's own body, which also influences its responses to new discoveries.

Journal Paper:
Kramar M, Alim K. 2021. Encoding memory in tube diameter hierarchy of living flow network. Proc Natl Acad Sci 118.
Other interesting stories:

• Bacteria-derived gene editing tool TALEN better than CRISPR in some cases
• Live microbes in oceans produce more hydrocarbons than oil seeps introduce, priming microbes to break down oil (paper)

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.