482 - Colony Concentric Clock Construction

Bacillus subtilis
By Y tambe,
CC BY-SA 3.0

This episode: Single-celled bacteria can act independently to create patterns and structure in their biofilm communities!
Download Episode (9.6 MB, 14.0 minutes)

Show notes:
Microbe of the episode: Dictyostelium discoideum Skipper virus

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Takeaways

Large multicellular organisms like us have interesting mechanisms for using one set of genetic instructions present in all cells to form a large, complex community of many different types of cells with different structures and functions, all working together. Single-celled microbes do not have the same requirements for genetic or structural complexity, but they do often display interesting communal patterns and behaviors.

In this study, bacteria growing in colonies on agar displayed a particular mechanism of pattern formation previously seen only in eukaryotes, called segmentation clock or clock and wavefront process. In this process, the cells in the colony are all acting individually without communication with each other, but nevertheless form a repeating ring structure in the colony as it grows, possibly allowing some measure of differentiation of cells that could help the community survive various challenges.

Journal Paper:
Chou K-T, Lee DD, Chiou J, Galera-Laporta L, Ly S, Garcia-Ojalvo J, Süel GM. 2022. A segmentation clock patterns cellular differentiation in a bacterial biofilm. Cell 185:145-157.e13.

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

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481 - Hijacker-Host Sequence Swap

Megavirus
By Chantal Abergel,
CC BY-SA 3.0

This episode: Gene transfers between viruses and eukaryotes have happened many times throughout evolutionary history!
Download Episode (7.5 MB, 10.9 minutes)

Show notes:
Microbe of the episode: Mycoplasma subdolum

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Takeaways

As we’ve all seen recently, viruses can cause a lot of trouble. Their biology requires them to be parasites inside the cells of their hosts, and they can cause devastating disease, so it’s hard to think of them as having played important roles in the development of life on Earth, including our own evolution.

However, this study found thousands of apparent historical transfers of genes from virus to host or from host to virus in the cells of all kinds of different eukaryotes. Some of these genes play important roles in the cell, helping to make them what they are.

Journal Paper:
Irwin NAT, Pittis AA, Richards TA, Keeling PJ. 2022. Systematic evaluation of horizontal gene transfer between eukaryotes and viruses. Nat Microbiol 7:327–336.

Other interesting stories:

• Building a device that translates signals from one microbe to communicate with another
• Cloaking antitumor bacteria to fight cancer without immune system interference

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

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480 - Bait Bottlenecks Bear Bacteria

Black bear
By Diginatur
CC BY-SA 3.0

This episode: Human-based food used as bait by hunters can reduce bears' gut microbe diversity!
Download Episode (5.9 MB, 8.6 minutes)

Show notes:
Microbe of the episode: Actinomadura verrucosospora

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Takeaways

Gut microbes are important for the health of most animals. In humans, many things can affect our gut microbe community, including diet, medications, and lifestyle. Eating a varied diet with diverse kinds of plant-based foods can maintain a healthy, functional community of many different kinds of microbe. However, eating mostly highly processed grain-based foods can reduce the diversity and functionality of the gut community.

This is also true in bears. In this study, when bears consumed more processed, grain-based human foods via hunters leaving such foods out as bait, the gut communities in these bears had reduced diversity of microbes. The effects of this reduced diversity were not determined, but it is reasonable to assume it was not good for the bears’ overall health.

Journal Paper:
Gillman SJ, McKenney EA, Lafferty DJR. 2022. Human-provisioned foods reduce gut microbiome diversity in American black bears (Ursus americanus). J Mammal 103:339–346.

Other interesting stories:

• 3D-printed electrode structures harvest electricity from bacterial photosynthesis
• Gut microbes are important for helping tadpoles survive in warmer conditions

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

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479 - Uncomplicated Critters Conquer Cancer

T. adhaerens
By Fortunato et al. 2021.
PLOS Biol e3001471
CC BY 4.0

This episode: Simple microscopic animals can survive extreme radiation by ejecting damaged cells that might otherwise become cancer!
Download Episode (7.3 MB, 9.2 minutes)

Show notes:
Microbe of the episode: Helleborus net necrosis virus

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Takeaways

Any multicellular organism with different types of cells needs some sort of cell regulation, to keep each cell type doing what it’s supposed to do for the good of the organism as a whole. We know what happens when this regulation fails and one type of cells starts multiplying out of control: cancer.

However, cancer has never yet been observed in certain organisms, including the simple microscopic animal Trichoplax adhaerens. In this study, these animals are exposed to large amounts of radiation and then observed over years to see if they can develop cancer or have interesting mechanisms of resisting it.

Journal Paper:
Fortunato A, Fleming A, Aktipis A, Maley CC. 2021. Upregulation of DNA repair genes and cell extrusion underpin the remarkable radiation resistance of Trichoplax adhaerens. PLOS Biol 19:e3001471.

Other interesting stories:

• Genes transferred from bacteria to algae helped land plants evolve

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

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478 - Babies Bear Bacterial Birthright

E. coli, a common gut microbe

This episode: How family members share gut microbes across multiple generations!
Download Episode (7.3 MB, 10.7 minutes)

Show notes:
Microbe of the episode: Dyozetapapillomavirus 1

Takeaways

Our gut’s microbial communities can greatly influence our health, for good or bad. The makeup of these communities can be influenced by many factors, including genetics, health status, diet, and other aspects of the environment we live in. We’ve learned a lot about this topic recently, but there’s a lot more we still don’t understand.

In this study, gut microbe samples from individuals spanning multiple generations in the same families were compared, to see how much influence family relationships and cohabitation could have on the gut communities. Both genetic relationship and living together had influences on which gut microbes different people shared.

Journal Paper:
Valles-Colomer M, Bacigalupe R, Vieira-Silva S, Suzuki S, Darzi Y, Tito RY, Yamada T, Segata N, Raes J, Falony G. 2022. Variation and transmission of the human gut microbiota across multiple familial generations. 1. Nat Microbiol 7:87–96.

Other interesting stories:

• Simple modification to interesting bacteria make them excrete nitrogen fertilizer
• Making carbon dioxide into useful chemicals with bacteria

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

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477 - Hijackers Hitchhike on Hyphal Highways

Phage stuck to non-host bacterium
By You et al, 2022,
ISMEJ 16:1275-1283
CC BY 4.0

This episode: Bacteriophages can hitch a ride on bacteria they don't infect to travel through soil on fungal filaments, potentially helping their carriers by infecting and killing their competitors!
Download Episode (7.1 MB, 10.3 minutes)

Show notes:
Microbe of the episode: Epinotia aporema granulovirus

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Takeaways

For tiny bacteria, partially dry soil can be like a vast system of caverns, with particles of soil separated by air-filled spaces much bigger than individual bacteria. Not all bacteria can swim through liquid, and those that can’t simply try to thrive as best they can wherever they may be. But for those that can swim, fungi and other filamentous organisms can form bridges between soil particles that motile bacteria can swim across, reaching new places.

In this study, phages were found to hitch a ride on bacteria they don’t normally infect, crossing fungus-like filaments to new places and infecting the bacteria they find there. The bacteria carrying them can also benefit from this interaction, since the phages help the carrier bacteria compete and establish a colony in the new location.

Journal Paper:
You X, Kallies R, Kühn I, Schmidt M, Harms H, Chatzinotas A, Wick LY. 2022. Phage co-transport with hyphal-riding bacteria fuels bacterial invasion in a water-unsaturated microbial model system. 5. ISME J 16:1275–1283.

Other interesting stories:

• Fungus species discovered in spacecraft assembly facility
• Oral microbes uniquely influence immune system interaction with mouth bones

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

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476 - Bamboo Breakdown Benefits Beetle Babies

Bamboo
By I Kenpei,
CC BY-SA 3.0

This episode: Beetles inoculate bamboo with a fungus that consumes the bamboo sugars to feed the beetle larvae!
Download Episode (7.7 MB, 11.2 minutes)

Show notes:
Microbe of the episode: Saccharomyces cerevisiae virus L-BC (La)

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Video: Lizard beetle laying its egg

Takeaways

The structural polymers that make up plants, such as cellulose, can be difficult for many organisms to digest. Some kinds of bacteria and fungi can do it, and some animals (cows, pandas, termites) partner with these microbes to be able to eat otherwise indigestible plant material. This includes insects such as leaf-cutter ants that farm external gardens of microbes, providing them plant material and then eating the resulting microbial growth.

In this study, the lizard beetle lays its eggs in bamboo and inoculates the walls of the bamboo with a fungus that provides food to the larvae. Chemical analyses suggest that the fungus only consumes the simple sugars in the bamboo rather than breaking down the tougher polymers, which raises questions about the evolution of this interaction.

Journal Paper:
Toki W, Aoki D. 2021. Nutritional resources of the yeast symbiont cultivated by the lizard beetle Doubledaya bucculenta in bamboos. Sci Rep 11:19208.

Other interesting stories:

• Using bacteria to detect and target colon cancer for imaging (paper)
• Filters made from kombucha cultures could work better than synthetic types

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.