484 - Bacteriophages Boost Brains

Lysogenic phage
By Rolf Lood et al.
BMC Microbiology
2008, 8:139
CC BY 2.5

This episode: Certain phages in the gut are linked with increases in performance on some cognitive tests!
Download Episode (7.5 MB, 10.9 minutes)

Show notes:
Microbe of the episode: Streptomyces bikiniensis

News item

Takeaways

Our gut microbiota includes a large number of viruses, mostly bacteriophages. These fall into two groups, the lytic kind that infects and reproduces itself immediately in a host, and the lysogenic kind that can integrate its genome into the host bacterial genome and remain dormant for long periods.

In this study, a higher proportion of lysogenic phages was correlated with increased performance on cognitive tests in multiple species. In humans, men showed a small increase in some tests and women in others. In mice and fruit flies, transplant or ingestion of phages was linked to increased memory performance.

Journal Paper:
Mayneris-Perxachs J, Castells-Nobau A, Arnoriaga-Rodríguez M, Garre-Olmo J, Puig J, Ramos R, Martínez-Hernández F, Burokas A, Coll C, Moreno-Navarrete JM, Zapata-Tona C, Pedraza S, Pérez-Brocal V, Ramió-Torrentà L, Ricart W, Moya A, Martínez-García M, Maldonado R, Fernández-Real J-M. 2022. Caudovirales bacteriophages are associated with improved executive function and memory in flies, mice, and humans. Cell Host Microbe 30:340-356.e8.


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.

483 - Recycling Resources Raises Robustness

E. coli

This episode: Adding tags to proteins to increase their degradation can help engineered bacteria grow and survive better under various conditions!
Download Episode (7.3 MB, 10.4 minutes)

Show notes:
Microbe of the episode: Lactococcus virus sk1

News item

Takeaways

Engineering bacteria with new genetic pathways allows us to use them in many new and promising applications. Some of these are industrial fermentations, growing large quantities of bacteria to use as catalysts for production of chemicals of interest, such as biofuels. But in other cases, engineered microbes can be most useful in less controlled environments, such as the soil. In these situations, the engineering can throw off their natural metabolic balance, making them less tolerant of the stresses of such environments.

In this study, a solution to this issue was tested using protein tags that signal the bacterial enzymes to degrade the engineered proteins. A variety of tags allowed for a variety of rates of degradation, allowing engineers to tune in the ideal rate. Bacteria with these engineered tags grew better in nutrient limited conditions than those without.

Journal Paper:
Szydlo K, Ignatova Z, Gorochowski TE. 2022. Improving the Robustness of Engineered Bacteria to Nutrient Stress Using Programmed Proteolysis. ACS Synth Biol 11:1049–1059.

Other interesting stories:

• Microbes found in tap water could influence composition of the gut microbiome (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.

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

News item

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!

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

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

News item

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!

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

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

News item

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!

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

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

News item

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!

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

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!

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