463 - Selectively Stimulating Cell Squatters

Bacteriophages
By Jancheva and Böttcher
2021, JACS 143:8344-8351
CC BY 4.0

This episode: Bacteria produce a compound that causes a phage lurking in the genome of a competing species to wake up and start killing that competitor!

Download Episode (8.2 MB, 12.0 minutes)

Show notes:
Microbe of the episode: Zaire ebolavirus

News item

Takeaways

Some bacteriophages infect and immediately destroy their hosts in a burst of new viruses, while others can be stealthier, integrating their genome into the genome of the host and remaining there quietly even over multiple generations of the bacteria. When something stresses the host, such as DNA damage, these integrated phages (prophages) become active and start producing new viruses, killing their host like the other kind does.

In this study, one kind of bacteria release a chemical that wakes up phages in a competitor species of bacteria. This is helpful for competition, but even more interesting is that out of the six prophages in the competitor species, the chemical wakes up only one of them. Such selective phage induction could be interesting to study.

Journal Paper:
Jancheva M, Böttcher T. 2021. A Metabolite of Pseudomonas Triggers Prophage-Selective Lysogenic to Lytic Conversion in Staphylococcus aureus. J Am Chem Soc 143:8344–8351.

Other interesting stories:

• Lab-evolved fungus strain could protect honeybees from mites

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.

462 - Super Ciliate Symbiont Set

Pseudoblepharisma tenue
By Muñoz-Gómez et al, 2021,
Sci Adv 7:eabg4102, CC BY 4.0

This episode: A eukaryote has symbionts living in it: green algae and also purple bacteria, a combo never seen before!

Download Episode (6.1 MB, 8.8 minutes)

Show notes:
Microbe of the episode: Staphylococcus virus phiETA

News item

Takeaways

Having bacteria as endosymbionts is fairly common in life on Earth: almost all eukaryotes have them in the form of mitochondria and sometimes chloroplasts. These former bacteria somehow got inside the ancestral eukaryote, either as parasites or as prey, and ended up as integral parts of their host's metabolic functions. Some organisms, especially insects, obtained bacterial endosymbionts more recently, that help them balance their metabolic needs when living on limited diets.

Algae have been known to be endosymbionts also, performing photosynthesis for their host. But in this study, a ciliate with both algae and purple photosynthetic bacteria as endosymbionts was discovered. Purple bacteria as symbionts is rare, and this combination has not been observed before. Interestingly, though algae produce oxygen through their photosynthesis, the ciliate prefers living in low-oxygen sediment at the bottom of a pond. The symbionts and their host seem to adjust their metabolisms as needed depending on the needs at the time; they may each perform photosynthesis, fermentation, or respiration if light, organic carbon, or oxygen are available.

Journal Paper:
Muñoz-Gómez SA, Kreutz M, Hess S. 2021. A microbial eukaryote with a unique combination of purple bacteria and green algae as endosymbionts. Sci Adv 7:eabg4102.

Other interesting stories:

• Oxygen-producing microbes could help treat acute strokes

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.

461 - Ingrained Invader Inhibits Infectors

Lambda phage
By Hans-Wolfgang Ackermann
Swiss Institute of Bioinformatics
CC BY 4.0

This episode: Training a phage strain on bacteria can increase its ability to control those bacteria for much longer than an untrained phage!

Download Episode (5.7 MB, 8.3 minutes)

Show notes:
Microbe of the episode: Pepper yellow leaf curl Indonesia virus

News item

Takeaways

With resistance to antibiotics spreading more and more among deadly bacteria, finding alternatives to treat infections is becoming more important. One option is phage therapy, using viruses that infect bacteria to weaken or wipe out pathogens, but this can be tricky. Sometimes it takes too long to prepare an effective population of phage for treatment, and sometimes the target pathogen evolves resistance to the phage too quickly

In this study, a phage that was trained, or pre-evolved, to infect specific bacteria more effectively, was able to dominate the population consistently and prevent it from becoming fully resistant. For comparison, against an untrained strain of the same phage, the bacteria developed almost complete resistance after several days.

Journal Paper:
Borin JM, Avrani S, Barrick JE, Petrie KL, Meyer JR. 2021. Coevolutionary phage training leads to greater bacterial suppression and delays the evolution of phage resistance. Proc Natl Acad Sci 118.

Other interesting stories:

• Engineered gut bacteria could sense and indicate bowel inflammation

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.

460 - Prokaryote Publicity Prevents Protist Processes

Emiliania huxleyi
By Alison R. Taylor
UNC Wilmington Microscopy
PLoS Biology, June 2011 Cover
CC BY 2.5

This episode: A bacterial communication signal makes algae stop growing, which helps them survive virus attacks!

Download Episode (5.3 MB, 7.7 minutes)

Show notes:
Microbe of the episode: Veillonella parvula

Takeaways

Many interesting interactions between microbes take place in the ocean. As single-celled organisms lacking complex sensory organs, many such interactions and communications are mediated by chemical signals. Some bacteria, for example, each produce small amounts of certain chemicals and release them into the environment. When the concentration of the chemical signal builds up to a certain point, the bacteria change their behavior to take advantage of their high numbers that must be present to produce so much of the signal. This process is called quorum sensing.

Some of these chemical signals can affect the behavior of organisms other than bacteria also. In this study, a common marine algal species was found to stop growing in response to a certain bacterial signal. This chemical inhibits an enzyme required for the algae to produce nucleotides to replicate their genomes. As a result, the algae are able to resist destruction by a virus that would otherwise decimate their populations.

Journal Paper:
Pollara SB, Becker JW, Nunn BL, Boiteau R, Repeta D, Mudge MC, Downing G, Chase D, Harvey EL, Whalen KE. 2021. Bacterial Quorum-Sensing Signal Arrests Phytoplankton Cell Division and Impacts Virus-Induced Mortality. mSphere 6:e00009-21.

Other interesting stories:

• Comparing ancient gut microbes from fecal fossils to modern gut communities / also this one

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.

459 - Prokaryotes Provide Polyp Perserverance

Coral
By Brocken Inaglory
CC BY-SA 4.0

This episode: Transplanting microbes from some corals to others could help the corals survive high temperatures!

Download Episode (5.7 MB, 8.3 minutes)

Show notes:
Microbe of the episode: Streptomyces olivaceoviridis

News item

Takeaways

The ever-rising temperatures of our modern world are putting more and more stress on various ecosystems. This is true even on the ocean floor: record-high temperatures damage reefs by causing coral bleaching, in which corals lose their photosynthetic endosymbionts. If conditions do not improve, these corals eventually die.

Corals have microbial symbionts other than the phototrophs, also. We know from ourselves and from plants that microbes can have big effects on their hosts, so it seemed worth testing whether symbionts from more heat-resistant corals could transfer heat resistance to more vulnerable individuals. Recipients of this treatment did show enhanced heat resistance, but the microbial community composition did not always change after the treatment.

Journal Paper:
Doering T, Wall M, Putchim L, Rattanawongwan T, Schroeder R, Hentschel U, Roik A. 2021. Towards enhancing coral heat tolerance: a “microbiome transplantation” treatment using inoculations of homogenized coral tissues. Microbiome 9:102.

Other interesting stories:

• Tiny bacterium kills larger bacterium that makes troublesome foam

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.

458 - Slimy Cells Stop Sinking

Colonies of strains with
different floating strengths
By Kessler et al. 2021,
J Bacteriol 203(11):e00023-21
CC BY 4.0

This episode: Bacteria can resist the force of gravity in liquid culture by covering themselves with goopy sugar polymers like parachutes!

Download Episode (10.4 MB, 15.2 minutes)

Show notes:
Microbe of the episode: Brevicoryne brassicae virus

Takeaways

Put bacteria in a centrifuge, and most of the time you end up with a compact pellet of cells at the bottom of the tube, and mostly cell-free liquid above it. Bacteria do have ways to remain suspended in liquid, even without constant stirring or shaking of the container, but swimming, for example, consumes energy.

In this study, artificial selection allowed the discovery of bacteria that could resist centrifuging speeds up to 15000 times the force of gravity, remaining suspended in liquid instead of forming a pellet. Production of polysaccharide was important, but not sufficient; for the most resistance to sinking, bacteria had to attach the polysaccharide to their cell surface, to act as a sort of parachute.

Journal Paper:
Kessler NG, Caraballo Delgado DM, Shah NK, Dickinson JA, Moore SD. 2021. Exopolysaccharide Anchoring Creates an Extreme Resistance to Sedimentation. J Bacteriol 203(11):e00023-21.

Other interesting stories:

• Engineered probiotic yeast could help prevent vitamin A deficiency

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.

457 - Small Cell Studies: Superior Scoops

Plant microbiome
By KMG Dastogeera et al.
CC BY-SA 4.0

This episode: Newspapers report on scientific studies about microbiomes a fair amount, but certain kinds of studies are more likely than others to show up in the news!

Download Episode (5.7 MB, 8.3 minutes)

Show notes:
Microbe of the episode: Cafeteriavirus-dependent mavirus

Takeaways

Research into the human microbiome has generated a lot of interest, even among non-scientists. This is especially true since the beginning of the Human Microbiome Project in 2007. But sometimes things are lost in translation from published studies into general news.

This study is a survey of microbiome studies reported in six different news sources from three different countries, either general news or business news. General news did a better job reporting on different kinds of microbiome studies proportionally, but certain kinds of studies were reported on proportionally more or less frequently than they were published.

Journal Paper:
Prados-Bo A, Casino G. 2021. Microbiome research in general and business newspapers: How many microbiome articles are published and which study designs make the news the most? PLOS ONE 16:e0249835.

Other interesting stories:

• Gut microbes in C-section babies can be similar to non-surgical births after several years

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.