BacterioFiles 407 - Fungus Facilitates Phototroph Feeding

Various Phomopsis fungi

Probably the last episode of the year. See you in the next!

This episode: Fungus living inside plants helps them form partnerships with nitrogen-fixing bacteria!

Download Episode (5.9 MB, 8.5 minutes)

Show notes:
Microbe of the episode: Prevotella intermedia

Takeaways
Plants are very good at acquiring carbon, but they can often use some help with other nutrients. Many form partnerships with microbes such as nitrogen-fixing bacteria or mycorrhizal fungi that can help gather nutrients from the soil better than the plants' own roots.

In this study, legume plants could form a partnership with nitrogen-fixing bacteria in its roots, but a fungus living inside the plant could enhance this partnership even more, increasing the amount of nitrogen acquired and influencing the community of microbes around the plant roots in ways favorable to all partners.

Journal Paper:
Xie X-G, Zhang F-M, Yang T, Chen Y, Li X-G, Dai C-C. 2019. Endophytic Fungus Drives Nodulation and N₂ Fixation Attributable to Specific Root Exudates. mBio 10:e00728-19, /mbio/10/4/mBio.00728-19.atom.

Other interesting stories:

• Diet could affect antibiotic impact on the gut microbiome
• Feeding gut microbes particular preferred foods can manipulate the community structure

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.

BacterioFiles 406 - Different DNA Destroys Disease Drivers

Neisseria gonorrhoeae colonies on agar
By Xishan01, CC BY-SA 3.0

This episode: DNA from related species can kill certain pathogens when they incorporate it into their genome!

Download Episode (7.9 MB, 11.5 minutes)

Show notes:
Microbe of the episode: Ungulate tetraparvovirus 3

Paper summary (paywall)

Takeaways
Neisseria gonorrhoeae, the bacteria that cause gonorrhea, have the unusual ability of taking up DNA from their surroundings at any time and making use of it in their own genome. This helps them acquire useful traits that help them survive better, such as antibiotic resistance. But it turns out that the ability is also a secret weakness!

This study showed that when N. gonorrhoeae takes up DNA from harmless, commensal species of Neisseria in the body, the DNA is similar enough to be incorporated into the genome but different enough that it kills the pathogen. This effect also occurs with a serious pathogen in the same genus, N. meningitidis.

Journal Paper:
Kim WJ, Higashi D, Goytia M, Rendón MA, Pilligua-Lucas M, Bronnimann M, McLean JA, Duncan J, Trees D, Jerse AE, So M. 2019. Commensal Neisseria Kill Neisseria gonorrhoeae through a DNA-Dependent Mechanism. Cell Host Microbe 26:228-239.e8.

Other interesting stories:

• Kombucha could be good model system for studying microbial cooperation
• Antidepressants can modify bacterial metabolism of serotonin in the gut

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.

BacterioFiles 405 - Coated Colonizers Counteract Corrosion

Coated bacteria on a coated surface
Rijavec et al. 2019, Adv Sci 1901408

This episode: Coating metal surfaces with artificial biofilms could help keep the surfaces corrosion-free even in the ocean!

Download Episode (6.3 MB, 9.1 minutes)

Show notes:
Microbe of the episode: Hymenopteran ambidensovirus 1

Takeaways
The ocean can be a harsh place for metal surfaces. Between the water, the salt, and oxygen (near the surface), corrosion is a common reality. Microbes in the ocean can contribute to this too, degrading metal structures to obtain energy for their metabolism. They colonize surfaces in biofilms that can be difficult to remove, a process called biofouling.

In this study, instead of trying to remove or prevent biofilms on surfaces, artificial biofilms were created by coating the surfaces and specially selected bacterial cells with polymers. This approach did not prevent colonization by other organisms in the sea, but preliminary results suggested that the community that did take up residence was not as corrosive as the communities found on uncoated steel.

Journal Paper:
Rijavec T, Zrimec J, Spanning R van, Lapanje A. 2019. Natural Microbial Communities Can Be Manipulated by Artificially Constructed Biofilms. Adv Sci 6:1901408.

Other interesting stories:

• Some microbe biofilms can protect outdoor metal sheets from corrosion
• How bacteria can be helpful for growing edible mushrooms (review)

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.

BacterioFiles 404 - Phages Force Food Finding

Synechococcus cyanobacteria

This episode: Another climate-related story: Cyanobacteria infected by viruses continue taking up nutrients from their environment, using it to make more viruses than would otherwise be possible!

Download Episode (6.3 MB, 9.2 minutes)

Show notes:
Microbe of the episode: Microcystis virus Ma-LMM01

News item

Takeaways
Though global warming is a global problem, accurate models for predicting where things are headed need to incorporate the activity of even the smallest organisms, if they're numerous enough. Photosynthesis and other activities of microbes in the oceans are a big sink for carbon, but cycles of other nutrients and also viruses can affect the carbon cycle.

In this study, phages infecting photosynthetic ocean bacteria were able to continue their host's uptake of nitrogen from the environment even after mostly shutting down the host's own protein production and growth. This has implications for how viruses affect carbon cycling by cyanobacteria and how quickly populations of these bacteria may grow or die off.

Journal Paper:
Waldbauer JR, Coleman ML, Rizzo AI, Campbell KL, Lotus J, Zhang L. 2019. Nitrogen sourcing during viral infection of marine cyanobacteria. Proc Natl Acad Sci 116:15590–15595.

Other interesting stories:

• Transplants of gut microbes help koalas eat wider range of food
• Skin bacteria can help attract (or repulse) mosquitoes (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.

BacterioFiles 403 - Mercury Modifies Microbe Metabolism

This episode: First episode of a climate-related arc! Considering microorganisms is important when predicting the amount of carbon coming from soil as temperature increases!

Download Episode (4.7 MB, 6.75 minutes)

Show notes:
Microbe of the episode: Streptomyces virus Zemlya

News item

Takeaways
Soil as a whole has a big influence on the climate of the planet, by enabling the communities of organisms that live in it to interact and grow, taking up gases from the atmosphere and putting others back in. Even aside from plants that grow in it, the other organisms in soil can respire and break down compounds to produce CO₂, adding to what's in the atmosphere already.

There has long been observed a relationship between ambient temperatures and this respiration in soil, such that more heat means more activity and more gases released from the soil, but today's study found that the microbial biomass in a given piece of land can have a big effect on the temperature/respiration relationship.

Journal Paper:
Čapek P, Starke R, Hofmockel KS, Bond-Lamberty B, Hess N. 2019. Apparent temperature sensitivity of soil respiration can result from temperature driven changes in microbial biomass. Soil Biol Biochem 135:286–293.

Other interesting stories:

• Phosphate-solubilizing bacteria could help replace fertilizer for plants (paper)
• Ciliate protists have bacterial microbiomes too

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.

BacterioFiles 402 - Microbe Membranes Mobilize Microglia

Microglia in rat brain tissue

This episode: Gut microbes can stimulate immune cells in mouse brains to fight off viral infections!

Download Episode (9.0 MB, 13.0 minutes)

Show notes:
Microbe of the episode: Streptoverticillium mobaraense

News item

Takeaways
The central nervous system, including the brain, is a protected area of the body. Pathogens that get in can do a lot of damage, including memory loss, paralysis, and death, so there's a strict barrier in healthy people that keeps most things out of this area: the blood-brain barrier. The immune system is also kept separate, so special cells called microglia do the patrolling and protection of the brain.

Nevertheless, microbes in the gut can influence the function of the immune system in the brain, even from a distance. In this study, mice lacking gut microbes did not have as effective an immune response to a virus infecting the brain, and it was found that molecules from bacterial outer membranes were sensed by microglia to activate their defensive response.

Journal Paper:
Brown DG, Soto R, Yandamuri S, Stone C, Dickey L, Gomes-Neto JC, Pastuzyn ED, Bell R, Petersen C, Buhrke K, Fujinami RS, O’Connell RM, Stephens WZ, Shepherd JD, Lane TE, Round JL. 2019. The microbiota protects from viral-induced neurologic damage through microglia-intrinsic TLR signaling. eLife 8:e47117.

Other interesting stories:

• Certain microbes associated with slower progression of degenerative disease in mice
• Fungus produces compound that neutralizes skunk odor

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.

BacterioFiles 401 - Phototrophs Fill Fungal Filaments

Algae inside fungal hypha

By Du et al. 2019

eLife e47815

This episode: In this partnership between fungus and algae, the algae eventually take up residence inside their partner!

Download Episode (8.4 MB, 12.1 minutes)

Show notes:
Microbe of the episode: Erwinia tracheiphila

News item/Summary article

Takeaways
Partnerships and cooperation between otherwise free-living organisms is common in the natural world. Partnering with a photosynthetic organism is a smart approach, allowing the partner to get its energy from the sun and making gathering nutrients easier for the phototroph, and possibly offering protection as well. But in most partnerships, each partner stays separated by its own cell membrane.

In this study, a fungus and an alga grow well together, exchanging carbon for nitrogen, similar to how lichens operate. But after a month or so of co-culture, the algae apparently enter the cells of the fungus somehow and live inside it, happily growing and dividing, turning the fungus green.

Journal Paper:
Du Z-Y, Zienkiewicz K, Vande Pol N, Ostrom NE, Benning C, Bonito GM. 2019. Algal-fungal symbiosis leads to photosynthetic mycelium. eLife 8:e47815.

Other interesting stories:

• Skin microbe transplants could produce healthier skin communities
• Algae took genes from bacteria to deal with harsh 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.

BacterioFiles 400 - Considering Consumables' Community Correlations

Fusobacterium

This episode: Figuring out how gut communities change with changes in diet!

Download Episode (6.1 MB, 8.8 minutes)

Show notes:
Microbe of the episode: Hepacivirus A

News item

Takeaways
Diet can play a big role in our health. It's not a magic pill that can cure or prevent anything, but a good diet can significantly reduce many health risks for the average person, compared with a bad diet.

Diet also has a big effect on the community of microbes in our gut, and this may play a role in the health effects we see from diet, so understanding how food and microbes interact is important. This study looked at the diet quality of participants in several food categories, and correlated this with various kinds of microbes found inside them.

Journal Paper:
Liu Y, Ajami NJ, El-Serag HB, Hair C, Graham DY, White DL, Chen L, Wang Z, Plew S, Kramer J, Cole R, Hernaez R, Hou J, Husain N, Jarbrink-Sehgal ME, Kanwal F, Ketwaroo G, Natarajan Y, Shah R, Velez M, Mallepally N, Petrosino JF, Jiao L. 2019. Dietary quality and the colonic mucosa–associated gut microbiome in humans. Am J Clin Nutr 110:701–712.

Other interesting stories:

• Sea slug uses defensive toxins that bacteria make for algae it eats
• Good bacteria help bats survive deadly fungus

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.

BacterioFiles 399 - Conductor Creating Carbon Canvases

Scanning probe microscope
image of graphene
By U.S. Army Material Command
CC BY 2.0

This episode: Bacteria can aide the production of the useful material graphene, using their ability to add electrons to external surfaces!

Download Episode (7.7 MB, 11.3 minutes)

Show notes:
Microbe of the episode: Brevibacterium frigoritolerans

News item

Takeaways
Advanced materials often take advanced techniques to create, but they offer numerous benefits: increased strength and flexibility, smaller size, more options. One such material is graphene, which is basically a sheet of carbon atoms linked together like chainmail. It is only a single atom thick but is amazingly strong, mostly transparent, and good at conducting heat and electricity.

The trick is, it's hard to make in large quantities cheaply and easily. Sheets of carbons can be obtained from blocks of graphite, but these sheets are graphene oxide, which lack the desirable properties of graphene. Chemical methods can be used to remove the oxidation, but they are harsh and difficult. Luckily, bacteria are great at microscopic remodeling. In this study, electron-transferring bacteria are able to reduce the graphene oxide to graphene with properties almost as good as are achieved by chemical reduction.

Journal Paper:
Lehner BAE, Janssen VAEC, Spiesz EM, Benz D, Brouns SJJ, Meyer AS, van der Zant HSJ. 2019. Creation of Conductive Graphene Materials by Bacterial Reduction Using Shewanella oneidensis. ChemistryOpen 8:888–895.

Other interesting stories:

• Frog skin gut bacteria correlate with resistance to deadly virus
• Skin microbiota could be transplanted to treat skin conditions (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.

BacterioFiles 398 - Marathon Microbes Maximize Mileage

Veillonella parvula

From Gronow et al. 2009

Stand Genomic Sci 2(1): 57-65

This episode: Bacteria found in the guts of serious athletes help mice exercise longer by transforming their metabolic waste!

Download Episode (7.3 MB, 10.6 minutes)

Show notes:
Microbe of the episode: Aggregatibacter (Actinobacillus) actinomycetemcomitans

News item

Takeaways
Our gut microbes affect many aspects of health, and many aspects of how we live affect our microbes. One such aspect is physical exertion, which has been associated with enrichment of various microbes in the guts of athletes. This observation led to the question: are these microbes just benefiting from the high levels of exertion, or are they able to contribute also?

This study found that certain such bacteria, when given to mice, enabled the mice to run for a longer period on a treadmill. These microbes break down lactic acid, which is generated in our bodies when we push our physical limits, but the study provided evidence that the longer run times were due not to removal of this waste product, but to the propionate compound produced by its degradation.

Journal Paper:
Scheiman J, Luber JM, Chavkin TA, MacDonald T, Tung A, Pham L-D, Wibowo MC, Wurth RC, Punthambaker S, Tierney BT, Yang Z, Hattab MW, Avila-Pacheco J, Clish CB, Lessard S, Church GM, Kostic AD. 2019. Meta-omics analysis of elite athletes identifies a performance-enhancing microbe that functions via lactate metabolism. Nat Med 25:1104–1109.

Other interesting stories:

• Aphids hijacked viral gene to determine whether they grow wings
• Phage therapy could help treat green sea turtles

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.

BacterioFiles 397 - Plant Promotes Pathogen-Prohibiting Partner

Bacillus subtilis

By Y tambe, CCBY-SA 3.0

This episode: Plants stimulate their root bacteria to compete better, and these bacteria help the plants resist disease!

Download Episode (7.3 MB, 10.6 minutes)

Show notes:
Microbe of the episode: Bacillus circulans

Takeaways
In some ways, plants' roots are like our gut. They both absorb nutrients, and they both have complex communities of microbes living alongside the host cells. These microbes can assist their hosts in various ways, and get fed in return.

In this study, one species of root bacterium is able to compete against others by producing an antimicrobial compound. The plant stimulates this production with chemical signals, and benefits from its symbionts' increased competitiveness because the bacterium helps the plant resist infection.

Journal Paper:
Ogran A, Yardeni EH, Keren-Paz A, Bucher T, Jain R, Gilhar O, Kolodkin-Gal I. 2019. The Plant Host Induces Antibiotic Production To Select the Most-Beneficial Colonizers. Appl Environ Microbiol 85:e00512-19.

Other interesting stories:

• Plant virus influences aphid viral infection, which possibly increases spread of both
• Producing bioplastics from low-cost carbon sources (paper)

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

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

BacterioFiles 396 - Bacteria Boost Blood Bank Budgets

Red blood cells

This episode: Bacterial enzymes could convert donated blood to be compatible with more people in need!

Download Episode (8.0 MB, 11.7 minutes)

Show notes:
Microbe of the episode: Cucumber leaf spot virus

News item

Takeaways
Blood transfusions using donated blood save many lives. Unfortunately, most donations can't be given to just anyone that needs blood; there must be a match in blood type between donor and recipient, or else a life-threatening reaction could occur in the recipient's body. So type A can't donate to type B, or vice versa, but type O is compatible with the other types.

In this study, bacterial enzymes found in human gut microbes have the ability to cleave off the unique type A and B sugars on the surface of red blood cells. This could allow the conversion of all donated blood to type O, greatly increasing the blood bank supply, but more testing is needed to develop the process.

Journal Paper:
Rahfeld P, Sim L, Moon H, Constantinescu I, Morgan-Lang C, Hallam SJ, Kizhakkedathu JN, Withers SG. 2019. An enzymatic pathway in the human gut microbiome that converts A to universal O type blood. Nat Microbiol 4:1475–1485.

Other interesting stories:

• Interesting new protist has novel swimming stroke
• Quantum dot-microbe hybrids power conversion of carbon dioxide to useful stuff

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

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

BacterioFiles 395 - Many Microbiome Mindsets

This episode: Five different ways of thinking about our relationship with our microbes!

Download Episode (20.4 MB, 29.8 minutes)

Show notes:
Microbe of the episode: Tuhoko rubulavirus 3

News item

Takeaways
The microbiome by itself is an amazingly complicated community of many different species, with different lifestyles and metabolisms, all living together in competition and cooperation. On top of that, interactions between the microbiome and our body and our lifestyle multiply the complexity even more.

This article explores five different views of the microbiome and how it fits into our body (or how the body fits in with the microbiome). From the organ view to the ecosystem view, each is a different way of looking at the different functions, dynamic patterns, and integration of the microbiome in its host, and each provides guidance for how to approach treatment of disease and maintenance of health.

Journal Paper:
Morar N, Bohannan BJM. 2019. The Conceptual Ecology of the Human Microbiome. The Quarterly Review of Biology 94:149–175.

Other interesting stories:

• New resource connecting drugs, foods, and microbiota enzymes for potential interactions (paper)
• Building cancer-killing viruses that are controlled with light (paper)

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

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

Special episode, hurricanes, and more

Hey all, I've been working on a somewhat special episode that is taking me longer than usual, so I don't have anything for this week. It may be up next week, but it is unlikely due to Hurricane Dorian and/or family events. Look forward to it!

BacterioFiles 394 - Skinny Cell Structure Supports

Bacillus subtilisBy Y tambe, CC BY-SA 3.0

This episode: Not as simple as it sounds—how rod-shaped bacteria maintain their shape!

Thanks to Dr. Ethan Garner for his contribution!

Download Episode (6.3 MB, 9.2 minutes)

Show notes:
Microbe of the episode: Erwinia virus M7

News item

Takeaways
Microbes seem like they should be a lot simpler than large multicellular organisms, but even what seems like it should be a simple system in microbes can be surprisingly complex. In this case, the system bacteria maintaining their particular cell shape.

Spherical cells have it easier: just add more cell material at every point. But for rods, they must make the cell longer without making it wider. How do they accomplish this? Two groups of proteins work together to help rod-shaped species grow, but how they work wasn't specifically known.

In this study, it was found that one group of proteins adds more cell material as it moves around the circumference, while the other adds structure to the cell that allows it to maintain shape. The more of these structural proteins present, the thinner the cell can stay.

Journal Paper:
Dion MF, Kapoor M, Sun Y, Wilson S, Ryan J, Vigouroux A, van Teeffelen S, Oldenbourg R, Garner EC. 2019. Bacillus subtilis cell diameter is determined by the opposing actions of two distinct cell wall synthetic systems. Nat Microbiol 4:1294–1305.

Other interesting stories:

• Giant viruses have genes encoding interesting chemical-metabolizing enzymes
• Tiny marine animal with two intriguing bacterial symbionts

Check out BacterioFiles featured in Top 10 Microbiology Podcasts

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

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

BacterioFiles 393 - Prokaryote Partner Prevents Pathogen Potency

Acanthamoeba
By J Lorenzo-Morales et al. (2015).
Parasite 22: 10, CC BY 4.0

This episode: Bacterial symbionts of amoebas help them survive bacterial infection, and prevent pathogens from spreading to others as much!

Download Episode (7.5 MB, 8.1 minutes)

Show notes:
Microbe of the episode: Eubacterium dolichum

News item

Takeaways
Amoebas are free-living, single-celled organisms, but they have some things in common with some cells of our immune system (macrophages). For example, certain bacterial pathogens can infect both in similar ways. So it can be useful to study the interactions of amoebas and bacteria to learn about our own immune defenses.

In this study, the amoeba Acanthamoeba castellanii has another bacterial symbiont that helps it resist killing by the bacterial pathogen Legionella pneumophila. Once the amoebas recovered from the infection, they were more resistant to future challenges. Even better, the symbiont prevented the pathogen from transforming into a more spreadable form like it does when infecting amoebas alone.

Journal Paper:
König L, Wentrup C, Schulz F, Wascher F, Escola S, Swanson MS, Buchrieser C, Horn M. 2019. Symbiont-Mediated Defense against Legionella pneumophila in Amoebae. mBio 10:e00333-19.

Other interesting stories:

• RNA-cutting CRISPR/Cas system induces bacterial dormancy to prevent phage replication
• Gut bacteria degrade/modify many different kinds of drugs (paper)

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

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

BacterioFiles 392 - Magnetic Microbes Maneuver Marine Manager

Calkinsia aureus
By djpmapleferryman
Uploaded by Shureg, CC BY 2.0

This episode: A marine protist can orient itself along magnetic fields thanks to bacterial symbionts on its surface that make magnetic nanoparticles!

Download Episode (7.2 MB, 7.9 minutes)

Show notes:
Microbe of the episode: Chlorocebus pygerythrus polyomavirus 3

Takeaways
Various kinds of bacteria can orient their movement along a magnetic field. These are called magnetotactic, and they use this ability to swim toward or away from the surface of their aquatic habitat, to adjust their oxygen exposure according to their preference.

No eukaryotic microbes have yet been discovered that can sense and react to magnetic fields like these prokaryotes. In this study, however, a protist was discovered that can do it via its partnership with ectosymbionts, or bacteria attached to its surface, that sense magnetism and orient their host's movement. In return, factors of the host's metabolism may feed its symbionts.

Journal Paper:
Monteil CL, Vallenet D, Menguy N, Benzerara K, Barbe V, Fouteau S, Cruaud C, Floriani M, Viollier E, Adryanczyk G, Leonhardt N, Faivre D, Pignol D, López-García P, Weld RJ, Lefevre CT. 2019. Ectosymbiotic bacteria at the origin of magnetoreception in a marine protist. Nat Microbiol 4:1088–1095.

Other interesting stories:

• Fungus infects mosquitoes and quickly kills them with engineered toxin
• Nose microbe helps mediate immune response to flu virus, in mouse study (paper)

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

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

No episode this week

Sorry, no episode this week, possibly next week too, but I am working on some good ones.

BacterioFiles 391 - Slime Stores Sodium Sensibility

Physarum polycephalum on a log

By frankenstoen - flickr, CC BY 2.5

This episode: Slime molds can learn to get used to salt and hold on to that memory even after a period of dormancy!

Download Episode (8.9 MB, 9.7 minutes)

Show notes:
Microbe of the episode: Nocardia transvalensis

News item

Takeaways
Slime mold Physarum polycephalum has many surprisingly intelligent abilities, despite being only a single cell. Studying how these abilities work in the cell can teach us new ways that life can do things. The ability of interest here is habituation, or learning not to avoid a chemical that seems unpleasant to the cell but is not necessarily harmful, especially with a food reward.

The slime mold can become habituated to salt, in this case, learning to tolerate it enough to pass through a gradient of increasing concentration to get to some food as quickly as it crosses the same distance with no salt present. The scientists here learned that the cell takes up sodium into itself as it habituates, and holds onto both sodium and its memory through a period of hibernation.

Journal Paper:
Boussard A., Delescluse J., Pérez-Escudero A., Dussutour A. 2019. Memory inception and preservation in slime moulds: the quest for a common mechanism. Phil Trans R Soc B 374:20180368.

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

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

BacterioFiles 390 - Friendly Phages Find Foes

E. coli bacteria

This episode: Bacteria carry deadly phages and use them against rival strains!

Download Episode (9.4 MB, 10.2 minutes)

Show notes:
Microbe of the episode: Bifidobacterium bifidum

News item

Takeaways
Bacteria such as Escherichia coli live in environments such as the gut with many other types of microbes, and often develop communities of microbes cooperating and/or competing with each other for resources. But in order to cooperate or compete, bacteria must first be able to identify and discriminate between themselves and others. Sometimes microbes do this by exchanging membrane molecules, or secreting chemical signals that only partners can detect, or transferring plasmids or producing antimicrobial compounds that kill competitors.

In the current study, scientists discovered a strain of E. coli that carries around phages that help them distinguish other strains and compete with them. When this strain encounters another, the phages it carries attack and destroy cells of the other strain, while leaving the carrier strain mostly unharmed. This strategy is not without cost, though; the viral proteins take resources to produce, and when there's no competing strains around, the virus can attack its carrier to some extent.

Journal Paper:
Song S, Guo Y, Kim J-S, Wang X, Wood TK. 2019. Phages Mediate Bacterial Self-Recognition. Cell Reports 27:737-749.e4.

Other interesting stories:

• E. coli adjusts its swimming to get around obstacles

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

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

BacterioFiles 389 - Prokaryotes Pacify Protein Problem

E. coli bacteria

This episode: Engineered bacteria could help people digest an essential nutrient when they can't digest it themselves!

Download Episode (8.5 MB, 9.3 minutes)

Show notes:
Microbe of the episode: Kadipiro virus

News item (paywall)

Science-Based Medicine blog article about phenylketonuria, Synlogic, and engineering bacteria to treat this disorder, with lots of good detail

Takeaways
Treating genetic disorders can be very difficult. Sometimes they can be managed, with lifestyle, diet, or medication, but cure has almost always been out of the picture. With a disorder such as phenylketonuria (PKU), for example, in which the body is unable to fully metabolize the amino acid phenylalanine, diet and medication may work to some extent.

In an effort to provide better options for PKU, scientists at Synlogic, Inc have created a strain of Escherichia coli that produces phenylalanine-degrading enzymes in the gut. The hope is that ingesting this bacterium could allow PKU patients to be less restrictive with their diet.

Journal Paper:
Isabella VM, Ha BN, Castillo MJ, Lubkowicz DJ, Rowe SE, Millet YA, Anderson CL, Li N, Fisher AB, West KA, Reeder PJ, Momin MM, Bergeron CG, Guilmain SE, Miller PF, Kurtz CB, Falb D. 2018. Development of a synthetic live bacterial therapeutic for the human metabolic disease phenylketonuria. Nat Biotechnol 36:857–864.

Other interesting stories:

• Probiotic molecule induces protection in mice against viral brain infection
• E. coli growing with artificially synthesized genome (Extra information)

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

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

Skipping a week

Sorry, no episode this week, due to vacations and busy-ness.

BacterioFiles 388 - Floor Fungi Fracture Phthalates

This episode: Microbes in household dust help degrade potentially harmful plasticizer chemicals!

Thanks to Ashleigh Bope for her contribution!

Download Episode (6.7 MB, 7.3 minutes)

Show notes:
Microbe of the episode: Rosa rugosa leaf distortion virus

News item

Takeaways
Modern life and technology comes with modern challenges, including exposure to chemicals in building materials and such that humans didn't encounter much before the last few generations. Phthalate esters, found in PVC and other materials, can accumulate in homes and cause some problems, especially in children.

Modern life is also new to microbes, but they are very adaptable and versatile. In this study, microbes in household dust show some ability to break down the phthalates over time. Whether this activity is significant and beneficial to residents remains to be discovered.

Journal Paper:
Bope A, Haines SR, Hegarty B, Weschler CJ, Peccia J, Dannemiller KC. Degradation of phthalate esters in floor dust at elevated relative humidity. Environ Sci: Processes Impacts.

Other interesting stories:

• Native fungi tag team to kill invasive insect pest (paper)

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

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

BacterioFiles 387 - Carbonate Creators Combat Cracking

Sporosarcina pasteurii

By Ghosh et al. 2019. 

PLoS ONE 14(1):e0210339 

CC BY 4.0

This episode: Bacteria strengthen concrete while helping to prevent damage from road salts!

Download Episode (6.8 MB, 7.4 minutes)

Show notes:
Microbe of the episode: Azospirillum brasilense

News item

Takeaways
Winter is a bad time for concrete outside. Water seeps into cracks and freezes, causing bigger cracks that widen into potholes. Even the road salts used to keep water from freezing can react with compounds in the cement to break down the structure of the concrete.

This study looks to bacteria for a solution for protecting concrete from these reactions. Sporosarcina pasteurii, given the right nutrients, can take the harmful salt compounds and turn them into minerals that strengthen the concrete instead of weakening it.

Journal Paper:
Ksara M, Newkirk R, Langroodi SK, Althoey F, Sales CM, Schauer CL, Farnam Y. 2019. Microbial damage mitigation strategy in cementitious materials exposed to calcium chloride. Construction and Building Materials 195:1–9.

Other interesting stories:

• Developing way for bacteria to make mother-of-pearl, a tough and useful material

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

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

BacterioFiles 386 - Cupola Contaminant Cleaners

Pisa cupola painting
By JoJan, CC BY-SA 3.0

This episode: Bacteria help gently clean residue off artworks painted on stone!

Download Episode (5.6 MB, 6.1 minutes)

Show notes:
Microbe of the episode: Cellulophaga virus Cba171

Takeaways
More and more cleaning products these days contain an ingredient called "enzymes." These are proteins that break down contaminants biologically instead of just removing them chemically, in a targeted manner.

In a similar approach, this study explores applying bacteria directly to classic artwork painted directly on stone, to clean up residues on the surface. These bacteria can produce enzymes on site and degrade the contaminants while leaving the underlying paint intact.

Journal Paper:
Ranalli G, Zanardini E, Rampazzi L, Corti C, Andreotti A, Colombini MP, Bosch‐Roig P, Lustrato G, Giantomassi C, Zari D, Virilli P. 2019. Onsite advanced biocleaning system on historical wall paintings using new agar-gauze bacteria gel. J Appl Microbiol 126:1785–1796.

Other interesting stories:

• Mouth bacteria prevent gum disease by interfering with activity of other bacteria (paper)
• Despite identical genetics, individual bacteria can behave differently through random variation

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

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

BacterioFiles 385 - Prokaryotes Protect Paper

Lysobacter enzymogenes 

attacking a fungal hypha

GFDL

This episode: Bacteria produce antifungal compounds that can protect paper from fungal deterioration!

Download Episode (6.8 MB, 7.4 minutes)

Show notes:
Microbe of the episode: Acetobacter aceti

Takeaways
Paper is a very useful information storage medium, but it is also somewhat delicious for microbes that can break it down as food, degrade the quality, and cause indelible stains and discoloration under the right conditions. Preventing this usually requires careful control, such as keeping humidity low, for storing paper for long periods.

In this study, scientists tested the ability of the bacterium Lysobacter enzymogenes to protect paper via the antifungal compounds it produces. This first required filtering out the pigments that the bacteria produced, to prevent them from discoloring the paper. Once a method for this filtering was in place, they found the bacterial culture supernatant could significantly reduce fungal growth on various kinds of paper, and protect the paper from staining and degradation.

Journal Paper:
Chen Z, Zou J, Chen B, Du L, Wang M. 2019. Protecting books from mold damage by decreasing paper bioreceptivity to fungal attack using de-coloured cell-free supernatant of Lysobacter enzymogenes C3. J Appl Microbiol 126:1772–1784.

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

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

BacterioFiles 384 - Moss Materials Modify Microbiota

Moss with fungi

This episode: Contact with soil materials and moss causes significant, though short-term, changes in the skin microbiota!

Thanks to Dr. Mira Grönroos for her contribution!

Download Episode (7.1 MB, 7.75 minutes)

Show notes:
Microbe of the episode: Leonurus mosaic virus

Takeaways
Exposure to microbes throughout life is thought to help calibrate the immune system to some extent, reducing the risk of allergies and asthma without losing defense against pathogens. In this study, rubbing soil or packets of moss on the skin changed the composition of the skin microbiota temporarily, so this may be a way to help with this important type of exposure, but it is not yet known how to achieve optimal long-term effects.

Journal Paper:
Grönroos M, Parajuli A, Laitinen OH, Roslund MI, Vari HK, Hyöty H, Puhakka R, Sinkkonen A. 2019. Short-term direct contact with soil and plant materials leads to an immediate increase in diversity of skin microbiota. MicrobiologyOpen 8:e00645.

Other interesting stories:

• Cadmium-resistant microbes can help plants take up more cadmium to clean up soil (paper)
• Plant symbionts acquired genes that turned them into insect pathogens (paper)

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

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