Monday, November 25, 2019

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:

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.

Monday, November 18, 2019

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:

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.

Monday, November 11, 2019

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:

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.

Monday, November 4, 2019

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:

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.

Monday, October 21, 2019

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:

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.

Monday, October 14, 2019

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:

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.

Monday, October 7, 2019

BacterioFiles 398 - Marathon Microbes Maximize Mileage

Veillonella parvula
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:

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.

Monday, September 30, 2019

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:

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.

Monday, September 23, 2019

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:

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.

Monday, September 16, 2019

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:

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.

Monday, September 2, 2019

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!

Monday, August 26, 2019

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:
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.

Monday, August 12, 2019

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:

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.

Monday, August 5, 2019

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:

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.

Monday, July 22, 2019

No episode this week

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

Monday, July 15, 2019

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.

Monday, July 8, 2019

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:

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.

Monday, July 1, 2019

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:

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.

Wednesday, June 26, 2019

Skipping a week

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

Sunday, June 16, 2019

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:

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.

Monday, June 10, 2019

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:

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.

Monday, June 3, 2019

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:

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.

Monday, May 27, 2019

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.

Monday, May 20, 2019

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:

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.

Monday, May 13, 2019

BacterioFiles 383 - Communities Carry Communicable Communities

Village in Fiji
By Merbabu~commonswiki
I'm back! This episode: Looking at how people in different villages share microbes!

Download Episode (6.5 MB, 7.0 minutes)

Show notes:
Microbe of the episode: Cristispira pectinis

Takeaways
Our microbiota, the communities of microbes living in and on our bodies, are incredibly diverse and varied. Each person's is different, and they can change drastically over time with changes in location, diet, lifestyle, and other factors.

Learning how our microbiota forms and changes and functions is important, because it can affect many aspects of health. In this study, villagers in the islands of Fiji share microbes with others in the same and other villages, but not always in patterns that might be expected.

Journal Paper:
Brito IL, Gurry T, Zhao S, Huang K, Young SK, Shea TP, Naisilisili W, Jenkins AP, Jupiter SD, Gevers D, Alm EJ. Transmission of human-associated microbiota along family and social networks. Nat Microbiol.

Other interesting stories:

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.

Monday, April 15, 2019

BacterioFiles 382 - Small Scavengers Suck Sizeable Cells

Rhodotorula prey yeast
By A doubt, CC BY-SA 3.0
This episode: Fungus-hunting amoebas have different strategies for detecting and preying on single-celled and filamentous fungi!

Also, a personal note: I'm going to be taking a few weeks off the podcast to be able to take full advantage of spring, but I'll be back as soon as the weather gets too hot.

Download Episode (7.5 MB, 8.2 minutes)

Show notes:
Microbe of the episode: Chondromyces catenulatus

Takeaways
Amoebas in the microbial world are like powerful predators, going around gobbling up whatever they find that's small enough, by a process called phagocytosis, in which they surround their prey with their cell membrane and engulf it. It's similar to macrophages or white blood cells as part of our immune system in our bodies.

The prey of amoebas includes bacteria, large viruses, and single-celled fungi called yeasts. In this study, scientists showed that some yeasts make great food sources for a certain kind of amoeba called Protostelium aurantium, while others either lack nutritional value or hide from the predators by covering up certain recognition molecules on their cell wall.

They found that the amoebas could also consume the spores of filamentous fungi, and could even attack the filaments, or hyphae. In this latter case, instead of engulfing the large filaments, they pierced the cells and extracted their contents, an approach named ruphocytosis, from the Greek for suck or slurp.

Journal Paper:
Radosa S, Ferling I, Sprague JL, Westermann M, Hillmann F. The different morphologies of yeast and filamentous fungi trigger distinct killing and feeding mechanisms in a fungivorous amoeba. Environ Microbiol.

Other interesting stories:

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.

Monday, April 8, 2019

BacterioFiles 381 - Chlorophyll Can Convey Cancer Characteristics

Tumor imaging by MSOT
By Peters et al. 2019,
Nat Commun 10:1191, CC BY 4.0
This episode: Pigmented bacteria can be used in a cancer imaging technique that combines light and sound!

Download Episode (8.9 MB, 9.75 minutes)

Show notes:
Microbe of the episode: Streptomyces bellus

Takeaways
Because "cancer" is a general term that describes many different forms of disease affecting different cells in different parts of the body, effective cancer treatment relies on understanding the location and physiology of the cancer in a given patient. New imaging technologies for diagnosis and analysis of cancer and for cancer research can be very valuable, especially if they don't require big investments of money and space.

One promising imaging technology is called multispectral optoacoustic imaging, or MSOT. This uses pulses of light to create vibrations as pigments in tissues absorb the light and undergo thermal expansion; these vibrations are then detected by ultrasound technology. This approach allows good resolution and depth of imaging without large equipment like MRI machines, but the best results require adding pigments into the body.

In this study, scientists showed that the photosynthetic pigments of purple non-sulfur bacteria can be useful in this optoacoustic imaging, providing a somewhat long-term, nontoxic approach. It proved especially interesting when they discovered that the wavelength spectrum changing over time was an indication of macrophage activity in the tumors.

Journal Paper:
Peters L, Weidenfeld I, Klemm U, Loeschcke A, Weihmann R, Jaeger K-E, Drepper T, Ntziachristos V, Stiel AC. 2019. Phototrophic purple bacteria as optoacoustic in vivo reporters of macrophage activity. Nat Commun 10:1191.

Other interesting stories:

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.

Monday, April 1, 2019

BacterioFiles 380 - Plant Promoter Produces Polymer

Herbaspirillum-like bacteria
in banana plants
Scientific Figure on
ResearchGate. CC BY-NC 4.0
This episode: A microbe that boosts plant growth needs to make storage polymers for both itself and the plant's sake!

Download Episode (7.1 MB, 7.75 minutes)

Show notes:
Microbe of the episode: Suid gammaherpesvirus 3

Takeaways
Bacteria that promote plant growth are fascinating and not too hard to find. Plants and microbes make good partners by each contributing something the other needs. Plants make sugars via photosynthesis that microbes can use as food, and microbes can gather nutrients that plants can't make, can drive off pathogens, and can contribute to plant growth in other ways.

However, plants aren't making sugars all the time, because the sun goes down every day. So what do partner microbes do at these times? In this study, a beneficial microbe Herbaspirillum seropedicae was found to produce a storage compound called polyhydroxyalkanoate, or PHA, that it could use to store food for times of scarcity. Mutants of this microbe that could not make the storage compound weren't very beneficial for their plant partners.

Journal Paper:
Alves LPS, Amaral FP do, Kim D, Bom MT, Gavídia MP, Teixeira CS, Holthman F, Pedrosa F de O, Souza EM de, Chubatsu LS, Müller-Santos M, Stacey G. 2019. Importance of Poly-3-Hydroxybutyrate Metabolism to the Ability of Herbaspirillum seropedicae To Promote Plant Growth. Appl Environ Microbiol 85:e02586-18.

Other interesting stories:

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.