486 - Biohybrid Bacteria Build Biomass

Azotobacter vinelandii

This episode: Incorporating light-absorbing molecules into bacterial membranes can allow bacteria to use solar energy to transform nitrogen gas into fertilizer!
Download Episode (6.5 MB, 9.9 minutes)

Show notes:
Microbe of the episode: Wheat dwarf virus

 

Takeaways

Turning nitrogen gas into biologically useful compounds, such as protein or ammonia for fertilizer, is an essential part of the global nitrogen cycle and therefore, for agriculture. Today much fertilizer is produced from nitrogen gas by a chemical process that requires large amounts of energy, contributing to global warming. But certain bacteria can perform the same process using special enzymes much more efficiently.

In this study, a light-absorbing molecule was inserted into the cell membrane of some of these bacteria, allowing them to use light energy directly to power the nitrogen converting enzymes. These "biohybrids" were able to produce convert significantly more nitrogen gas and produce additional bacterial biomass from it, showing promise for using such an approach for more sustainable microbial fertilizer production.

Journal Paper:
Chen Z, Quek G, Zhu J, Chan SJW, Cox‐Vázquez SJ, Lopez‐Garcia F, Bazan GC. 2023. A Broad Light‐Harvesting Conjugated Oligoelectrolyte Enables Photocatalytic Nitrogen Fixation in a Bacterial Biohybrid. Angew Chem Int Ed 62:e202307101.

Other interesting stories:

• Update on using mosquito bacteria to block mosquito-borne viruses

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.

477 - Hijackers Hitchhike on Hyphal Highways

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

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

Show notes:
Microbe of the episode: Epinotia aporema granulovirus

News item

Takeaways

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

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

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

Other interesting stories:

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

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

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

474 - Stalker Cells Stop Seafood Sickness

Halobacteriovorax predator cells
By Ooi et al, 2021,
Microbiology 167:001113
CC BY-NC

This episode: Predatory bacteria could protect lobster farms from disease-causing bacteria!
Download Episode (4.8 MB, 7 minutes)

Show notes:
Microbe of the episode: Gordonia rubripertincta

 

Takeaways

Antibiotics have done wonders for controlling bacterial pathogens. Many people have lived that would otherwise have died, and some industries have produced much more than they would have, particularly those involved in animal farming. However, more and more targeted pathogens are developing resistance to the antibiotics we have, and new ones are harder to discover, so alternative approaches are needed.

Here, predatory bacteria take the place of antibiotics in a study on farmed spiny lobsters. These predators swim after and attach to prey bacteria, hollowing out their contents to use as nutrients to make more predators. They do not hurt the lobsters, but the study finds they do reduce the number of pathogenic prey organisms injected into the lobsters at the same time.

Journal Paper:
Ooi MC, Goulden EF, Smith GG, Bridle ARY 2021. 2021. Predatory bacteria in the haemolymph of the cultured spiny lobster Panulirus ornatus. Microbiology 167:001113.

Other interesting stories:

• 3D-printing bacterial biofilms
• Review of latest in oncolytic (cancer-killing) viruses

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.

465 - Partners Produce Predator Prevention

Fungus cells with 
bacterial symbionts
By Büttner et al. 2021
PNAS 118:e2110669118
CC BY-NC-ND 4.0

This episode: Bacteria living inside soil fungus produce toxins that can protect their host from tiny predators!

Download Episode (7.7 MB, 11.2 minutes)

Show notes:
Microbe of the episode: Mycobacterium virus DLane

Takeaways

Soils have many different organisms cooperating and competing for resources. Some little worms called nematodes prey on fungi in the soil, while fungi may effectively defend themselves or strike back with toxins or traps that catch and kill the worms. On top of these interactions are other organisms that interact in various ways. In this study, bacteria living inside a kind of soil fungus produce toxins that defend the fungus against predatory nematodes.

Journal Paper:
Büttner H, Niehs SP, Vandelannoote K, Cseresnyés Z, Dose B, Richter I, Gerst R, Figge MT, Stinear TP, Pidot SJ, Hertweck C. 2021. Bacterial endosymbionts protect beneficial soil fungus from nematode attack. Proc Natl Acad Sci 118:e2110669118.

Other interesting stories:

• Sequencing stomach bacteria to find out how prehistoric populations migrated

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.

464 - Prodding Pollen's Popping Process

Pollen
(fromWikipedia)

This episode: Certain nectar-dwelling bacteria can induce pollen to germinate to access their tasty proteins!

Download Episode (6.0 MB, 8.8 minutes)

Show notes:
Microbe of the episode: Clostridium oceanicum

News item

Takeaways

Nectar in flowers seems like it would be a great place for microbes to live, since it has so much sugar, but it's actually somewhat difficult to thrive solely in and on nectar. The carbon in sugar is only one essential element for life, and there's enough of it that it can be overwhelming to the osmotic balance of many microbes. Pollen could provide more nutrients in the form of protein and the nitrogen that comes with it, but it is difficult to penetrate its hard shell.

In this study, certain kinds of bacteria that live in nectar were able to access more pollen protein than other microbes by inducing pollen to germinate, growing out of its shell, or burst and release the protein directly. These microbes only benefited from pollen that were still alive and able to germinate, and not from those that had been disabled.

Journal Paper:
Christensen SM, Munkres I, Vannette RL. 2021. Nectar bacteria stimulate pollen germination and bursting to enhance microbial fitness. Curr Biol 31:4373-4380.e6.

Other interesting stories:

• Bacteria recycling plastic into vanilla flavor

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.

454 - Hitchhiking Horticultural Helpers

Bacteria carrying spores
By Muok et al. 2021
ISME J, CC BY 4.0

This episode: Spores of some bacteria latch onto the tails of other bacteria and ride along as they move around in the soil!

Download Episode (5.5 MB, 8.0 minutes)

Show notes:
Microbe of the episode: Bohle iridovirus

News item

Takeaways

The soil is a complex environment, and microbes that live in soil need complex lifestyles to thrive. There are many examples of cooperation, competition, and other adaptations to highly varied situations.

In this study, bacteria that grow like filamentous fungi don't have the mechanisms to move autonomously, but their spores can hitch rides on other kinds of bacteria that swarm through the soil using their propeller-like tails called flagella to push themselves toward the plant roots they prefer to grow near.

Journal Paper:
Muok AR, Claessen D, Briegel A. 2021. Microbial hitchhiking: how Streptomyces spores are transported by motile soil bacteria. ISME J.

Other interesting stories:

• "How microbes in permafrost could trigger a massive carbon bomb"

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.

441 - Hyphal Hijacker Helps Harvests

Fungus growing in root
By Zhang et al. 2020
Molec Plant 13:1420-1433
CC BY-NC-ND 4.0

This episode: A fungus-infecting virus transforms the fungal foe into a friend of its host plant!

Download Episode (6.1 MB, 8.9 minutes)

Show notes:
Microbe of the episode: Hepacivirus J

News item

Takeaways

Viruses can be useful for treating various diseases, especially bacterial infections and cancer. Their ability to target certain cell types specifically makes them great at hunting down and killing disease-causing cells without harming the body's healthy tissue. And just as bacteriophages can work to treat bacterial disease in us, fungal viruses could help to treat serious fungal infections in crop plants.

In this study, a fungus-infecting virus goes beyond treating a deadly fungal disease in rapeseed plants. Fungus infected with this virus no longer causes disease, but lives in harmony with the host plant, protects it from other fungal diseases, and even helps it to grow better.

Journal Paper:
Zhang H, Xie J, Fu Y, Cheng J, Qu Z, Zhao Z, Cheng S, Chen T, Li B, Wang Q, Liu X, Tian B, Collinge DB, Jiang D. 2020. A 2-kb Mycovirus Converts a Pathogenic Fungus into a Beneficial Endophyte for Brassica Protection and Yield Enhancement. Mol Plant 13:1420–1433.

Other interesting stories:

• Engineering E. coli to turn carbon dioxide into biomass
• Radiation super-resistant bacteria survive 1 year exposed to low Earth orbit

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.

439 - Microbes Mitigate Mushroom Morbidity

Button mushrooms
By chris_73, CC BY-SA 3.0

This episode: Bacteria protect farmed mushrooms from damage by other bacteria by breaking down their toxins!

Download Episode (4.9 MB, 7.1 minutes)

Show notes:
Microbe of the episode: Tomato mosaic virus

Takeaways

Almost all organisms are vulnerable to pathogenic microbes that make them sick or cause damage. Most also have other microbes that help them grow better or protect them from pathogens. This includes animals, plants, and also fungi.

In this study, bacterial pathogens produce a toxin that causes button mushrooms to turn brown and rot. However, other bacteria can degrade this toxin and protect the fungus, and can also degrade molecules the pathogens produce to help them swarm to new places, restricting their movement.

Journal Paper:
Hermenau R, Kugel S, Komor AJ, Hertweck C. 2020. Helper bacteria halt and disarm mushroom pathogens by linearizing structurally diverse cyclolipopeptides. Proc Natl Acad Sci 117:23802–23806.

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.

431 - Conductive Cables Control Carbon

Cable bacteria around
plant roots
From Scholz et al. 2020
Nat Commun 11:1878

This episode: Cable bacteria around rice roots transport electrons and help prevent formation of methane!

Thanks to Vincent Scholz for his contribution!  
Download Episode (5.7 MB, 8.3 minutes)

Show notes:
Microbe of the episode: Vibrio alginolyticus

News item

Takeaways

Transforming other things into methane is a great way to make a living for some kinds of microbes. These tend to live under still water, like in rice fields or wetlands, or in the guts of cattle. And while this methane could be useful as natural gas if collected, it's a much more potent greenhouse gas than carbon dioxide when released into the atmosphere.

In this study, cable bacteria were inoculated into rice pots in the lab. Cable bacteria transfer electrons from deeper down in the ground up to the surface to generate energy, and in the process generate sulfate. This sulfate allows other microbes to outcompete the methane producers, reducing the amount of methane produced from rice cultivation in the lab. This may be helpful to reduce greenhouse gas emissions from rice agriculture.

Journal Paper:
Scholz VV, Meckenstock RU, Nielsen LP, Risgaard-Petersen N. 2020. Cable bacteria reduce methane emissions from rice-vegetated soils. 1. Nat Commun 11:1878.

Other interesting stories:

• Viruses in fecal transplants, not just bacteria, may be useful for health
• Superworms and their symbiont bacteria can degrade styrofoam

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.

426 - Sensory Cilia Supply Susceptibility

C. elegans roundworm
By Bob Goldstein, UNC Chapel Hill
CC BY-SA 3.0

This episode: A fungus paralyzes its tiny worm prey by acting on the worm's own sensory hairs!


Download Episode (6.0 MB, 8.7 minutes)

Show notes:
Microbe of the episode: Bat associated cyclovirus 9

Takeaways

Not all predators are fast or agile; some are sneaky, or good trap builders, or just good chemists. The predator club includes animals but also plants and even fungi. For example, the oyster mushroom fungus can paralyze roundworms in the soil that touch its filaments, then degrade their bodies and consume their nutrients.

The mechanism of this paralysis has been a mystery, but it's one step closer to being solved. This study found that intact sensory cilia, little hairs on the worm's head that help it sense its surroundings, are required for the paralysis to work. Worms with mutations in the structure of their cilia were protected from paralysis. How exactly the fungus acts on these cilia and the neurons they connect to, though, is still unknown.

Journal Paper:
Lee C-H, Chang H-W, Yang C-T, Wali N, Shie J-J, Hsueh Y-P. 2020. Sensory cilia as the Achilles heel of nematodes when attacked by carnivorous mushrooms. Proc Natl Acad Sci 117:6014–6022.

Other interesting stories:

• Bread waste could be good food for useful fermentations
• Symbiotic bacteria in beetle picked up gene that helps defend beetle eggs from 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.

423 - Roundworm Riders Route Rootworm Resistance

Western corn rootworm adult

By Siga, CC BY-SA 4.0

This episode: Helping insect-killing bacterial symbionts of nematodes evolve resistance to chemicals that major corn pests use to defend themselves!


Download Episode (10.0 MB, 14.0 minutes)

Show notes:
Microbe of the episode: Listeria virus PSA

Takeaways

Interactions between species and even kingdoms in nature can be complex and multilayered. This means that when we want to intervene to cause a particular outcome, there may be multiple points at which we can act, but the consequences may be hard to predict.

In this study, action was taken to counteract the damage the Western corn rootworm causes to corn crops, using a tiny roundworm that attacks the insect pest with deadly bacteria. The rootworm defends itself by accumulating plant-produced toxins that inhibit the bacteria. Directed evolution was used to make the bacteria more resistant, and this led to more effective killing of the pest.

Journal Paper:
Machado RAR, Thönen L, Arce CCM, Theepan V, Prada F, Wüthrich D, Robert CAM, Vogiatzaki E, Shi Y-M, Schaeren OP, Notter M, Bruggmann R, Hapfelmeier S, Bode HB, Erb M. 2020. Engineering bacterial symbionts of nematodes improves their biocontrol potential to counter the western corn rootworm. 5. Nat Biotechnol 38:600–608.

Other interesting stories:

• Altering pathogenic bacteria to reduce disease with genome-integrating phage (paper)
• Bacteria could inhibit fungus that causes deadly disease of bananas (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 415 - Global Glomus Growth Guesses

How mycorrhizal fungi work

By Nefronus, CC BY-SA 4.0

This episode: A global estimate of plants and their root fungi shows how agriculture may have greatly affected soil carbon storage over time!

Download Episode (5.7 MB, 8.3 minutes)

Show notes:
Microbe of the episode: Rhizobium virus RHEph4

News item

Takeaways
Even small organisms can have a big effect on the climate of the planet if there are enough of them. This includes trees, which are small relative to the planet, and also includes the fungi that attach to the roots of trees and other plants. These mycorrhizal fungi thread subtly through the soil, some occasionally popping up mushrooms, and transfer valuable nutrients they gather to the trees in exchange for carbon fixed from the air.

Knowing how big an effect a given kind of organism has requires knowing how much of it is around. This study collates data from various surveys of global plant populations and the fungi that interact with their roots, to estimate a global picture of the fungi below our feet. It estimates that a kind of fungus that stores more carbon in the soil may have been replaced in many areas with fungi that store less, or no fungi at all, due to the transformation of land from wild areas to farmland.

Journal Paper:
Soudzilovskaia NA, van Bodegom PM, Terrer C, Zelfde M van’t, McCallum I, Luke McCormack M, Fisher JB, Brundrett MC, de Sá NC, Tedersoo L. 2019. Global mycorrhizal plant distribution linked to terrestrial carbon stocks. Nat Commun 10:1–10.

Other interesting stories:

• Phages bind to fish mucosal surfaces and protect from infection
• Examining how archaea affect meteorites

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 412 - Carbon Concentration Complicates Crop Cooperation

Wheat plants
By Bluemoose, CC BY-SA 3.0

This episode: Looking at the effects of almost doubling CO₂ concentrations on the interaction between wheat varieties and beneficial fungi!

Download Episode (8.1 MB, 11.8 minutes)

Show notes:
Microbe of the episode: Lato River virus

News item

Takeaways
As the world's population grows, feeding everyone will grow more challenging. Advances in technology in the past have made today's population possible, but future advances may be needed, especially in the face of an increasing concentration of carbon dioxide in the atmosphere.

Soil microbes that partner with crop plants for the benefit of each may be part of the solution. One option to explore is a group called mycorrhizal fungi, which associate with plant roots to extend their nutrient-gathering ability, in exchange for carbon compounds produced by photosynthesis. This study examined the influence of increased carbon dioxide in the atmosphere on the interaction of several varieties of wheat with these fungi.

Journal Paper:
Thirkell TJ, Pastok D, Field KJ. Carbon for nutrient exchange between arbuscular mycorrhizal fungi and wheat varies according to cultivar and changes in atmospheric carbon dioxide concentration. Glob Change Biol.

Other interesting stories:

• Microbes could make paper whitening more environmentally friendly (paper)
• Compound from rotifers could prevent transmission of eukaryotic parasite

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 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 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 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:

• Finding potential antimicrobials from ant bacteria

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 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:

• Probiotic could help prevent viral infection (paper)
• Some bacteria can cut off their propellers when lacking food to power them

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 373 - Plant Pilots Prevent Parching

Emmer wheat

This episode: Beneficial fungi found inside wild grain plants help wheat plants grow better with less water!

Download Episode (7.1 MB, 7.75 minutes)

Show notes:
Microbe of the episode: Beijerinckia indica

Takeaways
As we have microbial communities in our guts, on our skin, and in various other places in and on our bodies, plants also have beneficial microbial symbionts around their roots, on their leaf surfaces, and even inside their tissues. These microbes can be bacteria, fungi, or other, and can help plants gather nutrients, resist diseases or pests, and other things.

In this study, some fungi living in grain plants—called endophytes, or "inside plants"—can help wheat tolerate drought and grow better with less water. Studying this system could lead to breakthroughs in wheat farming, all thanks to microbes.

Journal Paper:
Llorens E, Sharon O, Camañes G, García‐Agustín P, Sharon A. Endophytes from wild cereals protect wheat plants from drought by alteration of physiological responses of the plants to water stress. Environ Microbiol.

Other interesting stories:

• Searching bacterial metabolites for new insect repellants
• Antibiotic disruption of gut microbes can also mess with skeletal health
• Fibers derived from wood could encourage healthy gut microbes (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 372 - Roundworm Riders Repel Raiders

Nematode
By Bob Goldstein, UNC Chapel Hill
CC BY-SA 3.0

This episode: Bacteria that help nematodes prey on insects also help keep fungi from stealing their kills!

Download Episode (7.4 MB, 8.1 minutes)

Show notes:
Microbe of the episode: Artogeia rapae granulovirus

Takeaways
Soil is an incredibly complex ecosystem, with many different interactions constantly happening between plants, insects, bacteria, fungi, and other organisms, not to mention a large variety of shifting environmental conditions. All of these are competing with some and cooperating with others to try to survive and thrive the best they can.

One interesting interaction takes place between small roundworms in the soil, called nematodes, and bacteria they carry around that cause disease in insects. These nematodes prey on insects by injecting the bacteria into them, which kill and start digesting the insects. The nematodes then feed on the insects and the bacteria until the resources have been exhausted, and then move on to the next insect, taking some bacteria with them again.

In this study, the scientists wondered how these partners deal with competitors in the soil that might want to take advantage of their resources. They discover that the bacteria produce compounds that can repel and inhibit fungi that might otherwise steal their kills.

Journal Paper:
Shan S, Wang W, Song C, Wang M, Sun B, Li Y, Fu Y, Gu X, Ruan W, Rasmann S. The symbiotic bacteria Alcaligenes faecalis of the entomopathogenic nematodes Oscheius spp. exhibit potential biocontrol of plant- and entomopathogenic fungi. Microb Biotechnol.

Other interesting stories:

• Mice given gut microbes from healthy human babies don't get milk allergies
• New fungal species living in glaciers are losing their homes as glaciers disappear
• Toxins from cyanobacterial blooms can product tiny animals from pathogens

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 364 - Polyproteins Promote Producing Pabulum

Nitrogenase enzyme
By Jjsjjsjjs - Own work,
CC BY-SA 3.0

This episode: Engineering other organisms to fix nitrogen by combining the required enzyme components into giant proteins that then get cut into the regular-sized subunit components!


Download Episode (10.5 MB, 11.5 minutes)

Show notes:
Microbe of the episode: Blastochloris sulfoviridis

Journal commentary (paywall)

Journal Papers:
Yang J, Xie X, Xiang N, Tian Z-X, Dixon R, Wang Y-P. 2018. Polyprotein strategy for stoichiometric assembly of nitrogen fixation components for synthetic biology. Proc Natl Acad Sci 115:E8509–E8517.

Other interesting stories:

• How the human microbiota recovers after antibiotic treatment

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.

Episode outline: