BacterioFiles – Détails, épisodes et analyse

This episode: Trends of declining lichen populations and biocrust cover overall match trends of increasing temperatures in Colorado dryland!

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Show notes:
Microbe of the episode: Cherry chlorotic rusty spot associated partitivirus

Takeaways:

Global climate change is affecting almost every natural system on the planet, in predictable and also sometimes unexpected, complex ways. Microbes perform key roles in many different ecosystems, providing and recycling important nutrients and even macroscopic structure. One example of this is biocrusts in dryland environments, such as areas in the western US with low annual rainfall. Microbes other organisms form a stable surface binding soil and sand particles together, helping to retain moisture and prevent erosion and transformation of land into desert.

In this study of a Colorado park over more than 20 years, important species of symbiotic fungi and photosynthetic microbes in the form of lichens have declined significantly. The land is mostly untroubled by grazing or human activity, but changes in climate and moisture and the presence of invasive plants could affect lichens. However, the temperature increase over the decades showed the best correlation with the lichen decline. The loss of these species could lead to nutrient shortages in the long term for these communities.

Journal Paper:

Finger-Higgens R, Duniway MC, Fick S, Geiger EL, Hoover DL, Pfennigwerth AA, Van Scoyoc MW, Belnap J. 2022. Decline in biological soil crust N-fixing lichens linked to increasing summertime temperatures. Proc Natl Acad Sci USA 119:e2120975119.

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This episode: A virus partners with a parasitoid wasp to help exploit fruit fly victims!

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Show notes:
Microbe of the episode: Actinomadura livida

Takeaways Parasitoid wasps have an interesting lifestyle: they inject their eggs into the larvae of other insects, and their young hatch and grow up by consuming the host from the inside. Some of these wasps also inject a virus along with the egg, which supports the wasp offspring by suppressing the host immune system.

Most of these parasitoid helper viruses are integrated into the host wasp genome and are translated and produced as needed, but in this study, an independently replicating entomopoxvirus serves as an example of a virus-wasp mutualism. The study explores how the virus can infect the wasp prey, and how it gets passed on to wasp offspring.

Journal Paper:
Coffman KA, Hankinson QM, Burke GR. 2022. A viral mutualist employs posthatch transmission for vertical and horizontal spread among parasitoid wasps. Proc Natl Acad Sci 119:e2120048119.

 

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This episode: Gene transfers between viruses and eukaryotes have happened many times throughout evolutionary history!

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Show notes:
Microbe of the episode: Mycoplasma subdolum

News item

Takeaways As we've all seen recently, viruses can cause a lot of trouble. Their biology requires them to be parasites inside the cells of their hosts, and they can cause devastating disease, so it's hard to think of them as having played important roles in the development of life on Earth, including our own evolution.

However, this study found thousands of apparent historical transfers of genes from virus to host or from host to virus in the cells of all kinds of different eukaryotes. Some of these genes play important roles in the cell, helping to make them what they are.   Journal Paper:
Irwin NAT, Pittis AA, Richards TA, Keeling PJ. 2022. Systematic evaluation of horizontal gene transfer between eukaryotes and viruses. Nat Microbiol 7:327–336.

 

Other interesting stories:

• Building a device that translates signals from one microbe to communicate with another
• Cloaking antitumor bacteria to fight cancer without immune system interference

 

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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This episode: Human-based food used as bait by hunters can reduce bears' gut microbe diversity!

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Show notes:
Microbe of the episode: Actinomadura verrucosospora

News item

Takeaways Gut microbes are important for the health of most animals. In humans, many things can affect our gut microbe community, including diet, medications, and lifestyle. Eating a varied diet with diverse kinds of plant-based foods can maintain a healthy, functional community of many different kinds of microbe. However, eating mostly highly processed grain-based foods can reduce the diversity and functionality of the gut community.

This is also true in bears. In this study, when bears consumed more processed, grain-based human foods via hunters leaving such foods out as bait, the gut communities in these bears had reduced diversity of microbes. The effects of this reduced diversity were not determined, but it is reasonable to assume it was not good for the bears' overall health.   Journal Paper:
Gillman SJ, McKenney EA, Lafferty DJR. 2022. Human-provisioned foods reduce gut microbiome diversity in American black bears (Ursus americanus). J Mammal 103:339–346.

 

Other interesting stories:

• 3D-printed electrode structures harvest electricity from bacterial photosynthesis
• Gut microbes are important for helping tadpoles survive in warmer conditions

 

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This episode: Simple microscopic animals can survive extreme radiation by ejecting damaged cells that might otherwise become cancer!

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Show notes:
Microbe of the episode: Helleborus net necrosis virus

News item

Takeaways Any multicellular organism with different types of cells needs some sort of cell regulation, to keep each cell type doing what it's supposed to do for the good of the organism as a whole. We know what happens when this regulation fails and one type of cells starts multiplying out of control: cancer.

However, cancer has never yet been observed in certain organisms, including the simple microscopic animal Trichoplax adhaerens. In this study, these animals are exposed to large amounts of radiation and then observed over years to see if they can develop cancer or have interesting mechanisms of resisting it.   Journal Paper:
Fortunato A, Fleming A, Aktipis A, Maley CC. 2021. Upregulation of DNA repair genes and cell extrusion underpin the remarkable radiation resistance of Trichoplax adhaerens. PLOS Biol 19:e3001471.

 

Other interesting stories:

• Genes transferred from bacteria to algae helped land plants evolve

 

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This episode: How family members share gut microbes across multiple generations!

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Show notes:
Microbe of the episode: Dyozetapapillomavirus 1

Takeaways Our gut's microbial communities can greatly influence our health, for good or bad. The makeup of these communities can be influenced by many factors, including genetics, health status, diet, and other aspects of the environment we live in. We've learned a lot about this topic recently, but there's a lot more we still don't understand.

In this study, gut microbe samples from individuals spanning multiple generations in the same families were compared, to see how much influence family relationships and cohabitation could have on the gut communities. Both genetic relationship and living together had influences on which gut microbes different people shared.   Journal Paper:
Valles-Colomer M, Bacigalupe R, Vieira-Silva S, Suzuki S, Darzi Y, Tito RY, Yamada T, Segata N, Raes J, Falony G. 2022. Variation and transmission of the human gut microbiota across multiple familial generations. 1. Nat Microbiol 7:87–96.

 

Other interesting stories:

• Simple modification to interesting bacteria make them excrete nitrogen fertilizer
• Making carbon dioxide into useful chemicals with bacteria

 

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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!

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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

 

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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This episode: Beetles inoculate bamboo with a fungus that consumes the bamboo sugars to feed the beetle larvae!

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Show notes:
Microbe of the episode: Saccharomyces cerevisiae virus L-BC (La)

News item

Video: Lizard beetle laying its egg

Takeaways The structural polymers that make up plants, such as cellulose, can be difficult for many organisms to digest. Some kinds of bacteria and fungi can do it, and some animals (cows, pandas, termites) partner with these microbes to be able to eat otherwise indigestible plant material. This includes insects such as leaf-cutter ants that farm external gardens of microbes, providing them plant material and then eating the resulting microbial growth.

In this study, the lizard beetle lays its eggs in bamboo and inoculates the walls of the bamboo with a fungus that provides food to the larvae. Chemical analyses suggest that the fungus only consumes the simple sugars in the bamboo rather than breaking down the tougher polymers, which raises questions about the evolution of this interaction.   Journal Paper:
Toki W, Aoki D. 2021. Nutritional resources of the yeast symbiont cultivated by the lizard beetle Doubledaya bucculenta in bamboos. Sci Rep 11:19208.

 

Other interesting stories:

• Using bacteria to detect and target colon cancer for imaging (paper)
• Filters made from kombucha cultures could work better than synthetic types

 

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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This episode: New techniques allow specific modifications in certain members of a complex community of microbes, without isolating them in pure culture first!

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Show notes:
Microbe of the episode: Tomato golden mosaic virus

News item

Takeaways The technology for understanding and manipulating microbial genetics has come a long way in a short time. It used to take years even to sequence a small genome, and now thousands can be sequenced in just a few days. The technology to change and even create genetic sequences is also much further advanced now than just a few decades ago. But still, many analyses and modifications require a pure culture of a microbe to carry out.

This study tested a method for modification of single or multiple species in a community of many. The method allows for identification of which species were successfully modified in targeted ways, and can allow the modified species to be extracted and studied individually.   Journal Paper:
Rubin BE, Diamond S, Cress BF, Crits-Christoph A, Lou YC, Borges AL, Shivram H, He C, Xu M, Zhou Z, Smith SJ, Rovinsky R, Smock DCJ, Tang K, Owens TK, Krishnappa N, Sachdeva R, Barrangou R, Deutschbauer AM, Banfield JF, Doudna JA. 2022. Species- and site-specific genome editing in complex bacterial communities. 1. Nat Microbiol 7:34–47.

 

Other interesting stories:

• Microbes that degrade plastic may be increasing in response to plastic pollution
• Algae in ocean communicate with each other using fluorescence

 

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

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This episode: Predatory bacteria could protect lobster farms from disease-causing bacteria!

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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

 

Email questions or comments to bacteriofiles at gmail dot 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.