098: Where’d The Clouds Go?

On This Week’s Show

  • Bacteria living on insects could provide new antibiotics
  • New letters to the DNA alphabet
  • A story of interspecies communication
  • The latest buzz on a new species rediscovered
  • The Climate Lounge
  • Pub Quiz

Science News with Nevena Hristozova, and Sophie McManus

Bacteria living on insects could provide new antibiotics

Nevena Hristozova

We’ve heard of the crisis with spreading antibiotic resistant pathogenic bacteria, which can be very very big problem in a very very short time. Until now, for the most part, antibiotics are discovered either by identifying new species producing them, by growing in the lab said species from soil samples and then isolating compounds they produce with antimicrobial properties. The problem with that is, that many bacteria are not easy to grow in the lab, because they only live in complex environments and in microbial communities. This means that the traditional way to stumble across new antibiotics to replace the useless ones due to antimicrobial resistance are becoming increasingly ineffective.

An interesting fact about antibiotics though is that they are so-called secondary metabolites. This means that they are synthesised by bacteria or fungi only after they pass the exponential growth phase of the colony and their synthesis depends on the availability of specific nutrients in the environment.

This and the need to find out alternative sources or ecosystems where antibiotic bacteria live, let researchers to exploring insects. Like pretty much any other imaginable place in the world, insects are a host of a plethora of bacteria and fungi normally growing in or on them. As it turns out, scientist from the Department of Bacteriology, University of Wisconsin-Madison have discovered more than 10k strains of bacteria isolated from insects and some of them proved to be synthesising novel antibiotics able to kill even the most resistant fungi and bacteria that we know today and which could pose a severe threat to human life, being resistant to pretty much every existing antibiotic. More can be read in the article published in Nature under the title The antimicrobial potential of Streptomyces from insect microbiomes.

Medical News Today

Four new letters added to the DNA alphabet

Sophie McManus

Crazy story!

DNA, or deoxyribonucleic acid, is the carrier of our genetic information. DNA is made up of four ‘letters’ – A, C, T, G. Adenine, cytosine, thymine, guanine. Arranged in different combinations, these letters build up the ‘language’ of our genes – all 22,000 of them, in the case of humans.

In research published a few days ago in Science, Florida-based researchers have doubled the natural number of life’s building blocks, creating for the first time a synthetic, eight-letter genetic language. This seems to store and transcribe information just like natural DNA.

According to Floyd Romesberg, a chemical biologist not involved with this work, this is a real conceptual breakthrough. It implies there’s nothing inherently special about the combination of chemicals in DNA and that synthetic life could be supported with this new kinda alphabet soup.

Normally, as a pair of DNA strands twist around each other in a double helix, the chemicals on each strand pair up: A bonds to T, and C bonds with G. Apple tart, chocolate gateau.

For a long time, scientists have tried to add more pairs of these chemicals, also known as bases, to this genetic code. For example, ‘unnatural’ bases were actually generated back in the 1980s. In 2014 a pair of unnatural bases was inserted into a living cell.

But this is the first time it has been to demonstrated that the complementary ‘unnatural’ bases recognise and bind to each other, and that the double helix that they form actually maintains its structure.

Finally, the team showed that the synthetic DNA could be faithfully transcribed into RNA. “The ability to store information is not very interesting for evolution,” says Steven Benner, the lead researcher of the study. “You have to be able to transfer that information into a molecule that does something.”

The researchers call the resulting eight-letter language ‘hachimoji’ after the Japanese words for ‘eight’ and ‘letter’. S B P Z.

Live Science, Nature

How gut bacteria controls gene expression through “interspecies communication”

Nevena Hristozova

What if I told you that free will is not a thing? It seems that we have the proof for this, at least at a metabolic level.

A new study reveals for the first time that certain bacteria can secrete a compound called nitric oxide which is known to regulate gene expression. We’ve known that nitric oxide is involved in gene expression regulation for a while. This new study though, examined how bacteria producing NO might be using it to alter the expression of the genes of their host worm.

Researchers describe this interaction between host a worm and a bacteria as a form of “interspecies communication.” In the lab they tested what would happen if a bacteria on which the worm feeds, produces excessive Nitric Oxide amounts. Turns out the genetic expression of the worm is altered since Nitric Oxide is a naturally occuring signaling molecule in gene expression and it ends up developing deformities and dying prematurely. In reality, this doesn’t happen, but now that such mechanism of interspecies genetic control is known, the scientists are setting off to discover if similar mechanisms are not causing some pathologies in humans too. With the massive expansion of the field of gut microbiota and the search for the healthy microbiome and the gut microbial community imbalances which contribute to development of diseases, this new piece of the puzzle sure makes things even more interesting.

The study in question is published in the journal Cell under the title Regulation of MicroRNA Machinery and Development by Interspecies S-Nitrosylation.

New Atlas

World’s largest bee rediscovered

Sophie McManus

Tune out if you have a phobia of large insects…..

The world’s largest bee has been found once more in Indonesia. This is after decades that we thought it was lost to science forever.

Wallace’s Giant Bee Megachile pluto

A single live female was found. The species is known as Wallace’s Giant Bee, named after famed naturalist Alfred Wallace who characterised it in 1858. It’s as big as an adult human thumb, if that means very much. More precisely it is over 4 cm long with a wingspan of 6cm. Something you’d hope would avoid your lemonade glass.

Lovely – “It was absolutely breathtaking to see this ‘flying bulldog’ of an insect that we weren’t sure existed anymore, to have real proof right there in front of us in the wild,” said natural history photographer, Clay Bolt, who took the first photos and video of the species alive. “To actually see how beautiful and big the species is in life, to hear the sound of its giant wings thrumming as it flew past my head, was just incredible. “

Wallace described his namesake as a large wasp like black insect with immense jaws.

There are no legal barriers to trading this bee. “By making the bee a world-famous flagship for conservation, we are confident that the species has a brighter future than if we just let it quietly be collected into oblivion,” said Robin Moore, of Global Wildlife Conservation (GWC).

BBC Science and Environment, Science News,

The Climate Lounge

Where’d The Clouds Go?

Tom Di Liberto

There are a few things that I do when things get crazy to calm myself down. To remind myself to breathe and to put things into perspective (and I’d love to hear yours too!). Over the last several years, I’ve had a need to do this a lot. All I’ve had to do is turn on Twitter to see the latest dumpster fire to crank out a few curse words and an “Are you f***ing kidding me!”.

One thing I love to do and is so entirely on brand for someone who studies the atmosphere like me, is to go outside and just look at the clouds for a bit. I’ll put animals to the shapes I’ll put grotesquely correct latin names to the clouds. And I’ll just sit and watch then blow away as if they take with them the anger I’ve been bottling up.

Flash now to this week, I turn on Twitter because I’m a masochist and what do I see that pisses me off? Well, a brand new study that says that if we warm the planet 6˚C CLOUDS DISAPPEAR which then leads to an additional warming of 8˚C. WHAT?!!

Okay, technically it’s just the type of clouds known as stratocumulus clouds, but those low clouds cover about 20% of the tropical oceans, and are everywhere in the subtropics too. These clouds cool the planet by shading the surface from the sun.

Now clouds have always been a sort of X-Factor when it comes to global climate change. 56 million years ago an already warmer than now earth went into overdrive warming by an additional 6˚C during a period known as the Paleocene-Eocene Thermal Maximum or PETM (i just made up that pronunciation, I apologize). During this time, a massive global extinction event happened oceans became jacuzzi hot in the tropics, mammals became smaller to deal with less nutrition, and violent storms wrecked the planet massive flash floods and droughts occurred. It was an awful time to be alive, but the thing was, the PETM got hotter and more extreme than our climate models have theoretically predicted. And the reason that is becoming more evident is the impact from clouds.

The process is simple enough. Warming leads to less clouds which means less sunlight reflected meaning a warming earth and boom a feedback loop. But this was all speculative. Research published in the journal Nature has taken a closer look at this. Tapio Schneider and colleagues used a high resolution climate model simulation to see how warming affecting stratocumlus clouds. They found that reduction in clouds could explain how temperatures got so warm during the PETM.

Basically what Tapio Schneider of Cal Tech and Colleen Kaul and Kyle Pressel have done is highlight a major uncertainty that exists when we keep warming the planet. But again how did they do this? It’s hard to model clouds because they are much smaller than the grid cells in climate models. So Dr. Schneider and colleagues ran a roughly 25 km2 patch of stratocumulus clouds off California through their models for 2 million core-hours on supercomputers in Switzerland and California. The clouds disappeared for two main reasons, as Earth’s sky and surface get hotter it makes things more turbulent in the clouds mixing the moist air up and brining dry air down in a process called entrainment. This breaks up the cloud.

Second, the greenhouse effect makes the upper atmosphere warmer and more humid, which means the cooling of the top of the clouds from above is not as efficient. This cooling is needed because it lets cold moist air sink in the cloud allowing warm moist air from the surface to rise. Less cooling thinner clouds.

And just as interesting, they found a tipping point. Once CO2 level got to 1200 ppm (we are at 400 now but could reach 1200 in a worst case scenario during the next century) stratocumulus clouds disappear and temperatures rapidly increase by 8˚C in addition to the 4˚C from CO2 induced warming. Um… that’s really really really bad.

As Natalia Wolchover puts it in her article in Quanta Magazine, imagine crocodiles in the Arctic and scorched mostly lifeless tropical regions. Not good.

But before you go off worried that the clouds are disappearing please remember that if we even get close to that point there already would have been humongous and horrible climate change impacts already including rapidly rising seas and ice melt, a de-oxygenated ocean and super dooper heat waves. And as Brian Kahn says in Earther, more likely than not some group would have tried geoengineering at that point to makes things better. So while this research is important in finding out more about our climate don’t worry about the clouds. It’d be a sort sh*t cherry on top of globally warmed sh*t sundae.


Pub Quiz

The latest science news in quiz form. Can you beat the Blue Streak team?

In Closing

That concludes this episode of the Blue Streak Science Podcast.

If you have any suggestions or comments email us at podcast@bluestreakscience.com

You can subscribe to our show on Apple Podcasts, Spotify and any number of podcast directories.

If you have an iOS device like an iPhone or an iPad you can get the Blue Streak Science app from the App Store.

This show is produced by the Blue Streak Science team, and edited by Pro Podcast Solutions.

Our hosts today were Nevena Hristozova, Sophie McManus, and Tom Di Liberto.

I’m JD Goodwin.  

Thank you for joining us.

And remember…follow the science!

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