Another amazing tardigrade survival skill is discovered.
- Apparently, some water bears can even beat extreme UV light.
- It may be an adaptation to the summer heat in India.
- Special under-skin pigments neutralize harmful rays.
Stressor testing<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU1MzIzMS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyMjc2MDc4Mn0.5R6DAfzsq29zvETCEH1sR9rprcnJv_L0KyUW2qedslE/img.jpg?width=980" id="c6b71" class="rm-shortcode" data-rm-shortcode-id="e7afe644fc94631ed9ea6837ed3920d3" data-rm-shortcode-name="rebelmouse-image" alt="water bear illustration" />
3D illustration of a tardigrade
Credit: Dotted Yeti/Shutterstock<p>It seems at times like scientists enjoy playing the "let's see if <em>this</em> kills them" game with tardigrades, a game that humans usually lose. After searching the campus of the Indian Institute of Science, researchers gathered some water bears and brought them back to the lab to see what they could handle.</p><p>The scientists found that after they exposed <a href="http://cshprotocols.cshlp.org/content/2018/11/pdb.emo102301.full" target="_blank"><em>Hypsibius exemplaris</em></a> tardigrades to very high doses — 1 kilojoule (kJ) per square meter — of UV light for about 15 minutes, they would in fact die over the next 24 hours. However, when they aimed the same blasts at the reddish-brown tardigrades…nothing. The humans even quadrupled the UV intensity and, nope, they tracked the water bears for 30 days, and a majority of them, 60 percent, were still fine.</p><p>As is often the case with tardigrades, the question is how?</p>
Turning deadly light blue<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU1MzIwMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMTM1NTE2N30.n8FiCLgp5aTqmYby2bjpeu9QJRTV7KzaB9tmTHBzWtk/img.jpg?width=980" id="5d4cc" class="rm-shortcode" data-rm-shortcode-id="7aa8735a958123bcfb269920eb4d2aed" data-rm-shortcode-name="rebelmouse-image" />
Tardigrade's normal appearance (left), and under inverted fluorescence (right)
Credit: Suma et al., Biology Letters (2020)<p>When the researchers examined the tardigrades under an inverted fluorescence microscope they found that when they were exposed to UV light, they became blue. The researchers' hypothesis is that these tardigrades carry fluorescent pigments beneath their skin that they deploy as necessary to transform UV light into simple benign, blue light. It may be that this ability has emerged as an evolutionary response to southern tropical India's often-extreme heat. The study says that typical summer-day UV levels in this region are about 4kJ per square meter.</p><p>Of the 40 percent of the reddish-brown tardigrades that had died before 30 days — mostly after about 20 days — the scientists concluded they had less pigment with which to neutralize UV light.</p><p>When the scientists extracted the pigment from the UV champions and coated some <em>Hypsibius exemplaris</em> tardigrades with the stuff, their resistance to UV exposure was also enhanced, boosting their survival rate to almost twice that of their uncoated brethren.</p><p>Autofluorescence has been found in other animals — parrots, scorpions, chameleons, and frogs, among others — so it's not completely unheard of. In parrots, for example, autofluorescence is hypothesized to be involved in tweaking coloration during mating rituals. Still, surprise, tardigrades seem to be putting it to unusual use by employing it for UV protection. </p>
The microbes that eventually produced the planet's oxygen had to breathe something, after all.
- We owe the Earth's oxygen to ancient microbes that photosynthesized and released it into the world's oceans.
- A long-standing question has been: Before oxygen, what did they breathe?
- The discovery of microbes living in a hostile early-Earth-like environment may provide the answer.
Unassuming but remarkable microbial mats<p> Photosynthesis chiefly requires sunlight, water, and CO<sup>2</sup>. The CO<sup>2</sup> gets broken down into carbon and oxygen — the plant uses some of this oxygen and releases the rest. Without oxygen molecules, though, how did this work? </p><p> There are known microbial mats today that live in oxygen-free environments, but they're not thought to be sufficiently like their ancestors to explain ancient photosynthesis in an oxygen-free environment. </p><p> There have been a few oxygen stand-ins proposed. Photosynthesis can work with iron molecules, but fossil-record evidence doesn't support that idea. Hydrogen and sulphur have also been proposed, though evidence for them is also lacking. </p><p> The spotlight began to shift to arsenic in the first decade of the millennium when arsenic-breathing microbial mats were discovered in two hypersaline California lakes, <a href="https://science.sciencemag.org/content/308/5726/1305.abstract" target="_blank">Searles Lake</a> and <a href="https://www.discovermagazine.com/planet-earth/mono-lake-bacteria-build-their-dna-using-arsenic-and-no-this-isnt-about-aliens" target="_blank" rel="noopener noreferrer">Mono Lake</a>. In 2014, Visscher and colleagues <a href="https://www.nature.com/articles/ngeo2276" target="_blank">unearthed indications</a> of arsenic-based photosynthesis, or "arsenotrophic," microbial mats deep in the fossil record of the Tumbiana Formation of Western Australia. </p><p> Still, given the ever-shifting geology of the planets, the fractured ancient fossil record makes definitive study of ancient arsenotrophic photosynthesis difficult. The fossil record can't identify the role of the arsenic it reveals: was it involved in photosynthesis or just a toxic chemical that happened to be there? </p><p>Then, last year, arsenic-breathing microorganisms <a href="https://www.washington.edu/news/2019/05/01/arsenic-breathing-life-discovered-in-the-tropical-pacific-ocean/" target="_blank" rel="noopener noreferrer">were discovered</a> in the Pacific Ocean. A sulphur bacterium, <em>Ectothiorhodospira sp.</em> was also recently found to be metabolizing arsenic into <a href="https://en.wikipedia.org/wiki/Arsenite" target="_blank">arsenite</a> in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5064118/" target="_blank" rel="noopener noreferrer">Big Soda Lake</a> in Nevada. </p>
An ancient Earth environment, today<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ0NzIxMC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1OTQwOTYyN30.v96ZRXpIAf4yzDwcvXzVV3Fa4qULtUMxanXguPHD2wI/img.jpg?width=980" id="9eec4" class="rm-shortcode" data-rm-shortcode-id="a23585c057ee50ed500b96125e4a6b05" data-rm-shortcode-name="rebelmouse-image" />
a Map of Northern Chile; b Detail of frame showing Laguna La Brava in the southern Atacama; c The channel showing the mats in purple; d Hand sample, cross-section; e Microscopic image of bacteria.
Credit: Visscher, et al./Communications Earth & Environment<p>The study reports on Visscher's discovery of a living microbial mat thriving in an arsenic environment in Laguna La Brava in the Atacama Desert in Chile. "We started working in Chile," Visscher tells <a href="https://today.uconn.edu/2020/09/without-oxygen-earths-early-microbes-relied-arsenic-sustain-life/" target="_blank"><em>UConn Today</em></a>, "where I found a blood-red river. The red sediments are made up by <a href="https://en.wikipedia.org/wiki/Anoxygenic_photosynthesis" target="_blank">anoxogenic</a> photosynthetic bacteria. The water is very high in arsenic as well. The water that flows over the mats contains hydrogen sulfide that is volcanic in origin and it flows very rapidly over these mats. There is absolutely no oxygen."</p><p>The mats had not previously been studied, and the conditions in which they live are tantalizingly similar to those of early Earth. It's a high-altitude, permanently oxygen-free state with extreme temperature swings and lots of UV exposure. </p><p>The mats that somewhat resemble Nevada's purple <em>Ectothiorhodospira sp.</em> are going about their business of making carbonate deposits, forming new stromatolites. Most excitingly, those deposits contain evidence that the mats are metabolizing arsenic. The rushing waters surrounding the mats are also rich in hydrogen sulphide and arsenic.</p><p>Says Visscher, "I have been working with microbial mats for about 35 years or so. This is the only system on Earth where I could find a microbial mat that worked absolutely in the absence of oxygen."</p><p>Not that Earth is the only place where this could happen. Visscher notes that the equipment they used for studying the Laguna La Brava mats is not unlike the system aboard the Mars Perseverance Rover. "In looking for evidence of life on Mars, they will be looking at iron, and probably they should be looking at arsenic also."</p>
German researchers have just solved the mystery of how these substances work.
- As pathogens' resistance grows, scientists are searching for a class of drugs that could replace antibiotics.
- Antivitamins that switch off vitamins in bacteria are being investigated.
- Scientists have been struggling to understand how naturally occurring antivitamins do what they do.
Shutting down the dance of the proteins<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU3Nzk5OS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzMDk4NzI5NX0.FPVenf2jQ4I4raQqn5EpK_DxCGoYRSw3wzIzryl2ys0/img.jpg?width=980" id="27eb8" class="rm-shortcode" data-rm-shortcode-id="6cfa008038077a6fbcab3f53d2af6cf8" data-rm-shortcode-name="rebelmouse-image" alt="Vitamin B1" />
Image source: Ekaterina_Minaeva/Shutterstock<p>The study was led by <a href="https://www.uni-goettingen.de/en/89703.html" target="_blank">Dr. Kai Tittmann's</a> group from the Göttingen Center for Molecular Biosciences at the University of Göttingen in collaboration with <a href="https://www3.mpibpc.mpg.de/groups/de_groot/bgroot.html" target="_blank">Bert De Groot's Computational Biomolecular Dynamics Group</a> from the Max Planck Institute for Biophysical Chemistry Göttingen, and with <a href="https://www.chem.tamu.edu/rgroup/begley/" target="_blank">Tadhg Begley's group</a> from Texas A&M University in College Station, Texas.</p><p>The B1 antivitamin is naturally occurring, and is produced by bacteria as a means of killing off competing bacteria. Its critical atom appears in an apparently unimportant location, deepening the mystery.</p><p>To see how that single atom was doing such an effective job, the researchers used <a href="https://www.pnas.org/content/97/7/3171" target="_blank">high-resolution protein crystallography</a>. This allowed them to observe the interaction between the B1 antivitamin and B1 on an atomic level.<br></p><p>What they saw was that the antivitamin completely interrupted the "dance of protons" that's seen in functioning proteins. Tittmann <a href="https://www.uni-goettingen.de/en/3240.html?id=5964" target="_blank">says</a>, "Just one extra atom in the antivitamin acts like a grain of sand in a complex gear system by blocking its finely tuned mechanics." (Tittmann's group was the first to document this "dance" in <a href="https://www.technologynetworks.com/proteomics/news/dance-of-the-protons-discovery-shows-proteins-instant-message-324139" target="_blank">2019</a>.)</p>
Antivitamins don’t bother humans<p>One particularly significant finding of the new research is that, although the B1 antivitamin prevents B1 from functioning in bacteria, it doesn't interfere with the vitamin for humans. This offers hope that antivitamins can be developed that target and neutralize pathogens without doing harm to patients.</p><p>De Groot's team created computer simulations to learn why humans are unaffected by the errant atom, and found that, "The human proteins either do not bind to the antivitamin at all or in such a way that they are not 'poisoned.'"</p><p>The possibility that antivitamins may at some point be ready to step in and replace failing antibiotics is not totally unexpected. Antivitamins were <a href="https://chemistry-europe.onlinelibrary.wiley.com/doi/epdf/10.1002/cbic.201500072" target="_blank">actually used</a> in the development of antibiotic and <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/antiproliferative-drug" target="_blank" rel="noopener noreferrer dofollow">antiproliferative</a> drugs such as prontosil and aminopterin. And there are already some antivitamin medicines in use, notably antagonists for vitamins B12, B9, and K.</p>
The human body is endlessly fascinating.
- Last year, it was reported that a Belgian man arrested for drunk driving brewed the alcohol in his own gut.
- The disorder, auto-brewery syndrome, occurred after he took a round of antibiotics.
- He was cured after a fecal donation from his daughter.
What is Fecal Microbiota Transplantation (FMT)?<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="29f77231a58d168a5819bc02e41d66b9"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/Awn3haOpfcI?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Fecal transplants, or bacteriotherapy, help replenish bacterial balance, especially when antibiotics kill too many "good" bacteria. The procedure is most often performed by colonoscopy, though sometimes a nasoduodenal tube is required. While there are a variety of tests needed before doctors will perform bacteriotherapy, fecal transplants actually <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4895930/" target="_blank">date back</a> at least 1,700 years to Traditional Chinese Medicine.</p><p>Fecal transplants are most commonly performed to treat diseases caused by the bacteria, <em>C. difficile</em>. Over 15,000 people <a href="https://www.nih.gov/news-events/news-releases/clinical-trial-testing-fecal-microbiota-transplant-recurrent-diarrheal-disease-begins" target="_blank">die every year</a> from such diseases. </p><p>Researchers are constantly learning more about the incredible complexity and importance of the microbiome. Besides gut-related disorders, bacteriotherapy <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4895930/" target="_blank" rel="noopener noreferrer dofollow">may soon be used</a> to treat a variety of ailments, including obesity, chronic fatigue syndrome, diabetes, hay fever, and eczema. </p><p>The doctors feel confident recommending this particular intervention. Treating ABS often involves changes in diet, probiotics, and drug therapy. Yet antibiotics have strange effects on the microbiome, and in this case, it was enough to make him resistant to the usual therapies. </p><p>The team in Belgium is hopeful they've found another avenue for treating ABS. </p><p style="margin-left: 20px;">"Moreover, we can imagine a future point - after additional research to evaluate the safety of faecal microbiota transplantation - at which this approach might become standard therapy for gut fermentation syndrome."</p><p>--</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a>, <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank" rel="noopener noreferrer dofollow">Facebook</a> and <a href="https://derekberes.substack.com/" target="_blank" rel="noopener noreferrer dofollow">Substack</a>. His next book is</em> "<em>Hero's Dose: The Case For Psychedelics in Ritual and Therapy."</em></p>
The physical action of handwashing plus the properties of soap is a one-two punch for the virus.
- A common recommendation from experts to help protect against coronavirus is to wash your hands often, but why? It turns out that each time you do it is an effective two-pronged attack.
- As Kate the Chemist explains, the virus has a weak outer membrane. By using the proper handwashing technique, you're actually breaking through that membrane and ripping the virus apart.
- Soap is an important part of the equation because of its two sides: the hydrophobic side (which grabs onto the virus), and the hydrophilic side (which grabs onto the water). Washing your hands with soap for at least 20 seconds allows the virus to be rinsed away.