Better Know a Microbe

This colorful painting “Ecology of Lyme” is both science and art, showing the interconnected factors associated with Lyme Disease–Earth being altered by a changing climate, a deer, a mouse, invasive Japanese barberry and three stages of deer ticks. It’s the result of a University of Maine graduate researcher wanting to show the big picture and an artist wanting to help: bit.ly/2w66O3O   Image Credit: Illustration by Olaf Hajek

Haematococcus pluvialis

A freshwater green algae that is commonly harvested for an antioxidant it produces. Those little circles that look like eyes are pyrenoids, which are used to concentrate carbon dioxide. Useful if you’re underwater, where CO2 levels are lower than in the air. 

The relationship between a squid and its live-in bacteria

without this symbiosis, the squid’s light organ never reaches its mature form..

(Illustration by Paul Jackman)

by NATURE, NEWS FEATURE

You can blame microbes in the sky for your rainy day.

Bacteria are all around us—even in the atmosphere. Under the right wind conditions, air currents sweep up ultra-light microbes, which can drift as high as the stratosphere. For instance, a 2012 study appearing in the journal Proceedings of the National Academy of Sciences identified over 300 different families of bacteria floating amid the clouds.

As it turns out, these airborne microbes seem to influence the weather. Recently on Science Friday, we spoke with Cindy Morris, a microbial ecologist at the French National Institute for Agricultural Research in Avignon, France, and Athanasios Nenes, a professor of atmospheric sciences and chemical and biomolecular engineering at Georgia Tech in Atlanta, Georgia, to understand how microbes participate in precipitation.

For rain to form, millions of tiny water droplets must aggregate in clouds and become heavy enough to fall, according to Morris. And for that to happen, “in the temperate regions, you need a freezing process, where an ice crystal then will collide with droplets that are also cold, but they haven’t frozen yet. And this is how the heavy droplets can form,” said Morris.

But cloud tops aren’t at temperatures conducive to freezing. So how do they produce rain?

Albert Einstein (whose birthday we celebrate today) once said:

“I have no special talent. I am only passionately curious.”

What are you curious about? Is there’s something you’ve always wanted to know? Or a question that just popped into your head? We pledge to use science (and animation, and art, and music) to answer it. Skunk Bear is looking for Good Questions to guide our next series of videos. Submit here: npr.org/skunkbear.

Curator of Micropaleontology Angelina Messina found beauty and wonder in some of the Museum’s tiniest specimens. She joined the staff in the 1930s, and with the help of Assistant Curator Eleanor Salmon, prepared catalogs of foraminifera—miniscule organisms that provide important markers to geologists and hold vital records of ancient climates within their fossilized chambers. Messina’s work won international recognition. Her 69-volume Catalogue of Foraminifera was a seminal work in micropaleontology, used in universities and every major micropaleontological laboratory of the large oil companies, and she also co-founded the journal Micropaleontology in 1955. Her work classifying the Museum’s foraminifera collection is still used by paleontologists, geologists, and climate scientists today. The collection itself is now part of a National Science Foundation-funded project to re-house and CT scan important specimens. 

What’s the difference between a pandemic, epidemic and outbreak? This handy guide can help. 

Bacteriophage drawing by Sandra Culliton. 

Bacteriophages are viruses that infect bacteria. They are also the most abundant organisms on our planet, there are around 10 phages for every single bacterium in the world!

Finding life on Mars has captured the imagination of generations, but experts still aren’t sure what exactly we’re looking for. The Danakil Depression in Ethiopia, with a landscape of boiling pools of water and mounds of salt and sulfur that itself seems extraterrestrial, might offer some clues. Despite being one of the lowest, hottest and driest places on Earth, the region is host to extremophiles–– microbes that thrive in these inhospitable conditions.

Dr. Felipe Gómez Gómez of the Centro de Astrobiología in Madrid, who is working on isolating and studying these bacteria, believes learning to identify life in extreme environments here on Earth is the key to identifying any alien life that might be out there.

“What is life? What are the limits of life? Scientists don’t agree on what is life,” Dr. Gómez said. “If we find life on Mars, would we be able to recognize it? We don’t know.”

These organisms might also provide insight into how potential life-forms might survive in the sparse environment of Mars. From the article:

These simple organisms can survive with a “very small battery,” and were probably among the first bacteria on Earth, Dr. Gómez said. “That is what makes them so interesting from an astrobiological point of view.”

Organisms such as chemolithotrophs don’t require traditional means of sustenance like light and organic compounds and instead use inorganic compounds such as sulfide, hydrogen and ammonia as energy sources. Though they might be a far cry from little green men with antennae, they could offer us a more realistic idea of what to expect if and when we finally make “first contact”.

Microscope Monday: Dinoflagellates Unite

“If you’re making resolutions for a healthier new year, consider a gut makeover.”

This is the starting sentence of a recent article in the New York Times, “A Gut Makeover for the New Year.” Given the recent uptick in research on the many effects the intestinal microbiota may have on human health–– our nutritional intake, our immune systems, and even diseases ranging from allergies to diabetes to depression–– a ‘makeover’ of these microbes could have a huge effect. 

Much of the composition of the microbiome is established early in life, shaped by forces like your genetics and whether you were breast-fed or bottle-fed. Microbial diversity may be further undermined by the typical high-calorie American diet, rich in sugar, meats and processed foods. But a new study in mice and people adds to evidence that suggests you can take steps to enrich your gut microbiota. Changing your diet to one containing a variety of plant-based foods, the new research suggests, may be crucial to achieving a healthier microbiome.

Achieving this healthier microbiome, the article admits, will probably not be an easy feat, and will take an as-yet unspecified amount of time.

“The nutritional value of food is influenced in part by the microbial community that encounters that food,” said Dr. Jeffrey Gordon, the senior author of the new paper and director of the Center for Genome Science and Systems Biology at the Washington University School of Medicine in St. Louis. Nutritional components of a healthy diet have to be viewed from “the inside out,” he said, “not just the outside in.”

Dr. Gordon’s study, published in Cell Host & Microbe recently, looked into how diet affects this microbial community. Human gut bacteria was placed into sterile mice, who were fed various diets and analyzed. Among the most interesting findings were that a ‘calorie restricted’ group of mice (eating less than 1,800 calories a day of plant-based foods for two years) had a richer microbial community and more strains of “good” bacteria. Mice fed a ‘typical American diet” (3,000 calories a day featuring processed cheese, lunch meats, and few fruits and vegetables) did not fare quite as well.

Prion-like protein spotted in bacteria for the first time

Prions, the infectious agents best known for causing degenerative brain disorders such as ‘mad cow’ disease, may have been spotted in bacteria.

A section of a protein in Clostridium botulinum, the microbe that causes botulism, can behave like a prion when it is inserted into yeast and Escherichia coli bacteria, researchers report in the 13 January issue of Science1.

Prions are formed by proteins that can fold in a number of structurally distinct ways. A prion version of a protein can perpetuate itself in an infectious manner by converting normal forms of that protein into the prion version.

Scientists first discovered prions in the 1980s as the agents behind fatal brain disorders known as transmissible spongiform encephalopathies. Since then, researchers have found the misfolded proteins in mammals, insects, worms, plants and fungi2, and learned that not all prions harm their hosts.

But until now, prions were only seen in the cells of eukaryotic organisms, a group that includes animals, plants and fungi.

 Spinning toy reinvented as low-tech centrifuge

Growing up in India, Manu Prakash entertained himself with a bottle cap that spun around on two strings that he tugged with his fingers. As a physical biologist at Stanford University in California, he is now transforming that simple toy, called a whirligig, into a cheap tool to help diagnose diseases such as malaria.

Prakash started this project, the results of which are published on 10 January in Nature Biomedical Engineering1, after a research trip to Uganda in 2013. While visiting health-care clinics, he noticed that most lacked a working centrifuge — or the electricity to power one — and could not separate blood samples to perform basic disease diagnostics.

“One clinic used its broken centrifuge as a doorstop,” says Prakash, a 2016 MacArthur ‘genius grant’ winner who has also invented a foldable paper microscope2. “When we got back from Africa we asked ourselves, ‘Can we do centrifugation with no electricity, using only human power?’

Unique microbial photosynthesis discovered: Finding could be used for waste treatment, energy

Researchers at Washington State University have discovered a new type of cooperative photosynthesis that could be used in engineering microbial communities for waste treatment and bioenergy production.

They report today on the unique metabolic process seen for the first time in a pair of bacteria in Nature Communications.

Photosynthetic bacteria account for nearly half of the world’s food production and carbon-based organic material. The research could also improve understanding of lake ecology.Researchers at Washington State University have discovered a new type of cooperative photosynthesis that could be used in engineering microbial communities for waste treatment and bioenergy production.They report today on the unique metabolic process seen for the first time in a pair of bacteria in Nature Communications.Photosynthetic bacteria account for nearly half of the world’s food production and carbon-based organic material. The research could also improve understanding of lake ecology.

Phuc T. Ha, Stephen R. Lindemann, Liang Shi, Alice C. Dohnalkova, James K. Fredrickson, Michael T. Madigan, Haluk Beyenal. Syntrophic anaerobic photosynthesis via direct interspecies electron transfer. Nature Communications, 2017; 8: 13924 DOI: 10.1038/NCOMMS13924

A recent episode of Science Friday explores the rhythm of the gut microbiome. Just as humans have a daily schedule, it seems that the microbiomes of our gut do too, influenced by our diet, movements, and health.

In the segment, Microbiologist Lawrence David of Duke University speaks of a yearly diary that he kept, which recorded the makeup of the biomes in his gut and mouth. Then, we learn more about a new study out in Cell titled, Microbiota Diurnal Rhythmicity Programs Host Transcriptome Oscillations. In it, “Immunologist Eran Elinav and his team looked at the circadian rhythm of gut microbes in mice. They found that those microbes changed locations and metabolic output throughout the day.”