Designing More Useful Bacteria

An illustration of viruses called phages infecting a bacterial cell.
Illustration Credit: Behnoush Hajian

In a step forward for genetic engineering and synthetic biology, researchers have modified a strain of Escherichia coli bacteria to be immune to natural viral infections while also minimizing the potential for the bacteria or their modified genes to escape into the wild.

The work promises to reduce the threats of viral contamination when harnessing bacteria to produce medicines such as insulin as well as other useful substances, such as biofuels. Currently, viruses that infect vats of bacteria can halt production, compromise drug safety, and cost millions of dollars.

“We believe we have developed the first technology to design an organism that can’t be infected by any known virus,” said the study’s first author, Akos Nyerges, research fellow in genetics in the lab of George Church in the Blavatnik Institute at Harvard Medical School and the Wyss Institute for Biologically Inspired Engineering.

“We can’t say it’s fully virus-resistant, but so far, based on extensive laboratory experiments and computational analysis, we haven’t found a virus that can break it,” Nyerges said.

The work also provides the first built-in safety measure that prevents modified genetic material from being incorporated into natural cells, he said.

Dry forests and savannas vital for Brazil’s climate goals

Cerrado savanna
Photo Credit Tim Hill

Brazil must protect and restore its dry forests and savannas to achieve its climate goals, new research shows.

Attention in Brazil and worldwide often focusses on the Amazon rainforest – ignoring damage and destruction of these seasonally dry biomes, which contain vast biodiversity and carbon stores.

The new study, led by the universities of Exeter and Campinas, says cost-effective restoration of savannas and dry forests could lock in 1.5 billion tons of carbon in 100 years.

But restoration takes time, and the researchers say protecting existing ecosystems is the best option for Brazil to reach its 2030 climate goals.

“Ongoing land-use change – especially the destruction of ecosystems to create agricultural land – makes Brazil the world’s fifth-biggest greenhouse gas emitting country,” said Dr Lucy Rowland, from Global Systems Institute at the University of Exeter.

“Denoising” a Noisy Ocean

Study lead author Ella Kim (pink helmet) helps deploy a HARP instrument package.
Photo Credit: Ana Širović

Come mating season, fishes off the California coast sing songs of love in the evenings and before sunrise. They vocalize not so much as lone crooners but in choruses, in some cases loud enough to be heard from land. It’s a technique of romance shared by frogs, insects, whales, and other animals when the time is right.

For most of these vocal arrangements, the choruses are low-frequency. They’re hard to distinguish from the sounds of ships passing in the night among others.

Biologists, however, have long been interested in listening in on them in the name of understanding fish behavior toward an ultimate goal: They can help preserve fish populations and ocean health by identifying spawning seasons to inform fisheries management.

Now scientists at Scripps Institution of Oceanography at UC San Diego and colleagues have developed a way for computers to sift through sounds collected by field acoustic recording packages known as HARPs and process them faster than even the most trained human analysts. The method represents a major advance in the field of signal processing with uses beyond marine environments.

Research team proves bacteria-killing viruses deploy genetic code-switching to deceive hosts

ORNL scientists proved the theory that bacteria-destroying viruses called bacteriophages use genetic code-switching to first infect and later overwhelm their hosts.
Illustration Credit: Andy Sproles/ORNL, U.S. Dept. of Energy

Scientists at the Department of Energy’s Oak Ridge National Laboratory have confirmed that bacteria-killing viruses called bacteriophages deploy a sneaky tactic when targeting their hosts: They use a standard genetic code when invading bacteria, then switch to an alternate code at later stages of infection.

Their study provides crucial information on the life cycle of phages. It could be a key step toward the development of new technologies such as therapeutics targeting human pathogens or methods to control phage-bacterial interactions in applications ranging from plant production to carbon sequestration.

Scientists have predicted since the mid-1990s that some organisms may use an alternate genetic code, but the process had never been observed experimentally in phages. ORNL researchers obtained the first experimental validation of this theory using uncultivated phages in human fecal samples and the lab’s high-performance mass spectrometry to reveal the intricacies of how phage proteins are expressed in the host organism. The work is detailed in Nature Communications.

For the first time, controlling the degree of twist in nanostructured particles

An array of different growth conditions, spanning from left-handed twists made with only left-handed cystine to flat pancakes made with a 50-50 mix to right-handed twists made only with right-handed cystine. The ability to control the degree of twist in a curling, nanostructured material could be a useful new tool in chemistry and machine vision.
Image Credit: Prashant Kumar, Kotov Lab, University of Michigan.

Being able to decide not only whether a micron-scale particle twists but also how much could open new avenues for machine vision and more

Micron-sized “bow ties,” self-assembled from nanoparticles, form a variety of different curling shapes that can be precisely controlled, a research team led by the University of Michigan has shown.

The development opens the way for easily producing materials that interact with twisted light, providing new tools for machine vision and producing medicines.

While biology is full of twisted structures like DNA, known as chiral structures, the degree of twist is locked in—trying to change it breaks the structure. Now, researchers can engineer the degree of twist.

Such materials could enable robots to accurately navigate complex human environments. Twisted structures would encode information in the shapes of the light waves that reflect from the surface, rather than in the 2D arrangement of symbols that comprise most human-read signs. This would take advantage of an aspect of light that humans can barely sense, known as polarization. The twisted nanostructures preferentially reflect certain kinds of circularly polarized light, a shape that twists as it moves through space.

New Fossil Analysis Reveals Dinosaur with Record-Holding 15-Meter-Long Neck

 A rendering of the sauropod known as Mamenchisaurus sinocanadorum, which had a 15-meter-long neck, about 10 feet longer than a typical school bus.
Illustration Credit: Júlia d'Oliveira

With their long necks and formidable bodies, sauropod dinosaurs have captured people’s imaginations since the first relatively complete sauropod fossils were discovered in the United States in the late 1800s. Now an international team led by Stony Brook University paleontologist Andrew J. Moore, PhD, has revealed that a Late Jurassic Chinese sauropod known as Mamenchisaurus sinocanadorum sported a 15-meter-long neck. A new analysis of this dinosaur, published in the Journal of Systematic Paleontology, provides fresh insights on the evolution of the iconic sauropod body.

For sauropods, the long neck was the anatomical key to achieving a large body size. To power such a large body, sauropods had to be efficient at gathering foodstuffs, and that's what a long neck was built for. A sauropod could plant itself in one spot and hoover up surrounding vegetation, conserving energy while taking in tons of food. Having a long neck probably also allowed enormous sauropods to shed excess body heat by increasing their surface area, much like the ears of elephants. This way of life – long neck-fueled, quadrupedal gigantism – is not one that is available to mammals or any other form of life today. The sauropod lifestyle was exceptionally successful: their lineage appeared early in dinosaur evolutionary history and persisted until the final days of the Mesozoic, when an asteroid wiped out all dinosaurs (except birds).

Game-changing high-performance semiconductor material could help slash heat emissions

WVU researchers Sergio Andres Paredes Navia, Cesar Octavio Romo de la Cruz, Liang Liang and Ellena Gemmen use an electron microscope to study the nanostructure of a new oxide ceramic material with the potential to make thermoelectric generators efficient enough to capture a significant portion of the waste heat that industrial systems like power plants emit.
Photo Credit: Courtesy of West Virginia University

Researchers at West Virginia University have engineered a material with the potential to dramatically cut the amount of heat power plants release into the atmosphere.

A team led by Xueyan Song, professor and George B. Berry Chair of Engineering at the Benjamin M. Statler College of Engineering and Mineral Resources, has created an oxide ceramic material that solves a longstanding efficiency problem plaguing thermoelectric generators. Those devices can generate electricity from heat, including power plant heat emissions, which contribute to global warming.

The breakthrough oxide ceramic Song’s team produced “achieved a record-high performance that had been deemed impossible,” she said. “We demonstrated the best thermoelectric oxide ceramics reported in the field worldwide over the past 20 years, and the results open up new research directions that could further increase performance.”

Oxide ceramics are from the same family as materials like pottery, porcelain, clay bricks, cement and silicon, but contain various metallic elements. They’re hard, resistant to heat and corrosion, and well-suited for high-temperature applications in air. They can serve as the material for thermoelectric generator components.

Bypassing antibiotic resistance with a combination of drugs

A confocal microscopy image of macrophages treated with MTX (cyan) that have eaten bacteria (magenta)
Image Credit: © Singapore-MIT Alliance for Research and Technology (SMART)

By combining an antibiotic with an anti-cancer agent, an international team has developed a treatment capable of circumventing the antibiotic resistance of the bacterium Enterococcus faecalis.

Antibiotic resistance is one of the world’s most pressing health challenges: in 2019, nearly 5 million people died from an infection associated with or attributed to antibiotic resistance. A research consortium involving the Singapore-MIT Alliance for Research and Technology (SMART), the Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University (NTU), the Massachusetts Institute of Technology (MIT) and the University of Geneva (UNIGE) has tackled the potentially deadly Enterococcus faecalis bacterium, most strains of which have developed resistance to common antibiotics. The scientists have developed an innovative strategy that consists of adding mitoxantrone, an anti-cancer agent, to vancomycin, the main antibiotic used in this context. The combination of these two drugs targets simultaneously the bacteria and the human immune system, and circumvents resistance. These promising results can be read in the journal Science Advances.

Scientists have new tool to estimate how much water might be hidden beneath a planet’s surface

Exoplanets similar to Earth, artist concept.
Image Credit: NASA

Scientists from the University of Cambridge now have a way to estimate how much water a rocky planet can store in its subterranean reservoirs. It is thought that this water, which is locked into the structure of minerals deep down, might help a planet recover from its initial fiery birth.

The researchers developed a model that can predict the proportion of water-rich minerals inside a planet. These minerals act like a sponge, soaking up water which can later return to the surface and replenish oceans. Their results could help us understand how planets can become habitable following intense heat and radiation during their early years.

Planets orbiting M-type red dwarf stars — the most common star in the galaxy — are thought to be one of the best places to look for alien life. But these stars have particularly tempestuous adolescent years — releasing intense bursts of radiation that blast nearby planets and bake off their surface water.

Immune cell gives possible explanation for sex differences in pancreatic cancer

Left to Right: Fei He Photo Credit: Yifei Chen | Dhifaf Sarhan. Photo Credit: Stefan Zimmerman

Immunotherapy is an effective form of therapy for different types of cancer. However, for pancreatic cancer, its effect is limited and differs between men and women. Researchers at Karolinska Institutet have now found a possible explanation for this sex difference. The study, which is published in Cancer Research, reveals the presence of an immune cell in women with pancreatic cancer that obstructs the body’s immune response. The results can pave the way for a more sex-specific treatment.

“More and more evidence is coming in that male and female hormones affect our immune system, but much remains to be done before sex can be included as a self-evident biological factor in medical research and therapy,” says the paper’s first author Fei He, former visiting researcher at the Department of Laboratory Medicine, Karolinska Institutet. “Our results provide new perspectives that can have high impact on the treatment of cancer.”

In recent years, immunotherapy, which stimulates the immune system to attack cancer cells, has contributed significantly to the treatment of different kinds of cancer, such as melanoma and lung, kidney and liver cancer. However, it is much less effective against pancreatic cancer, which remains one of the deadliest kinds of cancer that leaves patients, on average, with four to six months left to live after diagnosis.