Ammonia oxidation – Platinum nanoparticles caught in action

Ammonia oxidation – Platinum nanoparticles caught in action

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Ammonia oxidation is a key reaction in the chemical industry, essential for global agriculture and mining, and it also helps limit emissions of this irritating and polluting gas. A SOLEIL team, in collaboration with researchers from CEA-Grenoble, used advanced techniques on the SixS beamline to observe in real time how platinum nanoparticles—used as catalysts for this reaction—deform and change shape during oxidation.
By combining surface diffraction and Bragg coherent diffraction imaging (BCDI), the scientists revealed that the size, shape, and internal strain of the particles directly influence their catalytic efficiency and selectivity. Their results, published in Applied Catalysis B: Environmental, deepen our understanding of this reaction and pave the way for the design of more efficient and durable catalysts, with major implications for both industry and the environment.

The oxidation of ammonia (NH₃) is a vital industrial process for producing nitric oxide (NO), an essential intermediate in the manufacture of nitric acid (HNO₃)—used in fertilizers, explosives, and dyes. However, ammonia oxidation does not produce NO alone; it also generates nitrous oxide (N₂O) and nitrogen gas (N₂). All three products have industrial relevance, and the challenge lies in maximizing the yield of one or the other—this is known as Selective Catalytic Oxidation.
For over a century, platinum (Pt) has been the reference catalyst for NO production. Interestingly, it is used in the form of micrometric wires woven into metallic gauzes rather than as dispersed nanoparticles—one of the last remaining examples of bulk solid catalysts in industrial use. These wires are metallic and polycrystalline, composed of grains similar in size to the particles studied here. Yet, despite more than a hundred years of research, the precise mechanisms by which platinum particles or crystals influence the selectivity and efficiency of the reaction remain only partially understood, particularly under real operating conditions (high temperature, pressure, and gas mixtures).

Read more on the SOLEIL website

Image: Figure 1: Distribution of platinum nanoparticles. Round (blue) and elongated (red) particles display distinct catalytic behaviors.

Tailwind for fusion research in Germany

Tailwind for fusion research in Germany

High-Tech Agenda Germany to strengthen fusion-related research. European XFEL will be a vital partner.

With the High-Tech Agenda Germany, the German government has set the course for the advancement of fusion-related research in Germany. The action plan ‘Germany on the way towards a fusion power plant’ defines measures to build the world’s first fusion power plant in Germany.

Nuclear fusion, as it takes place in the sun, promises an almost inexhaustible source of energy. At its core, it involves the fusion of lighter atoms such as hydrogen, deuterium and tritium into heavier atoms such as helium. This produces huge amounts of energy, which is to be harvested in a power plant.

The world’s largest X-ray laser, the European XFEL in Schenefeld near Hamburg, is predestined for investigating fundamental processes of fusion. In particular, researchers at European XFEL want to contribute to investigating the critical early phases of fusion-related reactions. Its instruments are equipped with powerful lasers that generate the very high energy densities required to create plasma, an extremely hot state of matter. Using the extremely short and intense X-ray laser flashes of the European XFEL, the researchers would be able to analyse the reactions taking place step by step. This would provide extremely detailed images of the inside of fusion experiments, right down to the atomic level.

“With our X-ray laser, we can precisely investigate how fusion-related processes take place,” explains Prof Thomas Feurer, Managing Director and Chairman of the Management Board of European XFEL. “This enables researchers to better understand the complex processes and better predict the conditions under which a fusion reaction begins and how it can be optimised.”

“The European XFEL was built with a future-proof design, enabling it to continuously expand its capabilities to meet emerging scientific challenges,” so Feurer. “This forward-looking approach positions us to contribute within a short time to the next level of fusion research.”

Read more on the European XFEL website

Image: Thomas Feurer giving an outlook on how the world’s largest X-ray laser can significantly support research in the field of fusion energy

Credit: European XFEL

The role of lichens in the evolutionary process of life on Earth

The role of lichens in the evolutionary process of life on Earth

Measurements carried out in several beamlines of Sirius provided strong evidence for the classification of the fossil Spongiophyton nanum as a lichen, suggesting a strong contribution of these organisms to the process of evolution of life in terrestrial environments.

A broad international effort involving several research institutions brought together experts from Brazil, Australia, the United States, the United Kingdom and France to unravel a great enigma in the history of the evolution of life on Earth. The research, which was featured on the cover of the journal Science Advances, demonstrated that the organism Spongiophyton nanum was, in fact, one of the oldest and most widely distributed lichens in Earth’s history. 

The researchers used multiple beamlines from Sirius — CNPEM’s synchrotron light source — during the investigations, employing advanced imaging and characterization techniques using synchrotron light, making it possible to reveal microstructures and chemical signatures preserved in fossils with very high resolution. The work also included experiments at other large international facilities, such as Diamond Light Source and Advanced Photon Source.

Read more on the LNLS website

Image: Artistic reconstruction of Spongiophyton nanum during the Early Devonian period in the polar environments of the Paraná Basin. Image from “The rise of lichens during the colonization of terrestrial environments”

Credit: Science Advances, 2024. Available at: https://www.science.org/doi/10.1126/sciadv.adw7879

Nanoscale under gigapressure

Nanoscale under gigapressure

Research team led by DESY and MAX IV scientists adapts important X-ray analysis method for use with difficult-to-move samples

Sometimes a change of perspective can make a world of difference. A team of scientists from DESY and MAX IV as well as University of Bayreuth has rearranged the method in which one can use an X-ray beam to image a sample without using high-quality lenses. The method, called ptychography, has been widely used at synchrotrons and free-electron lasers to analyse the inner workings of materials quickly enough while avoiding major damage to the sample by the X-rays. The team has turned the standard method of ptychography on its head: Instead of moving the sample around the X-ray beam, they have figured out how to move the X-ray beam itself in a way that does not alter the properties of the X-rays while still accomplishing the effect of ptychographic analysis. Moreover, they have tested the method on a sample that is in and of itself difficult to move – short-lived states of matter under extreme conditions of pressure and temperature. The team has published their findings in the Proceedings of the U.S. National Academy of Sciences (PNAS).

X-ray ptychography has become, in recent years, a standard technique in the toolbox of researchers using X-ray light sources. In a wide variety of fields, including biology and geology, the technique has been critical for imaging the interiors of samples up to atomic-scale detail non-destructively, revealing details on a scale that methods of light and electron microscopy cannot reach. Up to now, ptychography has been accomplished by using extremely precise sample movers that would change the position of the sample relative to the X-ray beam by tiny lengths – sometimes to the nanometre level – creating a grid pattern of sequentially imaged spots that eventually revealed the full image. Called high-resolution phase-contrast imaging, it has provided insights into the nanoscale structures of tiny biological structures, mineral deposits, computer chips and much more.

Read more on the DESY website

Image: Two views of an extreme-states experiment: To the left is an X-ray micrograph of the sample set up, which consisted of a piece of elemental iron surrounded by solid oxygen, itself surrounded by a rhenium gasket within a diamond anvil cell creating intense pressure. To the right is a ptychographic reconstruction of the area of the sample hit by X-rays, shown with a green circle. In that area using their new ptychographic method, the team could reconstruct the oxidation of the iron being melted by the intense pressure. An extreme-states experiment of this kind has not before been imaged in this way.

Credit: Tang Li, DESY

X-Rays Shed Light on Possible New Treatments for TB

X-Rays Shed Light on Possible New Treatments for TB

SCIENTIFIC ACHIEVEMENT

X-ray diffraction data, collected at the Advanced Light Source (ALS) and other Department of Energy light sources, revealed the crystal structure of CMX410, a new compound that targets a key enzyme (Pks13) in the cell membrane of the bacterium responsible for tuberculosis (TB).

SIGNIFICANCE AND IMPACT

CMX410 is a promising new candidate to treat TB, including multidrug-resistant strains.

New treatments needed to tackle an old foe

TB is a deadly infectious disease caused by the bacterium Mycobacterium tuberculosis (Mtb). According to the World Health Organization, an estimated 10.8 million people contracted TB globally in 2023, and 1.25 million died from the disease. While antibiotics are effective for drug-sensitive TB cases, multidrug-resistant Mtb strains can evade common drug therapies.

Drug-resistant cases require a regimen that is often more expensive, toxic, and time-intensive. Patients are required to take six or more medications daily for up to 20 months. New approaches are urgently needed to shorten the course of drug interventions and address widespread multidrug-resistant strains.

A multi-institutional study led by researchers at Texas A&M University and the Calibr-Skaggs Institute for Innovative Medicine sought to find new treatments to address multidrug-resistant TB. The team screened a library of 406 compounds that belong to an active class of molecules [i.e., sulfur fluoride exchange (SuFEx)] to evaluate their efficacy against Mtb. The team developed one promising compound into CMX410, which targets Pks13, an enzyme essential for microbial cell wall biosynthesis.

Read more on the ALS website

Image: A cross-section of the crystal structure for the enzyme Pks13 (the surface colored pink and blue by hydrophobicity) as it interacts with CMX410 (shown as stick-like structure), a new drug candidate for TB

Credit: ALS

Alexandra Pacureanu gets Wellcome Discovery Award in collaboration with the Francis Crick Institute

Alexandra Pacureanu gets Wellcome Discovery Award in collaboration with the Francis Crick Institute

ESRF scientist Alexandra Pacureanu is the recipient of the Wellcome Discovery Award, together with a team at the Francis Crick Institute, to develop X-ray nanoimaging technology to study the mechanisms of information processing in the neural circuits of olfaction.

The grant, worth £3.9 million shared between the two institutions, will support computational research in X-ray nanotomography and coherent X-ray imaging, sample preparation and data analysis developments, and the study of how neural circuits transform sensory information in the mouse olfactory system.   

The team will aim to accurately link neuronal activity with comprehensive cell connectivity, and to uncover how smells are represented in the brain and how the olfactory bulb transforms the sensory signals.

The project has two overarching aims: to develop X-ray nanoimaging technology for connectomics (ESRF leadership) and to apply the technology to uncover the neural circuit mechanisms of odour representation (Francis Crick Institute leadership). Alexandra Pacureanu is leading the ESRF team and Andreas Schaefer is leading the Francis Crick Institute team.

Read more on the ESRF website

Zinc redistribution within the plant root system as a mechanism of adaptation

Zinc redistribution within the plant root system as a mechanism of adaptation

Researchers from the Faculty of Biology, University of Warsaw, grew tobacco plants in a transparent soil system that mimics natural conditions, allowing for a controlled heterogeneous distribution of nutrients. They discovered that when some parts of the roots had access to Zn while others did not, the Zn‑deficient roots did not show the usual Zn deficiency response. This suggested a previously unknown distribution of Zn within the root system, from “Zn‑sufficient” roots to “Zn‑deficient” ones.

To confirm that Zn was redistributed within the plant body, a collaboration with the POLYX beamline team was established to use micro X‑ray fluorescence (μXRF) imaging at the Polish National Synchrotron Radiation Center SOLARIS. This state of the art technique enabled them to visualize Zn distribution at high resolution directly in plant tissues. The analyses revealed that under uneven Zn conditions, the element accumulated evenly in the root system but, surprisingly, there was a preferential accumulation of Zn in the leaf veins, providing new insight into potential Zn distribution routes. The researchers also linked these physiological changes to the activity of key Zn transports, such as NtZIP4B (a Zn importer), NtHMA4a/b (Zn exporters), and NtNAS (a Zn chelator). Interestingly, the position of Zn in the soil—whether in upper or lower layers—affected how strongly genes coding these transporters were expressed and how much Zn reached the leaves.

Read more on the SOLARIS website

Image: The figure shows series of experiments about plants coping with uneven access to zinc in the soil. Using an innovative “transparent soil” system and micro‑XRF at SOLARIS, scientists from the University of Warsaw observed how roots transport zinc from zones with sufficient supply to zinc‑deficient parts of the root system, ensuring stable plant growth. This discovery opens new perspectives for sustainable fertilization and improving crop quality.

Structural surprise in motor protein may point to new strategies for controlling disease

Structural surprise in motor protein may point to new strategies for controlling disease

Motor proteins are tiny “machines” inside cells that use chemical energy to move along molecular tracks and carry out essential processes like chromosome segregation during cell division. When a cell splits to make two new cells (called daughter cells), it carefully shares its instructions (chromosomes) so each new cell knows how to grow and work properly.

A group of motor proteins known as kinesin-8 proteins helps regulate how chromosomes are distributed between daughter cells — a process that, when disrupted, can lead to genomic instability. This instability is a key factor in the development of many diseases, including cancer.

“You can think of kinesins as tiny robots walking along train tracks to help organize and move chromosomes during cell division,” says John Allingham, professor and associate head of research in the Department of Biomedical and Molecular Sciences at Queen’s University.

While most research on kinesins has focused on the “feet” or motor domains — regions that walk along microtubule tracks — Allingham’s group turned their attention to the less-studied “body” or stalk region, which connects the feet and enables them to work together.

Recently, Allingham and his colleagues determined the structure of the stalk region of the fungal kinesin-8 protein Kip3, using Canada’s only synchrotron research facility, the Canadian Light Source (CLS) at the University of Saskatchewan. Their findings, published in Structure, reveal an unexpected architecture that could reshape our understanding of how kinesin-8 proteins assemble and function.

“What we expected to find was a long, coiled structure typical of other kinesin families,” says Allingham. “Instead, we discovered that this region folds into a compact helical bundle — more like a folded camping chair than a long, flexible pole.”

Read more on the CLS website

Image: John Allington (far right) and his research team

Credit: CLS

Phosphorous chains – a 1D material with 1D electronic properties

Phosphorous chains – a 1D material with 1D electronic properties

For the first time, a team at BESSY II has succeeded in demonstrating the one-dimensional electronic properties of a material through a highly refined experimental process. The samples consisted of short chains of phosphorus atoms that self-organise at specific angles on a silver substrate. Through sophisticated analysis, the team was able to disentangle the contributions of these differently aligned chains. This revealed that the electronic properties of each chain are indeed one-dimensional. Calculations predict an exciting phase transition to be expected as soon as these chains are more closely packed. While material consisting of individual chains with longer distances is semiconducting, a very dense chain structure would be metallic.

The material world consists of atoms that combine to manifold different substances. As a rule, atoms bond with each other both in one plane and perpendicular to it. However, some atoms such as carbon can also form graphene, a two dimensional (2D) hexagonal network in which they are connected only in one plane. Also, the element phosphorus can form stable 2D networks. 2D materials are an exciting area of research due to their amazing electronic and optical properties. Theoretical considerations suggest that the electro-optical properties of one-dimensional structures could be even more extraordinary.

Read more on the HZB website

Image: The image taken with the scanning tunnelling microscope shows the phosphorus atoms arranged in short chains on a silver substrate.

Credit: © HZB/Small Structures (2025)/10.1002/sstr.202500458

Disorder begins at the surface of quantum materials

Disorder begins at the surface of quantum materials

A new study reveals that the response of quantum materials to light is more complex than previously assumed. Using ultrafast X-ray pulses at the X-ray free electron laser SwissFEL, researchers found that the surface of a layered manganese oxide reacts differently than the bulk when its orbital order is disturbed. These results challenge the idea that light-induced changes happen uniformly and suggest that the path from order to disorder is shaped by local differences inside the material. 

In certain materials, the electrons arrange themselves in a well-defined, ordered pattern. This internal order can influence everything from how the material conducts electricity to how it responds to magnetic fields. One example is the layered manganese oxide and quantum material La0.5Sr1.5MnO4, in which electrons of manganese atoms arrange themselves into a regular pattern – known as orbital ordering – leading to distinctive electronic and magnetic behaviour.

Researchers are increasingly interested in how light can be used to understand and control the orbital state of these materials. With the right kind of light pulse, it may be possible to switch or reshape their properties at incredible speeds. Therefore, understanding how these materials switch is an important step to making devices.

In many devices, surfaces of and interfaces between materials are known to play a major role in the device properties. Yet until now, it has not been possible to measure how quantum materials change at the surface when switched at high speeds by light. Previous studies have only captured the average response over the whole crystal. 

In this study, a team of scientists led by Aarhus University asked if the average response measured to date accurately captures the processes that occur at the surface, which will be relevant for any device. Remarkably, they found that they did not. 

Read more on the PSI website

Image: Using ultrafast X-rays from SwissFEL, scientists have revealed unexpected light responses in quantum materials

Credit: © AdobeStock

Orbital-Driven Frustrated Electron Hopping in a 2D Lattice

Orbital-Driven Frustrated Electron Hopping in a 2D Lattice

Scientists show that Pd5AlI2 can mimic the electronic behavior of frustrated lattices, creating both flat and Dirac-like bands from a simple square lattice.

This work reveals a new way to achieve the exotic electronic properties of frustrated lattices in simple, stable materials, opening paths to discover and design novel quantum materials.

Electron hopping on periodic lattice structures leads to unusual electronic behavior. In particular, hopping on two-dimensional frustrated lattices such as kagome, dice, and Lieb creates band structures that include both massless, Dirac-like bands and flat ( dispersionless) bands. Since real materials with dice and Lieb lattices are rare and their experimental realization has so far been limited to optical lattices of ultracold atoms, researchers have proposed another approach: using the arrangement of atomic orbitals to reproduce the same frustrated hopping seen in these lattices. This method could expand the range of materials that show frustrated electron hopping, though it has not yet been demonstrated in practice.

Read more on the NSLS-II website

Image: a) Orbital orientation of PdAl layer in Pd5AlI2 forms a checkerboard lattice. (b & c) ARPES Fermi surface map and band structure (blue) along the 

path (inset; red) of the surface BZ. DFT calculated band structure is overlaid on top (dashed grey) with bands linked to the decorated checkerboard model highlighted in cyan and red.

Iron under the ARPES Lens: how spin and magnetism shape the metal’s surface state

Iron under the ARPES Lens: how spin and magnetism shape the metal’s surface state

Researchers from the Jerzy Haber Institute of Catalysis and Surface Chemistry of the Polish Academy of Sciences in Kraków have carried out advanced experiments using angle-resolved photoemission spectroscopy (ARPES). They discovered a new surface state of iron Fe(001), whose symmetry changes depending on the magnetization direction of the layer. The results of their study have been published in the prestigious New Journal of Physics.

The electronic band structure of iron has been investigated for decades, but earlier studies were limited by experimental constraints. Today, with access to high-resolution ARPES facilities, such as the Phelix beamline at the Solaris synchrotron in Kraków, scientists can explore the electronic states of materials with unprecedented precision.

For the first time, the existence of a surface state on Fe(001) was unambiguously demonstrated in the epitaxial Fe/Au(001) system. Moreover, the Kraków team was the first to map this state across the full range of energy and momentum. Previous experiments, for example on Fe(001)/W(001), had been restricted to only a few high-symmetry directions or normal emission. By examining the surface state throughout the Brillouin zone, the researchers identified specific regions where spin–orbit coupling modifies the surface electronic states depending on the magnetization direction.

Read more on the SOLARIS website

Image: Surface state of Fe(001)/Au(001) within entire Brillouin zone and Rashba effect at the zone boudary

How CHESS Helped Reveal Hidden Differences in Our DNA Packaging

How CHESS Helped Reveal Hidden Differences in Our DNA Packaging

How does pressure affect the molecules that organize our DNA?

Using high-pressure X-ray scattering at CHESS, researchers revealed surprising differences between conventional and centromeric nucleosomes. This research sheds light on how our genetic material withstands extreme conditions and stays resilient under stress.

A nucleosome is the basic repeating subunit of chromatin packaged inside the cell’s nucleus. In humans, about six feet of DNA must be packaged into a nucleus with a diameter less than a human hair, and nucleosomes play a key role in that process.

What happens when you squeeze DNA? Can pressure reveal something about how our genetic material is packed, protected, and accessed?

Dr. Kushol Gupta, a structural biologist at the University of Pennsylvania, is pursuing this question and found that turning up the pressure might be one of the best ways to peek into how life organizes itself at the atomic scale.

In a new study published in Chromosome Research, Gupta and collaborators used high-pressure small-angle X-ray scattering (HP-SAXS) at CHESS to explore how different parts of our DNA, particularly nucleosomes, respond to extreme physical stress. 

Experiments were carried out at the NSF and NIH-funded beamline ID7A1 at CHESS using a custom-built hydrostatic pressure cell that was designed by Durgesh Rai and Richard Gillilan and is capable of reaching upwards of 400 megapascals (MPa), i.e., roughly 4,000 times atmospheric pressure, or four times the pressure at the bottom of the Mariana Trench.

Cracking Open the Chromatin Code

Inside each cell, DNA is tightly packed into a material called chromatin, which is made up of DNA and proteins that help organize the genome and control gene activity.

Nucleosomes are the molecular “reels” that organize our DNA, helping package nearly six feet of genetic material into each tiny cell. The canonical nucleosome consists of DNA coiled around a core of histone H3 proteins. But not all nucleosomes are created equal. Some nucleosomes are found at the centromere, the region of a chromosome that plays a key role in cell division, and contain a specialized protein called CENP-A, a variant of histone H3.

“Centromeric nucleosomes are unique in both their composition and their function,” said Gupta. “But understanding what makes them physically different from conventional nucleosomes has been difficult, especially in realistic, solution-based environments.”

Gupta, a crystallographer by training, specializes in using scattering techniques to study biological structures, and wanted to go beyond static snapshots of these particles. He wanted to see how they behave, flex, and respond under pressure.

What they found was quite revealing.

Read more on the CHESS website

Image: A nucleosome is the basic repeating subunit of chromatin packaged inside the cell’s nucleus. In humans, about six feet of DNA must be packaged into a nucleus with a diameter less than a human hair, and nucleosomes play a key role in that process.

Credit: National Human Genome Research Institute

Thyroid gland as one of the important reservoirs of microplastics in the human body

Thyroid gland as one of the important reservoirs of microplastics in the human body

A research team from Lublin under the scientific supervision of Prof. Jolanta Flieger conducted groundbreaking studies on the distribution of micro- and nanoplastics (MP, NP) in the human body, utilising advanced spectroscopic and microscopic techniques at the SOLARIS. Post-mortem tissue samples were analysed, revealing uneven translocation of MP and a particular affinity of the thyroid gland for their accumulation (40.4 MP/g). The findings suggest a potential link between the presence of MP in the thyroid and the increasing incidence of endocrine disorders and head and neck cancers.

The problem of environmental pollution with microplastics (MP) is growing. Currently, it is difficult to avoid contact with products made of polymeric materials [1]. The latest studies confirm the possibility of MP entering the human body through the digestive tract, respiratory tract or skin and translocation to various organs [2]. MP toxicity is associated with the release of hazardous substances into the body based on the “Trojan horse effect” and with the small size of MP [3]. To date, studies on the health effects of MP accumulation are conducted in vitro on cell lines or in vivo on animal models, which do not reflect the conditions of chronic accumulation to which humans are exposed [4]. In turn, population studies on humans examine MP accumulation in selected organs [5]. Less attention is paid to the accumulation of nanoplastics (NP) and natural polymers. The study of MP in tissues also encounters many methodological problems. References: In the study on several tissues collected post mortem from one patient, a new trend of research on the distribution of MPs in the body was initiated in order to identify organs that preferentially accumulate foreign particles. The tissues were digested and filtered. Both the material collected on the filter and the filtrates were examined to find particles of micro- and nano-size (<20 nm). Techniques dedicated to the identification of polymers were used; MALDI-TOF MS, optical microscopy, SEM-EDS and the rarely used O-PTIR microscope technology. O-PTIR infrared measurements with sub-micron spatial resolution confirmed the presence of micro- and nanoparticles and were used to identify the polymers.

Read more on the SOLARIS website

Image: Experiments underway on the CIRI beamline at SOLARIS

Credit: SOLARIS

Cosmic dust could have sparked life on Earth

Cosmic dust could have sparked life on Earth

New research has found that amino acids, the building blocks of life, may have travelled to Earth on interstellar dust grains, potentially helping kickstart biology as we know it.

In a recent study published in the Monthly Notices of the Royal Astronomical Society, Stephen Thompson, I11’s principal beamline scientist, and Sarah Day, I11 beamline scientist, explored how amino acids like glycine and alanine could survive the harsh conditions of space and make their way to Earth embedded in cosmic dust.  

Amino acids are the molecular foundations of proteins and enzymes, which drive every biological process in living organisms. While scientists have long debated whether these molecules formed on Earth or arrived from space, this new study offers compelling evidence that cosmic dust may have played a crucial role in delivering them. The team synthesised tiny particles of amorphous magnesium silicate, a major component of cosmic dust, and deposited amino acids – glycine, alanine, glutamic acid, and aspartic acid – onto them. Using infrared spectroscopy and synchrotron X-ray powder diffraction, they then examined how these molecules behaved when the silicate particles were heated, simulating the warming that occurs as dust grains travelled through the early solar system. 

They found that only glycine and alanine successfully adhered to the silicate particles. These amino acids formed crystalline structures and in the case of alanine remained stable at temperatures well above its melting point. The study also found that the two mirror-image forms of alanine (L- and D-alanine) behaved differently under heating, with L-alanine showing more reactivity than its D-form. Glycine, on the other hand, was lost from the silicate at temperatures lower than its pure decomposition point, indicating that it detached from the grain surface rather than breaking down.  

The team prepared two batches of amorphous silicate and subjected one batch to heat treatment prior to depositing the amino acids. This was to remove hydrogen atoms from the silicate surface, producing two silicates with differing surface properties, which were also found to influence the temperatures at which the amino acids were lost.    

These subtle differences may have had profound implications for the types of molecules that seeded life on Earth. 

Read more on the Diamond website

Image: Stephen Thompson, I11’s principal beamline scientist, and Sarah Day, I11 beamline scientist, working on their cosmic dust research

Credit: Diamond Light Source   

Novel antibiotic overcomes drug-resistant bacteria

Novel antibiotic overcomes drug-resistant bacteria

Antibiotics fight bacteria in different ways. Some kill bacteria by destroying their cell walls. Others bind to bacteria’s ribosomes, halting their ability to produce proteins. Over time, bacteria evolved defense mechanisms against these threats. One mechanism is a chemical modification of the ribosome that resembles a push pin on a chair, which interferes with the antibiotic’s ability to bind to its binding site. 

Recently a team of scientists synthesized an antibiotic that can engage such modified ribosomes by pushing the “push pin” out of the way, as shown by an X-ray crystallography structural study conducted at the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science user facility at DOE’s Argonne National Laboratory. Dubbed BT-33, the novel therapeutic is active against the deadliest and most antibiotic-resistant bacteria, known collectively as ESKAPE pathogens, as well as other gram-negative bacteria, in mice. Designed to attain its binding shape prior to binding, the antibiotic can serve as a powerful model for future antibiotics.

BT-33 belongs to a class of antibiotics called lincosamides, which bind to the ribosome and halt protein production. The primary lincosamide, clindamycin, was so widely used that bacteria developed numerous defenses against them, including acquiring new genes in healthcare settings that rendered lincosamides ineffective. Nevertheless, no new lincosamide has been approved since 1970.

The scientists behind BT-33 set out to fill that void. BT-33 is the third iteration of a molecule the team reported in Nature in 2021, called iboxamycin. It was followed by cresomycin, reported in Science, in 2024. Each iteration involved structural changes to different parts of the molecule that overall improved the molecule’s ability to bind to the ribosome. Each structural change was made possible by inventing new chemical combinations that had never existed before.

Iboxamycin, the first in the series, added a new chemical group at the top end of the clindamycin molecule. That addition alone was enough to enable iboxamycin to accomplish what clindamycin could not: It overcame the defense mechanism produced by the CFR gene.

The CFR gene, first identified in 2000, encodes a protein that installed a modification on the ribosome; much like putting a push pin on a chair, the modification makes it too uncomfortable for the antibiotic to bind. The addition of the chemical group in iboxamycin that is absent from clindamycin resulted in such a strong engagement of the drug with its “chair” that the push pin got moved out of the way.

Cresomycin, the second molecule in the series, was based on a revolutionary design hypothesis called preorganization: The scientists aimed to create a molecule that adopted its shape before binding to its target. To that end, the team added a unique ten-atom ring to the bottom, giving the molecule additional rigidity. Using NMR spectroscopy, they confirmed that the molecule in solution looked exactly the same as if it were already bound to the ribosome, confirming that their design hypothesis worked.

Cresomycin proved so powerful that it overcame the resistance of the six most resistant and dangerous bacteria, collectively given the acronym ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp).

Read more on APS website

Image: Structure of BT-33 (yellow) bound to the catalytic center of the bacterial ribosome, showing the van der Waals contact of the fluorine atom (green) of BT-33 with the nucleotides of the ribosomal RNA (cyan).