Plate Tectonics in the Archean: Observation versus Interpretation

Peer-Reviewed Publication

SCIENCE CHINA PRESS

 

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ANCIENT PLATE TECTONICS IN THE ARCHEAN PERIOD DIFFERS FROM MODERN PLATE TECTONICS IN THE PHANEROZOIC PERIOD BECAUSE OF THE HIGHER MANTLE TEMPERATURES INSIDE THE EARLY EARTH, THE THICKER BASALTIC CRUST, AND THE NON-DEPLETION OF MELT-MOBILE INCOMPATIBLE TRACE ELEMENTS IN THE MANTLE.

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CREDIT: ©SCIENCE CHINA PRESS

The plate tectonics theory established in the 20th century has been successful in interpreting many geological phenomena, processes and events that have occurred in the Phanerozoic. However, the theory has often struggled to provide a coherent framework in interpreting geological records not only in the continental interior but also in the Precambrian period. In the traditional plate tectonics theory dealing with the relationship between plate tectonics and continental geology, continental interior tectonics was often separated from continental margin tectonics in the inheritance and development of their structure and composition. This separation led to the illusion as if the plate tectonics theory is not applicable to Precambrian geology, particularly in interpreting the fundamental geological characteristics of Archean cratons.

This integrated study is presented by Prof. Yong-Fei Zheng at University of Science and Technology of China. It focuses on available observations from Archean geology and inspects their interpretations against the following three characteristic features in the Archean Earth: (1) convective mantle temperatures were as high as 1500-1700°C, (2) newly formed basaltic oceanic crust was as thick as 30-40 km, and (3) the asthenosphere had a composition similar to the primitive mantle rather than the depleted mantle at present. On this basis, the author has successfully applied the plate tectonics theory in the 21st century to interpretation of major geological phenomena on Archean cratons (Fig. 1). The results eliminate the illusion that the Archean continental crust did not originate from a regime of plate tectonics.

Through upgrading the plate tectonics theory from the traditional kinematic model in the 20th century to a holistic kinematic-dynamic model in the 21st century and systematically examining the vertical transport of matter and energy at plate margins, it is evident that plate tectonics can interpret the common geological characteristics of Archean cratons, such as lithological associations, structural patterns and metamorphic evolution. By deciphering the structure and composition of convergent plate margins as well as their dynamics, the formation and evolution of continental crust since the Archean can be divided into ancient plate tectonics in the Precambrian and modern plate tectonics in the Phanerozoic.

This approach provides a new perspective on and deep insights into the evolution of early Earth and the origin of continental crust. It leads to the development of alternative tectonic models, envisaging vertical movements in the realm of stagnant lid tectonics, including not only bottom-up processes such as mantle plumes and heat pipes but also top-down processes such as lithospheric foundering and subduction (Fig. 2). In fact, these vertical processes were not unique to the Archean but persisted into the Phanerozoic. They result from mantle poloidal convection at different depths, not specific to any particular period in Earth’s history.

Furthermore, Archean tonalite-trondhjemite-granodiorite (TTG) rocks would result from partial melting of the over-thick basaltic oceanic crust at convergent plate margins. The structural patterns of gneissic domes and greenstone keels would result from the buoyancy-driven emplacement of TTG magmas and its interaction with the basaltic crust at fossil convergent margins, and komatiites in greenstone belts would be the product of mantle plume activity in the regime of ancient plate tectonics. The widespread distribution of high-grade metamorphic rocks in a planar fashion, rather than in zones, is ascrible to separation of the gneissic domes from the greenstone belts.

In addition, volcanic associations in the Archean are short of calc-alkaline andesites, suggests the shortage of sediment accretionary wedges derived from weathering of granitic continental crust above oceanic subduction zones. Penrose-type ophiolites are absent in Archean igneous associations, which can be ascribed to the formation of basalt accretionary wedges during the subduction initiation of microplates when only the upper volcanic rocks of mid-ocean ridges were offscrapped from the incipiently subducting slab. The absence of blueschist and eclogite as well as classic paired metamorphic belts suggests that convergent plate margins were over-thickened through either warm subduction or hard collision of the thick oceanic crust at moderate geothermal gradients. Therefore, only by correctly recognizing and understanding the nature of Archean cartons can plate tectonics reasonably interpret their fundamental geological characteristics.

As soon as the upgraded version of plate tectonic theory in the 21st century is integrated with the three characteristic features of Archean Earth, it can make a revolutionary progress in resolving the previous challenges to interpretations of the Archean continental geology. Therefore, this article provide robust arguments for deciphering of the inheritance and development relationships between ancient and modern plate tectonics regimes. The results not only contribute to the origin and evolution of continental crust on early Earth but also shed light on the geodynamic mechanism of how early Earth evolved from stagnant lid tectonics to mobile lid tectonics.

 

See the article:

Zheng Y-F. 2024. Plate tectonics in the Archean: Observations versus interpretations. Science China Earth Sciences, 67(1): 1-30;

https://doi.org/10.1007/s11430-023-1210-5

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JOURNAL

Science China Earth Sciences

DOI

10.1007/s11430-023-1210-5 

 

Scientists engineer plant microbiome for the first time to protect crops against disease

Breakthrough could dramatically cut the use of pesticides and unlock other opportunities to bolster plant health

Peer-Reviewed Publication

UNIVERSITY OF SOUTHAMPTON

Scientists have engineered the microbiome of plants for the first time, boosting the prevalence of ‘good’ bacteria that protect the plant from disease.

The findings published in Nature Communications by researchers from the University of Southampton, China and Austria, could substantially reduce the need for environmentally destructive pesticides.

There is growing public awareness about the significance of our microbiome – the myriad of microorganisms that live in and around our bodies, most notably in our guts. Our gut microbiomes influence our metabolism, our likelihood of getting ill, our immune system, and even our mood.

Plants too host a huge variety of bacteria, fungi, viruses, and other microorganisms that live in their roots, stems, and leaves. For the past decade, scientists have been intensively researching plant microbiomes to understand how they affect a plant’s health and its vulnerability to disease.

“For the first time, we’ve been able to change the makeup of a plant’s microbiome in a targeted way, boosting the numbers of beneficial bacteria that can protect the plant from other, harmful bacteria,” says Dr Tomislav Cernava, co-author of the paper and Associate Professor in Plant-Microbe Interactions at the University of Southampton.

“This breakthrough could reduce reliance on pesticides, which are harmful to the environment. We’ve achieved this in rice crops, but the framework we’ve created could be applied to other plants and unlock other opportunities to improve their microbiome. For example, microbes that increase nutrient provision to crops could reduce the need for synthetic fertilisers.”

The international research team discovered that one specific gene found in the lignin biosynthesis cluster of the rice plant is involved in shaping its microbiome. Lignin is a complex polymer found in the cell walls of plants – the biomass of some plant species consists of more than 30 per cent lignin.

First, the researchers observed that when this gene was deactivated, there was a decrease in the population of certain beneficial bacteria, confirming its importance in the makeup of the microbiome community.

The researchers then did the opposite, over-expressing the gene so it produced more of one specific type of metabolite – a small molecule produced by the host plant during its metabolic processes. This increased the proportion of beneficial bacteria in the plant microbiome.

When these engineered plants were exposed to Xanthomonas oryzae – a pathogen that causes bacterial blight in rice crops, they were substantially more resistant to it than wild-type rice.

Bacterial blight is common in Asia and can lead to substantial loss of rice yields. It’s usually controlled by deploying polluting pesticides, so producing a crop with a protective microbiome could help bolster food security and help the environment.

The research team are now exploring how they can influence the presence of other beneficial microbes to unlock various plant health benefits.

Microbiome homeostasis on rice leaves is regulated by a precursor molecule of lignin biosynthesis is published in Nature Communications and is available online.

Contact

Steve Williams, Media Relations, University of Southampton press@soton.ac.uk or 023 8059 3212.

Notes for editors

1. Microbiome homeostasis on rice leaves is regulated by a precursor molecule of lignin biosynthesis is published in Nature Communications and is available here: https://www.nature.com/articles/s41467-023-44335-3
2. For Interviews with Dr Tomislav Cernava please contact Steve Williams, Media Relations, University of Southampton press@soton.ac.uk or 023 8059 3212.
3. Image: Rice paddies in China. Credit: Houxiang Kang

Additional information

The University of Southampton drives original thinking, turns knowledge into action and impact, and creates solutions to the world’s challenges. We are among the top 100 institutions globally (QS World University Rankings 2023). Our academics are leaders in their fields, forging links with high-profile international businesses and organisations, and inspiring a 22,000-strong community of exceptional students, from over 135 countries worldwide. Through our high-quality education, the University helps students on a journey of discovery to realise their potential and join our global network of over 200,000 alumni. www.southampton.ac.uk

www.southampton.ac.uk/news/contact-press-team.page

Follow us on X: https://twitter.com/UoSMedi

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JOURNAL

Nature Communications

DOI

10.1038/s41467-023-44335-3 

ARTICLE TITLE

Microbiome homeostasis on rice leaves is regulated by a precursor molecule of lignin biosynthesis

ARTICLE PUBLICATION DATE

2-Jan-2024

 

Groundwater is vital to the health of our planet: A call for greater protection

An international study classifies groundwater as a keystone ecosystem and proposes ways to improve its protection to preserve biodiversity and mitigate climate change

Peer-Reviewed Publication

JOHANNES GUTENBERG UNIVERSITAET MAINZ

 

IMAGE: 

EXAMPLE OF A KARST SYSTEM IN THE PLITVICE LAKES NATIONAL PARK IN CROATIA: KARST GROUNDWATER AQUIFERS ARE MAJOR AND IMPORTANT HABITATS.

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CREDIT: PHOTO/©: ROBERT REINECKE

Water is the basis of all life on Earth. However, the crucial role of groundwater in sustaining both humanity and biodiversity over the long term is frequently neglected. In a recently published paper, an international team of researchers has outlined, for the first time, why groundwater should be treated as a keystone ecosystem. "Groundwater is not only in itself a major ecosystem but is also of critical relevance to ecosystems on the Earth's surface," emphasized Professor Robert Reinecke of Johannes Gutenberg University Mainz (JGU), a specialist in Earth system modeling. He made major contributions to the paper, which outlines concepts for improved groundwater protection to reduce the loss of biodiversity and to compensate for the effects of climate change.

About half of the world's urban population depends on groundwater for their supply of drinking water

Groundwater is the largest unfrozen reserve of freshwater on Earth. It supplies the drinking water needs of almost 50 percent of the world's urban population. Countries such as Denmark, for example, obtain their drinking water entirely from groundwater. "Throughout the world, some 1,000 cubic kilometers of water are pumped to the Earth's surface every year. Sadly, we consume far more than what is naturally replenished," said Reinecke. About a third of the largest groundwater catchment areas are at risk of depletion, indicating an ongoing decline in groundwater levels.

The supply of drinking water for humans clearly is one aspect of the problem. Another aspect is the dependence of ecosystems on groundwater, which has been repeatedly overlooked in global biodiversity conservation agendas so far. Roughly 52 percent and thus more than half of all surface areas have a medium-to-high interaction with groundwater. This figure increases to 75 percent when excluding deserts and high mountains, regions where groundwater is scarce or the water table can be very deep. "Interaction in this context means that water from rivers and lakes enters the groundwater while groundwater, in its turn, rises to the surface and feeds wetlands, rivers, and other kinds of surface water areas." Reinecke adds that groundwater is also a valuable habitat for thousands of different subterranean creatures, including cavefish, blind eels, and transparent shrimp.

International team of researchers proposes a science-policy integrated groundwater conservation agenda

As the researchers stated in their report published in Global Change Biology: "Disregarding the importance of groundwater as an ecosystem ignores its critical role in preserving surface biomes. To foster timely global conservation of groundwater, we propose elevating the concept of keystone species into the realm of ecosystems, claiming groundwater as a keystone ecosystem that influences the integrity of many dependent ecosystems." 51 researchers from various countries – from Australia to India and the Philippines, from Italy and Finland to Brazil and Canada – participated in the study.

With regard to German law, Robert Reinecke points out that groundwater is not yet defined as a habitat under the German Federal Nature Conservation Act but only as a resource and is thus not subject to the corresponding protection. "We need to change this very urgently," emphasized Reinecke, citing the statistics collected by the German Environment Agency (UBA) that show that the quality of approximately 32 percent of all groundwater bodies in Germany is poor because of chemical contamination. The main causes of this are nitrate levels and pollution by pesticides.

The researchers propose eight key themes to design a science-policy integrated groundwater conservation agenda. As given ecosystems above and below the ground intersect at many levels, it is essential to consider groundwater as a vital element determining the health of our planet – to mitigate the loss of biodiversity and provide a counterbalance to climate change. "Water is indispensable to life on Earth. If we don't pay sufficient attention to the ecological integrity of the freshwater resources of our planet, we not only put the sustainability of whole ecosystems at risk but we also jeopardize our own way of life," concluded Reinecke.

 

Related links:
https://earthsysmod.uni-mainz.de/ – Earth System Modeling group at the JGU Institute of Geography

Read more:
https://press.uni-mainz.de/second-report-on-the-status-of-global-water-resources-published/ – press release "Second report on the status of global water resources published" (12 Oct. 2023)

 

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JOURNAL

Global Change Biology

DOI

10.1111/gcb.17066 

ARTICLE TITLE

Groundwater is a hidden global keystone ecosystem

 

Researchers rely on the earth's magnetic field to verify an event mentioned in the Old Testament

New technology interprets archaeological findings from Biblical times

Peer-Reviewed Publication

TEL-AVIV UNIVERSITY

 

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ONE OF THE STUDIED BURNT MUDBRICKS.

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CREDIT: DR. YOAV VAKNIN

• The new study scientifically corroborates an event described in the Second Book of Kings – the conquest of the Philistine city of Gath by Hazael King of Aram.
• The method is based on measuring the magnetic field recorded in burnt bricks. The researchers: "Our findings are important for determining the intensity of the fire and the scope of destruction in Gath – the largest and most powerful city in the land at the time, and also for understanding construction practices in the region."

A breakthrough achieved by researchers from four Israeli universities – Tel Aviv University, The Hebrew University of Jerusalem, Bar-Ilan University and Ariel University– will enable archaeologists to identify burnt materials discovered in excavations and estimate their firing temperatures. Applying their method to findings from ancient Gath (Tell es-Safi in central Israel), the researchers validated the Biblical account: "About this time Hazael King of Aram went up and attacked Gath and captured it. Then he turned to attack Jerusalem" (2 Kings 12, 18). They explain that unlike previous methods, the new technique can determine whether a certain item (such as a mud brick) underwent a firing event even at relatively low temperatures, from 200°C and up. This information can be crucial for correctly interpreting the findings. 

 

The multidisciplinary study was led by Dr. Yoav Vaknin from the Sonia & Marco Nadler Institute of Archaeology, Entin Faculty of Humanities, at Tel Aviv University, and the Palaeomagnetic Laboratory at The Hebrew University. Other contributors included: Prof. Ron Shaar from the Institute of Earth Sciences at The Hebrew University, Prof. Erez Ben-Yosef and Prof. Oded Lipschits from the Sonia & Marco Nadler Institute of Archaeology at Tel Aviv University, Prof. Aren Maeir from the Martin (Szusz) Department of Land of Israel Studies and Archaeology at Bar-Ilan University and Dr. Adi Eliyahu Behar from the Department of Land of Israel Studies and Archaeology and the Department of Chemical Sciences at Ariel University. The paper has been published in the scientific journal PLOS ONE.

 

Prof. Lipschits: "Throughout the Bronze and Iron Ages the main building material in most parts of the Land of Israel was mud bricks. This cheap and readily available material was used to build walls in most buildings, sometimes on top of stone foundations. That's why it's so important to understand the technology used in making these bricks."

 

Dr. Vaknin adds: "During the same era dwellers of other lands, such as Mesopotamia where stone was hard to come by, would fire mud bricks in kilns to increase their strength and durability. This technique is mentioned in the story of the Tower of Babel in the Book of Genesis: "They said one to another, Come, let us make bricks and fire them thoroughly. So they used brick for stone"(Genesis 11, 3). Most researchers, however, believe that this technology did not reach the Land of Israel until much later, with the Roman conquest. Until that time the inhabitants used sun-dried mud bricks. Thus, when bricks are found in an archaeological excavation, several questions must be asked: First, have the bricks been fired, and if so, were they fired in a kiln prior to construction or in situ, in a destructive conflagration event? Our method can provide conclusive answers."

 

The new method relies on measuring the magnetic field recorded and 'locked' in the brick as it burned and cooled down. Dr. Vaknin: "The clay from which the bricks were made contains millions of ferromagnetic particles – minerals with magnetic properties that behave like so many tiny 'compasses' or magnets. In a sun-dried mud brick the orientation of these magnets is almost random, so that they cancel out one another. Therefore, the overall magnetic signal of the brick is weak and not uniform. Heating to 200°C or more, as happens in a fire, releases the magnetic signals of these magnetic particles and, statistically, they tend to align with the earth's magnetic field at that specific time and place. When the brick cools down, these magnetic signals remain locked in their new position and the brick attains a strong and uniformly oriented magnetic field, which can be measured with a magnetometer. This is a clear indication that the brick has, in fact, been fired.

 

In the second stage of the procedure, the researchers gradually 'erase' the brick's magnetic field, using a process called thermal demagnetization. This involves heating the brick in a special oven in a palaeomagnetic laboratory that neutralizes the earth's magnetic field. The heat releases the magnetic signals, which once again arrange themselves randomly, canceling each other out, and the total magnetic signal becomes weak and loses its orientation.

 

Dr. Vaknin: "We conduct the process gradually. At first, we heat the sample to a temperature of 100°C, which releases the signals of only a small percentage of the magnetic minerals. We then cool it down and measure the remaining magnetic signal. We then repeat the procedure at temperatures of 150°C, 200°C, and so on, proceeding in small steps, up to 700°C. In this way the brick's magnetic field is gradually erased. The temperature at which the signal of each mineral is 'unlocked' is approximately the same as the temperature at which it was initially 'locked', and ultimately, the temperature at which the magnetic field is fully erased was reached during the original fire."

 

The researchers tested the technique in the laboratory: they fired mud bricks under controlled conditions of temperature and magnetic field, measured each brick's acquired magnetic field, then gradually erased it. They found that the bricks were completely demagnetized at the temperature at which they had been burned – proving that the method works.    

 

Dr. Vaknin: "Our approach enables identifying burning which occurred at much lower temperatures than any other method. Most techniques used for identifying burnt bricks are based on actual changes in the minerals, which usually occur at temperatures higher than 500°C – when some minerals are converted into others."

 

Dr. Eliyahu Behar: "One of the common methods for identifying mineralogical changes in clay (the main component of mud bricks) due to exposure to high temperatures is based on changes in the absorption of infrared radiation by the various minerals. In this study we used this method as an additional tool to verify the results of the magnetic method." Dr. Vaknin: "Our method is much more sensitive than others because it targets changes in the intensity and orientation of the magnetic signal, which occur at much lower temperatures. We can begin to detect changes in the magnetic signal at temperatures as low as 100°C, and from 200°C and up the findings are conclusive."

 

In addition, the method can determine the orientation in which the bricks cooled down. Dr. Vaknin: "When a brick is fired in a kiln before construction, it records the direction of the earth's magnetic field at that specific time and place. In Israel this means north and downward. But when builders take bricks from a kiln and build a wall, they lay them in random orientations, thus randomizing the recorded signals. On the other hand, when a wall is burned in-situ, as might happen when it is destroyed by an enemy, the magnetic fields of all bricks are locked in the same orientation."

 

After proving the method's validity, the researchers applied it to a specific archaeological dispute: was a specific brick structure discovered at Tell es-Safi - identified as the Philistine city of Gath, home of Goliath - built of pre-fired bricks or burned on location? The prevalent hypothesis, based on the Old Testament, historical sources, and Carbon-14 dating attributes the destruction of the structure to the devastation of Gath by Hazael, King of Aram Damascus, around 830 BCE. However, a previous paper by researchers including Prof. Maeir, head of the Tell es-Safi excavations, proposed that the building had not burned down, but rather collapsed over decades, and that the fired bricks found in the structure had been fired in a kiln prior to construction. If this hypothesis were correct, this would be the earliest instance of brick-firing technology discovered in the Land of Israel. 

 

To settle the dispute, the current research team applied the new method to samples from the wall at Tell es-Safi and the collapsed debris found beside it. The findings were conclusive: the magnetic fields of all bricks and collapsed debris displayed the same orientation – north and downwards. Dr. Vaknin: "Our findings signify that the bricks burned and cooled down in-situ, right where they were found, namely in a conflagration in the structure itself, which collapsed within a few hours. Had the bricks been fired in a kiln and then laid in the wall, their magnetic orientations would have been random. Moreover, had the structure collapsed over time, not in a single fire event, the collapsed debris would have displayed random magnetic orientations. We believe that the main reason for our colleagues' mistaken interpretation was their inability to identify burning at temperatures below 500°C. Since heat rises, materials at the bottom of the building burned at relatively low temperatures, below 400°C, and consequently the former study did not identify them as burnt – leading to the conclusion that the building had not been destroyed by fire. At the same time, bricks in upper parts of the wall, where temperatures were much higher, underwent mineralogical changes and were therefore identified as burnt - leading the researchers to conclude that they had been fired in a kiln prior to construction. Our method allowed us to determine that all bricks in both the wall and debris had burned during the conflagration: those at the bottom burned at relatively low temperatures, and those that were found in higher layers or had fallen from the top –at temperatures higher than 600°C."

 

Prof. Maeir: "Our findings are very important for deciphering the intensity of the fire and scope of destruction at Gath, the largest and most powerful city in the Land of Israel at the time, as well as understanding the building methods prevailing in that era. It's important to review conclusions from previous studies, and sometimes even refute former interpretations, even if they came from your own school." Prof. Ben-Yosef adds: "Beyond their historical and archaeological significance, ancient building methods also had substantial ecological implications. The brick firing technology requires vast quantities of combustive materials, and in ancient times this might have led to vast deforestation and even loss of tree species in the area. For example, certain species of trees and shrubs exploited by the ancient copper industry in the Timna Valley have not recovered to this day and the industry itself ultimately collapsed once it had used up its natural fuels. Our findings indicate that the brick firing technology was probably not practiced in the Land of Israel in the times of the Kings of Judah and Israel."

  

The studied area during excavation.

CREDIT

Tell es-Safi/Gath Archaeological Project, Bar-Ilan University

 

Dr. Yoav Vaknin

CREDIT

Tel Aviv University

Link to the article:

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0289424

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DOI

10.1371/journal.pone.0289424 

 

Scientists solve mystery of how predatory bacteria recognizes prey

Peer-Reviewed Publication

UNIVERSITY OF BIRMINGHAM

A decades-old mystery of how natural antimicrobial predatory bacteria are able to recognize and kill other bacteria may have been solved, according to new research.

In a study published today (4th January) in Nature Microbiology, researchers from the University of Birmingham and the University of Nottingham have discovered how natural antimicrobial predatory bacteria, called Bdellovibrio bacterivorous, produce fibre-like proteins on their surface to ensnare prey.

This discovery may enable scientists to use these predators to target and kill problematic bacteria that cause issues in healthcare, food spoilage and the environment.

The research was funded by the Wellcome Trust Investigator in Science Award (209437/Z/17/Z).

Professor of Structural Biology at the University of Birmingham, Andrew Lovering said: “Since the 1960s Bdellovibrio bacterivorous has been known to hunt and kill other bacteria by entering the target cells and eating them from the inside before later bursting out. The question that had stumped scientists was ‘how do these cells make a firm attachment when we know how varied their bacterial targets are?’”

Professor Lovering and Professor Liz Sockett, from the School of Life Sciences at the University of Nottingham, have been collaborating in this field for almost 15 years. The breakthrough came when Sam Greenwood an undergraduate student, and Asmaa Al-Bayati, a PhD student in the Sockett lab, discovered that the Bdellovibrio predators lay down a sturdy vesicle (a “pinched-off” part of the predator cell envelope) when invading their prey.  

Professor Liz Sockett explained: “The vesicle creates a kind of airlock or keyhole allowing Bdellovibrio entry into the prey cell. We were then able to isolate this vesicle from the dead prey, which is a first in this field. The vesicle was analysed to reveal the tools used during the preceding event of predator/prey contact. We thought of it as a bit like a locksmith leaving the pick, or key, as evidence, in the keyhole.

“By looking at the vesicle contents, we discovered that because Bdellovibrio doesn’t know which bacteria it will meet, it deploys a range of similar prey recognition molecules on its surface, creating lots of different ‘keys’ to ‘unlock’ lots of different types of prey.”

The researchers then undertook an individual analysis of the molecules, demonstrating that they form long fibres, approximately ten times longer than common globular proteins. This allows them to operate at a distance and “feel” for prey in the vicinity.

In total, the labs counted 21 different fibres. Researchers Dr Simon Caulton, Dr Carey Lambert and Dr Jess Tyson worked on how they operated both at the cellular and molecular level. They were supported by fibre gene-engineering by Paul Radford and Rob Till. The team then began to attempt linking a particular fibre to a particular prey-surface molecule. Finding out which fibre matches which prey, could enable an engineering approach which sees bespoke predators targeting different types of bacteria.

Professor Lovering continued: “Because the predator strain we were looking at comes from the soil it has a wide killing range, making this identification of these fibre and prey pairs very difficult. However, on the fifth attempt to find the partners we discovered a chemical signature on the outside of prey bacteria that was a tight fit to the fibre tip. This is the first time a feature of Bdellovibrio has been matched to prey selection.”

Scientists in this field will now be able to use these discoveries to ask which fibre set is used by the different predators they study and potentially attribute these to specific prey. Improving understanding of these predator bacteria could enable their usage as antibiotics, to kill bacteria that degrade food, or ones which are harmful to the environment.

Professor Lovering concluded: “We know that these bacteria can be helpful, and by fully understanding how they operate and find their prey, it opens up a world of new discoveries and possibilities.”

ENDS

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JOURNAL

Nature Microbiology

DOI

10.1038/s41564-023-01552-2 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Bdellovibrio bacteriovorus uses chimeric fibre proteins to recognize and invade a broad range of bacterial hosts

ARTICLE PUBLICATION DATE

4-Jan-2024

 

Conflict in full swing: Forest bats avoid large areas around fast-moving wind turbines

Peer-Reviewed Publication

LEIBNIZ INSTITUTE FOR ZOO AND WILDLIFE RESEARCH (IZW)

 

IMAGE: 

GREATER MOUSE-EARED BAT (MYOTIS MYOTIS)

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CREDIT: PHOTO BY KARIN SCHNEEBERGER/LEIBNIZ-IZW

Not only do many bats die at wind turbines, the turbines also displace some species from their habitats over large areas. When the turbines are in operation at relatively high wind speeds, the activity of bat species that hunt in structurally dense habitats such as forests drops by almost 80 per cent within a radius of 80 to 450 metres around the turbine. This is the result of a scientific investigation led by scientists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) and the Philipps-Universität Marburg, which is published in the journal Global Ecology and Conservation. The team suggests that one of the causes of this avoidance behaviour is the noise emission of the turbine rotors, which increases with increasing wind speed.

More and more wind turbines are being installed worldwide in order to meet the need for an increase in the proportion of renewable energy sources in response to the goals of national climate strategies. In Germany, around 30,000 onshore wind turbines are currently in operation, and as suitable locations become increasingly scarce, the search for sites now also extends to additional, potentially less suitable locations. These include forests as potential sites – and with these diverse and sensitive habitats. Many European bat species, such as the greater mouse-eared bat (Myotis myotis), live and forage in forests and are therefore potentially affected by the expansion of wind energy in or near forests. A new scientific investigation by a team led by Christian Voigt from the Leibniz-IZW and Nina Farwig from the Philipps-Universität Marburg shows that this not only poses the direct risk of colliding with the wind turbine rotors, but also has indirect negative effects on these species. The scientists found that the forest specialists among the bats avoid wind turbines over a distance of several hundred metres once the turbines are in operation and the wind speeds are relatively high.

“We investigated the activity of different bat species in different wind conditions and during the operation of wind turbines in forests in the German federal state of Hessen,” says Julia Ellerbrok, a former doctoral student in the project and now a postdoctoral research fellow in the Department of Biology at the Philipps-Universität Marburg. “We found that the activity of bats, which usually forage in narrow, structurally dense vegetation of forests, decreases by 77 % on average within a radius of 80 to 450 metres around the wind turbines with increasing wind speed when the turbines are in operation. In contrast, bat activity was unaffected by wind speed when the turbines were switched off.” The team therefore concludes that factors directly related to the operation of the turbines at relatively high wind speeds must be responsible for such avoidance behaviour.

“The rotor movements of wind turbines not only generate so-called wake turbulences, but also substantial noise. Both factors can affect bats over several hundred metres”, says Christian Voigt, head of the Department of Evolutionary Ecology at the Leibniz-IZW. “Forest bats that hunt under the canopy presumably do not come into contact with the wake vortices. Rather, they could be affected by the noise emissions of the turbines, even if the frequency range of the noise is far below those of the echolocation calls. If bats actively avoid noise emissions from wind turbines, they lose valuable habitat on a large scale.”

Wind turbines in forests pose several problems for bats, the scientists sum up: Not only do forest bats lose valuable habitats – both through clearing during the construction of the wind turbines and by avoiding the wind turbines once they are in operation. Bats that hunt above the treetops can also be potentially killed by the rotating blades. In order to minimise the potential long-term ecological impact of wind turbines on bat populations in forested areas, wind turbines should only be erected in structurally poor forest plantations where only few bats live. Future research should focus on investigating the effects of noise emissions from wind turbines on bats in more detail, the team concludes in the paper.

 

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JOURNAL

Global Ecology and Conservation

DOI

10.1016/j.gecco.2023.e02782 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Activity of forest bats declines with increasing wind speed when wind turbines are operating

 

Unlocking the secrets of disease-causing fungus Aspergillus fumigatus

Ground-breaking research published in Nature Communications offers insights into deadly fungal disease, writes Dr Özgür Bayram of Maynooth University's Biology Department

Peer-Reviewed Publication

MAYNOOTH UNIVERSITY

An international team of researchers, led by Professor Gustavo Goldman of the University of São Paulo and Maynooth University’s Dr Özgür Bayram, has unveiled ground-breaking findings on Aspergillus fumigatus, which can cause deadly disease in humans.
 
The saprophytic fungus is notorious for causing a spectrum of human diseases, known collectively as aspergillosis, in individuals undergoing cancer treatments and organ transplants as well as those with cystic fibrosis and chronic obstructive pulmonary disease.
 
The human pathogen is at the forefront of the World Health Organization's priority list, ranking as the most significant among health-threatening fungal pathogens.
 
The study, published in the latest issue of the prestigious journal Nature Communications, sheds light on the intricate mechanisms underlying the virulence of Aspergillus fumigatus, specifically focusing on the crucial role of mycotoxin gliotoxin production. Gliotoxin helps this fungus to kill human immune cells including macrophages and neutrophiles.
 
Aspergillus fumigatus relies on a delicate balance in regulating gliotoxin production to prevent excess and mitigate toxicity to the fungus itself. The research team, led by Prof Goldman and Dr Bayram, identified the pivotal roles played by GliT oxidoreductase and GtmA methyltransferase in the self-protection mechanism of gliotoxin. Both enzymes were observed to be localised in the cytoplasm and vacuoles during gliotoxin production.
 
In a ground-breaking revelation, the study demonstrates the pivotal role of the Mitogen-Activated Protein kinase MpkA in both gliotoxin production and self-protection. MpkA was found to physically interact with GliT and GtmA, influencing their regulation and subsequent presence in vacuoles — an association not previously made or demonstrated in relation to gliotoxin production.
 
The researchers emphasise the significance of compartmentalisation of cellular events and the orchestrated interplay of these key enzymes for the effective production of gliotoxin and the self-defence mechanism of the fungus.
 
“We have been collaborating with international research teams using our expertise on identification of protein complexes. Our collaboration with Professor Goldman has led to high impact research on revealing the pathogenic traits of human pathogen Aspergillus fumigatus,” Dr Bayram said.
 
"Our work not only unravels the complex interplay of molecular actors within Aspergillus fumigatus but also underscores the importance of understanding these mechanisms for potential therapeutic interventions against aspergillosis.”

The findings contribute significantly to the understanding of fungal pathogenesis and open avenues for targeted approaches in combating diseases caused by Aspergillus fumigatus.
 
“The implications extend beyond mere discovery; there's potential for developing therapeutic approaches,” Dr Bayram said. “For instance, the newfound knowledge might lay the foundation for a treatment targeting aspergillus infections in patients. Such a breakthrough could have profound implications for individuals undergoing cancer treatments, organ transplants, those with cystic fibrosis, and those managing chronic obstructive pulmonary disease (COPD).”
 
The study was funded by São Paolo Research Foundation and Science Foundation Ireland. The research paper is titled: Aspergillus fumigatus mitogen-activated protein kinase MpkA is involved in gliotoxin production and self-protection.
 
The project involved a major collaborative effort between Maynooth University fungal biologists, Dr Özgür Bayram (Fungal Genetics and Secondary Metabolism), Dr Özlem Sarikaya Bayram (Agricultural Epigenetics) and molecular biotechnology researcher, Aimee Traynor.

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JOURNAL

Nature Communications

DOI

10.1038/s41467-023-44329-1 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Aspergillus fumigatus mitogen-activated protein kinase MpkA is involved in gliotoxin production and self-protection

ARTICLE PUBLICATION DATE

2-Jan-2024