Climate: Lessons from the latest global warming

By analysing sediments dating back to the global warming that happened 56 million years ago, a team from the UNIGE is taking a new look at our climate future.

Peer-Reviewed Publication

UNIVERSITÉ DE GENÈVE

 

IMAGE: PETM WAS MARKED BY AN INCREASE IN THE SEASONALITY AND INTENSITY OF RAINFALL. THIS INCREASED THE MOBILITY OF RIVER CHANNELS - THE DEEPEST AREAS OF A RIVER - AND RESULTED IN THE TRANSPORT OF LARGE QUANTITIES OF FLUVIAL CLAYS DEPOSITED ON ADJACENT ALLUVIAL PLAINS TO THE DEEP OCEAN. view more 

CREDIT: © LUCAS VIMPERE

56 million years ago, the Earth experienced one of the largest and most rapid climate warming events in its history: the Paleocene-Eocene Thermal Maximum (PETM), which has similarities to current and future warming. This episode saw global temperatures rise by 5-8°C. It was marked by an increase in the seasonality of rainfalls, which led to the movement of large quantities of clay into the ocean, making it uninhabitable for certain living species. This scenario could be repeated today. This is what a team from the University of Geneva (UNIGE) has revealed, thanks to the analysis of sediments taken from the deep waters of the Gulf of Mexico. These results can be found in the journal Geology.

The Paleocene-Eocene Thermal Maximum (PETM), which occurred 56 million years ago, is the largest and most rapid climatic disturbance of the Cenozoic era (65.5 million years ago to the present day). Exceptional both in terms of its amplitude (5-8°C increase) and its suddenness (5,000 years, a very short time on a geological scale), this episode was marked by a warming of temperatures on a global scale. It lasted for about 200 000 years and led to numerous marine and terrestrial extinctions.

It would have been caused by a high concentration of carbon dioxide - the famous CO2 - and methane in the atmosphere, two powerful greenhouse gases. As is the case currently, these gases may have been released by several phenomena, certainly in combination: the release of methane hydrates trapped on the seabed, the sudden and significant melting of the permafrost, and the injection of magma into the organic sediments of the western edge of Norway. The origin of these processes is still under debate. The impact of a meteorite and/or the effects of intense volcanic activity in the depths of the North Atlantic could be responsible.

A geological ‘‘archive’’ of unprecedented quality

Because of the many similarities between the PETM and the current warming, the geological remains of this period are being closely studied by scientists. A team from the UNIGE is now reporting new elements. ‘‘The objective of our study was to investigate the influence of these climatic changes on sedimentary systems, i.e. on the processes of sediment formation and deposition, and to understand how these changes could have been transmitted from the atmosphere to the depths of the ocean,’’ explains Lucas Vimpere, a post-doctoral scholar at the Section of Earth and Environmental Sciences of the UNIGE’s Faculty of Science and first author of the study.

The researchers analysed sediments taken from more than 8km deep in the Gulf of Mexico. This basin acts as a giant ‘‘sink’’ into which material eroded and transported from the North American continent over millions of years is discharged. ‘‘For reasons of cost and infrastructure, the sediments used to study the PETM are generally taken from shallow marine or continental environments. Thanks to the collaboration of an oil company, we were able to obtain a sample of unprecedented quality, without any alteration’’, says the researcher. The 543-metre-long core contains a 180-metre-thick PETM sedimentary record, making it the most complete geological ‘‘archive’’ of this period in the world.

More clay on the ocean floor

The UNIGE scientists found that it was composed first of a large layer of clay and then of a layer of sand, a counter-intuitive result. ‘‘At the time of the PETM, we thought that there had been more precipitation, and therefore more erosion, and that large quantities of sand had then been transported first by the fluvial systems into the oceans. However, thanks to our sample, we were able to determine that it was the clays and not the sands that were transported in the first instance’’, explains Sébastien Castelltort, full professor at the Earth and Environmental Sciences Section of the UNIGE Faculty of Science, and last author of the study.

This established that the period was not marked by an increase in the annual rate of precipitation but by an increase in its seasonality and intensity. ‘‘This resulted in increased mobility of the river channels - the deepest areas of a river - which in turn transported large quantities of fluvial clays deposited on the adjacent alluvial plains to the ocean depths. We can now consider the presence of clay in deep basins as a marker of increased rainfall seasonality,’’ says Lucas Vimpere. The phenomenon has led to an increase in ocean turbidity that is harmful to marine life, especially corals.

‘‘The PETM is a potential analogue of current warming. As recent IPCC reports show, we are also now seeing an increase in the seasonality and intensity of rainfall. As our study shows, this is likely to destabilise sedimentary systems in the same way as during the PETM and with the same consequences for the oceans and living species,’’ explains Lucas Vimpere. These new data can now be integrated into modelling aimed at predicting the evolution and consequences of global warming.

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JOURNAL

Geology

DOI

10.1130/G50641.1 

METHOD OF RESEARCH

News article

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Carbon isotope and biostratigraphic evidence for an expanded Paleocene–Eocene Thermal Maximum sedimentary record in the deep Gulf of Mexico

Facile and scalable production of a fuel-cell nanocatalyst for the hydrogen economy

Simple and creative approach for the synthesis of platinum-based alloy nanoparticles through heat treatment

Peer-Reviewed Publication

INSTITUTE FOR BASIC SCIENCE

 

IMAGE: MICROSCOPIC (STEM AND TEM) IMAGES OF THE DEVELOPED CATALYST AND ITS PEMFC POWER PERFORMANCE. COMPARED TO THE STATE-OF-THE-ART FUEL CELL CATALYSTS, THE CATALYST DEVELOPED BY THE CNR-IBS TEAM SHOWED ALMOST TWICE THE POWER PERFORMANCE PER PLATINUM USE. view more 

CREDIT: INSTITUTE FOR BASIC SCIENCE

A fuel cell is an electric power generator that is capable of producing electricity from hydrogen gas while discharging only water as a waste product. It is hoped that this highly efficient clean energy system will play a key role in the adoption of the hydrogen economy, replacing the combustion engines and batteries in automobiles and trucks, as well as power plants.

However, the cost of platinum, which can be up to ~30,000 USD per kg, has been a major limitation, making fuel cell catalysts to be prohibitively expensive. The production methods of highly-performing catalysts have also been complicated and largely limited. Accordingly, the development of a facile and scalable production method for platinum-based fuel cell catalysts is an urgent challenge, together with enhancing catalytic performance and stability while using a minimum amount of platinum.

To tackle this issue, a research team led by Prof. SUNG Yung-Eun and Prof. HYEON Taeghwan at the Center for Nanoparticle Research (CNR) within the Institute for Basic Science (IBS), South Korea has discovered a novel method for the production of nanocatalysts. The researchers demonstrated that these uniformly sized (3-4 nanometers) cobalt-platinum (Co-Pt) alloy nanoparticles can be produced by simple heat treatment. This method has combined features of the ease of the synthesis of the impregnation method, along with the precise control over the size and shape of the nanocrystals similar to the colloidal method.

 

The novel Co-Pt alloy nanocatalysts developed by the CNR-IBS team consist of two oppositely-charged metal complexes, specifically Co and Pt ions surrounded by bipyridine and chlorine ligands, respectively. The research team hypothesized that a simple heat treatment would cause the bipyridine ligand to thermally decompose into a carbon shell that can protect the growing Co-Pt alloy nanoparticles. After optimizing the heat treatment condition, they succeeded in obtaining a highly uniform nanocatalyst with nanoparticles of only 3-4 nanometer sizes.

In the nanocatalyst developed by the group, Co and Pt atoms were arranged in a regular way called the ‘intermetallic phase’, where the unstable Co atoms are stabilized by the surrounding Pt atoms. Additionally, when nitrogen was effectively doped onto the carbon support, ionomers (proton conductors) were homogeneously dispersed over the entire catalyst layer in the fuel cell, which better facilitated the supply of oxygen gas to the surface of the Co-Pt nanocatalyst.

These structural features added up to a much-enhanced power performance in the proton-exchange-membrane fuel cell, exhibiting high specific rated power of 5.9 kW/gPt, which is about twice that of the current performance in a commercial hydrogen vehicle.[1] The catalyst produced by the team has achieved most of the 2025 targets set by the U.S. Department of Energy (DOE) with the goal of stable long-term operation of the fuel cell.

The CNR-IBS team strongly believes that this study would stimulate the development of next-generation fuel cell catalysts. These findings would also contribute to the improvements in the catalytic performance and durability of alloy nanocatalysts for various other electrocatalytic applications.

Prof. Hyeon, stated, “Design of a novel bimetallic compound as a precursor material has been the critical starting point in this study. We have developed a platform technology to produce a complicated form of alloy nanocatalysts through a simple and scalable method, and finally achieved an enhanced fuel cell power performance with less amount of platinum used.”

Prof. Sung remarked, “A world-class level of fuel cell performance has been achieved in this research, surpassing most of the 2025 targets of U.S. DOE by lessening the amount of platinum that can contribute up to around 40% of the cost of fuel cells.” He added, “We expect that this study, together with some follow-up studies, would greatly impact the growth of the hydrogen vehicle industry and the realization of hydrogen economy in the near future.”

 

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[1] D. A. Cullen, K. C. Neyerlin, R. K. Ahluwalia, R. Mukundan, K. L. More, R. L. Borup, A. Z. Weber, D. J. Myers & A. Kusoglu, Nature Energy 2021, 6, 462–474.

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DOI

10.1039/D2EE04211H 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Scalable production of an intermetallic Pt–Co electrocatalyst for high-power proton-exchange-membrane fuel cells

Feathered ‘fingerprints’ reveal potential motivation for migratory patterns of endangered seabirds

Peer-Reviewed Publication

UNIVERSITY OF SOUTH AUSTRALIA

 

IMAGE: SEABIRD FEATHERS CAN PROVIDE CLUES ABOUT THEIR LONG-DISTANCE FORAGING. view more 

CREDIT: DR LAUREN ROMAN, CSIRO

With the largest wingspan of any living bird, the Wandering Albatross is a giant of the sea. But like several other tube-nosed bird species, it is under threat of extinction.

 

Now, world first research from CSIRO and the University of South Australia shows that the feathers of seabirds such as the Wandering Albatross can provide clues about their long-distance foraging, which could help protect these species from further decline.

 

Comparing 15 element concentrations in the feathers of 253 tube-nosed seabirds of the Southern Hemisphere (representing 15 species), researchers found that the feathers of large seabirds (400g+) such as the Wandering Albatross (and other highly mobile seabirds) contained nutrients that did not solely match the availability of nutrients in the seawater at the collection site.

 

Conversely, smaller bird species that foraged more locally had feathers with trace element concentrations that were ten-to-hundred-fold higher than those of larger bird species, clearly representing the ocean basins in which they were feeding.

 

UniSA’s Associate Professor S. ‘Topa’ Petit says feather profiles can help decipher the movements and habitats of open ocean seabirds.

 

“From the lab work led by Dr Farzana Kastury, we found that small seabirds’ feathers contained substantial amounts of elements that matched their foraging environments, whereas large seabirds, irrespective of which ocean their feathers were collected from, all showed similar trace elements, suggesting they are feeding from a range of different ocean basins,” Assoc Prof Petit says

 

“Small birds that spend a lot of time feeding on planktonic crustaceans in particular areas acquire specific elements from those areas. In contrast, larger birds do not have the same element signature because they forage across multiple ocean basins.

 

“Our work with feathers may explain why species like the Wandering Albatross that breed slowly and that are difficult to study because of their open ocean habits travel over such extraordinary distances.

 

“It points at the significance of micronutrient availability and associated ocean processes in the conservation of seabirds.”

 

Research leader, CSIRO’s Dr Lauren Roman, says understanding factors that affect the distribution of a threatened group of seabirds will help us better protect them in the future.

 

“It’s fascinating to think that highly mobile marine animals may be travelling long distances to meet their mineral needs, in addition to their energy needs,” Dr Roman says.

 

“But what this also tells us is that we must continue to protect biodiverse marine areas to ensure micronutrient availability for threatened bird species.

 

“One of the biggest threats to biodiverse marine areas is climate change, as it has the potential to affect nutrient cycles and distribution across the Southern Ocean.

 

“While more research needs to be done, this work expands our ecological knowledge about oceanic species and the significance of micronutrient availability for the survival of seabirds like the Wandering Albatross.”

 

Notes to editors:

 

• The project was funded by a BirdLife Australia’s Australian Bird Environment Fund grant and Sea World Research and Rescue Foundation Inc (SWRRFI) Marine Vertebrates grant.

 

• The study is published in Global Ecology and Biogeography.

 

…………………………………………………………………………………………………………………………

Contacts for interview:

UniSA - Assoc Prof S. ‘Topa’ Petit T: +61 8 830 25194  E: Sophie.Petit@unisa.edu.au

CSIRO – Dr Lauren Roman E: Lauren.Roman@csiro.au
Media contact: Annabel Mansfield M: +61 479 182 489 E: Annabel.Mansfield@unisa.edu.au

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JOURNAL

Global Ecology and Biogeography

DOI

10.1111/geb.13629 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Animal tissue samples

ARTICLE TITLE

Nutrients and seabird biogeography: Feather elements differ among oceanic basins in the Southern Hemisphere, reflecting bird size, foraging range and nutrient availability in seawater

Arming vegetables with anti-inflammatory properties using plant pigments

Scientists explore the therapeutic potential of betalain-engineered vegetables in conferring anti-inflammatory properties

Peer-Reviewed Publication

TOKYO UNIVERSITY OF SCIENCE

 

IMAGE: A) PHENOTYPES OF FRUITS OF WILD-TYPE (TW) AND BETALAIN-TRANSGENIC TOMATO LINES (TB) DURING FRUIT DEVELOPMENT. B) TRANSCRIPT LEVELS OF TNF (THE PROINFLAMMATORY GENE) IN COLONS OF DSS-INDUCED COLITIS MICE WERE LOWER IN MICE TREATED WITH TB EXTRACT AND TW/BET MIXED WATER, COMPARED TO MICE WITH DSS ALONE. view more 

CREDIT: GEN-ICHIRO ARIMURA FROM TOKYO UNIVERSITY OF SCIENCE

Betalains are a class of plant pigments that are responsible for the characteristic red-violet (betacyanin) or yellow (betaxanthin) color of certain fruits and vegetables. These naturally occurring, water-soluble, and nitrogen-containing pigments are commonly used as food coloring agents. Recently, research findings have brought to the forefront, the strong antioxidant potential of betalains, making them potential candidates to produce health foods and combat various diseases. At present, betalains are only produced in plants of the order Caryophyllales and higher fungi. Hence, metabolic engineering has been explored to genetically modify cultivable non-Caryophyllales plants, to enhance the production and scalability of these pigments.

Although transgenic betalain-accumulating plants have been developed over the years, their applications in producing healthcare food resources are yet to be explored.

To address this gap, a collaborative research team from Tokyo University of Science (TUS) and Iwate Biotechnology Research Center, Japan, led by Professor Gen-ichiro Arimura from TUS, attempted to genetically modify potato and tomato plants to produce betacyanin. Their aim was to test the therapeutic efficacy of betacyanin producing tomatoes and potatoes against murine models of colitis and inflammation-inducing macrophages. Their findings were published in Biotechnology & Bioengineering on January 26, 2023. Discussing the results of this study, Prof. Arimura says, “We successfully engineered potato tubers and tomato fruits to co-express betacyanin biosynthesis genes [genes for CYP76AD1 from Beta vulgaris, DOD (DOPA 4,5-dioxygenase) and 5GT (cyclo-DOPA 5-O-glucosyltransferase) from Mirabilis jalapa] under the control of suitable promoters. This enhanced the endogenous accumulation of betanin and isobetanin—two common types of betacyanin—in these transgenic vegetables. The accumulation of these pigments made them appear dark red in color upon maturation, as compared to their wild-type counterparts.”

Since macrophages play an important role in several inflammatory diseases, the team further tested the therapeutic efficacy of these transgenic vegetables in macrophage-like cells (RAW264.7), following immune response stimulation by lipopolysaccharides (LPS). They observed that the extracts of the transgenic tomato fruit exerted higher anti-inflammatory activity compared to their wild-type counterparts. This was attributed to a decrease in the LPS-stimulated transcription of the proinflammatory cytokine gene—a Tnf-α gene, within transgenic cells.

“These findings were in line with the anti-inflammatory effects of transgenic tomato that we observed in the intestines of murine models with dextran sulfate sodium (DSS)-induced colitis. A marked improvement in their body weight loss and disease activity index was observed through the suppression of the DSS-stimulated transcription of proinflammatory genes – genes for Tnf-α, Il6 and Cox-2,” adds Prof. Arimura, while discussing the results derived from the other experiment in mice. Moreover, the additive and synergistic action of betacyanin with natural fruit components (such as lycopene in tomato) further boosted the amelioration of colitis in murine models. Interestingly, while significant anti-inflammatory effects were observed with transgenic tomato extracts at 100–1000-fold dilutions, this was not the case with transgenic potatoes, despite substantial production of betanin and isobetanin. The reason for this is speculated to be the presence of unknown antagonists in transgenic potatoes that work against betacyanin’s anti-inflammatory function, but is yet to be confirmed.

“Tomatoes genetically engineered to produce betacyanins were found to have substantial health promoting effects. Although natural plant sources of betalains such as beetroots exist, these pigments demonstrate poor stability in high temperatures and extreme pH. This indicates that betacyanin producing transgenic tomato lines are more likely to be effective as health foods when ingested in their raw state,” summarizes Prof. Arimura.

What are the potential applications of these findings? He further adds, “Although there is no commercial cultivation of edible genetically modified crops in Japan, we expect that their applications as health foods through production in enclosed plant factories and other facilities will lead to the widespread use of recombinant plants in Japan.”

We are confident that betalain engineering will soon become a promising avenue to improve the commercial production of health foods, that boost food supply while simultaneously conferring health benefits to its consumers.  

 

***

 

Reference                    

DOI: https://doi.org/10.1002/bit.28335

 

About The Tokyo University of Science
Tokyo University of Science (TUS) is a well-known and respected university, and the largest science-specialized private research university in Japan, with four campuses in central Tokyo and its suburbs and in Hokkaido. Established in 1881, the university has continually contributed to Japan's development in science through inculcating the love for science in researchers, technicians, and educators.

With a mission of “Creating science and technology for the harmonious development of nature, human beings, and society", TUS has undertaken a wide range of research from basic to applied science. TUS has embraced a multidisciplinary approach to research and undertaken intensive study in some of today's most vital fields. TUS is a meritocracy where the best in science is recognized and nurtured. It is the only private university in Japan that has produced a Nobel Prize winner and the only private university in Asia to produce Nobel Prize winners within the natural sciences field.

Website: https://www.tus.ac.jp/en/mediarelations/

 

About Professor Gen-ichiro Arimura from Tokyo University of Science
Dr. Gen-ichiro Arimura is a Professor at the Department of Biological Science and Technology within the Faculty of Advanced Engineering at the Tokyo University of Science (TUS), Japan. He obtained his PhD from Hiroshima University and has worked in the field of plant biology for several years before moving to TUS in 2013. With a research career spanning over two decades, he is a senior and well-respected researcher with over 100 publications to his credit. His research focus includes plant biotechnology, ecology, and biochemistry.

 

Funding information
This study was financially supported in part by a Japan Society for the Promotion of Science (JSPS) KAKENHI (20H02951), a JSPS Joint Research Project (J21-740), and a Research Grant of Sapporo Bioscience Foundation to GA. 

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JOURNAL

Biotechnology and Bioengineering

DOI

10.1002/bit.28335 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Lab-produced tissue samples

ARTICLE TITLE

Metabolic engineering of betacyanin in vegetables for anti-inflammatory therapy

Unique feature of the Moon to be named in honour of trailblazing mathematician Melba Roy Mouton

Business Announcement

INTERNATIONAL ASTRONOMICAL UNION

 

IMAGE: MELBA MOUTON, A MATHEMATICIAN AND COMPUTER PROGRAMMER IN NASA’S TRAJECTORY AND GEODYNAMICS DIVISION AT NASA'S GODDARD SPACE FLIGHT CENTER IN GREENBELT, MARYLAND. view more 

CREDIT: NASA

The Working Group for Planetary System Nomenclature of the International Astronomical Union (IAU) has approved an official name for a mesa-like lunar mountain that towers above the landscape carved by craters near the Moon’s south pole. This unique feature will now be referred to as Mons Mouton, after NASA mathematician and computer programmer Melba Roy Mouton (MOO-tawn).

The name Mons Mouton was proposed to the Working Group for Planetary System Nomenclature (WGPSN) of the IAU by members of NASA’s Volatiles Investigating Polar Exploration Rover (VIPER) team. The flat-topped mountain is adjacent to the western rim of the Nobile crater, on which VIPER will land and explore during its approximately 100-day mission as part of NASA’s Artemis program. The mountain is also one of 13 candidate landing regions for NASA’s Artemis III mission, which is intended to send astronauts to the lunar surface, including the first woman to set foot on the Moon.

The IAU theme for naming mountains (denoted ‘mons’) on the Moon focuses on “scientists who have made outstanding or fundamental contributions to their fields.” The lunar landmark naming honours and recognises Mouton’s life, her accomplishments as a computer scientist, and her contributions to NASA’s missions.

Mouton was first employed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in 1959, just a year after the space agency was established. She became the head mathematician who led a group of ‘human computers’, who tracked the Echo 1 and 2 satellites, launched into Earth’s orbit in 1960 and 1964, respectively.

A few years later, in 1961, Mouton was the head programmer responsible for the Mission and Trajectory Analysis Division’s Program Systems Branch — the team who coded computer programs used to calculate spacecraft locations and trajectories, giving NASA the ability to track spacecraft while in orbit.

Before retiring in 1973, after a career at NASA that spanned 14 years, Mouton had become the assistant chief of research programmes for the Trajectory and Geodynamics Division at Goddard. In appreciation of her dedicated service and outstanding accomplishments, which culminated in the successful Apollo 11 Moon landing on 20 July 1969, she was recognised with an Apollo Achievement Award.

"Melba Mouton was one of our pioneering leaders at NASA,” said Sandra Connelly, the acting associate administrator for science at NASA Headquarters in Washington. “She not only helped NASA take the lead in exploring the unknown in air and space, but she also charted a path for other women and people of color to pursue careers and lead cutting-edge science at NASA.”

Mons Mouton is a wide, relatively flat-topped mountain, about the size of the state of Delaware, and was created over billions of years by lunar impacts, which sculpted it out of its surroundings. As a result, Mons Mouton stands as tall as Denali — the tallest mountain in North America —– approximately 6000 metres higher than its neighbouring features on the Moon’s south pole. Because it is relatively untouched by bombardments, scientists believe Mons Mouton is much more ancient — possibly billions of years older than its surroundings. A ring of huge craters — evidence of its pulverising distant past — lies around its base; some have cliff-like edges, descending into areas of permanent darkness. Its rolling hilltop is peppered with smaller rocks and pebbles as well as lots of enticing craters that are frequently blanketed in freezing shifting shadows.

“Mons Mouton represents a great spot for VIPER — our solar-powered Moon rover that we’ll drive and conduct science in near real time,” said Sarah Noble, VIPER program scientist at NASA Headquarters in Washington. “It features high sunny spots, it’s relatively flat, satellite data shows signs of water ice, and it allows long stretches of direct communication with our ground station on Earth.” 

VIPER will be the first resource mapping mission beyond Earth. It will search at and below the lunar surface to determine the location and concentration of any ice that could eventually be harvested to sustain human exploration on the Moon, Mars, and beyond and it will help advance scientific exploration of the Moon by helping to understand how water is created and deposited throughout the Solar System. It is planned to deliver VIPER to the Moon in late 2024 under NASA’s Commercial Lunar Payload Services (CLPS) initiative. 

More information

The IAU is the international astronomical organisation that brings together more than 12 000 active professional astronomers from more than 100 countries worldwide. Its mission is to promote and safeguard astronomy in all its aspects, including research, communication, education and development, through international cooperation. The IAU also serves as the internationally recognised authority for assigning designations to celestial bodies and the surface features on them. Founded in 1919, the IAU is the world's largest professional body for astronomers.

Links

• NASA press release and video

 Using spiders as environmentally-friendly pest control

Groups of spiders could be used as an environmentally-friendly way to protect crops against agricultural pests. New research suggests that web-building groups of spiders can eat a devastating moth of commercially important crops like tomato and potato.

Peer-Reviewed Publication

UNIVERSITY OF PORTSMOUTH

 

IMAGE: LARGE WEB OF THE GROUP-LIVING SPIDER CYRTOPHORA CITRICOLA view more 

CREDIT: DR LENA GRINSTED

Groups of spiders could be used as an environmentally-friendly way to protect crops against agricultural pests.

That's according to new research, led by the University of Portsmouth, which suggests that web-building groups of spiders can eat a devastating pest moth of commercially important crops like tomato and potato worldwide.

The tomato leafminer moth, Tuta absoluta,has developed resistance to chemical insecticides, which cause human and environmental damage, so different approaches, like using natural predators such as spiders, are needed to combat infestations. 

The researchers explored the use of tropical tent web spiders, Cyrtophora citricola, as pest control, as these spiders form groups and are not cannibalistic, and they create large webs to capture prey.

In lab settings, different types of prey - the small tomato leafminer, flightless fruit flies (Drosophila hydei) and larger black soldier flies (Hermetia illucens) - were introduced to colonies of spiders of varying body sizes. Researchers found that larger spiders built larger webs and generally caught more prey, and they easily caught and ate the tomato leafminer and fruit flies, while the larger black soldier flies were rarely caught. 

Dr Lena Grinsted, Senior Lecturer in Zoology in the School of Biological Sciences at the University of Portsmouth, and lead author of the study, said: “Our findings suggest that tropical tent web spiders have the potential to be an effective biological control agent of flying insect pests, at least after growing to medium-sized juveniles.

“Because they have evolved the ability to live in groups, these spiders might be better suited for biological control than more aggressive, solitary spiders that are prone to cannibalism. 

“Spiders that can form groups of hundreds, or even thousands, of interconnected webs can provide large surface areas of capture webs capable of intercepting high frequencies of airborne insects. Spider colonies also provide a substrate for other spider species, further increasing the number of predators and therefore, potentially increasing pest insect capture capability within colonies.”

Climate change due to human overpopulation and fossil fuel dependence is facilitating the spread of invasive pest species of agricultural crops, such as the tomato leafminer, by expanding their habitable environment ranges.

Tropical tent web spiders are found in colonies around the world and their global range overlaps with regions of moth infestations, including Mediterranean Europe, Africa, Asia, and the Middle East, whose environmental health and economic stability could greatly benefit from this sustainable agricultural approach. Also, as these spiders are already found in these regions, the introduction of pest control spiders will be unlikely to significantly damage native biodiversity.

The researchers further investigated the seasonal variations in web sizes in southern Spain, and found that pest control would be most effective in the tomato planting and growing season in May and June. 

However, they found that a wasp species (Philolema palanichamyi) found in the region, whose larvae eat spider eggs, could be detrimental to the spider colony. The researchers found that about half of the spider egg sacs were infected with zero surviving spiderlings.

Dr Grinsted added: “If wasp infections are controlled, these spiders could form an important part of an integrated pest management system. This could potentially lead to a reduction of reliance on chemical pesticides, resulting in reduced pollutants in soils, waterways, and food chains in the future. 

“Future studies are now needed to investigate whether the spiders may negatively impact crop pollination by also catching and feeding on bees and other key pollinators.”

The study, published in the journal Insects, involved researchers from the universities of Portsmouth and Nottingham, and Ben-Gurion University of the Negev in Israel.

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JOURNAL

Insects

DOI

10.3390/insects14010034 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Group-Living Spider Cyrtophora citricola as a Potential Novel Biological Control Agent of the Tomato Pest Tuta absoluta

Leipzig researchers develop efficient process for chemical terpene synthesis

Potential applications in food, cosmetics and pharmaceutical industries

Peer-Reviewed Publication

UNIVERSITÄT LEIPZIG

 

IMAGE: IN THE ILLUSTRATION, THE CATALYST – THE CAT – GIVES A CARBON CHAIN A PERSISTENT FORM, WHICH IS REPRESENTED BY THE CLAMPS. IN REALITY, THE STRONGLY BINDING SOLUTION ACTS AS A CATALYST IN WHICH HYDROGEN ATOMS HAVE BEEN REPLACED BY FLUORINE ATOMS. THE “GLUE” IS THE REACTION. view more 

CREDIT: DR CHRISTOPH SELG

A team of scientists led by Professor Tanja Gulder at Leipzig University’s Institute of Organic Chemistry, together with colleagues from the University of Regensburg, has developed a simplified and efficient method for the artificial production of terpenes. Terpenes are a very extensive and diverse class of natural products that perform a wide range of functions in nature and are also used industrially. Until now, producing them has required a wide variety of starting scenarios, some with harsh conditions, or has been based on substances taken from nature. The new method, on the other hand, follows a flexible and resource-saving modular principle. This allows the targeted production of these important natural substances from simple and readily available starting materials. To do this, the team replicated naturally occurring enzymatic processes using fluorinated alcohol / catalyst solutions. The method can be used widely in existing laboratories. The research findings have now been published in Nature Communications.

Wide range of terpenes in nature

Terpenes are what give pine needles their scent, and beer and orangeade their taste. They play a key role in how living things like insects, but also we humans, communicate, and in defence mechanisms, for instance in plants against animal predators, fungi and bacteria. In human biology, terpenes also play an important role in metabolic processes. 

Terpenes have long been used industrially on a large scale: in the production of foodstuffs and food supplements, in perfumes, and in pharmaceuticals, such as cancer and COVID-19 drugs. “We need quite a lot of tonnes of a wide variety of terpenes every year, and that means we also have to be able to produce them synthetically in an efficient and sustainable way – and that’s a big problem,” says Professor Tanja Gulder, who holds the professorship for Biomimetic Catalysis at Leipzig University.

In nature, enzymes form terpenes through targeted folding

“Nature has a unique way of making each of these molecular compounds,” says Gulder. “This involves the use of so-called terpene cyclases, proteins with 100 to 1,000 amino acids. These enzymes press simple and mobile carbon chains into a specific three-dimensional form that determines the appearance of the product,” Gulder adds. Once the reaction has taken place, the shape of the respective terpene remains unchangeable. The reaction takes place in what is known as an enzyme pocket in the active centre of the enzyme, which carries a blueprint of the form to be produced. After the reaction is complete, the enzyme releases the finished product and the process is repeated with the next building block. “It can be thought of as a fast-moving molecular manufacturing machine,” says Gulder. 

Atomic details matter

There are terpenes that are similar in terms of the type and number of their atomic compounds – but whose spatial arrangements are different. “In a simple case, such atomic differences determine whether something tastes like caraway or orange,” says Gulder. However, such differences could also mean that one terpene acts completely differently in the human organism than the other. Errors here can have fatal consequences. “And depending on the way the carbon chains are put into the enzyme pocket, different terpenes come out, which is also part of the complexity in nature,” explains Gulder.

Extraction difficult so far

The researcher points out that previous approaches to recreating terpenes in the lab required very different and harsh initial conditions, such as a highly acidic environment or low temperatures, adding that this is neither effective nor environmentally friendly for large-scale production. The extraction of terpenes from organisms such as plants, animals and fungi has also reached its limits. “You can’t cut down all the Pacific yews to isolate taxol for a cancer drug. It would take the bark of twelve mature specimens of this not-very-widespread tree species to make one gram of the active ingredient,” says Gulder. At the moment, a precursor of the desired terpene is extracted from needles of another tree species and then processed further.

“So we wanted to see how we could replicate nature’s processes in a test tube and achieve the greatest possible flexibility and efficiency.”

The solution: Liquid construction kit with fluorinated alcohol

The team succeeded in building a custom-fit, enzyme-like environment for the formation of terpenes, consisting of readily available chemical substances. This can work like a construction kit: by adding different starting materials and additives that act as catalysts, different terpenes can be produced artificially.

At the heart of the new approach are the properties of fluorinated alcohol: “We had found that when hydrogen atoms in alcohols were replaced with fluorine atoms, the resulting fluorinated alcohol exhibited extreme bonding forces. In such solutions, molecules form helices or rings that stack up to form tubes,” explains Professor Gulder. By adding chemicals, it is possible to influence the size and shape of these structures.

“Basically, we have built an artificial enzyme pocket in the form of a structured solution into which our respective starting material can fold. As in nature, forms persist after the reaction.”

Computer simulations were also used to develop this new method. Professor Tanja Gulder explains: “Our colleagues Philipp Dullinger and Professor Dominik Horinek of the University of Regensburg calculated which three-dimensional structures, so which shapes, the alcohols form with the additives used in each case. This was important to identify suitable catalysts that would lead us to the desired terpenes.”

Realisable in standard chemistry laboratories

The method does not require any additional infrastructure, it can be applied in chemistry laboratories at no additional cost, and can be easily scaled up for application to large-scale production. What is more, the process requires no heavy or precious metals. “This makes it broadly applicable and more sustainable than previous methods,” explains Gulder, who was previously a Heisenberg professor at the Technical University of Munich. “It is an example of the forward-looking research focus on multifunctional catalysis at Leipzig University, and at the CTC major research centre that has just been approved in the Leipzig area.” Its focus will be on sustainable catalysis in an industrial context.

Professor Tanja Gulder

CREDIT

Swen Reichhold, Leipzig University

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JOURNAL

Nature

DOI

10.1038/s41467-023-36157-0 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Enzyme-Like Polyene Cyclizations Catalyzed by Dynamic, Self-Assembled, Supramolecular Fluoro Alcohol-Amine Clusters

ARTICLE PUBLICATION DATE

13-Feb-2023

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