Category Archives: food

Quantum dots as pollen labels: tracking pollinators

Caption: This bee was caught after it visited a flower of which the pollen grains were labelled with quantum dots. Under the microscope one can see where the pollen was placed, and actually determine which insects carry the most pollen from which flower. Credit: Corneile Minnaar

Fascinating, yes? Next, the news and, then, the video about the research,

A February 14, 2019 news item on ScienceDaily announces research from South Africa,

A pollination biologist from Stellenbosch University in South Africa is using quantum dots to track the fate of individual pollen grains. This is breaking new ground in a field of research that has been hampered by the lack of a universal method to track pollen for over a century.

A February 13, 2019 Stellenbosh University press release (also on EurekAlert but published February 14, 2019) by Wiida Fourie-Basson, which originated the news item, expands on the theme,

In an article published in the journal Methods in Ecology and Evolution this week, Dr Corneile Minnaar describes this novel method, which will enable pollination biologists to track the whole pollination process from the first visit by a pollinator to its endpoint – either successfully transferred to another flower’s stigma or lost along the way.

Despite over two hundred years of detailed research on pollination, Minnaar says, researchers do not know for sure where most of the microscopically tiny pollen grains actually land up once they leave flowers: “Plants produce massive amounts of pollen, but it looks like more than 90% of it never reaches stigmas. For the tiny fraction of pollen grains that make their way to stigmas, the journey is often unclear–which pollinators transferred the grains and from where?”

Starting in 2015, Minnaar decided to tread where many others have thus far failed, and took up the challenge through his PhD research in the Department of Botany and Zoology at Stellenbosch University (SU).

“Most plant species on earth are reliant on insects for pollination, including more than 30% of the food crops we eat. With insects facing rapid global decline, it is crucial that we understand which insects are important pollinators of different plants–this starts with tracking pollen,” he explains.

He came upon the idea for a pollen-tracking method after reading an article on the use of quantum dots to track cancer cells in rats (https://doi.org/10.1038/nbt994). Quantum dots are semiconductor nanocrystals that are so small, they behave like artificial atoms. When exposed to UV light, they emit extremely bright light in a range of possible colours. In the case of pollen grains, he figured out that quantum dots with “fat-loving” (lipophilic) ligands would theoretically stick to the fatty outer layer of pollen grains, called pollenkitt, and the glowing colours of the quantum dots can then be used to uniquely “label” pollen grains to see where they end up.

The next step was to find a cost-effective way to view the fluorescing pollen grains under a field dissection microscope. At that stage Minnaar was still using a toy pen from a family restaurant with a little UV LED light that he borrowed from one of his professors.
“I decided to design a fluorescence box that can fit under a dissection microscope. And, because I wanted people to use this method, I designed a box that can easily be 3D-printed at a cost of about R5,000, including the required electronic components.” (view video at https://youtu.be/YHs925F13t0

[or you can scroll down to the bottom of this post]

So far, the method and excitation box have proven itself as an easy and relatively inexpensive method to track individual pollen grains: “I’ve done studies where I caught the insects after they have visited the plant with quantum-dot labelled anthers, and you can see where the pollen is placed, and which insects actually carry more or less pollen.”
But the post-labelling part of the work still requires hours and hours of painstaking counting and checking: “I think I’ve probably counted more than a hundred thousand pollen grains these last three years,” he laughs.

As a postdoctoral fellow in the research group of Prof Bruce Anderson in the Department of Botany and Zoology at Stellenbosch University, Minnaar will continue to use the method to investigate the many unanswered questions in this field.

Here’s a link to and a citation for the paper,

Using quantum dots as pollen labels to track the fates of individual pollen grains by Corneile Minnaar and Bruce Anderson. Methods in Ecology and Evolution DOI: https://doi.org/10.1111/2041-210X.13155 First published: 25 January 2019

This paper is behind a paywall.

Here is the video,

Food nanoparticles and their effect on intestinal flora (i.e., your gut microbiome)

This work from Germany is largely speculative. The scientists seem to be interested in exploring how engineered nanoparticles and naturally occurring nanoparticles in food affect your gut. From a January 29, 2019 news item on ScienceDaily,

The intestinal microbiome is not only key for food processing but an accepted codeterminant for various diseases. Researchers led by the University Medical Center of Johannes Gutenberg University Mainz (JGU) identified effects of nanoparticles on intestinal microorganisms. The ultra-small particles adhere to intestinal microorganisms, thereby affecting their life cycle as well as cross talk with the host. One of the researchers’ observations was that nanoparticles’ binding inhibits the infection with Helicobacter pylori, a pathogen implicated in gastric cancer. The findings will stimulate further epidemiological studies and pave the way for the development of potential ‘probiotic’ nanoparticles for food. The discoveries were published in Science of Food.

A January 29, 2019 Johannes Gutenberg University Mainz (JGU) press release (also on EurekAlert), which originated the news item, provides more detail,

Due to their minute size, nanoparticles have unique characteristics and capabilities, such as adhering to microstructures. Nanotechnology is as an important driver of innovation for both consumer industry and medicine. In medicine, the focus is on improving diagnostics and therapeutics, while industry addresses mainly product optimization. Hence, synthetic nanoparticles are already used as additives to improve the characteristics of food. But how can we use nanotechnology more efficiently and safely in food? And are there unknown effects of nanoparticles, which need to be further exploited?

Nutrition strongly influences the diversity and composition of our microbiome. ‘Microbiome’ describes all colonizing microorganisms present in a human being, in particular, all the bacteria in the gut. In other words, your microbiome includes your intestinal flora as well as the microorganisms that colonize your skin, mouth, and nasal cavity.

Scientists and clinicians are interested in microbiomes because of their positive or negative effects on the host. These include modulation of our immune system, metabolism, vascular aging, cerebral functioning, and our hormonal system. The composition of the microbiome seems to play an important role for the development of various disorders, such as cardiovascular diseases, cancer, allergies, obesity, and even mental disorders. “Hence, nutrition and its containing nanoparticulates may affect the microbiome-host balance, finally influencing human health. In order to reduce potential risks and, ideally, promote health, the impact of dietary nanoparticles needs to be understood,” emphasized Professor David J. McClements from the Department of Food Science at the University of Massachusetts in Amherst, USA.

“Prior to our studies, nobody really looked whether and how nano-additives directly influence the gastrointestinal flora,” commented Professor Roland Stauber of the Department of Otolaryngology, Head, and Neck Surgery at the Mainz University Medical Center. “Hence, we studied at a wide range of technical nanoparticles with clearly defined properties in order to mimic what happens to currently used or potential future nanosized food additives. By simulating the journey of particles through the different environments of the digestive tract in the laboratory, we found that the all tested nanomaterials were indeed able to bind to bacteria.” explained Stauber.

The scientists discovered that these binding processes can have different outcomes. On the one hand, nanoparticle-bound microorganisms were less efficiently recognized by the immune system, which may lead to increased inflammatory responses. On the other hand, ‘nano-food’ showed beneficial effects. In cell culture models, silica nanoparticles inhibited the infectivity of Helicobacter pylori, which is considered to be one of the main agents involved in gastric cancer.

‘It was puzzling that we were able to also isolate naturally occurring nanoparticles from food, like beer, which showed similar effects. Nanoparticles in our daily food are not just those added deliberately but can also be generated naturally during preparation. Nanoparticulates are already omnipresent,” concluded Stauber.

The insights of the study will allow to derive strategies for developing and utilizing synthetic or natural nanoparticles to modulate the microbiome as beneficial ingredients in functional foods. “The challenge is to identify nanoparticles that fit the desired purpose, perhaps even as probiotic food supplements in the future. Challenge accepted,” emphasized Stauber and his team.

Here’s a link to and a citation for the paper,

Nanosized food additives impact beneficial and pathogenic bacteria in the human gut: a simulated gastrointestinal study by Svenja Siemer, Angelina Hahlbrock, Cecilia Vallet, David Julian McClements, Jan Balszuweit, Jens Voskuhl, Dominic Docter, Silja Wessler, Shirley K. Knauer, Dana Westmeier, & Roland H. Stauber. npj Science of Foodvolume 2, Article number: 22 (2018) DOI: https://doi.org/10.1038/s41538-018-0030-8 Published 04 December 2018

This paper is open access.

Cellulose and natural nanofibres

Specifically, the researchers are describing these as cellulose nanofibrils. On the left of the image, the seed look mores like an egg waiting to be fried for breakfast but the image on the right is definitely fibrous-looking,

Through contact with water, the seed of Neopallasia pectinata from the family of composite plants forms a slimy sheath. The white cellulose fibres anchor it to the seed surface. Courtesy: Kiel University (CAU)

A December 18, 2018 news item on Nanowerk describes the research into seeds and cellulose,

The seeds of some plants such as basil, watercress or plantain form a mucous envelope as soon as they come into contact with water. This cover consists of cellulose in particular, which is an important structural component of the primary cell wall of green plants, and swelling pectins, plant polysaccharides.

In order to be able to investigate its physical properties, a research team from the Zoological Institute at Kiel University (CAU) used a special drying method, which gently removes the water from the cellulosic mucous sheath. The team discovered that this method can produce extremely strong nanofibres from natural cellulose. In future, they could be especially interesting for applications in biomedicine.

A December 18, 2018 Kiel University press release, which originated the news item, offers further details about the work,

Thanks to their slippery mucous sheath, seeds can slide through the digestive tract of birds undigested. They are excreted unharmed, and can be dispersed in this way. It is presumed that the mucous layer provides protection. “In order to find out more about the function of the mucilage, we first wanted to study the structure and the physical properties of this seed envelope material,” said Zoology Professor Stanislav N. Gorb, head of the “Functional Morphology and Biomechanics” working group at the CAU. In doing so they discovered that its properties depend on the alignment of the fibres that anchor them to the seed surface

Diverse properties: From slippery to sticky

The pectins in the shell of the seeds can absorb a large quantity of water, and thus form a gel-like capsule around the seed in a few minutes. It is anchored firmly to the surface of the seed by fine cellulose fibres with a diameter of just up to 100 nanometres, similar to the microscopic adhesive elements on the surface of highly-adhesive gecko feet. So in a sense, the fibres form the stabilising backbone of the mucous sheath.

The properties of the mucous change, depending on the water concentration. “The mucous actually makes the seeds very slippery. However, if we reduce the water content, it becomes sticky and begins to stick,” said Stanislav Gorb, summarising a result from previous studies together with Dr Agnieszka Kreitschitz. The adhesive strength is also increased by the forces acting between the individual vertically-arranged nanofibres of the seed and the adhesive surface.

Specially dried

In order to be able to investigate the mucous sheath under a scanning electron microscope, the Kiel research team used a particularly gentle method, so-called critical-point drying (CPD). They dehydrated the mucous sheath of various seeds step-by-step with liquid carbon dioxide – instead of the normal method using ethanol. The advantage of this method is that evaporation of liquid carbon dioxide can be controlled under certain pressure and temperature conditions, without surface tension developing within the sheath. As a result, the research team was able to precisely remove water from the mucous, without drying out the surface of the sheath and thereby destroying the original cell structure. Through the highly-precise drying, the structural arrangement of the individual cellulose fibres remained intact.

Almost as strongly-adhesive as carbon nanotubes

The research team tested the dried cellulose fibres regarding their friction and adhesion properties, and compared them with those of synthetically-produced carbon nanotubes. Due to their outstanding properties, such as their tensile strength, electrical conductivity or their friction, these microscopic structures are interesting for numerous industrial applications of the future.

“Our tests showed that the frictional and adhesive forces of the cellulose fibres are almost as strong as with vertically-arranged carbon nanotubes,” said Dr Clemens Schaber, first author of the study. The structural dimensions of the cellulose nanofibers are similar to the vertically aligned carbon nanotubes. Through the special drying method, they can also vary the adhesive strength in a targeted manner. In Gorb’s working group, the zoologist and biomechanic examines the functioning of biological nanofibres, and the potential to imitate them with technical means. “As a natural raw material, cellulose fibres have distinct advantages over carbon nanotubes, whose health effects have not yet been fully investigated,” continued Schaber. Nanocellulose is primarily found in biodegradable polymer composites, which are used in biomedicine, cosmetics or the food industry.

Here’s a link to and a citation for the paper,

Friction-Active Surfaces Based on Free-Standing Anchored Cellulose Nanofibrils by Clemens F. Schaber, Agnieszka Kreitschitz, and Stanislav N. Gorb. ACS Appl. Mater. Interfaces, 2018, 10 (43), pp 37566–37574 DOI: 10.1021/acsami.8b05972 Publication Date (Web): September 19, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Terahertz imagers at your fingertips

It seems to me that I stumbled across quite a few carbon nanotube (CNT) stories in 2018. This one comes courtesy of Japan (from a June 28, 2018 news item on Nanowerk),

Researchers at Tokyo Tech have developed flexible terahertz imagers based on chemically “tunable” carbon nanotube materials. The findings expand the scope of terahertz applications to include wrap-around, wearable technologies as well as large-area photonic devices.

Here’s a peek at an imager,

Figure 1. The CNT-based flexible THz imager (a) Resting on a fingertip, the CNT THz imager can easily wrap around curved surfaces. (b) Just by inserting and rotating a flexible THz imager attached to the fingertip, damage to a pipe was clearly detected. Courtesy Tokyo Tech

A June 28, 2018 Tokyo Tech Institute press release (also on Eurekalert), which originated the news item, provides more detail,

Carbon nanotubes (CNTs) are beginning to take the electronics world by storm, and now their use in terahertz (THz) technologies has taken a big step forward.

Due to their excellent conductivity and unique physical properties, CNTs are an attractive option for next-generation electronic devices. One of the most promising developments is their application in THz devices. Increasingly, THz imagers are emerging as a safe and viable alternative to conventional imaging systems across a wide range of applications, from airport security, food inspection and art authentication to medical and environmental sensing technologies.

The demand for THz detectors that can deliver real-time imaging for a broad range of industrial applications has spurred research into low-cost, flexible THz imaging systems. Yukio Kawano of the Laboratory for Future Interdisciplinary Research of Science and Technology, Tokyo Tech, is a world-renowned expert in this field. In 2016, for example, he announced the development of wearable terahertz technologies based on multiarrayed carbon nanotubes.

Kawano and his team have since been investigating THz detection performance for various types of CNT materials, in recognition of the fact that there is plenty of room for improvement to meet the needs of industrial-scale applications.

Now, they report the development of flexible THz imagers for CNT films that can be fine-tuned to maximize THz detector performance.

Publishing their findings in ACS Applied Nano Materials, the new THz imagers are based on chemically adjustable semiconducting CNT films.

By making use of a technology known as ionic liquid gating1, the researchers demonstrated that they could obtain a high degree of control over key factors related to THz detector performance for a CNT film with a thickness of 30 micrometers. This level of thickness was important to ensure that the imagers would maintain their free-standing shape and flexibility, as shown in Figure 1 [see above].

“Additionally,” the team says, “we developed gate-free Fermi-level2 tuning based on variable-concentration dopant solutions and fabricated a Fermi-level-tuned p-n junction3 CNT THz imager.” In experiments using this new type of imager, the researchers achieved successful visualization of a metal paper clip inside a standard envelope (see Figure 2.)

Non-contact, non-destructive visualization

Figure 2. Non-contact, non-destructive visualization

The CNT THz imager enabled clear, non-destructive visualization of a metal paper clip inside an envelope.

The bendability of the new THz imager and the possibility of even further fine-tuning will expand the range of CNT-based devices that could be developed in the near future.

Moreover, low-cost fabrication methods such as inkjet coating could make large-area THz imaging devices more readily available.

1 Ionic liquid gating

A technique used to modulate a material’s charge carrier properties.

2 Fermi level

A measure of the electrochemical potential for electrons, which is important for determining the electrical and thermal properties of solids. The term is named after the Italian–American physicist Enrico Fermi.

3 p-n junction

Refers to the interface between positive (p-type) and negative (n-type) semiconducting materials. These junctions form the basis of semiconductor electronic devices.

Here’s a link to and a citation for the paper,

Fermi-Level-Controlled Semiconducting-Separated Carbon Nanotube Films for Flexible Terahertz Imagers by Daichi Suzuki, Yuki Ochiai, Yota Nakagawa, Yuki Kuwahara, Takeshi Saito, and Yukio Kawano. ACS Appl. Nano Mater., 2018, 1 (6), pp 2469–2475 DOI: 10.1021/acsanm.8b00421 Publication Date (Web): June 6, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Genetic engineering: an eggplant in Bangladesh and a synthetic biology grant at Concordia University (Canada)

I have two bits of genetic engineering news.

Eggplants in Bangladesh

I always marvel at their beauty,

Bt eggplant is the first genetically engineered food crop to be successfully introduced in South Asia. The crop is helping some of the world’s poorest farmers feed their families and communities while reducing the use of pesticides. Photo by Cornell Alliance for Science.

A July 17, 2018 news item on phys.org describes a genetic engineering application,

Ansar Ali earned just 11,000 taka – about $130 U.S. dollars – from eggplant he grew last year in Bangladesh. This year, after planting Bt eggplant, he brought home more than double that amount, 27,000 taka. It’s a life-changing improvement for a subsistence farmer like Ali.

Bt eggplant, or brinjal as it’s known in Bangladesh, is the first genetically engineered food crop to be successfully introduced in South Asia. Bt brinjal is helping some of the world’s poorest farmers to feed their families and communities, improve profits and dramatically reduce pesticide use. That’s according to Tony Shelton, Cornell professor of entomology and director of the Bt brinjal project funded by the United States Agency for International Development (USAID). Shelton and Jahangir Hossain, the country coordinator for the project in Bangladesh, lead the Cornell initiative to get these seeds into the hands of the small-scale, resource-poor farmers who grow a crop consumed daily by millions of Bangladeshis.

A July 11, 2018 Cornell University news release by Krisy Gashler, which originated the news item, expands on the theme (Note: Links have been removed),

Bt brinjal was first developed by the Indian seed company Mahyco in the early 2000s. Scientists inserted a gene from the bacterium Bacillus thuringiensis (thus the name, Bt) into nine brinjal varieties. The plants were engineered to resist the fruit and shoot borer, a devastating insect whose larvae bore into the stem and fruit of an eggplant. The insects cause up to 80 percent crop loss.

The Bt protein produced by the engineered eggplant causes the fruit and shoot borer larva to stop feeding, but is safe for humans consuming the eggplant, as proven through years of biosafety trials. In fact, Bt is commonly used by organic farmers to control caterpillars but has to be sprayed frequently to be effective. The Bt eggplant produces essentially the same protein as in the spray. More than 80 percent of field corn and cotton grown in the U.S. contains a Bt gene for insect control.

“Farmers growing Bt brinjal in Bangladesh are seeing three times the production of other brinjal varieties, at half the production cost, and are getting better prices at the market,” Hossain said.

A recent survey found 50 percent of farmers in Bangladesh said that they experienced illness due to the intense spraying of insecticides. Most farmers work in bare feet and without eye protection, leading to pesticide exposure that causes skin and eye irritation, and vomiting.

“It’s terrible for these farmers’ health and the health of the environment to spray so much,” said Shelton, who found that pesticide use on Bt eggplant was reduced as much as 92 percent in commercial Bt brinjal plantings. “Bt brinjal is a solution that’s really making a difference in people’s lives.”

Alhaz Uddin, a farmer in the Tangail district, made 6,000 taka growing traditional brinjal, but had to spend 4,000 taka on pesticides to combat fruit and shoot borer.

“I sprayed pesticides several times in a week,” he said. “I got sick many times during the spray.”

Mahyco initially wanted to introduce Bt brinjal in India and underwent years of successful safety testing. But in 2010, due to pressure from anti-biotechnology groups, the Indian minister of the environment placed a moratorium on the seeds. It is still in effect today, leaving brinjal farmers there without the effective and safe method of control available to their neighbors in Bangladesh.

Even before the Indian moratorium, Cornell scientists hosted delegations from Bangladesh that wanted to learn about Bt brinjal and the Agricultural Biotechnology Support Project II (ABSP II), a consortium of public and private institutions in Asia and Africa intended to help with the commercial development, regulatory approval and dissemination of bio-engineered crops, including Bt brinjal.

Cornell worked with USAID, Mahyco and the Bangladesh Agricultural Research Institute to secure regulatory approval, and in 2014 the Bangladeshi government distributed a small number of Bt brinjal plants to 20 farmers in four districts. The next year 108 farmers grew Bt brinjal, and the following year the number of farmers more than doubled to 250. In 2017 the number increased to 6,512 and in 2018 to 27,012. The numbers are likely even higher, according to Shelton, as there are no constraints against farmers saving seeds and replanting.

“Farmers who plant Bt brinjal are required to plant a small perimeter of traditional brinjal around the Bt variety; research has shown that the insects will infest plants in the buffer area, and this will slow their evolutionary development of resistance to the Bt plants,” Shelton said.

In a March 2017 workshop, Bangladeshi Agriculture Minister Begum Matia Chowdhury called Bt brinjal “a success story of local and foreign collaboration.”

“We will be guided by the science-based information, not by the nonscientific whispering of a section of people,” Chowdhury said. “As human beings, it is our moral obligation that all people in our country should get food and not go to bed on an empty stomach. Biotechnology can play an important role in this effect.”

Here’s what an infested eggplant looks like,

Non-Bt eggplant infested with fruit and shoot borer. Photo by Cornell Alliance for Science

It looks more like a fig than an eggplant.

This is part of a more comprehensive project as revealed in a March 29, 2016 Cornell University news release issued on the occasion of a $4.8M, three-year grant from the U.S. Agency for International Development (USAID),

… The award supports USAID’s work under Feed the Future, the U.S. government’s global initiative to fight hunger and improve food security using agricultural science and technology.

In the Feed the Future South Asia Eggplant Improvement Partnership, Cornell will protect eggplant farmers from yield losses and improve their livelihoods in partnership with the Bangladesh Agricultural Research Institute (BARI) and the University of the Philippines at Los Baños. Eggplant, or brinjal, is a staple crop that is an important source of income and nutrition for farmers and consumers in South Asia.

Over the past decade, Cornell has led the Agricultural Biotechnology Support Project II (ABSPII), also funded by USAID, that prompted a consortium of institutions in Asia and Africa to use the tools of modern biotechnology, particularly genetic engineering, to improve crops to address major production constraints for which conventional plant breeding tools have not been effective.

In October 2013, Bangladesh became the first country in South Asia to approve commercial cultivation of a genetically engineered food crop. In February 2014, Matia Chowdhury, the Bangladesh minister of agriculture, released four varieties of Bt brinjal to 20 farmers. With the establishment of the 20 Bt brinjal demonstration plots in 2014 and 104 more in 2015, BARI reported a noticeable decrease in fruit and shoot borer infestation, increased yields, decreased use of pesticide and improved income for farmers.

The Feed the Future South Asia Eggplant Improvement Partnership addresses and integrates all elements of the commercialization process — including technology development, regulation, marketing, seed distribution, and product stewardship. It also provides strong platforms for policy development, capacity building, gender equality, outreach and communication.

Moving on from practical applications …

Canada’s synthetic biology training centre

It seems Concordia University (Montréa) is a major Canadian centre for all things ‘synthetic biological’. (from the History and Vision webpage on Concordia University’s Centre for Applied Synthetic Biology webspace),

History and vision

Emerging in 2012 from a collaboration between the Biology and Electrical and Computer Engineering Departments, the Centre received University-wide status in 2016 growing its membership to include Biochemistry, Journalism, Communication Studies, Mechanical, Industrial and Chemical Engineering.


Timeline

T17-36393-VPRG-Timeline-graphic-promo-v4

You can see the timeline does not yet include 2018 development(s). Also it started as “a collaboration between the Biology and Electrical and Computer Engineering Departments?” This suggests a vastly different approach to genetic engineering that that employed in the “eggplant” research. From a July 16, 2018 posting on the Genome Alberta blog,

The Natural Sciences and Engineering Research Council of Canada (NSERC) has committed $1.65 million dollars over six years to establish a research and training program at Concordia’s Centre for Applied Synthetic Biology.

The funds were awarded after Malcolm Whiteway (…), professor of biology and the Canada Research Chair in Microbial Genomics, and the grant application team submitted a proposal to NSERC’s Collaborative Research and Training Experience (CREATE) program.

The Synthetic Biology Applications CREATE program — or SynBioApps — will help students acquire and develop important professional skills that complement their academic education and improve their job-readiness.

‘Concordia is a natural fit’

“As the Canadian leader in synthetic biology and as the home of the country’s only genome foundry, Concordia is a natural fit for a training program in this growing area of research,” says Christophe Guy, vice-president of Research and Graduate Studies.

“In offering a program like SynBioApps, we are providing our students with both a fundamental education in science and the business skills they’ll need to transition into their professional careers.”

The program’s aims are twofold: First, it will teach students how to design and construct cells and proteins for the development of new products related to human health, green technologies, and fundamental biological investigations. Second, it will provide cross-disciplinary training and internship opportunities through the university’s District 3 Innovation Center.

SynBioApps will be open to students from biology, biochemistry, engineering, computing, and mathematics.

“The ability to apply engineering approaches to biological systems promises to revolutionize both biology and industry,” says Whiteway, who is also a member of the Centre for Applied Synthetic Biology.

“The SynBioApps program at Concordia will provide a training program to develop the students who will both investigate the biology and build these industries.”

You can find out more about Concordia’s Centre for Applied Synthetic Biology here (there are jobs listed on their home page) and you can find information about the Synthetic Biology Applications (SynBioApps) training programme here.

Do you want that coffee with some graphene on toast?

These scientists are excited:

For those who prefer text, here’s the Rice University Feb. 13, 2018 news release (received via email and available online here and on EurekAlert here) Note: Links have been removed),

Rice University scientists who introduced laser-induced graphene (LIG) have enhanced their technique to produce what may become a new class of edible electronics.

The Rice lab of chemist James Tour, which once turned Girl Scout cookies into graphene, is investigating ways to write graphene patterns onto food and other materials to quickly embed conductive identification tags and sensors into the products themselves.

“This is not ink,” Tour said. “This is taking the material itself and converting it into graphene.”

The process is an extension of the Tour lab’s contention that anything with the proper carbon content can be turned into graphene. In recent years, the lab has developed and expanded upon its method to make graphene foam by using a commercial laser to transform the top layer of an inexpensive polymer film.

The foam consists of microscopic, cross-linked flakes of graphene, the two-dimensional form of carbon. LIG can be written into target materials in patterns and used as a supercapacitor, an electrocatalyst for fuel cells, radio-frequency identification (RFID) antennas and biological sensors, among other potential applications.

The new work reported in the American Chemical Society journal ACS Nano demonstrated that laser-induced graphene can be burned into paper, cardboard, cloth, coal and certain foods, even toast.

“Very often, we don’t see the advantage of something until we make it available,” Tour said. “Perhaps all food will have a tiny RFID tag that gives you information about where it’s been, how long it’s been stored, its country and city of origin and the path it took to get to your table.”

He said LIG tags could also be sensors that detect E. coli or other microorganisms on food. “They could light up and give you a signal that you don’t want to eat this,” Tour said. “All that could be placed not on a separate tag on the food, but on the food itself.”

Multiple laser passes with a defocused beam allowed the researchers to write LIG patterns into cloth, paper, potatoes, coconut shells and cork, as well as toast. (The bread is toasted first to “carbonize” the surface.) The process happens in air at ambient temperatures.

“In some cases, multiple lasing creates a two-step reaction,” Tour said. “First, the laser photothermally converts the target surface into amorphous carbon. Then on subsequent passes of the laser, the selective absorption of infrared light turns the amorphous carbon into LIG. We discovered that the wavelength clearly matters.”

The researchers turned to multiple lasing and defocusing when they discovered that simply turning up the laser’s power didn’t make better graphene on a coconut or other organic materials. But adjusting the process allowed them to make a micro supercapacitor in the shape of a Rice “R” on their twice-lased coconut skin.

Defocusing the laser sped the process for many materials as the wider beam allowed each spot on a target to be lased many times in a single raster scan. That also allowed for fine control over the product, Tour said. Defocusing allowed them to turn previously unsuitable polyetherimide into LIG.

“We also found we could take bread or paper or cloth and add fire retardant to them to promote the formation of amorphous carbon,” said Rice graduate student Yieu Chyan, co-lead author of the paper. “Now we’re able to take all these materials and convert them directly in air without requiring a controlled atmosphere box or more complicated methods.”

The common element of all the targeted materials appears to be lignin, Tour said. An earlier study relied on lignin, a complex organic polymer that forms rigid cell walls, as a carbon precursor to burn LIG in oven-dried wood. Cork, coconut shells and potato skins have even higher lignin content, which made it easier to convert them to graphene.

Tour said flexible, wearable electronics may be an early market for the technique. “This has applications to put conductive traces on clothing, whether you want to heat the clothing or add a sensor or conductive pattern,” he said.

Rice alumnus Ruquan Ye is co-lead author of the study. Co-authors are Rice graduate student Yilun Li and postdoctoral fellow Swatantra Pratap Singh and Professor Christopher Arnusch of Ben-Gurion University of the Negev, Israel. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of computer science and of materials science and nanoengineering at Rice.

The Air Force Office of Scientific Research supported the research.

Here’s a link to and a citation for the paper,

Laser-Induced Graphene by Multiple Lasing: Toward Electronics on Cloth, Paper, and Food by Yieu Chyan, Ruquan Ye†, Yilun Li, Swatantra Pratap Singh, Christopher J. Arnusch, and James M. Tour. ACS Nano DOI: 10.1021/acsnano.7b08539 Publication Date (Web): February 13, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

h/t Feb. 13, 2018 news item on Nanowerk

NanoFARM: food, agriculture, and nanoparticles

The research focus for the NanoFARM consortium is on pesticides according to an October 19, 2017 news item on Nanowerk,

The answer to the growing, worldwide food production problem may have a tiny solution—nanoparticles, which are being explored as both fertilizers and fungicides for crops.

NanoFARM – research consortium formed between Carnegie Mellon University [US], the University of Kentucky [US], the University of Vienna [Austria], and Aveiro University in Prague [Czech Republic] – is studying the effects of nanoparticles on agriculture. The four universities received grants from their countries’ respective National Science Foundations to discover how these tiny particles – some just 4 nanometers in diameter – can revolutionize how farmers grow their food.

An October ??, 2017 Carnegie Mellon University news release by Adam Dove, which originated the news item, fills in a few more details,

“What we’re doing is getting a fundamental understanding of nanoparticle-to-plant interactions to enable future applications,” says Civil and Environmental Engineering (CEE) Professor Greg Lowry, the principal investigator for the nanoFARM project. “With pesticides, less than 5% goes into the crop—the rest just goes into the environment and does harmful things. What we’re trying to do is minimize that waste and corresponding environmental damage by doing a better job of targeting the delivery.”

The teams are looking at related questions: How much nanomaterial is needed to help crops when it comes to driving away pests and delivering nutrients, and how much could potentially hurt plants or surrounding ecosystems?

Applied pesticides and fertilizers are vulnerable to washing away—especially if there’s a rainstorm soon after application. But nanoparticles are not so easily washed off, making them extremely efficient for delivering micronutrients like zinc or copper to crops.

“If you put in zinc oxide nanoparticles instead, it might take days or weeks to dissolve, providing a slow, long-term delivery system.”

Gao researches the rate at which nanoparticles dissolve. His most recent finding is that nanoparticles of copper oxide take up to 20-30 days to dissolve in soil, meaning that they can deliver nutrients to plants at a steady rate over that time period.

“In many developing countries, a huge number of people are starving,” says Gao. “This kind of technology can help provide food and save energy.”

But Gao’s research is only one piece of the NanoFARM puzzle. Lowry recently traveled to Australia with Ph.D. student Eleanor Spielman-Sun to explore how differently charged nanoparticles were absorbed into wheat plants.

They learned that negatively charged particles were able to move into the veins of a plant—making them a good fit for a farmer who wanted to apply a fungicide. Neutrally charged particles went into the tissue of the leaves, which would be beneficial for growers who wanted to fortify a food with nutritional value.

Lowry said they are still a long way from signing off on a finished product for all crops—right now they are concentrating on tomato and wheat plants. But with the help of their university partners, they are slowly creating new nano-enabled agrochemicals for more efficient and environmentally friendly agriculture.

For more information, you can find the NanoFARM website here.

Popping (nano)bubbles!

Who doesn’t love to pop bubbles? Well, there’s probably someone out there but it does seem to be a near universal delight (especially with the advent of bubble wrap which I’ve seen more than one person happily popping). Scientists are no more immune to that impulse than the rest of us although they approach the whole endeavour from a more technical perspective where popping bubbles becomes destabilization and bubble rupture. From a Sept. 28, 2017 American Institute of Physics (AIP) news release (also on EurekAlert),

Nanobubbles have recently gained popularity for their unique properties and expansive applications. Their large surface area and high stability in saturated liquids make nanobubbles ideal candidates for food science, medicine and environmental advancements. Nanobubbles also have long lifetimes of hours or days, and greater applicability than traditional macrobubbles, which typically only last for seconds.

The stability of nanobubbles is well understood, but the mechanisms causing their eventual destabilization are still in question. Using molecular dynamics simulations (MDS), researchers from the Beijing University of Chemical Technology explored the effect of surfactants — components that lower surface tension — on the stabilization of nanobubbles. They report their findings on the surprising mechanisms of destabilization [emphasis mine] for both soluble and insoluble surfactants this week [Sept. 25-29, 2017] in Applied Physics Letters, from AIP Publishing.

Researchers investigated the differences between soluble and insoluble surfactants and their varying influence on nanobubble stability using MDS software. They created a controled model system where the only variables that could be manipulated were the number of surfactants and the interaction between the surfactant and the substrate, the base of the model where the bubble is formed, to measure the direct influence of surfactants on nanobubble stability.

Analyzing both soluble and insoluble surfactants, the group focused on two possible mechanisms of destabilization: contact line depinning, where the surfactant flexibility reduces the forces responsible for stabilizing the bubble shape, causing it to rupture from lack of inner surface force; and surface tension reduction, causing a liquid to vapor phase transition.

The found soluble surfactants initiated nanobubble depinning when a large amount, roughly 80 percent, of the surfactant was adsorbed by the substrate, eventually causing the nanobubbles to burst.

“However, when small concentrations of soluble surfactant were introduced it remained dissolved, and adsorption onto the substrate was insignificant, generating a negligible effect on nanobubble stability,” said Xianren Zhang at Beijing University of Chemical Technology.

Simulations with insoluble surfactants showed comparable results to soluble surfactants when interacting heavily with substrates, but a new mechanism was discovered demonstrating a liquid-to-vapor transition model of bubble rupture [emphasis mine].

The transition is similar to how we traditionally envision bubbles popping, occurring when a surfactant significantly reduces the surface tension on the outside of the nanobubble. Nanobubbles destabilize in this fashion when a large amount of surfactant is present, but little — around 40 percent — surfactant-substrate interaction occurs.

These findings are critical to understanding nanobubble stability and have implications for nanobubble interaction with other molecules, including proteins and contaminants. Nanobubble applications could revolutionize aspects of modern medicine such as ultrasound techniques, expand functions in food science, and improve waste water treatment. But better characterizing basic properties like instability is essential to fully utilizing their potential in these applications.

There researchers have made this image illustrating their work available,

Several typical snapshots for nanobubbles losing their stability with various concentrations of surfactants and levels of interaction with substrates. In each picture, top panel shows evolution of the system with all involved particles, while in the bottom panel, solvent molecules are not shown to clarify the effect of surfactants. CREDIT: Qianxiang Xiao, Yawei Liu, Zhenjiang Guo, Zhiping Liu, and Xianren Zhang

Here’s a link to and a citation for the paper,

How nanobubbles lose stability: Effects of surfactants featured by Qianxiang Xiao, Yawei Liu, Zhenjiang Guo, Zhiping Liua, and Xianren Zhang. Appl. Phys. Lett. 111, 131601 (2017); doi: http://dx.doi.org/10.1063/1.5000831

This paper is open access.

A jellyfish chat on November 28, 2017 at Café Scientifique Vancouver get together

Café Scientifique Vancouver sent me an announcement (via email) about their upcoming event,

We are pleased to announce our next café which will happen on TUESDAY,
NOVEMBER 28TH at 7:30PM in the back room of YAGGER'S DOWNTOWN (433 W
Pender).

JELLYFISH – FRIEND, FOE, OR FOOD?

Did you know that in addition to stinging swimmers, jellyfish also cause
extensive damage to fisheries and coastal power plants? As threats such
as overfishing, pollution, and climate change alter the marine
environment, recent media reports are proclaiming that jellyfish are
taking over the oceans. Should we hail to our new jellyfish overlords or
do we need to examine the evidence behind these claims? Join Café
Scientifique on Nov. 28, 2017 to learn everything you ever wanted to
know about jellyfish, and find out if jelly burgers are coming soon to a
menu near you.

Our speaker for the evening will be DR. LUCAS BROTZ, a Postdoctoral
Research Fellow with the Sea Around Us at UBC’s Institute for the
Oceans and Fisheries. Lucas has been studying jellyfish for more than a
decade, and has been called “Canada’s foremost jellyfish
researcher” by CBC Nature of Things host Dr. David Suzuki. Lucas has
participated in numerous international scientific collaborations, and
his research has been featured in more than 100 media outlets including
Nature News, The Washington Post, and The New York Times. He recently
received the Michael A. Bigg award for highly significant student
research as part of the Coastal Ocean Awards at the Vancouver Aquarium.

We hope to see you there!

You can find out more about Lucas Brotz here and about Sea Around Us here.

For anyone who’s curious about the jellyfish ‘issue’, there’s a November 8, 2017 Norwegian University of Science and Technology press release on AlphaGallileo or on EurekAlert, which provides insight into the problems and the possibilities,

Jellyfish could be a resource in producing microplastic filters, fertilizer or fish feed. A new 6 million euro project called GoJelly, funded by the EU and coordinated by the GEOMAR Helmholtz Centre for Ocean Research, Germany and including partners at the Norwegian University of Science and Technology (NTNNU) and SINTEF [headquartered in Trondheim, Norway, is the largest independent research organisation in Scandinavia; more about SINTEF in its Wikipedia entry], hopes to turn jellyfish from a nuisance into a useful product.

Global climate change and the human impact on marine ecosystems has led to dramatic decreases in the number of fish in the ocean. It has also had an unforseen side effect: because overfishing decreases the numbers of jellyfish competitors, their blooms are on the rise.

The GoJelly project, coordinated by the GEOMAR Helmholtz Centre for Ocean Research, Germany, would like to transform problematic jellyfish into a resource that can be used to produce microplastic filter, fertilizer or fish feed. The EU has just approved funding of EUR 6 million over 4 years to support the project through its Horizon 2020 programme.

Rising water temperatures, ocean acidification and overfishing seem to favour jellyfish blooms. More and more often, they appear in huge numbers that have already destroyed entire fish farms on European coasts and blocked cooling systems of power stations near the coast. A number of jellyfish species are poisonous, while some tropical species are even among the most toxic animals on earth.

“In Europe alone, the imported American comb jelly has a biomass of one billion tons. While we tend to ignore the jellyfish there must be other solutions,” says Jamileh Javidpour of GEOMAR, initiator and coordinator of the GoJelly project, which is a consortium of 15 scientific institutions from eight countries led by the GEOMAR Helmholtz Centre for Ocean Research in Kiel.

The project will first entail exploring the life cycle of a number of jellyfish species. A lack of knowledge about life cycles makes it is almost impossible to predict when and why a large jellyfish bloom will occur. “This is what we want to change so that large jellyfish swarms can be caught before they reach the coasts,” says Javidpour.

At the same time, the project partners will also try to answer the question of what to do with jellyfish once they have been caught. One idea is to use the jellyfish to battle another, man-made threat.

“Studies have shown that mucus of jellyfish can bind microplastic. Therefore, we want to test whether biofilters can be produced from jellyfish. These biofilters could then be used in sewage treatment plants or in factories where microplastic is produced,” the GoJelly researchers say.

Jellyfish can also be used as fertilizers for agriculture or as aquaculture feed. “Fish in fish farms are currently fed with captured wild fish, which does not reduce the problem of overfishing, but increases it. Jellyfish as feed would be much more sustainable and would protect natural fish stocks,” says the GoJelly team.

Another option is using jellyfish as food for humans. “In some cultures, jellyfish are already on the menu. As long as the end product is no longer slimy, it could also gain greater general acceptance,” said Javidpour. Finally yet importantly, jellyfish contain collagen, a substance very much sought after in the cosmetics industry.

Project partners from the Norwegian University of Science and Technology, led by Nicole Aberle-Malzahn, and SINTEF Ocean, led by Rachel Tiller, will analyse how abiotic (hydrography, temperature), biotic (abundance, biomass, ecology, reproduction) and biochemical parameters (stoichiometry, food quality) affect the initiation of jellyfish blooms.

Based on a comprehensive analysis of triggering mechanisms, origin of seed populations and ecological modelling, the researchers hope to be able to make more reliable predictions on jellyfish bloom formation of specific taxa in the GoJelly target areas. This knowledge will allow sustainable harvesting of jellyfish communities from various Northern and Southern European populations.

This harvest will provide a marine biomass of unknown potential that will be explored by researchers at SINTEF Ocean, among others, to explore the possible ways to use the material.

A team from SINTEF Ocean’s strategic program Clean Ocean will also work with European colleagues on developing a filter from the mucus of the jellyfish that will catch microplastics from household products (which have their source in fleece sweaters, breakdown of plastic products or from cosmetics, for example) and prevent these from entering the marine ecosystem.

Finally, SINTEF Ocean will examine the socio-ecological system and games, where they will explore the potentials of an emerging international management regime for a global effort to mitigate the negative effects of microplastics in the oceans.

“Jellyfish can be used for many purposes. We see this as an opportunity to use the potential of the huge biomass drifting right in front of our front door,” Javidpour said.

You can find out more about GoJelly on their Twitter account.

Cellulose- and chitin-based biomaterial to replace plastics?

Although the term is not actually used in the news release, one of the materials used to create a new biomaterial could safely be described as nanocellulose. From a Sept. 20, 2017 Pennsylvania State University (Penn State) news release (also on EurekAlert) by Jeff Mulhollem,

An inexpensive biomaterial that can be used to sustainably replace plastic barrier coatings in packaging and many other applications has been developed by Penn State researchers, who predict its adoption would greatly reduce pollution.

Completely compostable, the material — a polysaccharide polyelectrolyte complex — is comprised of nearly equal parts of treated cellulose pulp from wood or cotton, and chitosan, which is derived from chitin — the primary ingredient in the exoskeletons of arthropods and crustaceans. The main source of chitin is the mountains of leftover shells from lobsters, crabs and shrimp consumed by humans.

These environmentally friendly barrier coatings have numerous applications ranging from water-resistant paper, to coatings for ceiling tiles and wallboard, to food coatings to seal in freshness, according to lead researcher Jeffrey Catchmark, professor of agricultural and biological engineering, College of Agricultural Sciences.

“The material’s unexpected strong, insoluble adhesive properties are useful for packaging as well as other applications, such as better performing, fully natural wood-fiber composites for construction and even flooring,” he said. “And the technology has the potential to be incorporated into foods to reduce fat uptake during frying and maintain crispness. Since the coating is essentially fiber-based, it is a means of adding fiber to diets.”

The amazingly sturdy and durable bond between carboxymethyl cellulose and chitosan is the key, he explained. The two very inexpensive polysaccharides — already used in the food industry and in other industrial sectors — have different molecular charges and lock together in a complex that provides the foundation for impervious films, coatings, adhesives and more.

The potential reduction of pollution is immense if these barrier coatings replace millions of tons of petroleum-based plastic associated with food packaging used every year in the United States — and much more globally, Catchmark noted.

He pointed out that the global production of plastic is approaching 300 million tons per year. In a recent year, more than 29 million tons of plastic became municipal solid waste in the U.S. and almost half was plastic packaging. It is anticipated that 10 percent of all plastic produced globally will become ocean debris, representing a significant ecological and human health threat.

crab shells

The material is comprised of cellulose pulp from wood or cotton, and chitosan, derived from chitin, the primary ingredient in the exoskeletons of arthropods and crustaceans. The main source of chitin is shells from lobsters, crabs and shrimp. Image: © iStock Photo OKRAD

The polysaccharide polyelectrolyte complex coatings performed well in research, the findings of which were published recently in Green Chemistry. Paperboard coated with the biomaterial, comprised of nanostructured fibrous particles of carboxymethyl cellulose and chitosan, exhibited strong oil and water barrier properties. The coating also resisted toluene, heptane and salt solutions and exhibited improved wet and dry mechanical and water vapor barrier properties.

“These results show that polysaccharide polyelectrolyte complex-based materials may be competitive barrier alternatives to synthetic polymers for many commercial applications,” said Catchmark, who, in concert with Penn State, has applied for a patent on the coatings.

“In addition, this work demonstrates that new, unexpected properties emerge from multi-polysaccharide systems engaged in electrostatic complexation, enabling new high-performance applications.”

Catchmark began experimenting with biomaterials that might be used instead of plastics a decade or so ago out of concerns for sustainability. He became interested in cellulose, the main component in wood, because it is the largest volume sustainable, renewable material on earth. Catchmark studied its nanostructure — how it is assembled at the nanoscale.

He believed he could develop natural materials that are more robust and improve their properties, so that they could compete with synthetic materials that are not sustainable and generate pollution — such as the low-density polyethylene laminate applied to paper board, Styrofoam and solid plastic used in cups and bottles.

“The challenge is, to do that you’ve got to be able to do it in a way that is manufacturable, and it has to be less expensive than plastic,” Catchmark explained. “Because when you make a change to something that is greener or sustainable, you really have to pay for the switch. So it has to be less expensive in order for companies to actually gain something from it. This creates a problem for sustainable materials — an inertia that has to be overcome with a lower cost.”

lab vials

The amazingly sturdy and durable bond between carboxymethyl cellulose and chitosan is the key. The two very inexpensive polysaccharides, already used in the food industry and in other industrial sectors, have different molecular charges and lock together in a complex that provides the foundation for impervious films, coatings, adhesives and more. Image: Penn State

Funded by a Research Applications for Innovation grant from the College of Agricultural Sciences, Catchmark currently is working to develop commercialization partners in different industry sectors for a wide variety of products.

“We are trying to take the last step now and make a real impact on the world, and get industry people to stop using plastics and instead use these natural materials,” he said. “So they (consumers) have a choice — after the biomaterials are used, they can be recycled, buried in the ground or composted, and they will decompose. Or they can continue to use plastics that will end up in the oceans, where they will persist for thousands of years.”

Also involved in the research were Snehasish Basu, post-doctoral scholar, and Adam Plucinski, master’s degree student, now instructor of engineering at Penn State Altoona. Staff in Penn State’s Material Research Institute provided assistance with the project.

The U.S. Department of Agriculture supported this work. Southern Champion Tray, of Chattanooga, Tennessee, provided paperboard and information on its production for experiments.

Here’s a link to and a citation for the paper,

Sustainable barrier materials based on polysaccharide polyelectrolyte complexes by
Snehasish Basu, Adam Plucinski, and Jeffrey M. Catchmark. Green Chemistry 2017, 19, 4080-4092 DOI: 10.1039/C7GC00991G

This paper is behind a paywall. One comment, I found an anomaly on the page when I visited. At the top of the citation page, it states that this is issue 17 of Green Chemistry but the citation in the column on the right is “2017, 19 … “, which would be issue 19.