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Hacking Photosynthesis | Earth Wise

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A team led by the University of Illinois has been pursuing a project called Realizing Increased Photosynthetic Efficiency or RIPE, which has the aim of improving photosynthesis in order to provide farmers with higher-yielding crops in an increasingly challenging climate.  Photosynthesis is the natural, sunlight-powered process that plants use to convert carbon dioxide into sugars that fuel growth, development, and for us, crop yield.

If we think of photosynthesis as a factory line composed of multiple machines, the growth of plants is limited by the slowest machines in the line.  The RIPE project has identified some steps in photosynthesis that are slower than others and are attempting to enable plants to build more machines to speed up those slower steps.

The researchers modeled a total of 170 steps in the process of photosynthesis to identify how plants could manufacture sugars more efficiently.  In the study, the team increased crop growth by 27% by resolving two constraints:  one in the first part of photosynthesis where plants turn light energy into chemical energy and one in the second part when carbon dioxide is turned into sugars.

The researchers effectively hacked photosynthesis by adding a more efficient transport protein from algae to enhance the energy conversion process. 

In the greenhouse, these changes improved crop productivity by 52%, but in field trials, which are a more important test, these photosynthetic hacks boosted crop production by 27%.

Ultimately, the team hopes to translate these discoveries to a series of staple food crops, such as cassava, cowpea, corn, soybean and rice, which are needed to feed the world’s growing population this century.

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Photosynthetic hacks can boost crop yield, conserve water

Photo, posted June 14, 2017, courtesy of Alex Holyoake via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Has Wheat Changed for the Worse? | Earth Wise

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In recent years, the number of people affected by celiac disease, wheat allergies, or gluten or wheat sensitivity has increased dramatically.  Why this should be is not well understood.  One theory is that modern wheat varieties contain more immunoreactive protein than those used in the past.  Researchers at two German research institutions investigated this issue in detail. 

Wheat grains contain about 70% starch.  Proteins constitute 10 to 12% of wheat, and nearly 80% of that protein is gluten.  Gluten is a compound mixture of two types of protein subgroups:  gliadins and glutenins.

The researchers investigated the protein content of 60 preferred wheat varieties in use during the period between 1891 and 2010, making use of an extensive seed archive.  They selected 5 leading wheat varieties for each decade over that 120-year period and cultivated the plants under the same geographical and climate conditions.

The results were that the modern wheat varieties actually contain slightly less protein than old ones.  Gluten content itself has been essentially constant over the 120 years, although the proportion of gliadins (which are the prime suspect for causing undesired immune responses) was actually 18% lower while the proportion of glutenins was 25% higher.

Overall, they found no evidence that the immunoreactive potential of wheat has changed over the years as a result of the cultivation factors.

The researchers note that some of the other, less significant proteins in wheat have not been investigated with regard to their physiological effects, so there is more work to be done.  But so far, the culprit for increasing wheat sensitivity has not been found.

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Is modern wheat off the hook?

Photo, posted July 3, 2009, courtesy of Clare Black via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protecting Fresh Produce | Earth Wise

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Fresh fruits and vegetables can sometimes become contaminated by microorganisms during their long journey from fields to restaurants and grocery stores.  Contaminated produce can spoil other produce, which increases the number of fruits and vegetables in the supply chain that can cause illnesses. 

In order to prevent this cross-contamination between produce, researchers from Texas A&M University have designed a coating that can be applied to food-contact surfaces, like buckets, rollers, and conveyor belts.  The newly-created dual-function coating is both water-repellent and germicidal.  In other words, it can both repel and kill.  Without water, the researchers say bacteria can’t stick or multiply on surfaces, drastically reducing contamination.

To make this dual-function coating, the researchers chemically-attached a thin layer of silica to an aluminum sheet.  They then added a mixture of silica and lysozyme, a naturally-occurring germicidal protein found in egg whites and tears.  Together, the silica-aluminum and the silica-lysozyme formed microscopic bumps and crevices.  According to the research team, this rough texture, albeit microscopic, is the key to the coating’s superhydrophobic properties.  

The researchers tested the coating’s effectiveness at curbing the growth of two strains of disease-causing bacteria:  Salmonella and Listeria.  Upon review, the number of bacteria found on the dual-coating surfaces was 99.99% less than what was found on the uncoated surfaces. 

Despite the success in preventing bacterial spread, the research team said more research needs to be done to see how well the coating works for mitigating viral cross-contamination.  Since the coating would need to be reapplied after a certain amount of use, the researchers also plan to develop more permanent, dual-function coatings. 

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New dual-action coating keeps bacteria from cross-contaminating fresh produce

Photo, posted April 14, 2012, courtesy of U.S. Department of Agriculture via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protecting Canola Crops From Frost

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Canola is one of Canada’s most valuable crops.  In fact, Canada is the world’s largest exporter of canola oil.  The international market for canola oil is $27 billion a year.  The oil is very popular because it has a relatively low amount of saturated fat, a substantial amount of monosaturated fat, and is very neutral tasting.

Canadian canola farmers worry a great deal about late season, non-lethal frosts because the frosts prevent chlorophyll – a photosynthetic pigment in the seeds – from breaking down, a process they call “degreening”.  The farmers seek to have high-quality yellow embryos at seed maturity.  When the harvest contains more than 2% of green seeds, it can no longer produce Grade No. 1 quality oil.  When green seeds are processed to extract canola oil, the chlorophyll in the seeds reduces the oil’s storability and quality.  As a result, farmers receive a lower price for frost-damaged green seed canola.  This costs Canadian farmers and estimated $150 million annually.

Researchers at the University of Calgary have developed gene-based technology to produce canola plants that can withstand late-season frost and still produce high-quality seed.  They identified a specific protein that controls chlorophyll breakdown and seed maturity.  Genetic manipulation is able to enhance the seed degreening system.  They were able to reduce the amount of chlorophyll in the genetically modified canola lines by 60% after the plants were exposed to non-lethal frost. 

Ultimately, the researchers plan to develop a method to incorporate the modification into canola hybrid lines in such a way that it will be readily accepted by consumers concerned about genetically modified organisms.

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New technology helps protect valuable canola crops from frost

Photo, posted August 29, 2018, courtesy of Tinker and Rove via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Powerful Case For Protecting Whales

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Efforts to mitigate climate change typically face two major challenges.  One is to find effective ways to reduce the amount of atmospheric carbon dioxide.  The other is how to raise enough money to implement climate mitigation strategies. 

Many proposed solutions to climate change, like carbon capture and storage, are complex, expensive, and in some cases, untested.  What if there was a low-tech solution that was effective and economical?

Well, it turns out there is one, and it comes from a surprisingly simple, “no-tech” strategy to capture CO2: increase global whale populations. 

According to a recent analysis by economists with the International Monetary Fund, whales help fight climate change by sequestering CO2 in the ocean. 

Whales sequester carbon in a few ways.  They hoard it in their fat and protein-rich bodies, stockpiling tons of carbon apiece.  When whales die, they turn into literal carbon sinks on the ocean floor.  While alive, whales dive to feed on tiny marine organisms like krill and plankton before surfacing to breathe and excrete. Those latter activities release an enormous plume of nutrients, including nitrogen, iron, and phosphorous, into the water.  These so-called “poo-namis” stimulate the growth of phytoplankton, microscopic marine algae that pull CO2 out of the air and return oxygen to the air via photosynthesis.  Phytoplankton are responsible for every other breath we take, contributing at least 50% of all oxygen to the atmosphere and capturing approximately 40% of all CO2 produced. 

With other economic benefits like ecotourism factored in, economists estimate that each whale is worth $2 million over its lifetime, making the entire global population possibly a one trillion dollar asset to humanity.

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How much is a whale worth?

Photo, posted June 12, 2013, courtesy of Gregory Smith via Flickr.

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Climate Change And Nutrients

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Ending hunger isn’t a question of producing enough food.  Globally, enough food is produced to feed all 7.7 billion people on the planet.  But despite this, approximately 1 in 9 people go hungry.  Conflict, natural disasters, and extreme poverty are some of the main drivers of global hunger. 

Climate change is another.  The more frequent and intense extreme weather events increase food insecurity and malnutrition by destroying land, livestock, crops, and food supplies.  Climate change makes growing crops harder every year, especially for those who lack the tools and technology to adapt. 

But the challenge of reducing hunger and malnutrition is to not only produce foods that provide enough calories, but to also produce foods that make enough necessary nutrients widely available.  According to new research, climate change is projected to significantly reduce the availability of critical nutrients such as protein, iron, and zinc over the next 30 years.  The total impact of climate change could reduce global per capita nutrient availability of protein, iron, and zinc by 19.5%, 14.4%, and 14.6%, respectively.

While higher levels of carbon dioxide can boost growth in plants, wheat, rice, corn, barley, potatoes, soybeans, and vegetables are all projected to suffer nutrient losses of about 3% on average by 2050 due to the elevated CO2 levels.

The study, which was co-authored by an international group of researchers and published in the peer-reviewed journal, Lancet Planetary Health, represents the most comprehensive synthesis of the impacts of climate change on the availability of nutrients in the global food supply to date. 

Climate change is complicating the quest to end global hunger and malnutrition. 

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Rising CO2, climate change projected to reduce availability of nutrients worldwide

Photo, posted April 30, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Why Choose Chicken Over Beef?

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Food production is a major driver of climate change.  It’s responsible for more than a quarter of all greenhouse gas emissions.  But the environmental impact of different foods varies greatly, and making seemingly insignificant changes can actually have significant impacts. 

According to a first-ever national study of U.S. eating habits and their carbon footprints, choosing chicken over beef will cut your dietary carbon footprint in half.

The National Health and Nutrition Examination Survey asked more than 16,000 participating Americans to name all the foods they consumed in the past 24 hours. The research team then calculated the carbon footprint of what people said they ate.  If a respondent consumed broiled beef steak, for example, researchers calculated what the carbon footprint would have been had broiled chicken been consumed instead.   

The study’s findings illustrate how making one simple substitution can significantly reduce a person’s dietary carbon footprint.  A diet’s carbon footprint is the amount of greenhouse gas emissions that result from the energy, fertilizer, land use, and other inputs necessary to produce food.

In general, animal-based foods have a bigger carbon footprint than plant-based foods.  For example, producing beef uses 20 times the land and emits 20 times the emissions as growing beans (per gram of protein), and requires 10 times more resources than producing chicken. 

According to the World Resources Institute, keeping the increase in global warming below 2°C will be impossible without limiting the global rise in meat consumption. 

Last year, the EAT-Lancet Commission report found that a radical transformation of the global food system was needed because it’s threatening the stability of the climate. 

Make a change – big or small – today. 

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Choosing chicken over beef cuts our carbon footprints a surprising amount

Photo, posted August 30, 2011, courtesy of Ken Hawkins via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Whopping Change

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Burger King, the global hamburger fast food giant, recently made a huge announcement:  Customers will soon have the option to select either a beef patty or a plant-based patty when ordering the iconic Whopper sandwich. 

Burger King’s plant-based patty will be made by Impossible Foods, a California startup founded in 2011 with the explicit goal of decreasing the world’s reliance on animal agriculture.  Impossible Foods signature product, the Impossible burger, has already debuted as a slider in White Castle’s 380 or so stores.  It’s also being added to the menu at all 570 Red Robin locations.  Other plant-based innovators, such as Beyond Meat, have also found some mainstream success.  But the Impossible Whopper and the planned national roll-out at Burger King’s 7,200 locations is the biggest deal to date.

Impossible Foods’ major innovation comes from its use of heme, which is an iron-rich protein that in essence is what makes meat taste like meat.  Impossible Foods cultivates heme directly from plants – soybean plant roots to be exact – and then mass produces it using yeast.  This is then mixed with other plant-based ingredients to achieve the nutty texture of ground beef.

Meat production is one of the biggest single contributors to climate change.  The Impossible burger represents a better choice for the environment.  It requires 87% less water, 96% less land, and produces 89% fewer greenhouse gas emissions when compared with beef burgers.  At Burger King, the Impossible Whopper will have the same amount of protein as the regular Whopper, but 15% less fat and 90% less cholesterol. 

Meatless continues to push into the mainstream.

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Behold the Beefless ‘Impossible Whopper’

Photo, posted November 27, 2018, courtesy of Sarah Stierch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hydrogen From Water And Sun

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There are research efforts around the world seeking ways to produce hydrogen starting from water and using clean energy.  Finding an economical and scalable way to do this is a key to the so-called hydrogen economy.

A recent study at Argonne National Laboratory makes use of a chemical reaction pathway central to plant biology to create a process that converts water into hydrogen using energy from the sun.

The process combines two membrane-bound protein complexes to perform the conversion of water molecules into hydrogen and oxygen.

The first protein complex, which the researchers call Photosystem I, is a membrane protein that uses energy from light to feed electrons to an inorganic catalyst that makes hydrogen.  But this represents only half of the overall process.

A second protein complex that they call Photosystem II uses energy from light to split water and take electrons from it.  The electrons are then fed to Photosystem I.

The two protein complexes are embedded in thylakoid membranes, which are like those found inside the oxygen-creating chloroplasts in plants.  This membrane is an essential part of pairing the two photosystems.  It supports both of the photosystems and provides a pathway for transferring electrons between the proteins.

The researchers also make use of a synthetic catalyst made from nickel or cobalt that replaces expensive platinum catalysts used in conventional water-splitting schemes.  Combining the light-triggered transport of electrons with the synthetic catalyst results in what the researchers call the “Z-scheme”, an adaptation of photosynthesis to produce hydrogen.

The next step is to incorporate the scheme into a living system which the researchers hope will lead to a practical system for hydrogen production.

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Discovery adapts natural membrane to make hydrogen fuel from water

Photo, posted December 25, 2017, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hacking Photosynthesis

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There is an enzyme known as RuBisCo that is involved in carbon fixation, the process plants use to convert carbon dioxide into sugar molecules.  The RuBisCo molecule is inside the leaves of most plants and is probably the most abundant protein in the world.

RuBisCo picks up carbon dioxide from the air and uses energy from the sun to turn the carbon into sugar molecules.  This process of photosynthesis is pretty much the foundation of life on Earth.

Wonderful as it is, the process is not perfect.  RuBisCo is not very selective in grabbing molecules from the air.  It picks up oxygen as well as CO2 and it produces a toxic compound when it does that.

Plants operate a whole other complicated chemical process to deal with this toxic byproduct and uses up a lot of energy along the way, leaving less energy for making leaves or food that we can eat.

A research program at the University of Illinois called Realizing Increased Photosynthetic Efficiency (or RIPE) has been trying to correct this problem; they have been trying to hack photosynthesis.  And they may well have succeeded.

Using genetic modification on tobacco plants, they have shut down the existing detoxification process and set up a much more efficient new one.  The result is super plants that grow faster and up to 40% bigger.

The next step is to get it to work on plants that people actually rely upon for food, like tomatoes, soybeans and black-eyed peas (which are a staple food crop in sub-Saharan Africa where food is scarce.)

It will be years before we know if the process can really produce more food and be safe, but it may end up leading to a major increase in crop productivity.

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Scientists Have ‘Hacked Photosynthesis’ In Search Of More Productive Crops

Photo, posted June 10, 2013, courtesy of Boon Hong Seto via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Weird Answer To A Serious Problem

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Resistance to antibiotics is a rising problem that costs an estimated 700,000 lives each year.  Some experts predict that if the problem can’t be solved, that number could grow to 10 million deaths annually by 2050.  As a result, researchers around the world are investigating multiple ways to help fight antibiotic resistance.

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Spider Silk

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Spider silk – the protein fiber spun by spiders to make webs, nests, cocoons, and wrapping for prey that they stash away – is a remarkable substance.  Its mechanical properties combine high tensile strength and high extensibility or ductility.  This allows spider silk to absorb a lot of energy before breaking.   It is stronger than steel, but not as strong as Kevlar, for example.  On the other hand, it is tougher than either.

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Plant Protein On The Rise

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The United Nations declared 2016 to be the International Year of Pulses.  Pulses, which are also known as grain legumes, are a group of 12 crops that includes dry beans, dry peas, chickpeas and lentils.  They are high in protein as well as fiber and various vitamins.  Pulse crops are highly sustainable and require much less water than many other food crops.  So there is a real effort underway to promote their production as part of improving food security around the world.

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Carbon Dioxide And Bees

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The decline of bee populations worldwide is a serious problem that threatens much of agriculture.  From 2006 to 2011, losses in managed honeybee colonies in the U.S. averaged 33 percent a year.  In recent years, beekeepers have had to replace 50 percent of their colonies each year.

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The Incredible Shrinking Bison

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As the climate warms, all sorts of things are happening in the environment.   We know about shrinking ice caps, retreating glaciers, strange winter weather, and so forth.  But there are other things that may happen that are unexpected and puzzling.

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