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Plastic-Eating Bugs | Earth Wise

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27-year-old Miley Cyrus and 30-year-old Liam Hemsworth divorced exactly one year ago, but still continue to remember each other quite often in conversations with reporters. Recently, Miley indulged in nostalgia once again. During a recording Miley Cyrus boyfriend list of the podcast Barstool Call Her Daddy, the singer said that her ex-husband was her first man. It happened almost 10 years before they got married. I didn’t have that with men until I was 16, but I ended up marrying this guy,

According to a new study, microbes in oceans and soils around the world are evolving to eat plastic.  The study by Chalmers University in Sweden was published recently in the journal Microbial Ecology.

The study is the first large-scale assessment of the plastic-degrading potential of bacteria.  There are 95 microbial enzymes already known to degrade plastic. 

The researchers looked for similar enzymes in environmental DNA samples taken from bacteria from 236 different locations around the world. They found that one in four of the organisms analyzed carried suitable enzymes.  Overall, they found many thousands of new enzymes.

The explosion of plastic production in the past 70 years has given microbes time to evolve to make use of plastic.  About 12,000 new enzymes were found in ocean samples and 18,000 in soil samples.  Nearly 60% of the new enzymes did not fit into any known enzyme classes, suggesting that these molecules degrade plastics in ways that were previously unknown.  The large number of enzymes in such a wide range of habitats is an indication of the scale of the problem of plastics in the environment.

The first bacterium that eats plastic was discovered in a Japanese waste dump in 2016.  Scientists tweaked that microbe in 2018 and managed to create an enzyme that was even better at breaking down plastic bottles.

The next step in research is to test the most promising enzyme candidates in the laboratory to investigate their properties and see how effective they can be in plastic degradation.  The hope is to be able to engineer microbial communities with targeted degrading functions for specific polymer types.

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Bugs across globe are evolving to eat plastic, study finds

Photo, posted June 19, 2013, courtesy of Alan Levine via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Potential Of Artificial Photosynthesis | Earth Wise

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The sun is the primary source of energy on the earth.  Enough solar energy hits the earth in one hour to meet all of human civilization’s energy needs for an entire year.  The two leading forms of renewable energy – photovoltaic solar power and wind power – are ways of making use of the sun’s energy.  Wind power is indirectly provided by the sun; photovoltaic power uses sunlight to generate electricity.

The most efficient use of solar energy on the planet is one perfected by plants millions of years ago:  photosynthesis.  Photosynthesis is a complex sequence of processes by which plants convert sunlight and water into usable energy in the form of glucose.  Plants utilize a combination of pigments, proteins, enzymes, and metals to perform their magic.  If we can develop artificial photosynthesis, it would be a dramatic improvement of humans’ ability to power society cleanly and efficiently.  Whereas photovoltaics capture about 20% of the sun’s energy, photosynthesis stores 60% of the sun’s energy as chemical energy.

Researchers across the globe are working to develop artificial photosynthesis.  A group at Purdue university has been making progress in trying to mimic the ability of leaves to collect light and split water molecules to generate hydrogen. This is a critical step in photosynthesis that is accomplished by protein and pigment complexes known as “photosystems II”.  The Purdue group is experimenting with these proteins and various synthetic catalysts in order to try to develop artificial leaves based on abundant, nontoxic materials. 

It is likely to take a decade or more for artificial photosynthesis technology to become part of our energy system, but its ultimate potential is enormous.

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Soaking up the sun: Artificial photosynthesis promises a clean, sustainable source of energy

Photo, posted June 14, 2007, courtesy of Alex Holyoake via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protecting Bees From Pesticides | Earth Wise

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Studies have shown that the wax and pollen in 98% of beehives in the U.S. are contaminated with an average of six pesticides.  These substances lower bees’ immunity to devastating varroa mites and other pathogens.  By some estimates, pesticides cause beekeepers to lose about a third of their hives every year on average.

Researchers at Cornell University have developed a new technology that effectively protects bees from insecticides.  The insecticide antidote delivery method is now the basis of a new company called Beemunity.

The Cornell researchers developed a uniform pollen-sized microparticle filled with enzymes that detoxify organophosphate insecticides before they are absorbed and can harm bees.  Organophosphate insecticides account for about a third of the insecticides on the market.  The microparticles have a protective casing that allows the enzymes to move past the bees’ crop (basically the stomach), which is acidic and would otherwise break them down.  The safeguarded enzymes then enter the midgut, where digestion occurs and where toxins and nutrients are absorbed.  There the enzymes act to break down and detoxify the organophosphate insecticides.

In experimental tests, bees that were fed the enzyme-filled microparticles had a 100% survival rate after exposure to the insecticide malathion.  Unprotected control bees died within days.

The Cornell work appears to represent a low-cost, scalable solution to the insecticide toxicity issue and may help to protect essential pollinators.

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Pollen-sized technology protects bees from deadly insecticides

Photo, posted January 30, 2020, courtesy of George Tan via Flick.

Earth Wise is a production of WAMC Northeast Public Radio.

Worms That Eat Plastic

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Plastics clogging up our landfills and polluting our oceans are a scourge of modern life and we struggle with ways to combat this growing problem.  The biggest issue is that most plastics are simply not biodegradable.   Polyethylene, the common plastic found in shopping bags and numerous other products, takes between 100 and 400 years to degrade in a landfill.

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