Panda Poop Could Be Used to Make Biofuel

Panda Xiao Liwu from the San Diego Zoo.  Photo courtesy of Johann Balleis via Wikimedia Commons

The giant panda spends 12 hours a day hungrily devouring between 20 to 40 pounds of bamboo. As a result, it poops—a lot. In fact, dozens of times a day. New research provides evidence that all that poo could prove useful, one day, to fuel your car.

“We have discovered microbes in panda feces [that] might actually be a solution to the search for sustainable new sources of energy,” said Mississippi State University researcher, Ashli Brown in a statement at a meeting of the American Chemical Society (ACS) on September 10.

For more than two years, Brown and her colleagues, along with scientists at the University of Wisconsin-Madison, have been studying microbes found in the panda feces of Ya Ya and Le Le, two pandas at the Memphis Zoo. Using DNA sequencing, the researchers have identified 40 microbes that live in the guts of these pandas. Those microbes could unlock a process to make biofuels in a cost-effective manner, thereby reducing our reliance on fossil fuels. 

The finding could address concerns about the use of corn, soybeans and other food crops in producing biofuels such as Ethanol.  Many worry that the process may raise food prices or cause food shortages. An Earth Policy Institute study claimed that the US grain grown in 2009 to make biofuels was enough to feed 330 million people.

Brown and other scientists claim it would be better to use non-food plant material, like corn stalks or cobs, to produce Ethanol.  But that requires special and expensive processes to break down the tough, dry plant matter, known as lignocellulose. The lignocellulose has to be pretreated using heat, high pressure, and acid. 

Scientists have long been researching alternative processes to break down the lignocellulose to create biofuels. Some say algae might be the answer. Others say termites. Brown and her colleagues declare it’s panda poop.

Why panda poop? Pandas have a unique physiology that helps them quickly and efficiently break down plant byproducts, in particular the woody bark of bamboo. They have a short digestive tract and, unlike other herbivores, such as cows, do not have extra stomachs to pretreat and digest hard lignocellulostic material. In fact, the intestinal system of the panda is the same structurally as that of a carnivore, but their digestive tract is full of microbes that have unusually potent enzymes, which break down and digest what they eat.   

Brown and her colleagues say these are the microbes that can transform lignocellulose into simple sugars.  Simple sugars can then be fermented into bioethanol. They theorize that the microbe genes producing those enzymes could be put into yeasts. The yeasts, in turn, could be mass-produced and harvested for biofuel production, thereby eliminating the current costly and energy-inefficient methods to break down non-food corn materials. 

In addition, Brown says the research will help the panda itself, one of the most endangered species on the planet. There are fewer than 2,500 left in the wild and only approximately 200 in captivity. Because many panda diseases affect the intestines, Brown postulates that her research will help improve the understanding of the relationship between the microbes and their host.

The researchers plan to expand their studies to examine feces samples from the zoo’s red pandas, another bamboo-eating species that looks more like a fox than its large, Oreo-colored cousin. They also hope to obtain more feces samples by collaborating with the Toronto Zoo.   

 

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