September 11, 2013
Future Biofuels May Rely On Panda Poop Microbes
April Flowers for redOrbit.com - Your Universe Online
Two years ago, redOrbit reported that scientists were researching the possibility of using panda poop to make biofuels.
“Who would have guessed that ‘panda poop’ might help solve one of the major hurdles to producing biofuels, which is optimizing the breakdown of the raw plant materials used to make the fuels?” Ashli Brown, PhD, said at the time. “We hope our research will help expand the use of biofuels in the future and help cut dependency on foreign oil. We also hope it will reinforce the importance of wildlife conservation.”
This year, the same team from Mississippi State University have been using poop donated by giant pandas Ya Ya and Le Le from the Memphis Zoo to shift production of biofuels away from corn and other food crops and toward corn cobs, stalks and other non-food plant material.
The researchers presented their findings at the 246th National Meeting & Exposition of the American Chemical Society (ACS), the world's largest scientific society. If the study continues as expected, soon giant pandas Er Shun and Da Mao in the Toronto Zoo will be making their own contributions.
"The giant pandas are contributing their feces," explained Brown, who heads the research. "We have discovered microbes in panda feces might actually be a solution to the search for sustainable new sources of energy. It's amazing that here we have an endangered species that's almost gone from the planet, yet there's still so much we have yet to learn from it. That underscores the importance of saving endangered and threatened animals."
Brown's team has identified more than 40 microbes living in the guts of giant pandas at the Memphis Zoo that could make biofuel production from plant waste easier and cheaper. Brown added that their research may also provide new information for keeping the giant pandas healthy.
The most common alternative fuel in the US is ethanol, made from corn. Ethanol, however, has fostered concerns that wide use of corn, soybeans and other food crops for fuel production may raise food prices or lead to shortages of food.
A better source of ethanol, according to Brown, would be corn stalks, corn cobs and other plant material not used for food production. Such use requires special processing to break down the tough lignocellulose material in plant waste and other crops, such as switchgrass, grown specifically for ethanol production. The production and processing is costly and breaking down the material requires a pretreatment step using heat and high pressure or acids. The research team is looking for bacteria that are highly efficient in breaking down lignocellulose and freeing up the material that can be fermented into ethanol.
Prime candidates for these types of bacteria are found in the digestive tracts of giant pandas. Pandas digest an almost exclusive diet of bamboo, as well as having a very short digestive tract that requires bacteria with unusually potent enzymes for breaking down lignocellulose.
"The time from eating to defecation is comparatively short in the panda, so their microbes have to be very efficient to get nutritional value out of the bamboo," Brown said. "And efficiency is key when it comes to biofuel production — that's why we focused on the microbes in the giant panda."
Brown's team collaborated with scientists at the University of Wisconsin-Madison to identify bacteria that break down lignocellulose into simple sugars, which can be fermented into bioethanol. Bacteria were identified that can transform such sugars into oils and fats for biodiesel production.
According to Brown, either the bacteria themselves or the enzymes in them that actually do the work could be part of the industrial process.
"These studies also help us learn more about this endangered animal's digestive system and the microbes that live in it, which is important because most of the diseases pandas get affect their guts," said Brown. "Understanding the relationships between the microbes and the pandas, as well as how they get their energy and nutrition, is extremely important from a conservation standpoint, as fewer than 2,500 giant pandas are left in the wild and only 200 are in captivity."
The team intends to expand their work to include samples from red pandas at the Memphis Zoo, which also eat bamboo. The researchers are collaborating with the Toronto Zoo to get samples of feces from giant pandas that arrived earlier in 2013.