Although commercial-scale biofuel production is a reality—with the conversion of food crops such as corn to ethanol—scientists still long to convert nonfood plant materials to biofuels. Converting nonplant materials is hard to do with any efficiency, and so scientists are turning to a seemingly unlikely ally: the giant panda.
Yesterday, at a meeting of the American Chemical Society, scientists described the contributions giant pandas are making toward biofuel production. “The giant pandas are contributing their feces,” explained Ashli Brown, Ph.D., who heads a biofuel research effort at Mississippi State University. “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.”
Dr. Brown and her students now have 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. At the meeting, Dr. Brown added that her team is using next-generation sequencing to identify useful enzymes, which includes enzymes that break down tough biomass, as well as compounds that generate oils and fats, which turn up in Panda feces. The oils and fats could be converted into biodiesel fuel.
Ethanol made from corn is the most common alternative fuel in the United States. However, it 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.
Dr. Brown pointed out that corn stalks, corn cobs, and other plant material not used for food production would be better sources of ethanol. However, that currently requires special processing to break down the tough lignocellulose material in plant waste and other crops, such as switchgrass, grown specifically for ethanol production. Breaking down this material is costly and requires a pretreatment step using heat and high pressure or acids. Dr. Brown and other scientists are looking for bacteria that are highly efficient in breaking down lignocellulose and freeing up the material that can be fermented into ethanol.
Bacteria in giant panda digestive tracts are prime candidates. Not only do pandas digest a diet of bamboo, but have a 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,” Dr. Brown said. “And efficiency is key when it comes to biofuel production—that’s why we focused on the microbes in the giant panda.”
When asked how quickly the research might lead to actual production, Dr. Brown noted that her university was already exploring ways the research might tie into existing biofuel projects, including those the department of chemical engineering.