One Endangered Giant Panda’s Waste is Humanity’s Biofuel Treasure

Although it is an endangered species, China’s giant panda may guide
humanity towards an improved process for creating ethanol, a renewable

An Introduction to the Giant Panda
The giant panda, Ailuropoda melanoleuca, is a native of China’s mountains in the Gansu, Shaanxi and Sichuan provinces. Its biological classification is ‘carnivorous bear,’ but it is famous for eating bamboo.

Male giant pandas have about a thirty pound advantage over females: 250 versus 220 pounds for the largest of each gender. They are about five feet long on average.

They are easily recognized for their white fur and distinctive black markings on the legs, ears, and around the eyes. Some speculate that this pattern may serve as camouflage in a snow-and-rock environment.

What Terrain Do Giant Panda Bears Prefer?

Giant pandas are found at elevations of 5-10,000 feet. Whether the forest is coniferous or deciduous, these bears require a dense undergrowth of bamboo.

Whether by preference, or because it is necessary for bamboo, these pandas live where the climate includes abundant heavy rain and frequent fog cover.

Giant Panda Chewing BambooPhoto: drs2biz

How Do Giant Pandas Live?

Giant pandas live fairly solitary lives, although they leave scent to mark territory. They might share territory, however, and meet casually in the course of foraging. Naturally they meet to mate; mothers rear their cubs until they reach the age of 18 to 24 months.

In the wild, almost the entire diet consists of bamboo, with minimal supplementation of grass or very small game. Zoos add some other fruits and vegetables, but the staple is always bamboo.

Since its digestive tract is almost as short as that of carnivorous bears, the panda ‘wastes’ a large percentage of its daily 30 pounds of fibrous food as feces. In the wild, a giant panda must forage and eat for ten to sixteen hours a day.

They also drink water from rivers, despite the high water content of fresh bamboo.

Giant Panda with BambooPhoto: Eric Kilby

Why is the Giant Panda an Endangered Species?

Like some other endangered species, the giant panda has both a limited habitat to support its specialized diet, and a low rate of reproduction.

If there were more lowland forests with available bamboo, giant pandas could move into those areas. However, the lowlands are generally under cultivation for agricultural crops.

An adult becomes sexually mature somewhere between ages five and seven, and remain fertile until perhaps age twenty. However, the female is only fertile for a few days each spring. If she cannot hook up with a willing and able male during that time, her annual reproductive opportunity is lost.

The new mother will not mate if she is caring for an infant under one year old. Normally only one cub, of a litter of two, will survive to adulthood. Generally, each female is lucky to raise half a dozen cubs to adulthood over her own lifetime.

Estimates of the wild population of giant pandas vary from 1,000 to about 1,600. Some 300 others live in zoos.

Giant Panda having LunchPhoto: Photocapy

The Potential for Biofuel Production

Recent research suggests using the bacteria found in giant panda intestines or feces as a model for converting grass or bamboo into biofuels. Much as termites use bacteria to convert cellulose into nutrients, so do the pandas’ intestinal flora break down lignocellulose.

If pursued and developed, this could lead to harvesting switchgrass or wood chips rather than food crops such as corn, as the feedstock for biodiesel or ethanol. Currently, the research expects to copy appropriate genes from the digestive bacteria into yeast. The transgenic yeast would process the cellulose into simple sugars or fuel alcohol.

This use of natural ‘cellulose digestion’ genes would result in a simpler and less energy-intensive means of biofuel production.

It would be ironic if the giant panda, a species endangered by human encroachment and its own dietary specializations, would contribute to rescuing us from the repercussions of global climate change by means of its intestinal bacteria.

As researcher Ashli Brown, Ph.D, said, “The discovery also teaches a lesson about the importance of biodiversity and preserving endangered animals.”

American Chemical Society via PhysOrg, “Panda poop may be a treasure trove of microbes for making biofuels“, Aug. 29 2011, referenced Sept. 28, 2011.
Smithsonian National Zoological Park, “Giant Pandas“, referenced Sept. 28, 2011.