Kevin Lee, owner of the Save More meat store, weighs a pork sparerib in Pacifica, Calif., Friday. The U.S. Department of Agriculture warned Thursday that record high corn prices, caused in part by the crop's diversion into ethanol production, is likely to produce a sudden drop in the supply of meat.

San Francisco ? The ethanol craze is putting the squeeze on corn supplies and causing food prices to rise.

Mexicans took to the streets last year to protest increased tortilla prices. The cost of chicken and beef in the United States ticked up because feed is more expensive.

That’s where biotechnology comes in.

Scientists are engineering microscopic bugs to extract fuel from a variety of noncorn sources, including the human urinary tract, a Russian fungus and the plant responsible for tequila.

The quest for alternative energy is more complicated than just finding a replacement for petroleum. Scientists and a growing number of biotechnology companies are attempting to remove corn from the ethanol equation because it has created huge demand for the global food staple.

“There is enormous growth potential” for alternative fuels, said McKinsey & Co analyst Jens Riese. “But we need to be smarter than just building the next corn ethanol plant.”

Researchers are racing against time. Already, 114 U.S. ethanol biorefineries are in operation and 80 more are under construction. Producers made nearly 5 billion gallons of ethanol last year, a 25 percent increase from the previous year.

And nearly all of it was made from edible corn kernels.

That’s good news for U.S. farmers, but consumers are suffering at the checkout stand because corn prices have nearly doubled over the last two years and will continue to climb.

And with farmers planting corn at unprecedented rates, often instead of other crops, prices for other products may soon rise as well.

Corn is a fundamental U.S. food ingredient, found in everything from soft drinks to cough syrup. It’s also a staple throughout Latin America, where residents may feel the sting of rising corn prices the most.

Backers of alternative production methods argue that a technological change is needed soon, before corn-based ethanol grows so large that other manufacturing methods will be squeezed out of the market.

That’s why genetic engineers from Berkeley to Florida are racing to produce ethanol without corn. They’re looking into termite guts, the human urinary tract and sap from palm trees for exotic microbes that can produce alternative fuel sources.

Scientists at DuPont Co., for instance, have been tinkering with the DNA of an agave-loving bug in a bid to make ethanol from corn waste rather than the kernel itself. Working with $19 million of its own money and the same amount from a Department of Energy grant, the chemical company hopes to have a pilot plant in operation by 2010.

The idea is to genetically engineer microscopic bugs such as bacteria and fungus to spit out enzymes that will break down just about every imaginable crop into ethanol. This would theoretically fulfill President Bush’s initiative to support flexible-fuel vehicles, which are capable of using gasoline and ethanol blends, and to cut gas consumption by 20 percent in 10 years.