By Brian Vastag
From Boston, at a meeting of the American Chemical Society
Slaughterhouse leftovers such as skin, tendons, bone, and cartilage are often processed into gelatin that’s used in many products, including pill coatings and capsules. The primary protein in gelatin, collagen, can now be extracted from an engineered strain of corn, researchers report, suggesting that the pharmaceutical industry could go vegetarian.
In 2004, scientists at the company FibroGen in South San Francisco, Calif., spliced a collagen gene into corn and grew a small plot of the transgenic crop in Nebraska. But it took until now to develop a four-step procedure to recover and purify the small amounts of collagen in the corn, reports Iowa State University’s Cheng Zhang, part of the team that collaborated with FibroGen to develop the process.
Unlike its animal–by-product cousin, the corn-derived collagen purified at Iowa State in Ames is uniform in composition and should be easier for drugmakers to work with, says FibroGen’s Julio Baez. It also eliminates the danger of transferring animal viruses to people via the slaughterhouse product.
“Right now there are 1,000 cows in every cold capsule,” Baez quips. After collagen extraction, corn waste could serve as a raw material for making ethanol or other products, he says (SN: 8/25/07, p. 120).
His team is now trying to boost the yield of corny collagen. The test crop generated just 3 milligrams of collagen per kilogram of kernels.
