The University of Colorado at Boulder-based BioServe Space Technologies Center is sending an intriguing biomedical experiment to the International Space Station April 19 to test the effects of long-term weightlessness on antibiotic production.

In collaboration with the Bristol-Myers Squibb Pharmaceutical Research Institute in Wallingford, Conn., the experiment is designed to examine the production rate of an anti-cancer agent, actinomycin D, in weightlessness. The project, along with two other experiments designed by other institutions and companies, will be the first commercial ventures to fly on the orbiting space station.

The international space station will soon receive a new biomedical experiment. Photo: NASA

Antibiotic compounds are naturally produced by microorganisms and can be used to fight a wide variety of infections, said David Klaus of BioServe, one of the principal investigators. Actinomycin D is a special class of antibiotic that also has applications in treating certain types of cancer.

Previous experiments by BioServe and Bristol-Myers Squibb beginning in 1995 aboard space shuttles showed the production of actinomycin D was increased by 75 percent, said Raymond Lam of Bristol-Myers Squibb, the other principal investigator on the experiment.

"In some instances, the flight samples had not yet even reached peak production by the end of the shuttle missions, which last about two weeks," said Klaus, also a CU-Boulder aerospace engineering associate professor. In contrast, the antibiotic experiment on the space station will last about three months, he said.

For the space station experiment, BioServe engineers have developed a more efficient flight-fermentation device that allows microbial cell cultures to be fed, their waste removed and byproducts periodically sampled. The device also exchanges gases from tiny pores in flat bags containing the microbial cell cultures with air in the space station.

Ground-based tests have shown that antibiotic production in the new apparatus is 200 times better than in the original test tubes, said Klaus. "The production levels being reached in the space flight hardware -- which has to meet stringent safety and power constraints for use in the shuttle or the space station -- are now approaching those of more typical lab methods on Earth," said Klaus.

"By gaining a better understanding of what is causing the stimulated production of antibiotics in space, scientists hope to design techniques that mimic the increase in productivity in labs on Earth," Klaus said. Even a small increase in Earth-based antibiotic production could produce substantial financial gain, he said.

The experiment will be flying on a device known as the Commercial Generic Bioprocessing Apparatus, or CGBA, a suitcase-sized payload designed and built by BioServe that has been used to carry out dozens of life science and biomedical experiments in space. Versions of the CGBA have flown on 14 shuttle missions, including two that flew on Russia's Mir Space Station before its demise in March 2001.

While the new antibiotic experiment is automated, it can be controlled and adjusted from BioServe's Remote Payload and Operations and Control Center on campus, said BioServe Director Louis Stodieck. It also will be monitored daily, primarily by CU-Boulder aerospace engineering alumnus and space station astronaut Jim Voss, who has been trained on the apparatus.

Headquartered in the aerospace engineering department of CU-Boulder's engineering college and involving both students and faculty, BioServe is a joint venture between NASA, CU-Boulder and Kansas State University that undertakes a variety of industry-driven, life science experiments.

"The International Space Station represents a new era for long- duration life sciences experiments, and everyone here is extremely excited," said Stodieck, also an associate research professor in CU's aerospace engineering department. BioServe plans to fly additional biomedical experiments on the orbiting station next year, as well as a K-12 educational payload, he said.