containers. While ground tests were completed for comparison to the inflight samples, final
data analysis has not been released.
KIDNEY CELL GENE EXPRESSION
Preliminary results indicated that an average of 60% of the kidney cell samples from CGBA-
KCGE were drawn into the Vacutainers. Although the sample size was smaller, the samples
were sufficient for postflight analysis. For the synaptogenesis experiment with fruit flies,
preliminary results indicated that although the CGBA hardware operated successfully, there
were unexpected temperature drifts above the planned temperature in 2 of the 2 containers.
While ground tests were completed for comparison to the in-flight samples, final data analysis
has not been released.
ANTIBIOTIC PRODUCTION IN SPACE
This experiment originally flew on Expedition 2 but was unable to function due to technical
issues. Its reflight took place during Expedition 4 where the hardware performed as planned.
Samples of antibiotic were taken at 4-day intervals. A total of 48 samples of Streptomyces
plicatus were used to produce the antibiotic compound actinomycin D for a span of 72 days on
orbit. The initial production of actinomycin D from in-orbit samples was higher than those
produced during the ground tests. This was true for samples that were taken on day 8 (15.6 %
increase) and day 12 (28.5% increase) of the investigation. Beginning at day 16, the ground
experiment produced more antibiotics than the in-orbit experiment. This trend continued for
the remainder of the experiment. The causes for the higher yield during the first 12 days of the
experiment are still unknown. One theory is that there is a shorter lag phase, which allowed ISS
samples to reach the growth and production phases sooner than the ground samples (Benoit
2005). Identifying the mechanism that caused increased production of antibiotics while in
microgravity and applying them to production on Earth could be advantageous to the
pharmaceutical industry. A method for transferring the microgravity research results to Earth-
based production has not yet been identified.
PUBLICATION(S)
Benoit MR, Li W, Stodieck LS, et al. Microbial antibiotic production aboard the International
Space Station. Applied Microbiology Biotechnology. 2006;70(4):403–411.
Klaus DM, Howard HN. Antibiotic efficacy and microbial virulence during spaceflight. Trends in
Biotechnology. March 24, 2006. doi: 10.1016/j.tibtech.2006.01.008.
Klaus D, Benoit M, Bonomo J, et al. Antibiotic production in space using an automated fed-
bioreactor system. AIAA International Space Station Utilization – 2001 , Cape Canaveral, FL;
October 15–18, 2001.
These investigations are complete and all results are published.