Bacterial growth curves (based on OD at 600 nm) under modeled reduced gravity (MRG) and normal gravity (NG) conditions, for E. coli in LB ( A ) and in M9 minimal media ( B ); for S. aureus in LB ( C ) and in dilute (1/50) LB ( D ). Down and up-arrows on growth curves indicate the time points at which exponential and stationary phase samples were collected, respectively. Bacterial specific growth rates (μmax; h-1) (E) and growth yields (maximum OD at 600 nm) (F) under MRG and NG conditions in various culture media. Values are means (n = 3) and the error bars represent ± standard error of the mean. * = Statistically significant difference between MRG and NG (Student's t-test, P < 0.05).