Autolysis of Escherichia coli and Bacillus subtilis cells in low gravity

The role of gravity in the autolysis of Bacillus subtilis and Escherichia c oli was studied by growing cells on Earth and in microgravity on Space Stat ion Mir, Autolysis analysis was completed by examining the death phase or e xponential decay of cells for approximately 4 months following the stationa ry phase. Consistent with published findings, the stationary-phase cell pop ulation was 170% and 90% higher in flight B. subtilis and E. coli cultures, respectively, than in ground cultures. Although both flight autolysis curv es began at higher cell densities than control curves, the rate of autolysi s in flight cultures was identical to that of their respective ground contr ol rates.