Effects of space flight, clinorotation, and centrifugation on the substrate utilization efficiency ofE. coli

  • Robert B. Brown
  • D. Klaus
  • P. Todd
Article

DOI: 10.1007/BF02881678

Cite this article as:
Brown, R.B., Klaus, D. & Todd, P. Microgravity sci. Technol. (2002) 13: 24. doi:10.1007/BF02881678

Abstract

Cultures of Escherichia coli grown in space reached a 25% higher average final cell population than those in comparably matched ground controls (p<0.05). However, both groups consumed the same quantity of glucose, which suggests that space flight not only stimulated bacterial growth as has been previously reported, but also resulted in a 25% more efficient utilization of the available nutrients. Supporting experiments performed in “simulated weightlessness” under clinorotation produced similar trends of increased growth and efficiency, but to a lesser extent in absolute values. These experiments resulted in increases of 12% and 9% in average final cell population (p<0.05), while the efficiency of substrate utilization improved by 6% and 9% relative to static controls (p=0.12 and p<0.05, respectively). In contrast, hypergravity, produced by centrifugation, predictably resulted in the opposite effect — a decrease of 33% to 40% in final cell numbers with corresponding 29% to 40% lower net growth efficiencies (p<0.01). Collectively, these findings support the hypothesis that the increased bacterial growth observed in weightlessness is a result of reduced extracellular mass transport that occurs in the absence of sedimentation and buoyancy-driven convection, which consequently also improves substrate utilization efficiency in suspended cultures.

Copyright information

© Springer 2002

Authors and Affiliations

  • Robert B. Brown
  • D. Klaus
    • 1
  • P. Todd
  1. 1.BioServe Space TechnologiesUniversity of ColoradoBoulderUSA