%0 Journal Article %1 Brown:2002:Microgravity-Sci-Technol:12521048 %A Brown, R B %A Klaus, D %A Todd, P %D 2002 %J Microgravity Sci Technol %K 22enzymegrowth %N 4 %P 24-29 %T Effects of space flight, clinorotation, and centrifugation on the substrate utilization efficiency of E. coli %U http://www.ncbi.nlm.nih.gov/pubmed/12521048 %V 13 %X 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.

@article{Brown:2002:Microgravity-Sci-Technol:12521048, 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.}, added-at = {2014-01-30T12:37:09.000+0100}, author = {Brown, R B and Klaus, D and Todd, P}, biburl = {https://www.bibsonomy.org/bibtex/2caa594f5408c7ca534db978b7977c58b/emmamryan}, description = {Effects of space flight, clinorotat... [Microgravity Sci Technol. 2002] - PubMed - NCBI}, interhash = {bf657b4c6562b3fb104d038ef4a634f6}, intrahash = {caa594f5408c7ca534db978b7977c58b}, journal = {Microgravity Sci Technol}, keywords = {22enzymegrowth}, number = 4, pages = {24-29}, pmid = {12521048}, timestamp = {2014-01-30T12:37:09.000+0100}, title = {Effects of space flight, clinorotation, and centrifugation on the substrate utilization efficiency of E. coli}, url = {http://www.ncbi.nlm.nih.gov/pubmed/12521048}, volume = 13, year = 2002 }