Abstract
For the BIOFILTER flight experiment a set of turbidity sensors was developed for the measurement of the growth rate of the bacteria Xanthobacter autrophicus GJ10 in a fluid medium. During the flight experiment on FOTON M2 in 2005, bacterial growth was measured revealing growth rates between 0.046–0.077 h − 1 in microgravity, i.e. approximately 1.5–2.5 times slower than routinely measured under optimal laboratory conditions on earth. To increase confidence in the equipment and for comparison of the results, a ground-reference experiment was carried out in 2006, using BIOFILTER hardware mounted on a random positioning machine (RPM). The RPM performed random rotations at 0.5°/min (for settling compensation) and 90°/min (for simulated microgravity) while the environment was controlled, accurately repeating the BIOFILTER flight temperature conditions. Despite the rotations of the RPM, a normal growth rate of 0.115 h − 1 was confirmed in both cases. The operation of the turbidity sensor was verified. Biological interpretation of the measurements is however compromised due to poor mixing and other unknown physical and biological phenomena that need to be addressed for further space experiments using these kinds of systems.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
de Vries, A., van Es, J., de Grave, W., van den Assem, D.: Thermal insulation of autonomous experiment containers in pressurized environments during pre-launch installation. Conference paper. 03ICES-72 (2003)
Janssen, D.B., Scheper, A., et al.: Degradation of halogenated aliphatic compounds by Xanthobacter autotrophicus GJ10. Appl. Environ. Microbiol. 49(3), 673–677 (1985) (Mar)
Kacena, M.A., Merrell, G.A., Manfredi, B., Smith, E.E., Klaus, D.M., Todd, P.: Bacterial growth in space flight: logistic growth curve parameters for Escherichia coli and Bacillus subtilis. Conference paper. Appl. Microbiol. Biotechnol. 51, 229–234 (1999)
Klaus, D., Simske, S., Todd, P., Stodiek, L.: Investigation of spaceflight effects on Escherichia coli and a proposed model of underlying physical mechanisms. Conference paper. Microbiology. 143, 449–455 (1997)
van Benthem, R., van den Assem, D., Kroonenman, J.: Compact optical sensor for real-time monitoring of bacterial growth for space applications. In: UEF Proceedings Micro-gravity Transport Processes in Fluid. Thermal, Biological and Material Sciences II, Banff, Canada (2001)
van Benthem, R.C., Krooneman, J., de Grave, W., Haminga-Dorenbos, H.: Thermal design and turbidity sensor for autonomous bacterial growth measurements in space-flight. Conference paper. New York Academy of Sciences Annals 1426-054 (2008)
van den Assem, D., van Benthem, R., Casteleijn, A.: Self compensating real-time biomass sensor. ESA conference publication. In: Proceeding of the First International Symposium on Micro-gravity Research and Applications in Physical Sciences and Biotechnology, Sorrento, Italy, 10–15 September 2000, ESA SP-454 vol. 1, pp. 1053–1059 (2001)
Van Loon, J.J.W.A.: Some history and use of the random positioning machine, RPM, in gravity related research. Adv. Space Res. 39, 1161–1165 (2007)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Open Access This is an open access article distributed under the terms of the Creative Commons Attribution Noncommercial License (https://creativecommons.org/licenses/by-nc/2.0), which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
About this article
Cite this article
van Benthem, R., de Grave, W. Turbidity Sensor for Bacterial Growth Measurements in Spaceflight and Simulated Micro-gravity. Microgravity Sci. Technol. 21, 349 (2009). https://doi.org/10.1007/s12217-008-9100-x
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s12217-008-9100-x