Abstract
Production of the antibacterial polypeptide microcin B17 (MccB17) by Escherichia coli ZK650 was inhibited by simulated microgravity. The site of MccB17 accumulation was found to be different, depending on whether the organism was grown in shaking flasks or in rotating bioreactors designed to establish a simulated microgravity environment. In flasks, the accumulation was cellular, but in the reactors, virtually all the microcin was found in the medium. The change from a cellular site to an extracellular one was apparently not a function of gravity, since extracellular production occurred in these bioreactors, irrespective of whether they were operated in the simulated microgravity or normal gravity mode. More probably, excretion is due to the much lower degree of shear stress in the bioreactors. Addition of even a single glass bead to the 50-ml medium volume in the bioreactor created enough shear to change the site of MccB17 accumulation from the medium to the cells.
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Selected References
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- Connell N., Han Z., Moreno F., Kolter R. An E. coli promoter induced by the cessation of growth. Mol Microbiol. 1987 Sep;1(2):195–201. doi: 10.1111/j.1365-2958.1987.tb00512.x. [DOI] [PubMed] [Google Scholar]
- Davagnino J., Herrero M., Furlong D., Moreno F., Kolter R. The DNA replication inhibitor microcin B17 is a forty-three-amino-acid protein containing sixty percent glycine. Proteins. 1986 Nov;1(3):230–238. doi: 10.1002/prot.340010305. [DOI] [PubMed] [Google Scholar]
- Fang A., Demain A. L. Influence of aeration and carbon source on production of microcin B17 by Escherichia coli ZK650. Appl Microbiol Biotechnol. 1997 May;47(5):547–553. doi: 10.1007/s002530050971. [DOI] [PubMed] [Google Scholar]
- Fang A., Pierson D. L., Mishra S. K., Koenig D. W., Demain A. L. Gramicidin S production by Bacillus brevis in simulated microgravity. Curr Microbiol. 1997 Apr;34(4):199–204. doi: 10.1007/s002849900168. [DOI] [PubMed] [Google Scholar]
- Fang A., Pierson D. L., Mishra S. K., Koenig D. W., Demain A. L. Secondary metabolism in simulated microgravity: beta-lactam production by Streptomyces clavuligerus. J Ind Microbiol Biotechnol. 1997 Jan;18(1):22–25. doi: 10.1038/sj.jim.2900345. [DOI] [PubMed] [Google Scholar]