title: Gramicidin S production by Bacillus brevis in simulated microgravity.
abstract: In a continuing study of microbial secondary metabolism in simulated microgravity, we have examined gramicidin S (GS) production by Bacillus brevis strain Nagano in NASA High Aspect Rotating Vessels (HARVs), which are designed to simulate some aspects of microgravity. Growth and GS production were found to occur under simulated microgravity. When performance under simulated microgravity was compared with that under normal gravity conditions in the bioreactors, GS production was found to be unaffected by simulated microgravity. The repressive effect of glycerol in flask fermentations was not observed in the HARV. Thus the negative effect of glycerol on specific GS formation is dependent on shear and/or vessel geometry, not gravity.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: A
authors.initials: A
authors.lastname: Fang
authors.forename: D L
authors.initials: DL
authors.lastname: Pierson
authors.forename: S K
authors.initials: SK
authors.lastname: Mishra
authors.forename: D W
authors.initials: DW
authors.lastname: Koenig
authors.forename: A L
authors.initials: AL
authors.lastname: Demain
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001407:Bacillus / Q000254:growth & development* / Q000378:metabolism*; D019149:Bioreactors; D005285:Fermentation; D005632:Fructose / Q000494:pharmacology; D005990:Glycerol / Q000494:pharmacology; D006096:Gramicidin / Q000096:biosynthesis*; D018470:Gravity, Altered / Q000009:adverse effects*; D007294:Inositol / Q000494:pharmacology; D018561:Space Simulation; D014481:United States; D018557:United States National Aeronautics and Space Administration
chemical_list: D000900:Anti-Bacterial Agents; D006096:Gramicidin; D005632:Fructose; D007294:Inositol; D005990:Glycerol