An examination was made of the effect of a variety of process parameters on the foam capacity of a fermentation broth. The foaming was found to be directly related to the concentration of bacillomycin L, a surface active antibiotic produced by a strain of Bacillus subtilis. Changing the pH was found to have no direct effect on foam capacity. Lowering the incubation temperature reduced foaming but only by decreasing the production of bacillomycin L. Likewise, reductions in the concentration of glutamic acid, the nitrogen source in the medium, resulted in corresponding reductions in foam capacity, bacillomycin concentration and biomass concentration. When glutamic acid was replaced with sodium nitrate, the effects were similar. However, when glutamic acid was replaced with ammonium chloride, cell growth was poor and bacillomycin production was very low. When the pH was controlled by increasing the amount of phosphate in the medium, growth returned to normal while bacillomycin concentration and foam capacity remained relatively low. When the phosphate was replaced with Tris buffer, both bacillomycin production and foam capacity increased to normal levels, indicating that the production of bacillomycin is inhibited by the presence of inorganic phosphates. Finally, when the overall electrolyte concentration of the Tris-buffered medium was increased by 3-4 times, bacillomycin production was high but much of the foaming was suppressed.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.60637 |
| Date | January 1991 |
| Creators | Kuzak, Stephen G. (Stephen Gerard) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Chemical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001259080, proquestno: AAIMM72253, Theses scanned by UMI/ProQuest. |
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