title: The influence of morphology on geldanamycin production in submerged fermentations of Streptomyces hygroscopicus var. geldanus.
abstract: The diverse morphology of the filamentous organism Streptomyces hygroscopicus var. geldanus was characterised by image analysis under various environmental conditions. In the presence of surfactant compounds, a significant decrease in the mean pellet diameter was observed. Cell aggregation was also influenced by spore inoculum level, with high concentrations reducing pellet size. In addition, the dispersion of pellets was found to increase with the inclusion of glass beads to submerged shake-flask cultures. In all cases, production of the secondary metabolite geldanamycin was determined to be dependent on the morphological profile of the organism, with a concomitant increase of 88% in geldanamycin yield observed as the mean pellet diameter was reduced by 70%. Thus, to maximise the yield of geldanamycin, it is necessary to limit pellet formation in Streptomyces hygroscopicus var. geldanus to an appropriate size.
authors.affiliation: Bioprocess Engineering Research Group, School of Biotechnology, Dublin City University, Dublin 9, Ireland.
authors.forename: Lynne F
authors.initials: LF
authors.lastname: Dobson
authors.forename: Cormac C
authors.initials: CC
authors.lastname: O'Cleirigh
authors.forename: Daniel G
authors.initials: DG
authors.lastname: O'Shea
mesh_terms: D016227:Benzoquinones / Q000378:metabolism*; D018533:Biomass; D046508:Culture Techniques / Q000379:methods*; D005285:Fermentation; D047029:Lactams, Macrocyclic / Q000378:metabolism*; D033081:Shear Strength; D013171:Spores, Bacterial / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013302:Streptomyces / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D013500:Surface Tension; D013501:Surface-Active Agents / Q000494:pharmacology
chemical_list: D016227:Benzoquinones; D047029:Lactams, Macrocyclic; D013501:Surface-Active Agents; C001277:geldanamycin