title: Retrofit of CD-6 (Smith) impeller in fermentation vessels.
abstract: We extended prior studies on the influence of impeller type on fermentation performance to include a novel low-power-number, high-efficiency radial flow impeller, the CD-6, possessing six curved blades on a disk turbine. Dual impeller combinations of CD-6/CD-6, CD-6/Maxflo T, and CD-6/HE-3 were compared with Rushton/Rushton and Maxflo T/Maxflo T base cases. Qualitative comparisons of unaerated and aerated power draw in both water and glycerol were conducted. These suggested minimal power drops with aeration for dual CD-6 impellers and hybrids containing the CD-6 impeller design. We also examined fermentation performance for Streptomyces and Glarea secondary metabolite fermentations. A qualitative comparison of the data suggested that dual CD-6 impellers and hybrids containing the CD-6 impeller design resulted in reasonable power draws, improved mass transfer rates with airflow increases, and acceptable peak titers. These arrangements may warrant further study under a wider range of production conditions.
authors.affiliation: Bioprocess Research and Development, Merck Research Laboratories, Rahway, NJ 07065, USA. beth_junker@merck.com
authors.forename: B H
authors.initials: BH
authors.lastname: Junker
authors.forename: Z
authors.initials: Z
authors.lastname: Mann
authors.forename: G
authors.initials: G
authors.lastname: Hunt
mesh_terms: D019149:Bioreactors; D001709:Biotechnology / Q000295:instrumentation / Q000379:methods; D003470:Culture Media; D004867:Equipment Design; D005285:Fermentation; D005658:Fungi / Q000254:growth & development*; D005990:Glycerol; D013302:Streptomyces / Q000254:growth & development*; D014867:Water
chemical_list: D003470:Culture Media; D014867:Water; D005990:Glycerol