title: Using a flexible shaft agitator to enhance the rheology of a complex fungal fermentation culture.
abstract: The rheology behavior of biological fluids particularly when the viscosity is high and rheology is complex, is an important issue to understand, particularly for studies in mass-transfer and for solving technical problems with mixing in stirred bioreactors. In this paper, the use of a Swingstir(®) impeller during the fermentation of Aspergillus oryzae resulted in decreases from the parameters of a power-law model, in viscosity and in the thixotropic behavior of a cultivation broth. The results showed that both the K L a and the alpha amylase activity were improved when using the Swingstir(®) in comparison with Fullzone(®) impeller (FZ) at the same level of energy consumption. Increasing the pellet porosity during mixing via the Swingstir(®) resulted in increases in oxygen mass transfer and the average shear stress.
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, 1-1 Rokkodaicho, Nada-ku, Kobe, 657-8501, Japan. nargesghobadi@stu.kobe-u.ac.jp.
authors.forename: Narges
authors.initials: N
authors.lastname: Ghobadi
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, 1-1 Rokkodaicho, Nada-ku, Kobe, 657-8501, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Ogino
authors.affiliation: Division of Process Equipment, Kobelco Eco-Solutions, Co., LTD, 19, Nijima, Harimacho, Kakogun, Hyogo, 675-0155, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Ogawa
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, 1-1 Rokkodaicho, Nada-ku, Kobe, 657-8501, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Ohmura
mesh_terms: D001236:Aspergillus oryzae / Q000254:growth & development*; D019149:Bioreactors; D008954:Models, Biological; D012212:Rheology
keywords: Aspergillus oryzae; Fermentation; Fullzone; Rheology; Swingstir®