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A study of the rheological properties of a non‐Newtonian Fermentation broth
Author(s) -
Leduy A.,
Marsan A. A.,
Coupal B.
Publication year - 1974
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260160106
Subject(s) - aureobasidium pullulans , fermentation , rheology , shear thinning , newtonian fluid , viscosity , apparent viscosity , polysaccharide , chemistry , food science , sucrose , non newtonian fluid , chromatography , materials science , biochemistry , thermodynamics , composite material , physics
Polysaccharide was synthesized by Aureobasidium pullulans (or Pullularia pullulans ) 2552 in a sucrose medium. The field apparent viscosity of the culture medium from shake flask experiments rose to 24,500 cP and then dropped toward its initial value as the fermentation progressed. The magnitude of the maximum apparent viscosity depended on the initial pH of the fermentation broth. The inoculum age influenced the cultivation period before which the maximum viscosity was reached. Rheograms of the fermentation broths showed a change in viscosity behavior from Newtonian to pseudoplastic, and then toward Newtonian characteristics during the fermentation. The calculated non‐Newtonian index was found to be a sensitive factor for the indication of the non‐Newtonian behavior. Such behavior could not be detected from rheograms. Viscosity profiles of polysaccharide isolated from various stages of the fermentation showed a change from Newtonian to pseudoplastic behavior depending on the concentration (0–2%) of polysaccharide.