Inhibition of microbial growth and metabolism by excess turbulence
Open Access
- 20 August 1991
- journal article
- review article
- Published by Wiley in Biotechnology & Bioengineering
- Vol. 38 (5), 552-556
- https://doi.org/10.1002/bit.260380514
Abstract
Excess turbulence caused by high-intensity stirring inhibited microbial growth and metabolism. In stirred tank bioreactors, the growth rate and lysine biosynthesis decreased in Brevibacterium flavum beyond 900 rpm, the growth rate of Trichoderma reesei on wheat straw beyond 150 rpm, and the growth rate of Saccharomyces cerevisae beyond 800 rpm. The term turbohypobiosis was introduced to describe this inhibition. Turbohypobiosis was characterized by a stress factor Fstr expressing the interaction of medium flow with microbial cells in local turbulent zones, dependent on the energy distribution of the stirring regime. Lysine synthesis was inhibited at significantly lower Fstr values than the growth of B. flavum. The main reason for the inhibition was shear effects causing decreased adenosine triphosphate (ATP) generation, lower O2 uptake, and lower specific growth rate of bacteria.Keywords
This publication has 6 references indexed in Scilit:
- Micromixing in fermentors: Metabolic changes inSaccharomyces cerevisiae and their relationship to fluid turbulenceBiotechnology & Bioengineering, 1990
- Stirring characteristics in bioreactorsAIChE Journal, 1990
- Biochemical reactions of Brevibacterium flavum depending on medium stirring intensity and flow structureActa Biotechnologica, 1989
- Variation in cellulase-constituting components fromTrichoderma reesei with agitation intensityBiotechnology & Bioengineering, 1988
- Combined submerged and solid substrate fermentation for the bioconversion of lignocelluloseBiotechnology & Bioengineering, 1987
- Bacterial injury: a reviewCanadian Journal of Microbiology, 1977