Mixing Considerations in Stirred Tank Bioreactors When Using Fluid Property Altering Microorganisms

Abstract

Stirred tank reactors are one of the standard reactors in the chemical industry and have been widely implemented for biological applications. They are used with viscous liquids, slurries, very low gas flow rates, and large liquid volumes. Stirred tank bioreactors are popular because a well-mixed state, required or preferred for numerous biological processes, is usually achieved in such situations; however, many production processes using microorganisms tend to experience fluid property alterations, which significantly impact mixing, operational parameters, and process results. The most troubling issues occur when a fluid gradually undergoes a viscosity change and/or slowly exhibits non-Newtonian behavior due to microorganism growth since these will alter the flow conditions and possibly limit the conversion rate or production scale. This paper provides an overview of the relevant mixing issues in stirred tank bioreactors when using a range of fluid viscosities, surface tensions, and/or non-Newtonian fluids. ABSTRACT Stirred tank reactors are one of the standard reactors in the chemical industry and have been widely implemented for biological applications. They are used with viscous liquids, lurries, very low gas flow rates, and large liquid vo lumes. tirred tank bioreactors are popular because a well-mixed state, required or prefetTed for numerous biological processes, is usually achieved in such situations; however, many production processes using microorganisms tend to experience fluid property alterations, which significantly impact mixing, operational parameters, and process results. The most troubling i ues occur when a fluid gradually undergoes a viscosity change and/or slowly exhibits non-Newtonian behavior due to microorganism growth since these will alter the flow conditions and possibly limit the conversion rate or production sca le. This paper provides an overview of the relevant mixing issues in tirred tank bioreactors when using a range of fluid viscosities, urface tensions, and/or non-Newtonian fluids .

Trends in Single‐Use Mixing for Biomanufacturing with an Insight Into Lonza Ibex® Solutions

“…The choice of mixers for biomanufacturing largely depends on whether the mixing requirement is for blending, dissolving, suspending, or homogenizing; other considerations include whether the solution needs to be stored, dispensed, heated/cooled, or weighed and which volumes will be handled [13,18,19]. An overview of a typical biomanufacturing process highlighting the different types of single-use mixers and the most common mixing conditions used in the various sections of a biomanufacturing facility is shown in Fig.…”