Methods and milliliter scale devices for high-throughput bioprocess design

Abstract

Based on electromagnetic simulations as well as on computational fluid dynamics simulations gas-inducing impellers and their magnetic inductive drive were optimized for stirred-tank reactors on a 10 ml-scale arranged in a bioreaction block with 48 bioreactors. High impeller speeds of up to 4,000 rpm were achieved at very small electrical power inputs (63 W with 48 bioreactors). The maxima of local energy dissipation in the reaction medium were estimated to be up to 50 W L(-1) at 2,800 rpm. Total power input and local energy dissipation are thus well comparable to standard stirred-tank bioreactors. A prototype fluorescence reader for 8 bioreactors with immobilized fluorometric sensor spots was applied for online measurement of dissolved oxygen concentration making use of the phase detection method. A self-optimizing scheduling software was developed for parallel control of 48 bioreactors with a liquid-handling system for automation of titration and sampling. It was shown on the examples of simple parallel batch cultivations of Escherichia coli with different media compositions that high cell densities of up to 16.5 g L(-1) dry cell mass can be achieved without pH-control within 5 h with a high parallel reproducibility (standard deviation<3.5%, n=48) due to the high oxygen transfer capability of the gas-inducing stirred-tank bioreactors.

Multiplex bacterial growth monitoring in 24‐well microplates using a dual optical sensor for dissolved oxygen and pH

“…Several other designs for microbioreactors with integrated optical sensors for oxygen and pH have been described, like one fabricated from poly(dimethylsiloxane) (PDMS) and glass (Zanzotto et al, 2004) or from PDMS and poly(methyl methacrylate) (PMMA; Zhang et al, 2006) and also a microfluidic PDMS bioreactor (Mehta et al, 2007). Forty-eight parallel bioreactors of 10 mL volume using optical sensors were also reported (Weuster-Botz et al, 2005). A recent detailed comparison also found good agreement between data from optical sensors for pH and DO and corresponding electrochemical sensors commonly used for larger scales during mammalian cell growth (Hanson et al, 2007).…”

Aerobic batch cultivation in micro bioreactor with integrated electrochemical sensor array

“…6 Several groups have reported successful batch fermentations on a millilitre scale with measurement of pH, dissolved oxygen, and biomass concentration [14][15][16][17][18] and even on a 5-250 microlitre scale. 19,20 In most of these designs, commercially available optical sensors with a limited measurement range are used for the online measurement of the pH and the dissolved oxygen concentration, thus limiting their applicability.…”

Introduction to animal cell culture technology—past, present and future

“…In this category of culture systems, reactor scales ranging from some 100 mls (the Infors AG Sixfors system and the DASGIP system, both using standard industry sensors for process control) over some milliliters (48 stirred-tank reactors arranged in a bioreaction block Weuster-Botz et al 2005) or a 12 mini stirred-tank bioreactor system equipped with disposable DO and pH optical sensing patches (Ge et al 2006)) down to several microliters (e.g. development of high-throughput bioprocessing devices based on the use of standard well plates (Girard et al 2001)) are included.…”