Improving an on-line feeding strategy for fed-batch cultures of hybridoma cells by dialysis and `Nutrient-Split'-feeding

Abstract

The concept of the feeding strategy was to minimise the formation of inhibiting metabolites and to increase the yield of monoclonal antibodies in fed-batch cultures of hybridoma cells by a balanced supply of substrates. A process control system based on ®eldbus technology was used for monitoring and control. External program routines were implemented to control dissolved oxygen (DO) and to calculate the oxygen uptake rate (OUR) and cumulative oxygen consumption (COC) simultaneously. A concentrated feed solution was supplied according to the off-line estimated stoichiometric ratio between oxygen and glucose consumption (GC). Feeding was initiated automatically when the OUR decreased due to substrate limitation. The antibody concentration increased three-fold compared to the conventional batch culture by applying this strategy. But it was not possible to avoid inhibition by ammonia during the fed-batch phase. This was accomplished by the use of a dialysis membrane. Dialysis fed-batch cultures were performed in a membrane dialysis reactor with a`nutrient-split' feeding strategy, where concentrated medium is fed to the cells and toxic metabolites are removed into a buffer solution. This resulted in a ten-fold increase of the antibody concentration compared to the batch. Amino acid concentrations were analysed to identify limiting conditions during the cultivation and to analyse the performance of the nutrient supply in the fed-batch and dialysis fed-batch.

High‐density microcarrier cell cultures for influenza virus production

“…Furthermore, medium removal without cell deterioration can be challenging. Finally, the development of strategies for control of the feed rate is essential and several approaches, e.g., medium addition based on stoichiometric correlations (Xie and Wang,1994) or oxygen uptake rate (Schwabe et al,1999) were proposed. An alternative to fed‐batch strategies is the continuous exchange of medium, which requires efficient cell retention.…”

Evaluation of selected control strategies for fed‐batch cultures of a hybridoma cell line

“…The cells were cultivated in IMDM (Iscove's modified Dulbecco's medium)/Ham's F‐12 or Dulbecco's modified Eagle's medium/Ham's F‐12 respectively as basal medium. Further details are given elsewhere [4,36,37].…”

“…During fed‐batch mode a feed containing 50–100 mM glucose in an amino acid/vitamin concentrate (referred to as ‘nutrient concentrate’ feed) and a 200 mM glutamine feed were applied [36]. The amino acid/vitamin concentrate matches a 10‐fold‐concentrated IMDM/Ham's F‐12 (1:1) medium without salts.…”

“…The present paper presents a comparison of four different fed‐batch strategies, including fixed feed trajectories, control via the OUR (stoichiometric feeding) [36], a priori determination of feed trajectories based on a kinetic model [37], and the OLFO‐control strategy [4]. The characteristics of the different strategies are illustrated on the basis of one example for each type of cultivation.…”

Model-Based Design of Process Strategies for Cell Culture Bioprocesses: State of the Art and New Perspectives

“…The determination of an adequate feed flow is mainly realized experimentally [22,23]. Feeding strategies that use additional data from the process include bolus-feeding, that is, the substitution of substrate that was consumed in a given time interval, and proportional feeding, which is based on the oxygen uptake rate (OUR) [22,24,25].…”