Abstract
An intermittent feeding system for shaking-flasks was developed to close the gap between batch operated shaking-flasks and fed-batch operated as well as pH-controlled stirred tank reactors. A precise syringe pump was connected via a substrate distribution system to individual 2/2-way miniature valves, one for each of up to 16 shaking-flask. The shaking-flasks were equipped with pH-probes. A process computer controls the intermittent feeding of substrates by tracking predefined individual feeding profiles as well as the base (or acid) addition for individual pH-control of the shaking-flasks. Higher concentrations of aerobic cells with higher cellular activities were achieved in fed-batch operated and pH-controlled shaking-flasks as compared to the conventional batch operation. Physiological effects of an intermittent feeding were studied in a stirred tank reactor with a recombinant E. coli strain, which expressed the GDP-mannose-pyrophosphorylase enzyme under the control of the lac-promoter.
| Original language | English |
|---|---|
| Pages (from-to) | 163-170 |
| Number of pages | 8 |
| Journal | Biochemical Engineering Journal |
| Volume | 7 |
| Issue number | 2 |
| DOIs | |
| State | Published - 2001 |
Keywords
- E. coli
- Fed-batch
- Intermittent feeding
- PH-control
- Parallel substrate feeding
- Shaking-flask