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J Schmieding

Publications and source records attributed to J Schmieding.

3 recordsLinked to original sources
PubMed1994

Perfusible and non-perfusible supports with monoclonal antibodies for bioaffinity chromatography of Escherichia coli penicillin amidase within its pH stability range.

Several monoclonal antibodies (mABs) have been prepared and immobilized for the biospecific isolation of penicillin amidase (PA) from Escherichia coli (EC 3.5.1.11), an enzyme without S-S bridges and a pH stability range of 4-9. During the immobilization the fluorescence emission maxima of the mABs were found to change from 336 nm to ca. 350 nm. Only one of these mABs was found to be suitable for preparative bioaffinity chromatography of PA within the pH stability range. This mAB was immobilized on different spherical supports (Eupergit C 250 L and Sepharose) and one perfusible support (Knauer Quick Disc) and used for analytical and preparative bioaffinity chromatography. Under isocratic conditions the plate height for the perfusible biospecific adsorbent was found to be an order of magnitude lower than for the other supports. The different forms of this proteolytically processed bacterial enzyme could not be separated, however, by the biospecific adsorbents. At the mAB density used in the adsorbents (10-30 microM), less than 30% of the theoretical binding capacity of the immobilized mABs could be used to adsorb the enzyme.

Animals↗
PubMed1992

The membrane dialysis bioreactor with integrated radial-flow fixed bed--a new approach for continuous cultivation of animal cells.

A hybridoma cell was cultivated continuously in a membrane dialysis bioreactor with an integrated radial-flow fixed bed consisting of porous Siran carriers over a period of 6 weeks. Antibodies accumulated to an average of 100 mg l-1, approx. 10 times more than in fixed bed cultures without dialysis membrane. Serum costs could be reduced about 85% due to an appropriate feeding strategy. Siran carriers with 3-5 mm diameter showed an advantage compared to those with 1-2 mm diameter. For the 3-5 mm carrier the specific glucose uptake rate and the MAb production rate were constant, if the velocity was between 0.09 mm s-1 and 0.75 mm s-1. At higher velocities cells are washed out of the bed. Furthermore antibody consistency and cell stability were verified in long-term cultivations over a period of 96 days. From an estimation of the antibody concentration reachable with the reactor concept under optimal conditions a concentration 45 times higher compared to axial-flow fixed bed reactors and 11 times higher compared to stirred tank reactors can be expected.

Animals↗