Industrial Biotransformations

Subtilisin
Bacillus licheniformis
● Due to substrate precipitation at lower temperatures, it is necessary to keep the temperature
above the melting point of the substrate (36 – 39 °C). The reaction temperature is maintained
at 38 – 43 °C. The reaction rate decreases slightly above 45 °C.
● The poor substrate solubility can also be overcome by dissolving the substrate in a water-miscible
cosolvent.
● Immobilization and reuse of the cheap enzyme are not commercially attractive in this case.
● A continuously operated disk separator reduces the number of extraction and filtration steps at
neutral and acidic pH.
3) Flow scheme
Not published.
4) Process parameters
conversion: 50 %
yield: 41 – 46 %
selectivity: high
ee: > 99 %
chemical purity: > 99 %
reactor type: batch
capacity: > 100 kg
residence time: 70 h
space-time-yield: 20 g · L –1 ·d –1
down stream processing: extraction, filtration, crystallization
enzyme supplier: Solvay Enzymes, germany
start-up date: 1991
closing date: 1992
company: Hoffmann La-Roche AG, Switzerland
EC 3.4.21.62
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