Mass production of thermostable D-hydantoinase by batch culture of recombinant Escherichia coli with a constitutive expression system
✍ Scribed by Dong-Cheol Lee; Geun-Joong Kim; Yoo-Kyong Cha; Cheo-Young Lee; Hak-Sung Kim
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 134 KB
- Volume
- 56
- Category
- Article
- ISSN
- 0006-3592
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✦ Synopsis
D-Hydantoinase is an industrial enzyme widely used for the synthesis of optically active D-amino acids. A gene encoding thermostable D-hydantoinase of Bacillus stearothermophilus SD-1 has previously been cloned and constitutively expressed by its native promoter in Escherichia coli XL1-Blue (Lee et al., 1996b). In this work, we attempted mass production of the D-hydantoinase by batch culture of the recombinant E. coli using glycerol as a carbon source. The plasmid content in cells increased in proportion to the culture temperature, which resulted in a two- or three-fold increase of the specific D-hydantoinase activity at 37 degrees C compared with that at 30 degrees C. The plasmid was stably maintained over 80 generations. When glycerol was initially added to a concentration of 100 g/L, the final biomass concentration reached about 50 g-dry cell weight/L in a 50 L-scale fermentation, resulting in the specific enzyme production of 3.8 x 10(4) unit/g-dry cell weight in a soluble form. Glycerol-using batch cultivation of recombinant E. coli was found to be a cost-effective process for the mass production of industrially useful D-hydantoinase. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 449-455, 1997.