High yield recombinant thermostable α-amylase production using an improved <it>Bacillus licheniformis </it>system
<p>Abstract</p> <p>Background</p> <p>Some strains of <it>Bacillus licheniformis </it>have been improved by target-directed screening as well as by classical genetic manipulation and used in commercial thermostable α-amylase and alkaline protease production f...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2009-10-01
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| Series: | Microbial Cell Factories |
| Online Access: | http://www.microbialcellfactories.com/content/8/1/58 |
| Summary: | <p>Abstract</p> <p>Background</p> <p>Some strains of <it>Bacillus licheniformis </it>have been improved by target-directed screening as well as by classical genetic manipulation and used in commercial thermostable α-amylase and alkaline protease production for over 40 years. Further improvements in production of these enzymes are desirable.</p> <p>Results</p> <p>A new strain of <it>B. licheniformis </it>CBBD302 carrying a recombinant plasmid pHY-amyL for <it>Bacillus licheniformis </it>α-amylase (BLA) production was constructed. The combination of target-directed screening and genetic recombination led to an approximately 26-fold improvement of BLA production and export in <it>B. licheniformis</it>. Furthermore, a low-cost fermentation medium containing soybean meal and cottonseed meal for BLA production in shake-flasks and in a 15 liter bioreactor was developed and a BLA concentration of up to 17.6 mg per ml growth medium was attained.</p> <p>Conclusion</p> <p>This production level of BLA by <it>B. licheniformis </it>CBBD302(pHY-amyL) is amongst the highest levels in Gram-positive bacteria reported so far.</p> |
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| ISSN: | 1475-2859 |