New recombinant Escherichia coli strain tailored for the production of poly(3-hydroxybutyrate) from agroindustrial by-products
A recombinant E. coli strain (K24K) was constructed and evaluated For poly(3-hydroxybutyrate) (PHB) production from whey and corn steep liquor as main carbon and nitrogen sources. This strain bears the pha biosynthetic genes from Azotobacter sp. strain FA8 expressed from a T5 promoter under the cont...
| Authors: | , , , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2006 |
| Country: | Argentina |
| Institution: | Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales |
| Repository: | Biblioteca Digital (UBA-FCEN) |
| Language: | English |
| OAI Identifier: | paperaa:paper_00992240_v72_n6_p3949_Nikel |
| Online Access: | http://hdl.handle.net/20.500.12110/paper_00992240_v72_n6_p3949_Nikel |
| Access Level: | Open access |
| Keyword: | Bioreactors Carbon Cells Genes Glass transition Molecular weight Nitrogen Polymers Volumetric analysis Azotobacter Cupriavidus necator Lactose operator Liquor Poly(3-hydroxybutyrate) (PHB) Escherichia coli carbon lactose lactose repressor nitrogen poly(3 hydroxybutyric acid) polymer unclassified drug bacterium ester gene expression genetic analysis plant extract agriculture alcoholic beverage article bacterial gene bacterial strain bioreactor corn Escherichia coli k24k evaluation fed batch culture glass transition temperature liquid molecular weight nonhuman pha gene productivity repressor gene volumetry Wautersia eutropha whey Agriculture Animals DNA Primers Hydroxybutyrates Industrial Waste Kinetics Milk Plasmids Polyesters Recombination, Genetic Zea mays |
| Summary: | A recombinant E. coli strain (K24K) was constructed and evaluated For poly(3-hydroxybutyrate) (PHB) production from whey and corn steep liquor as main carbon and nitrogen sources. This strain bears the pha biosynthetic genes from Azotobacter sp. strain FA8 expressed from a T5 promoter under the control of the lactose operator. K24K does not produce the lactose repressor, ensuring constitutive expression of genes involved in lactose transport and utilization. PHB was efficiently produced by the recombinant strain grown aerobically in fed-batch cultures in a laboratory scale bioreactor on a semisynthetic medium supplemented with the agroindustrial by-products. After 24 h, cells accumulated PHB to 72.9% of their cell dry weight, reaching a volumetric productivity of 2.13 g PHB per liter per hour. Physical analysis of PHB recovered from the recombinants showed that its molecular weight was similar to that of PHB produced by Azotobacter sp. strain FA8 and higher than that of the polymer from Cupriavidus necator and that its glass transition temperature was approximately 20°C higher than those of PHBs from the natural producer strains. Copyright © 2006, American Society for Microbiology. All Rights Reserved. |
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