Engineering of the 2,3-butanediol pathway of Paenibacillus polymyxa DSM 365
| Autor: | Volker Sieber, Jochen Schmid, Christoph von Schilling, Rosario Ciccone |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Mutant Bioengineering 01 natural sciences Applied Microbiology and Biotechnology Metabolic engineering 03 medical and health sciences chemistry.chemical_compound 010608 biotechnology Lactate dehydrogenase 2 3-Butanediol Butylene Glycols 030304 developmental biology Gene Editing 0303 health sciences Downstream processing biology Chemistry biology.organism_classification ddc Butanediol Biochemistry Metabolic Engineering Paenibacillus polymyxa CRISPR-Cas Systems Bacteria Biotechnology |
| Zdroj: | Metabolic engineering. 61 |
| ISSN: | 1096-7184 |
| Popis: | Paenibacillus polymyxa is a Gram-positive, non-pathogenic soil bacterium that has been extensively investigated for the production of R-,R-2,3-butanediol in exceptionally high enantiomeric purity. Rational metabolic engineering efforts to increase productivity and product titers were restricted due to limited genetic accessibility of the organism up to now. By use of CRISPR-Cas9 mediated genome editing, six metabolic mutant variants were generated and compared in batch fermentations for the first time. Downstream processing was facilitated by completely eliminating exopolysaccharide formation through the combined knockout of the sacB gene and the clu1 region, encoding for the underlying enzymatic machinery of levan and paenan synthesis. Spore formation was inhibited by deletion of spoIIE, thereby disrupting the sporulation cascade of P. polymyxa. Optimization of the carbon flux towards 2,3-butanediol was achieved by deletion of the lactate dehydrogenase ldh1 and decoupling of the butanediol dehydrogenase from its natural regulation via constitutive episomal expression. The improved strain showed 45 % increased productivity, reaching a final concentration of 43.8 g L−1 butanediol. A yield of 0.43 g g−1 glucose was achieved, accounting for 86 % of the theoretical maximum. |
| Databáze: | OpenAIRE |
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