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Poly-γ-glutamic acid (γ-PGA) is a promising environmental-friendly material with outstanding water solubility, biocompatibility and degradability. However, it is tough to determine the relationship between functional synthetic enzyme and the strains' yield or substrate dependency. We cloned γ-PGA synthetase genes pgsBCA and glutamate racemase gene racE from(More)
Poly-γ-glutamic acid (γ-PGA) is an important biopolymer with greatly potential in industrial and medical applications. In the present study, we constructed a metabolically engineered glutamate-independent Bacillus amyloliquefaciens LL3 strain with considerable γ-PGA production, which was carried out by single, double, and triple markerless deletions of(More)
We constructed a metabolically engineered glutamate-independent Bacillus amyloliquefaciens strain with considerable γ-PGA production. It was carried out by double-deletion of the cwlO gene and epsA-O cluster, as well as insertion of the vgb gene in the bacteria chromosome. The final generated strain NK-PV elicited the highest production of γ-PGA (5.12 g(More)
We herein adapted a markerless gene replacement method by combining a temperature-sensitive plasmid pKSV7 with a counterselectable marker, the upp gene encoding uracil phosphoribosyltransferase (UPRTase), for the poly-γ-glutamic acid (γ-PGA)-producing strain Bacillus amyloliquefaciens LL3. Deletion of the upp gene conferred LL3 5-fluorouracil (5-FU)(More)
Here, we attempted to elevate poly-gamma-glutamic acid (γ-PGA) production by modifying genes involved in glutamate metabolism in Bacillus amyloliquefaciens LL3. Products of rocR, rocG and gudB facilitate the conversion from glutamate to 2-oxoglutarate in Bacillus subtillis. The gene odhA is responsible for the synthesis of a component of the 2-oxoglutarate(More)
Microbial levan is an important biopolymer with considerable potential in food and medical applications. Bacillus amyloliquefaciens NK-ΔLP strain can produce high-purity, low-molecular-weight levan, but production is relatively low. To enhance the production of levan, six extracellular protease genes (bpr, epr, mpr, vpr, nprE and aprE), together with the(More)
Levan is a functional homopolymer of fructose with considerable applications in food, pharmaceutical and cosmetic industries. To improve the levan production in Bacillus amyloliquefaciens, the regulatory elements of sacB (encoding levansucrase) expression and levansucrase secretion were optimized. Four heterologous promoters were evaluated for sacB(More)
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