Mingfeng Cao

Learn More
A new glutamic acid independent poly-γ-glutamic acid (γ-PGA) producing strain, which was identified as Bacillus amyloliquefaciens LL3 by analysis of 16S rDNA and gyrase subunit A gene (gyrA), was isolated from fermented food. The product had a molecular weight of 470, 801 and l-glutamate monomer content of 98.47%. The pre-optimal medium, based on(More)
Bacillus amyloliquefaciens is one of most prevalent Gram-positive aerobic spore-forming bacteria with the ability to synthesize polysaccharides and polypeptides. Here, we report the complete genome sequence of B. amyloliquefaciens LL3, which was isolated from fermented food and presents the glutamic acid-independent production of poly-γ-glutamic acid.
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 a natural, biodegradable and water-soluble biopolymer of glutamic acid. This review is focused on nonrecombinant microbial production of γ-PGA via fermentation processes. In view of its commercial importance, the emphasis is on L-glutamic acid independent producers (i.e. microorganisms that do not require feeding with the(More)
A Bacillus amyloliquefaciens strain with enhanced γ-PGA production was constructed by metabolically engineering its γ-PGA synthesis-related metabolic networks: by-products synthesis, γ-PGA degradation, glutamate precursor synthesis, γ-PGA synthesis and autoinducer synthesis. The genes involved in by-products synthesis were firstly deleted from the starting(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)
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)
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)
Bacillus amyloliquefaciens NK-1 has the potential to produce levan and poly-gamma-glutamic acid (γ-PGA) simultaneously. However, it is not possible to purify each single product from the same strain because the extraction process is identical. We deleted the pgs cluster (for γ-PGA synthesis) from the NK-1 strain and constructed a γ-PGA-deficient NK-ΔLP(More)