title: Food-Grade Expression of d-Psicose 3-Epimerase with Tandem Repeat Genes in Bacillus subtilis.
abstract: An integrative food-grade expression system with tandem repeat target genes was constructed for the expression of d-psicose 3-epimerase (DPEase; EC 5.1.3.30). The DPEase gene fused with the P43 promoter constituted an independent monomeric expression cassette. Multimers of the expression cassette were constructed in vitro using the isocaudamer strategy. The recombinant integration plasmids pDG-nDPE (n = 1, 2, 3), which contained one, two, or three consecutive P43-DPEase tandem repeats, were integrated into the genome of B. subtilis. Then, the antibiotic resistance gene was deleted by the Cre/lox system, and the food-grade recombinant B. subtilis 1A751-nDPE (n = 1, 2, 3) with integrated tandem repeats of the P43-DPEase expression cassette were generated. The specific activity of the B. subtilis 1A751-3DPE was the highest among the recombinant strains and was ∼2.2-fold that of the 1A751-1DPE strain. Under the optimal conditions, 8 g/L of freeze-dried enzyme powder could convert 20% d-fructose (300 g/L) into d-allulose after 1 h.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University , Wuxi, Jiangsu 214122, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: He
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University , Wuxi, Jiangsu 214122, China.
authors.forename: Wanmeng
authors.initials: W
authors.lastname: Mu
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University , Wuxi, Jiangsu 214122, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of Microbiology, College of Life Sciences, Key Laboratory for Microbiological Engineering of Agricultural Environment of Ministry of Agriculture, Nanjing Agricultural University , 6 Tongwei Road, Nanjing, Jiangsu 210095, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University , Wuxi, Jiangsu 214122, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D055162:Biocatalysis; D003001:Cloning, Molecular; D003013:Clostridium / Q000201:enzymology* / Q000235:genetics; D004795:Enzyme Stability; D005524:Food Technology; D005632:Fructose / Q000737:chemistry* / Q000378:metabolism; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D019998:Racemases and Epimerases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D020080:Tandem Repeat Sequences; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; C003243:psicose; D005632:Fructose; D019998:Racemases and Epimerases
keywords: Bacillus subtilis; d-allulose; d-psicose 3-epimerase; food-grade; integration; tandem repeats