title: Alginate immobilization of recombinant Escherichia coli whole cells harboring L-arabinose isomerase for L-ribulose production.
abstract: Recombinant Escherichia coli whole cells harboring Bacillus licheniformis L-arabinose isomerase (BLAI) were immobilized with alginate. The operational conditions for immobilization were optimized with response surface methodology. Optimal alginate concentration, Ca(2+) concentration, and cell mass loading were 1.8% (w/v), 0.1 M, and 44.5 g L(-1), respectively. The interactions between Ca(2+) concentration, alginate concentration, and initial cell mass were significant. After immobilization of BLAI, cross-linking with 0.1% glutaraldehyde significantly reduced cell leakage. The half-life of immobilized whole cells was 150 days, which was 50-fold longer than that of free cells. In seven repeated batches for L-ribulose production, the productivity was as high as 56.7 g L(-1) h(-1) at 400 g L(-1) substrate concentration. The immobilized cells retained 89% of the initial yield after 33 days of reaction. Immobilization of whole cells harboring BLAI, therefore, makes a suitable biocatalyst for the production of L-ribulose, particularly because of its high stability and low cost.
authors: Department of Chemical Engineering, Konkuk University, 1 Hwayang-Dong, Gwangjin-Gu, Seoul, 143-701, Korea.
authors: Ye-Wang
authors: YW
authors: Zhang
authors: Ponnandy
authors: P
authors: Prabhu
authors: Jung-Kul
authors: JK
authors: Lee
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000096:biosynthesis*; D000464:Alginates / Q000737:chemistry; D001407:Bacillus / Q000201:enzymology*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D002470:Cell Survival; D018914:Cells, Immobilized / Q000201:enzymology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D007218:Industrial Microbiology / Q000379:methods; D015999:Multivariate Analysis; D010429:Pentoses / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D000464:Alginates; D001426:Bacterial Proteins; D010429:Pentoses; D011994:Recombinant Proteins; C100182:ribulose; D019747:Aldose-Ketose Isomerases; C019715:L-arabinose isomerase