title: Beta-glucanase productivity improvement via cell immobilization of recombinant Escherichia coli cells in different matrices.
abstract: The studies have been performed to analyze the production of beta-glucanase by a recombinant strain of Escherichia coli immobilized in different matrices. Porous sintered glass SIRAN, Ceramic supporting matrices and Broken Pumice stone as well as SIRAN Raschig-rings were examined for the immobilization of whole bacterial cells. The beta-glucanase activity of bacteria immobilized in CeramTec PST 5 (4-5 mm) was very low. CeramTec PST 5 (1.5-2.5 mm) was found to be the best carrier compared to all other matrices regarding glucanase production (630 U/ml) and compared to enzyme activity produced by free cells (500 U/ml). Different doses of matrices were applied (2, 5, 7, 10 g/lask) in the form of "matrix weight". Using 2 g/flask of CeramTec PST 5 (1.5-2.5 mm) yielded enzyme activity of 630 U/ml). CeramTec gives highest operational stability of beta-glucanase by repeated batch fermentation to 5 cycles, and activity reached 660 U/ml. Scanning electron microscopy observations showed a high number of vegetative cells that continued growth inside the matrices, indicating that beta-glucanase activity improvement was due to the immobilization of the cells.
authors: Bioprocess Development Department, Genetic Engineering and Biotechnology Research Institute (GEBRI) Mubarak City for Scientific Research and Technology Applications, New Bourg El-Arab City Universities and Research District, 21934 Alexandria, Egypt. ube@fermtech.techfak.uni-bielefeld.de
authors: Usama
authors: U
authors: Beshay
authors: Hesham
authors: H
authors: El-Enshasy
authors: I M K
authors: IM
authors: Ismail
authors: Hassan
authors: H
authors: Moawad
authors: Sawsan
authors: S
authors: Abd-El-Ghany
mesh_terms: D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D019149:Bioreactors; D018914:Cells, Immobilized / Q000378:metabolism; D002516:Ceramics; D003470:Culture Media; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D043326:Glucan 1,3-beta-Glucosidase / Q000096:biosynthesis* / Q000235:genetics; D008855:Microscopy, Electron, Scanning; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D017640:Silicates; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D011993:Recombinant Fusion Proteins; D017640:Silicates; D043326:Glucan 1,3-beta-Glucosidase; C005144:pumice