title: Improving production of thermostable and fluorescent holo-β-allophycocyanin by metabolically engineered Escherichia coli using response surface methodology.
abstract: A stable fluorescent holo-β-allophycocyanin (holo-ApcB) was produced by metabolically engineered Escherichia coli. The E. coli cells harbored two plasmids for expression of five genes that were involved in the holo-ApcB production. Response surface methodology was employed to investigate the individual and interactive effects of four variables, i.e., initial pH of culture medium, IPTG concentration, post-induction temperature, and induction start time, on holo-ApcB production by E. coli. The experimental results showed that the IPTG concentration, postinduction temperature, and induction start time had significant individual effects on holo-ApcB production. A significant interactive effect was also found between the initial pH of culture and induction start time. The maximum holo-ApcB production of 45.3 mg/L was predicted under the following optimized culture conditions: a postinduction temperature of 28.4°C, initial pH of culture of 7.3, IPTG concentration of 1.1 mM, and postinduction time of 66 min. Holo-ApcB production under the optimized culture conditions increased 5.8-fold, compared with that under the nonoptimized conditions. Response surface methodology proved to be a valuable tool for optimization of holo-ApcB production by metabolically engineered E. coli.
authors.affiliation: a Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences , Qingdao , China.
authors.forename: Huaxin
authors.initials: H
authors.lastname: Chen
authors.forename: Peng
authors.initials: P
authors.lastname: Jiang
authors.forename: Fuchao
authors.initials: F
authors.lastname: Li
authors.forename: Haizhen
authors.initials: H
authors.lastname: Wu
mesh_terms: D003470:Culture Media; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005285:Fermentation; D060847:Metabolic Engineering; D010798:Phycocyanin / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D013696:Temperature
chemical_list: D003470:Culture Media; C002497:allophycocyanin; D010798:Phycocyanin
keywords: Escherichia coli; fermentation; fluorescence; holo-β-allophycocyanin; optimization; response surface methodology