title: Optimization of culture conditions for enhanced lysine production using engineered Escherichia coli.
abstract: In this study, culture conditions, including dissolved oxygen (DO) content, presence of osmoprotectants, residual glucose concentration, and ammonium sulfate-feeding strategies, were investigated for decreasing the inhibition effects of acetic acid, ammonium, and osmotic stress on L-lysine fermentation by Escherichia coli. The results revealed that higher DO content and lower residual glucose concentration could decrease acetic acid accumulation, betaine supplementation could enhance osmotic stress tolerance, and variable speed ammonium sulfate-feeding strategy could decrease ammonium inhibition. Thus, with 25 % DO content, 0-5.0 g/L of residual glucose concentration, and 1.5 g/L of betaine supplementation, 134.9 g/L of L-lysine was obtained after 72 h of culture, with L-lysine yield and productivity of 45.4 % and 1.9 g/(L · h), respectively.
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering College of Life Science and Pharmacy, Nanjing University of Technology, Nanjing, 211816, People's Republic of China.
authors.forename: Hanxiao
authors.initials: H
authors.lastname: Ying
authors.forename: Xun
authors.initials: X
authors.lastname: He
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Kequan
authors.initials: K
authors.lastname: Chen
authors.forename: Pingkai
authors.initials: P
authors.lastname: Ouyang
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology; D000645:Ammonium Sulfate / Q000494:pharmacology; D003470:Culture Media / Q000737:chemistry; D046508:Culture Techniques / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D005285:Fermentation / Q000187:drug effects; D005818:Genetic Engineering; D008239:Lysine / Q000096:biosynthesis*; D009997:Osmotic Pressure; D010100:Oxygen / Q000494:pharmacology
chemical_list: D003470:Culture Media; D008239:Lysine; D019342:Acetic Acid; D010100:Oxygen; D000645:Ammonium Sulfate