Fermentation of 10% (w/v) sugar to D: (-)-lactate by engineered Escherichia coli B.
Derivatives of ethanologenic Escherichia coli K011 were constructed for D: (-)-lactate production by deleting genes encoding competing pathways followed by metabolic evolution, a growth-based selection for mutants with improved performance. Resulting strains, SZ132 and SZ186, contain native genes for sucrose utilization. No foreign genes are present in SZ186. Strain SZ132 also contains a chromosomally integrated endoglucanase gene (Erwinia chrysanthemi celY). Strain SZ132 produced over 1 mol lactate per liter of complex medium containing 10% (w/v) sugar (fermentation times of 48 h for glucose, 120 h for sucrose). Both strains produced 667-700 mmol lactate per liter of mineral salts medium. Yields for metabolized sugar ranged from 88% to 95% in both media.
Zhou
S
S
Department of Biological Sciences, Northern Illinois University, Dekalb, IL 60115, USA.
Yomano
L P
LP
Shanmugam
K T
KT
Ingram
L O
LO
D002264:Carboxylic Acids / Q000378:metabolism; D003470:Culture Media / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D005285:Fermentation / Q000235:genetics; D017353:Gene Deletion; D005818:Genetic Engineering / Q000379:methods; D005947:Glucose / Q000378:metabolism; D019344:Lactic Acid / Q000096:biosynthesis* / Q000737:chemistry; D009154:Mutation / Q000235:genetics; D013237:Stereoisomerism; D013395:Sucrose / Q000378:metabolism*; D014161:Transduction, Genetic
D002264:Carboxylic Acids; D003470:Culture Media; D019344:Lactic Acid; D013395:Sucrose; D005947:Glucose