title: High-level production of L-threonine by recombinantEscherichia coliwith combined feeding strategies.
abstract: The process of L-threonine production usingEscherichia coliTRFC was investigated, and the result showed that there was a large amount of acetic acid in the broth. The effects of acetic acid, which is a known inhibitory metabolite inE. colicultivation, on L-threonine production by recombinantE.coliTRFC were evaluated, and the result indicated that the growth ofE.coliTRFC and L-threonine formation were significantly inhibited in the presence of acetic acid. Two combined feeding strategies were applied to L-threonine fed-batch fermentation in order to investigate the effects of the feeding strategy on L-threonine fermentation. The results showed that using the combined feeding strategy of pseudo-exponential feeding and glucose-stat feeding resulted in high cell density (36.67 g L-1) and L-threonine production (124.57 g L-1) as well as low accumulation of by-products. This work provides a useful approach for large-scale production of L-threonine.
authors.affiliation: Department of Bioengineering, Jilin University , Changchun , P.R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Bioengineering, Tianjin University of Science and Technology , Tianjin , P.R. China.
authors.forename: Li-Kun
authors.initials: LK
authors.lastname: Cheng
authors.affiliation: Department of Bioengineering, Tianjin University of Science and Technology , Tianjin , P.R. China.
authors.forename: Ning
authors.initials: N
authors.lastname: Chen
keywords: Escherichia coli; L-threonine; acetic acid; combined feeding strategy