L-threonine production

Integration of Systems Biology with Bioprocess Engineering L-Threonine Production by Systems Metabolic Engineering of Escherichia Coli... 

S. marcescens Random mutation and selection to construct L-threonine production strain P-Hydroxynorvaline (a-amino-P-hydroxyvaleric acid)-resistant mutants were obtained 13.0 Komatsubara et al. [47]... 

E. coli The whole L-threonine operon was amplified by plasmid-based overexpression in E. coli L-threonine producer A threefold increase in L-threonine production 13.4 Miwa et al. [48]... 

E. coli Culture conditions for the production of L-threonine were investigated A high level of dissolved oxygen and lowering the required amino acids are effective for enhancing L-threonine production 65.0 Shimizu et al. [50]... 

S. marcescens Ammonia water is more beneficial than urea for the enhanced production of L-threonine as a nitrogen source A 77.2% increase in L-threonine production 100.0 Masuda et al. [51]... 

E. coli An impaired L-threonine uptake system enhanced L-threonine production in E. coli L-threonine producer The inability to take up L-threonine relieved negative effect of remaining feedback inhibition 100.0 Okamoto et al. [53]... 

E. coli The mutant aspartokinase III encoded by lysC was used to enhance L-threonine production A 30.9% increase in L-threonine production 14.4 Ogawa-Miyata et al. [57]... 

E. coli The effect of biotin and air condition on L-threonine production was investigated Supply of biotin and oxygen-enriched air improved 80.2 Lee et al. [52]... 

As mentioned earlier, L-threonine production can be enhanced by engineering the export or uptake system. An efficient L-threonine producer strain of E. coli KY10935, which was derived from the wild-type strain by multiple rounds of random mutation and selection, was able to produce 100 g L-1 L-threonine after 77 h cultivation [53]. In this strain, the two key enzymes in the L-threonine biosynthesis (homoserine dehydrogenase and homoserine kinase) were identified to be still inhibited by much lower intracellular concentrations of L-threonine than... 

Removal of negative regulations can also enhance L-threonine production. By removing L-lysine-mediated feedback inhibition of aspartokinase III encoded by the lysC gene, L-threonine production could be increased by 30.9% (11.0-14.4 g L 1) in E. coli mutant strain [57]. 

Case Study 2 Systems Metabolic Engineering ofE. coli for L-Threonine Production... 

Case Study 3 Construction of L-Threonine Production Strain Using a Reduced-Genome Strain ofE. coli and Its Metabolic Characterization by Transcriptome Analysis... 

Lee KH, Park JH, Kim TY et al (2007) Systems metabolic engineering of Escherichia coli for L-threonine production. Mol Syst Biol 3 149... 

Ishida M, Kawashima H, Sato K et al (1994) Factors improving L-threonine production by a three L-threonine biosynthetic genes-amplified recombinant strain of Brevibacterium lacto-fermentum. Biosci Biotech Biochem 58 768-770... 

Shimizu E, Oosumi T, Heima H et al (1995) Culture conditions for improvement of L-threonine production using a genetically self-cloned L-threonine hyperproducing strain of Escherichia coli K-12. Biosci Biotech Biochem 59 1095-1098... 

Masuda M, Takamatsu S, Nishimura N et al (1992) Improvement of nitrogen supply for L-threonine production by a recombinant strain of Serratia marcescens. Appl Biochem Biotechnol 37 255-265... 

Lee MH, Lee HW, Park JH et al (2006) Improved L-threonine production of Escherichia coli mutant by optimization of culture conditions. J Biosci Bioeng 101 127-130... 

Ogawa-Miyata Y, Kojima H, Sano K (2001) Mutation analysis of the feedback inhibition site of aspartokinase III of Escherichia coli K-12 and its use in L-threonine production. Biosci Biotech Biochem 65 1149-1154... 

Lee JH, Sung BH, Kim MS et al (2009) Metabolic engineering of a reduced-genome strain of Escherichia coli for L-threonine production. Microb Cell Lact 8 2... 

L-Threonine production by microbes was started in the 1970s, the auxotrophic and analog resistant mutant strains obtained for the purpose being cultured in the presence of amino acids which are required by the mutant. 

Song, K.H., Lee, H.H., and Hyun, H.H. (2000) Characterization of salt-tolerant mutant for enhancement of L-threonine production in Escherichia coli. Appl. Microbiol. Biotechnol., 54, 647-651. 

Lee KH, Park JH, Kim TY, Kim HU, Lee SY (2007) Systems metabolic engineering of Escherichia coli for L-threonine production. Mol Syst Biol 3 1-8 Lim SJ, Jung YM, Shin HD, Lee YH (2002) Amplification of the NADPH-related genes zfvf and gnd for the oddball biosynthesis of PHB in an E. coli transformant harboring a cloned phbCAB Operon. J Biosci Bioeng 93 543-549... 

Diesveld R.Tietze N, Fiirst O, Reth A, Bathe B, Sahm H. Activity of exporters of Escherichia coli in Corynebacterium glutamicum, and their use to increase L-threonine production.J Mol Microbiol Biotechnol 2009 16 198-207. 

Furukawa S, Ozaki A, Nakanishi T. L-threonine production by L-aspartate- and L-homoserine-resistant mutant of Escherichia coli. Appl Microbiol Biotechnol 1988 29 550-3. 

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