Improved l-threonine production of Escherichia coli mutant by optimization of culture conditions

Lee, Man-Hyo; Lee, Hongweon; Park, Jinho; Ahn, Jungoh; Jung, Joon-Ki; Hwang, Yong-Il

doi:10.1263/jbb.101.127

Cited by 36 publications

(27 citation statements)

References 18 publications

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“…[3] The fed-batch culture system by adding biotin and oxygen-enriched air to basal minimal salt medium was applied in L-threonine production using the E. coli MT201 strain and a production of threonine (80.2 g/L) was achieved. [4] Okamoto established an process for L-threonine fermentation with addition of D, L-methionine and iron by an L-methionine autotrophic E. coli mutant and achieved a final titer of 101g/L of threonine. [3] Various fermentation substrates and conditions were investigated by E. coli TRFC strain.…”

Section: Introductionmentioning

confidence: 99%

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Fed-Batch Fermentation of L- Threonine by Escherichia Coli Supplemented with B-Vitamins

Su¹,

Guo²,

Wang³

et al. 2017

Proceedings of the 2nd International Conference on Biomedical and Biological Engineering 2017 (BBE 2017)

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Section: Introductionmentioning

confidence: 99%

“…The effects of B-vitamins on L-threonine production by E. coli have not yet been systematically investigated so far. In this study, the effects ofVB 5 , VB 12 , VB 3 and VB 4 on the fermentation of L-threonine were investigated.…”

Section: Introductionmentioning

confidence: 99%

Fed-Batch Fermentation of L- Threonine by Escherichia Coli Supplemented with B-Vitamins

Su¹,

Guo²,

Wang³

et al. 2017

Proceedings of the 2nd International Conference on Biomedical and Biological Engineering 2017 (BBE 2017)

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“…Besides the strain improvement per se, fermentation condition optimization is another vital way to strengthen the required metabolic molecules overproduction. There are lots of examples that high metabolites yields were obtained through this operation, such as erythritol production by Torula sp., arachidonic acid by Mortierella alpine, etc (Clarke et al, 1988;Masuda et al, 1992;Yang and Su, 1993;Kim et al, 2000;Lin and Neubauer, 2000;Tarocco et al, 2005;Lee et al, 2006;Zhu et al, 2006;Andersson et al, 2007). Therefore we further developed the dissolved oxygen control strategy for L-glutamate production by C. glutamicum GDK-9.…”

Section: Introductionmentioning

confidence: 99%

Elementary mode analysis and metabolic flux analysis of L-glutamate biosynthesis byCorynebacterium glutamicum

Chen

Liu

et al. 2009

Ann. Microbiol.

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-In this study we applied elementary mode analysis and metabolic flux analysis to L-glutamate biosynthesis by Corynebacterium glutamicum GDK-9. The theoretically optimal flux distribution with the maximal L-glutamate yield and the actual flux distribution of L-glutamate production were determined, which suggested that phosphoenol-pyruvate (PEP), 2-oxoglutarate (2-OXO) and iso-citric acid (ICI) were the key nodes of L-glutamate biosynthesis. It was also indicated that the carbon-fixation reaction from CO 2 had great influence on the flux distribution of the key nodes. Besides, the biosynthesis of lactate could greatly decrease the L-glutamate yield. Therefore we further developed a rational dissolved oxygen control strategy to improve the L-glutamate production by strengthening the carbon-fixation reaction from CO 2 and reducing the lactate production. Under the optimized fermentation conditions, a final L-glutamate concentration of 141 g/L was obtained and the carbon yield of L-glutamate on glucose was 81.7%.

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“…To date, E. coli mutant strains remain the dominant industrial producers of L-threonine (6). Although there are many papers (8,10,14) and patents (4, 12) reporting L-threonine-producing strains of E. coli, not much is known about the genome and plasmid sequences of these producer strains. Here, we sequenced the genome of Escherichia coli XH140A containing a plasmid, a high-yield L-threonine producer in industry.…”

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confidence: 99%

Genome Sequence of Escherichia coli XH140A, Which Produces l -Threonine

et al. 2011

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Here we report the draft annotated genome sequence of Escherichia coli XH140A, which is used to produce L-threonine in industry. The genome sequence will allow the characterization of the molecular mechanisms underlying its beneficial properties.L-Threonine has been widely used as a supplement in the food, pharmaceutical, and cosmetics industries. Currently L-threonine is produced mainly by microbial fermentation. To date, E. coli mutant strains remain the dominant industrial producers of L-threonine (6). Although there are many papers (8,10,14) and patents (4, 12) reporting L-threonine-producing strains of E. coli, not much is known about the genome and plasmid sequences of these producer strains. Here, we sequenced the genome of Escherichia coli XH140A containing a plasmid, a high-yield L-threonine producer in industry.The genome was sequenced using the Illumina Solexa GA IIx instrument at Beijing Genomics Institute (BGI; Shenzhen, China). A library containing 500-bp inserts was constructed. Sequencing was performed with the paired-end strategy of 75-bp reads to produce 634 Mb of filtered sequences, representing a 136.6-fold coverage of the genome. The sequences were assembled into 184 contigs and 95 scaffolds using the SOAPdenovo package (11). The remaining intrascaffold gaps were closed by Sanger sequencing of PCR products. The complete nucleotide sequences of the plasmid pTHR were determined by Sanger sequencing using the primer walking strategy.Genome annotation was performed at the NCBI Prokaryotic Genomes Automatic Annotation Pipeline. Open reading frames were identified by Glimmer 3.02 (5) and Genemark (2). The resulting translations were used for a BLASTP (1) search against the GenBank NR database as well as the KEGG (7) and COG (15) databases. tRNA and rRNA genes were identified by tRNAscan-SE (13) and RNAmmer (9), respectively. The XH140A chromosome is 4,395,442 bp in length, with an average GϩC content of 50.80%. A total of 4,159 proteincoding genes, 72 tRNA genes, and 3 rRNA fragments were identified. Eighteen pseudogene were also identified, which suggested that Escherichia coli XH140A was selected by genetic engineering treatment. The plasmid pTHR of XH140A is 15,774 bp in length with an average GϩC content of 49.07%, which contains 13 protein-coding genes.In a comparative analysis of Escherichia coli XH140A with the reference genome Escherichia coli K-12 (3), we found an important mutation that may explain the molecular mechanisms for the production of L-threonine. A nonsense mutation in the acetolactate synthase 2 catalytic subunit gene ilvG blocked the pathway of L-threonine to L-isoleucine, which could make XH140A accumulate L-threonine. Interestingly, the plasmid pTHR did not have the threonine operon thrABC, which was different from what has been reported in several public papers and patents about L-threonine-producing strains (4, 6, 12). It is worth noting that the plasmid pTHR contained NAD/NADP transhydrogenase alpha-subunit and beta-subunit genes, which suggested that the balance of NAD...

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Improved l-threonine production of Escherichia coli mutant by optimization of culture conditions

Cited by 36 publications

References 18 publications

Fed-Batch Fermentation of L- Threonine by Escherichia Coli Supplemented with B-Vitamins

Fed-Batch Fermentation of L- Threonine by Escherichia Coli Supplemented with B-Vitamins

Elementary mode analysis and metabolic flux analysis of L-glutamate biosynthesis byCorynebacterium glutamicum

Genome Sequence of Escherichia coli XH140A, Which Produces l -Threonine

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