Use of an Alternative Pathway for Isoleucine Synthesis in Threonine-Producing Strains of Escherichia coli

Vybornaya, Tatiana V.; Yuzbashev, Tigran V.; Fedorov, A. S.; Bubnov, D. M.; Filippova, S. S.; Bondarenko, F. V.; Sineoky, S. P.

doi:10.1134/s0003683820070066

Cited by 3 publications

(2 citation statements)

References 15 publications

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“…On the other hand, the temperature identified, being 1.3 °C lower than that commonly reported for l -threonine production with E. coli , i.e. 37 °C [ 15 , 69 , 70 ], this result suggest that using Whey and RTVH might lead to energy savings in the bioprocess.…”

Section: Resultsmentioning

confidence: 62%

l-Threonine production from whey and fish hydrolysate by E. coli ATCC® 21277

Vélez Blandón,

Sánchez Henao,

Zapata Montoya

et al. 2023

Heliyon

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Section: Resultsmentioning

confidence: 62%

l-Threonine production from whey and fish hydrolysate by E. coli ATCC® 21277

Vélez Blandón,

Sánchez Henao,

Zapata Montoya

et al. 2023

Heliyon

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“…Notably, the gene encoded by tdh assumes a pivotal function in the process of threonine degradation. , The elimination of this particular gene has been demonstrated to positively impact the augmentation of l -threonine. Another NAD-dependent threonine dehydrogenase encoded by the yiaY gene, along with knockdown of the ltaE gene encoding threonine aldolase, are also suggested to improve the l -threonine production, , whereas the ilvA and tdcB genes encoding threonine dehydratase play important roles in l -isoleucine production. , Numerous researchers have shown that in E. coli, a single knockdown of nonessential genes such as yiaY , tdh , and ltaE that are related to the threonine metabolic pathway contribute to the l -threonine production.…”

Section: Introductionmentioning

confidence: 99%

Strategies to Enhance l-Isoleucine Synthesis by Modifying the Threonine Metabolism Pathway in Escherichia coli

Zhang,

Ye,

Fengmin

et al. 2024

ACS Omega

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L-threonine as an important precursor substance of L-isoleucine and improving its accumulation in Escherichia coli became an important idea to construct a chassis strain with high L-isoleucine production. Meanwhile, the effect of L-threonine metabolic pathway disruption in E. coli for the improved production of L-isoleucine remains unrevealed. In the present study, a mutant strain of E. coli was engineered by inactivating specific metabolic pathways (e.g., Δtdh, ΔltaE, and ΔyiaY) that were associated with L-threonine metabolism but unrelated to Lisoleucine synthesis. This was done with the aim to reduce the breakdown of Lthreonine and, thereby, increase the production of L-isoleucine. The results obtained demonstrated a 72.3% increment in L-isoleucine production from 4.34 to 7.48 g•L −1 in the mutant strain compared with the original strain, with an unexpected 10.3% increment in bacterial growth as measured at OD 600 . Transcriptome analysis was also conducted on both the mutant strain NXU102 and the original strain NXU101 in the present study to gain a comprehensive understanding of their physiological attributes. The findings revealed a notable disparity in 1294 genes between the two strains, with 658 genes exhibiting up-regulation and 636 genes displaying down-regulation. The activity of tricarboxylic acid (TCA) cycle-related genes was found to decrease, but oxidative phosphorylation-related genes were highly up-regulated, which explained the increased activity of the mutant strain. For instance, Llysine catabolism-related genes were found to be up-regulated, which reconfigured the carbon flow into the TCA cycle. The augmentation of acetic acid degradation pathway-related genes assisted in the reduction in acetic acid accumulation that could retard cell growth. Notably, substantial up-regulation of the majority of genes within the aspartate pathway could potentially account for the increased production of L-isoleucine in the present study. In this paper, a chassis strain with an L-isoleucine yield of 7.48 g•L −1 was successfully constructed by cutting off the threonine metabolic pathway. Meanwhile, transcriptomic analysis revealed that the cutting off of the threonine metabolic pathway induced perturbation of genes related to the pathways associated with the synthesis of Lisoleucine, such as the tricarboxylic acid cycle, glycolysis, and aspartic acid pathway.

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Heterotrophic and autotrophic production of L-isoleucine and L-valine by engineered Cupriavidus necator H16

Wang,

Yao,

et al. 2024

Bioresource Technology

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Use of an Alternative Pathway for Isoleucine Synthesis in Threonine-Producing Strains of Escherichia coli

Cited by 3 publications

References 15 publications

l-Threonine production from whey and fish hydrolysate by E. coli ATCC® 21277

l-Threonine production from whey and fish hydrolysate by E. coli ATCC® 21277

Strategies to Enhance l-Isoleucine Synthesis by Modifying the Threonine Metabolism Pathway in Escherichia coli

Heterotrophic and autotrophic production of L-isoleucine and L-valine by engineered Cupriavidus necator H16

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