In Escherichia coli, cofactor imbalance serves as a crucial limiting factor in cytidine biosynthesis, with nicotinamide adenine dinucleotide phosphate (NADPH) insufficiency representing the principal metabolic barrier. To overcome this limitation, an integrated engineering strategy targeting the enhancement of NADPH metabolism was implemented. Via CRISPR-Cas9-mediated multiplex genomic editing and strong constitutive promoter replacement, three NADPH-regenerating modules were concurrently enhanced: the membrane-bound transhydrogenase (pntAB), the oxidative pentose phosphate pathway (zwf-encoded glucose-6-phosphate dehydrogenase), and the decarboxylation shunt (gnd-encoded 6-phosphogluconate dehydrogenase). After 54-hour fermentation in 500 mL shake flasks, the cytidine titer of the engineered strain NXBG-20 reached 7.83 g/L, representing a 9.10-fold increase compared to the start strain. Systematic multi-omics profiling revealed that the metabolic network had undergone substantial alterations. These alterations were characterized by the redirection of glycolytic flux towards nucleotide precursor substances and the enhancement of ribose-5-phosphate biosynthesis. This engineering approach not only establishes a novel microbial platform for cytidine bioproduction but also provides mechanistic insights into cofactor-driven metabolic flux control.

Understanding the genetic mechanisms underlying cold and drought tolerance in grapevines is essential for developing climate-resilient cultivars adapted to challenging environmental conditions. The strategic selection and systematic breeding of premium-quality, desiccation-resistant wine grape cultivars constitutes a fundamental approach for advancing the long-term viability and qualitative enhancement of the wine industry. In this study, we used the reciprocal crosses offspring of the cultivars of Vitis vinifera L. ‘Ecolly’ and ‘Dunkelfelder’ as experimental materials, and conducted genetic analysis and comprehensive evaluation of the total water content (TW), free water content (FW), bound water content (BW), bound water to free water ratio (B/F), and water loss ratio (WLR) of canes collected and analysed over three successive seasons. The content of FW, BW, and B/F of canes in vitro of the hybrid populations were continuously distributed and conformed with a skewed normal distribution. Among them, the content of TW shows a certain maternal dominance. The TW of canes in vitro was significantly positively correlated with the FW, as well as the BW and B/F. The FW and BW, as well as the FW and B/F showed significant negative correlation. The correlation and regression coefficients between the content of TW and WLR in 2023 and 2024 were 0.5664 and 0.6172, 0.3208 and 0.3809, respectively. 2106016 exhibited a high B/F and low WLR, 2006024 exhibited a high TW and high BW, and 2110026 exhibited a high B/F, low WLR, and high BW. These three lines should be the focus of attention for both cold- and drought- resistance.

To establish an objective evaluation method for the aroma richness of Cabernet Sauvignon dry red wine integrated with machine learning and identify the key aroma compounds influencing wine aroma richness,volatile compounds in 14 Cabernet Sauvignon dry red wine samples from different production regions and vintages were subjected to qualitative/quantitative analysis and odor activity value(OAV)analysis by gas chromatography-mass spectrometry,basic physicochemical indicators determination,and sensory fuzzy comprehensive evaluation method based on fuzzy mathematics.Contents of titratable acid,residual sugar,volatile acid,alcohol content,free SO2,total phenols,tannins and anthocyanins,and the pH value were also determined.Orthogonal partial least squares discriminant analysis(OPLS-DA)was used to mine key differential compounds affecting aroma richness,and machine learning algorithms were finally applied to evaluate wine aroma richness.The results showed that 14 wine samples could be classified into four aroma richness grades(high,medium,low,and extremely low)using the sensory fuzzy comprehensive evaluation method.Further comparative analysis based on these four grades revealed that wine aroma richness was significantly positively correlated with titratable acid and volatile acid contents,as well as volatile fatty acid compound contents.OAV analysis indicated that the OAVs of ethyl acetate,isoamyl acetate,phenethyl acetate,and α-damascenone were significantly positively correlated with aroma richness.OPLS-DA results demonstrated that isobutanol,ethyl decanoate,decanal,phenethyl acetate,and α-damascenone(VIP＞1,P＜0.01)were the key differential aroma compounds affecting aroma richness,with vintage and production region significantly influencing damascenone content.Among three machine learning algorithms,backpropagation(BP)neural network,random forest(RF),and support vector machine(SVM),the RF algorithm exhibited high stability,and the important feature factors screened for aroma richness were mostly esters and volatile fatty acids.This study was expected to provide theoretical guidance for objective aroma evaluation and quality control in the actual production of Cabernet Sauvignon dry red wine.

[This corrects the article DOI: 10.1016/j.synbio.2025.12.009.].

As a pyrimidine nucleoside, cytidine is widely used in the medicine and food fields. Therefore, it is important to construct a microbial cell factory for efficient and sustainable cytidine production. Here, we perform modular metabolic engineering modifications on Bacillus subtilis 168 to achieve efficient synthesis of cytidine. First, the cytidine titer reached 0.88 g/L by blocking cytidine degradation and enhancing the cytidine de novo synthesis pathway. Next, the central carbon metabolism was modulated by knocking down CcpA, but the cytidine titer decreased instead. Transcriptome analysis revealed that differential genes were mainly enriched in PTS, glycolysis, TCA cycle, PP pathway, pyrimidine metabolism, aspartate metabolism, and glutamate metabolism. Then, by enhancing the l-aspartate and glutamine synthesis pathways, the cytidine titer was increased to 3.83 g/L. By strengthening the PP pathway to increase PRPP synthesis, the cytidine titer was further increased to 7.03 g/L. Finally, the cytidine titer reached 31.41 g/L by fed-batch fermentation in a 5 L fermenter, which was 4.47-fold that of shake flask fermentation. Overall, the efficient production of cytidine was accomplished through modular metabolic engineering, opening new pathways for the production of cytidine and other nucleosides.

Challenges arise in global viticulture due to low temperatures. To ensure the sustainable and high-quality development of the wine industry, it is essential to breed wine grape varieties that are not only of high quality but also possess cold hardiness. Intraspecific recurrent selection in Vitis vinifera can enhance cold hardiness while maintaining fruit quality. In this study, we used ‘Ecolly ’as an intermediary grape variety for crossing with ‘Cabernet Sauvignon’, ‘Marselan’, and ‘Dunkelfelder’, including three reciprocal crosses and a total of 1 657 intraspecific hybrids. We characterized the cold hardiness of these intraspecific hybrids and analyzed the genetic aspects of cold hardiness, ultimately identifying excellent strains with cold hardiness. Parameters like mean high-temperature exotherm (mHTE), mean low-temperature exotherm (mLTE), bound/free water ratio, water loss ratio in vitro, frost damage grades, and overall performance displayed partially normal distributions. In intraspecific hybrids, there was a maternal advantage in traits related to bound/free water ratio and water loss ratio. Some hybrid populations exhibited values for mHTE, mLTE, and water loss ratio that were lower than the low parent's values, while bound/free water ratio showed values higher than the high parent's values. Among the 1 657 intraspecific hybrids, 52 strains could bud under stress at −18 °C, and seven of these strains excelled in three important cold hardiness measures. Our study revealed that cold hardiness in V. vinifera is influenced by multiple genes and is a quantitative trait. Intraspecific hybridization can produce a small number of superior strains with enhanced cold hardiness.

The development of an engineered strain for efficient cytidine production holds significant value for both research and industrial applications. In this study, the pgi and edd genes were knocked out to reveal their roles involved in the regulation of efficient cytidine synthesis in Escherichia coli. The results showed that after 36 h of shaking flask fermentation, the pgi knockout strain E. coli NXBG-14 produced a cytidine concentration of 2.57 ± 0.04 g/L, and the pgi and edd double knockout strain E. coli NXBG-15 produced a cytidine titer of 2.68 ± 0.03 g/L, which represented enhancements of 1.68 and 1.75 times over the start strain, respectively. Transcriptome analysis revealed that the differentially expressed genes (DEGs) in the NXBG-14 strain were mainly enriched in the glycolytic pathway and the tricarboxylic acid (TCA) cycle. Additionally, 13C metabolic flow distribution indicated a significant increase in 6-phosphogluconate in the pentose phosphate pathway (PPP) for NXBG-15. These findings suggest that modifications of the pgi and edd genes redirect central carbon metabolism and promote cytidine accumulation.

CVD is one of the leading causes of death in the world today, so it is important to prevent and reduce the risk of CVD. The pathogenesis of CVD is mainly caused by atherosclerosis, which leads to cardiovascular impairment, and eventually leads to hypertension, coronary heart disease and other diseases. The research mainly focuses on the pathogenesis, the development of targeted drugs, or the use of AI technology to make targeted diagnosis and combine with models to treat patients. These methods are relatively costly and not universal, and some studies have shown that diet can prevent and improve the risk of CVD to a certain extent, but the complete dietary structure and related efficacy are not explained. This article analyzes the pathogenesis, symptoms, main risk factors, and the influence of trace elements on CVD and the regulation of CVD by Mediterranean diet (MD), and obtains the results of the impact of diet on human health and the regulation of CVD by the correct dietary structure. The purpose of this study is to focus on diet, a low-cost and universal method for the prevention and treatment of CVDs, and to make further progress in dietary structure and promotion. It provides a reference for future research on healthy dietary structure, and on the issue that the MD is not prevalent on a global scale, future research can focus more on adjusting the dietary structure to make it universal.

The modification of single or multiple genes via metabolic engineering can lead to the dysregulation of central metabolism and affect bacterial growth and metabolite accumulation. Meanwhile, transcription factor engineering can trigger metabolic network reprogramming at the global or systemic level, redirecting metabolic flux toward the synthetic pathways of target metabolites. In this study, we modulated pyrimidine and carbon-nitrogen metabolism in Bacillus subtilis through transcription factor engineering to promote the synthesis of cytidine, a drug intermediate. First, cytidine synthesis was enhanced by knocking out the transcriptional regulator PyrR, which increased the cytidine titer during shake flask fermentation to 0.67 g/L. Second, mutations in the transcriptional regulator catabolite control protein A (CcpA) significantly promoted cytidine synthesis, increasing the shake flask titer to 2.03 g/L. Finally, after culture in a 5 L fermenter, the cytidine titer reached 7.65 g/L, which was 3.77-fold that of shake flask fermentation. Moreover, a cytidine yield and productivity of 0.06 g/g glucose and 0.16 g/L/h, respectively, were achieved. Subsequently, the regulatory mechanisms through which PyrR and CcpA modification affect cytidine biosynthesis were explored through multi-omics analysis. Transcriptome and metabolome analysis revealed that coordinated alterations in carbon, nitrogen, nucleotide, and amino acid metabolism were essential to promote cytidine synthesis. However, the increased cytidine production in recombinant strains was attributed to the enhancement of pyrimidine metabolism, the Phosphotransferase (PTS) system, the tricarboxylic acid (TCA) cycle, the pentose phosphate (PP) pathway, and nitrogen metabolism. These results indicate that PyrR knockdown can enhance pyrimidine metabolic pathway and promote cytidine synthesis. CcpA mutation can reprogram the central carbon-nitrogen metabolic network, change the metabolic flow to de novo synthesis pathway of pyrimidine nucleoside, increase the supply of cytidine synthesis precursors and promote the accumulation of cytidine. Overall, regulation of engineered carbon and nitrogen metabolic networks is essential for improving the efficiency of microbial cell factories.

This study focused primarily on ‘Muscat Hamburg’ grape varieties of the same age cultivated in the eastern foothills of Helan Mountain, China, to comprehensively assess the effects of quilted and buried soil winter treatments on grapevine growth, fruit quality, and the microorganisms of grape skins. These results indicated that both the survival rates and phenological periods of the plants subjected to the quilted and buried soil treatments were remarkably consistent. In particular, quilted treatment led to improvements in the ripening coefficient of grape fruits, accompanied by significant increases in the concentrations of tannins, total phenols, and total anthocyanins within the grape skins. Additionally, there was an increase in the total phenol contents in the grape seeds. To analyze the specific microorganisms on mature grape berry surfaces under quilt covering and soil-burying practices, high-throughput sequencing 16S and internal transcribed spacer (ITS) methods were employed. The results indicated that the effects of the cover measures facilitated notable changes in the microbial community structure, with a pronounced influence on the fungal community structure. This study serves as a valuable foundation for advancing both theoretical research and practical applications related to the replacement of conventional soil-burying techniques.

In plants, growth and stress responses are tightly regulated by complex signaling networks that integrate environmental cues and internal energy states. The TOR (Target of Rapamycin) and SnRK1 (Snf1-related kinase 1) pathways play critical and opposing roles in this regulation. TOR promotes anabolic processes, such as protein synthesis and cell proliferation, facilitating growth when resources are abundant. In contrast, SnRK1 activates catabolic pathways under stress or nutrient deficiency, conserving energy and promoting survival. Recent studies have revealed significant crosstalk between TOR and SnRK1, highlighting their coordinated roles in maintaining metabolic balance. Furthermore, ABA (Abscisic acid), a key hormone in plants, interacts with both TOR and SnRK1, forming a regulatory axis that finely tunes plant growth and adaptation to environmental stresses. This review explores the regulatory mechanisms of TOR and SnRK1, the crosstalk between TOR and SnRK1 signaling, and the TOR-ABA-SnRK1 signaling network. It focuses on how these pathways collectively manage plant responses to fluctuating resources and environmental challenges. By understanding this balancing mechanism, we can identify strategies to enhance plant resilience and productivity in agricultural systems.

SnRK1 (Sucrose nonfermenting-related protein kinase 1), a kinase family that is evolutionarily conserved in plants and shares direct homology with yeast SNF1 and mammalian AMPK, is a core regulator of energy sensing. SnRK1 plays diverse roles in several physiological processes in plants, including but not limited to plant metabolism, energy homeostasis, growth, development, response to various biotic and abiotic stresses, and activation of plant defense mechanisms. By participating in various signal transduction and integration pathways, SnRK1 is pivotal for enhancing plant adaptability and yield. This review systematically explores the functions of SnRK1 in carbon and nitrogen metabolism, secondary metabolism, as well as its influence on growth and development, and responses to environmental stress. An in-depth study of SnRK1 kinase not only helps us to better understand how plants maintain their survival and productivity under the challenges of global climate change and resource constraints, but also provides a theoretical basis and potential targets for operation to improve crop traits, crop yield, and stress tolerance by means of genetic engineering, which is of great theoretical and practical significance for sustainable agricultural development and food security.

Myocardial fibrosis (MF) is a key factor endangering public health worldwide. Glycyrrhiza uralensis polysaccharide (GPS) exhibits various biological activities. However, its activity against MF has not been reported. Herein, a neutral polysaccharide (GPS-1-1) was isolated from GPS through column chromatography, its structure was characterized and potential mechanism regarding anti-MF activity was evaluated. Notably, the molecular weight of GPS-1-1 was 14.073 kDa, and the monosaccharides consist of glucose, arabinose and galactose, with a -> 4)-alpha-d-glucopyranose (Glcp)-(1 -> and -> 4, 6)-alpha-D-Glcp-(1 -> backbone. Western blotting and immunofluorescence showed that GPS-1-1 inhibited the expression of fibrosis-related proteins, such as Collagen, Vimentin, Fibronectin and alpha-SMA in TGF-beta 1-induced fibrosis of cardiac fibroblasts (CFs), and inhibited the expression of TGF-beta 1-induced CFs migration ability and matrix metalloproteinases (MMP-2 and MMP-9), thus inhibiting the deposition of extracellular matrix in CFs. Additionally, in vivo analysis showed that GPS-1-1 reduced inflammatory cell infiltration and collagen deposition in cardiac tissues of mice with MF, and it inhibited the expression of serum lactate dehydrogenase, creatine kinase, and fibrosis-related factors. Combined transcriptomics, molecular docking and Western blotting analysis showed that platelet-derived growth factor subunit B (PDGFB) was involved in the anti-fibrosis process of GPS-1-1. Furthermore, qRT-PCR and Western blotting showed that GPS-1-1 inhibited the expression of MAPK/PI3K/AKT pathway related proteins, such as ERK, p-ERK, JNK, PI3K and p-PI3K in TGF-beta 1-induced CFs through PDGFB. Altogether, this study showed that GPS-1-1 inhibits the activation of the MAPK/PI3K/AKT pathway by down-regulating PDGFB expression to exert its anti-MF activity and its potential to be developed as a functional food and drug.

This study evaluated the biological protective effects of non-Saccharomyces yeasts (NS), Pichia kluyveri (PK-19) and Hanseniaspora uvarum (YUN-268), during early wine fermentation and their impact on aroma production, providing technical support for low-sulfur wine production. Cabernet Sauvignon grape must was inoculated with NS yeast (0.6 x 106 or 2 x 106 CFU/mL) to initiate fermentation, followed by Saccharomyces cerevisiae (SC) after 48 h. Control group was single SC fermentation with or without sulfur dioxide (SO2). Microbial diversity was assessed using 16S rRNA and ITS (Internal Transcribed Spacer) sequencing, while physicochemical parameters and volatiles were quantified by HPLC and SPME-GC-MS. Results showed that after 48 h, SO2 reduced bacterial diversity with minimal effect on fungal diversity, compared to the SO2-free control. NS treatments, in contrast to SO2, significantly reduced fungal abundance (PK-19 by 7 %, YUN-268 by 34 %) and inhibited bacterial abundance, PK-19 significantly reduced acetic acid bacteria (Gluconobacter and Acetobacter by 82 % and 92 %, respectively), while YUN-268 reduced lactic acid bacteria (Lactococcus and Pediococcus by 53 % and 57 %, respectively). The relative abundance of lactic acid bacteria in the PK-19 increased to 64 %-78 %, with a highly significant positive correlation. After fermentation, compared to SO2 treatments, YUN-268 reduced tartaric acid (0.3-0.4 g/L), and PK-19 reduced malic acid (0.2-0.3 g/L), characteristic of malolactic fermentation. NS treatments significantly increased fruity esters, with YUN-268 boosting ethyl acetate (fivefold), and PK-19 significantly increasing ethyl lactate and ethyl succinate (ninefold and onefold, respectively). In conclusion, PK-19 and YUN-268 exhibited significant biological protective effects, outperforming SO2 treatments and enhancing the aroma quality of wine.

This study aimed to analyze the characteristics of Cabernet Sauvignon (CS) and Marselan (M) wines from different subregions on the eastern foothills of Helan Mountain. UHPLC-ESI-Q-ToF and HS-SPME-GC-MS were employed to analyze the metabolic properties of the wines, and QDA was combined for sensory characterization. The results indicated that chromaticity, total phenols, ethyl isobutyrate, n-decanoic acid, (-)-epigallocatechin, and epigallocatechin were key indicators for distinguishing CS wines from different subregions, whereas total acids, total phenols, hexanol, ethyl butyrate, protocatechuic acid, and (+)-catenin were key indicators for distinguishing M wines from different subregions. The richness and coordination of fruit, floral, dried fruit, spice, and green flavors in the wine were key indicators determining the flavor characteristics of wine in winemaking area. The key compounds with aroma of green, fruity, and floral that determine the core aroma, aroma coordination, and elegance of wine in the winemaking area include cis-2-exen-1-ol, ethyl palmate, octanoic acid, and n-decanoic acid.

Penicillin G acylase (PGA) serves as a critical biocatalyst for the hydrolysis of penicillin G, yielding 6-aminopenicillanic acid, a vital precursor for β-lactam semi-synthetic antibiotics. The catalytic efficiency of PGA, however, remains suboptimal in native Escherichia coli strains. To improve this, E. coli BL21 was engineered as a microbial cell factory via heterologous expression and site-directed mutagenesis to enhance PGA activity. The heterologous pga gene from Providencia rettgeri was integrated into E. coli BL21 (DE3) for the biosynthesis of PGA, achieving a PGA activity of 253 ± 2 U/mL after 16 hours of fermentation. The N167 site underwent mutation, producing the sites N167A and N167I. Plasmids carrying these mutations were introduced into E. coli BL21(DE3), and the enzymatic activities were recorded as 293 ± 3 U/mL for the N167A mutant and 238 ± 2 U/mL for the N167I mutant. This study not only introduces a novel approach to enhancing PGA activity but also illustrates the potential for catalytic optimization through targeted modifications of the enzyme's active site.

Aims Cytidine, as an important commercial precursor in the chemical synthesis of antiviral and antitumor drugs, is in great demand in the market. Therefore, the purpose of this study is to build a microbial cell factory with high cytidine production.Methods and results A mutant E. coli NXBG-11-F34 with high tolerance to uridine monophosphate structural analogs and good genetic stability was obtained by atmospheric room temperature plasma (ARTP) mutagenesis combined with high-throughput screening. Then, the udk and rihA genes involved in cytidine catabolism were knocked out by CRISPR/Cas9 gene editing technology, and the recombinant strain E. coli NXBG-13 was constructed. The titer, yield, and productivity of cytidine fermented in a 5 l bioreactor were 15.7 g l-1, 0.164 g g-1, and 0.327 g l-1 h-1, respectively. Transcriptome analysis of the original strain and the recombinant strain E. coli NXBG-13 showed that the gene expression profiles of the two strains changed significantly, and the cytidine de novo pathway gene of the recombinant strain was up-regulated significantly.Conclusions ARTP mutagenesis combined with metabolic engineering is an effective method to construct cytidine-producing strains.

Pyrimidine nucleosides, as intermediate materials of significant commercial value, find extensive applications in the pharmaceutical industry. However, the current production of pyrimidine nucleosides largely relies on chemical synthesis, creating environmental problems that do not align with sustainable development goals. Recent progress in systemic metabolic engineering and synthetic biology has enabled the synthesis of natural products like pyrimidine nucleosides through microbial fermentation, offering a more sustainable alternative. Nevertheless, the intricate and tightly regulated biosynthetic pathways involved in the microbial production of pyrimidine nucleosides pose a formidable challenge. This study focuses on metabolic engineering and synthetic biology strategies aimed at enhancing pyrimidine nucleoside production. These strategies include gene modification, transcriptional regulation, metabolic flux analysis, cofactor balance optimization, and transporter engineering. Finally, this research highlights the challenges involved in the further development of pyrimidine nucleoside-producing strains and offers potential solutions in order to provide theoretical guidance for future research endeavors in this field.

Bud mutation is a common technique for plant breeding and can provide a large number of breeding materials. Through traditional breeding methods, we obtained a plum plant with bud mutations (named “By”) from an original plum variety (named “B”). The ripening period of “By” fruit was longer than that of “B” fruit, and its taste was better. In order to understand the characteristics of these plum varieties, we used transcriptome analysis and compared the gene expression patterns in fruits from the two cultivars. Subsequently, we identified the biological processes regulated by the differentially expressed genes (DEGs). Gene ontology (GO) analysis revealed that these DEGs were highly enriched for “single-organism cellular process” and “transferase activity”. KEGG analysis demonstrated that the main pathways affected by the bud mutations were plant hormone signal transduction, starch and sucrose metabolism. The IAA, CKX, ARF, and SnRK2 genes were identified as the key regulators of plant hormone signal transduction. Meanwhile, TPP, the beta-glucosidase (EC3.2.1.21) gene, and UGT72E were identified as candidate DEGs affecting secondary metabolite synthesis. The transcriptome sequencing (RNA-seq) data were also validated using RT-qPCR experiments. The transcriptome analysis demonstrated that plant hormones play a significant role in extending the maturity period of plum fruit, with IAA, CKX, ARF, and SnRK2 serving as the key regulators of this process. Further, TPP, beta-glucosidase (EC3.2.1.21), and UGT72E appeared to mediate the synthesis of various soluble secondary metabolites, contributing to the aroma of plum fruits. The expression of BAG6 was upregulated in “B” as the fruit matured, but it was downregulated in “By”. This indicated that “B” may have stronger resistance, especially fungal resistance.

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 l-isoleucine synthesis. This was done with the aim to reduce the breakdown of l-threonine 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 OD600. 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, l-lysine 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 l-isoleucine, such as the tricarboxylic acid cycle, glycolysis, and aspartic acid pathway.