Journal: Synthetic and Systems Biotechnology

Article Title: Engineering Escherichia coli for robust Co-utilization of glucose and xylose enables high-titer succinate production from lignocellulosic hydrolysates

doi: 10.1016/j.synbio.2026.01.006

Figure Lengend Snippet: Investigation of xylose transport and PTS modification for succinate production. (A) Schematic representation of glucose and xylose transport routes in different E. coli strains, highlighting the key transporters and metabolic nodes influencing carbon flux; (B) Intracellular ATP levels in strains C600, MG1655, and BW25113 during aerobic growth on xylose; (C) Comparison of succinate and by-product accumulation between the parental strain C600 and engineered strain ESC2 under anaerobic conditions; (D) Fermentation performance of PTS-modified strain ESC3, showing sugar utilization, biomass generation, and succinate production; (E–F) Growth profiles of engineered ESC3 derivatives in defined medium with xylose (E) or glucose–xylose mixtures (F). All experimental data were performed in triplicate, and error bars represent the standard deviation. Statistical analysis was performed using a two-tailed Student's t -test (∗∗p < 0.01, ∗∗∗p < 0.001).

Article Snippet: In this study, we systematically engineered E. coli C600 (ATCC 23724) [ ], a strain with efficient and low-energy xylose transport, as the chassis for succinate production from lignocellulosic sugars.

Techniques: Modification, Comparison, Standard Deviation, Two Tailed Test

Journal: Synthetic and Systems Biotechnology

Article Title: Engineering Escherichia coli for robust Co-utilization of glucose and xylose enables high-titer succinate production from lignocellulosic hydrolysates

doi: 10.1016/j.synbio.2026.01.006

Figure Lengend Snippet: Construction of a succinate-producing strain from C600. (A) Metabolic map illustrating targeted knockouts ( ldhA , pflB , ptsG , adhE and pta-ackA ) and expression/integration of pck to redirect flux toward succinate; (B) Two-stage fermentation scheme comprising aerobic growth using shaking flasks and followed by anaerobic production in serum bottles; (C–D) Succinate fermentation of six engineered strains cultured on xylose (C) or glucose–xylose mixtures (D). All experimental data were performed in triplicate, and error bars represent the standard deviation.

Article Snippet: In this study, we systematically engineered E. coli C600 (ATCC 23724) [ ], a strain with efficient and low-energy xylose transport, as the chassis for succinate production from lignocellulosic sugars.

Techniques: Expressing, Cell Culture, Standard Deviation

Journal: Synthetic and Systems Biotechnology

Article Title: Engineering Escherichia coli for robust Co-utilization of glucose and xylose enables high-titer succinate production from lignocellulosic hydrolysates

doi: 10.1016/j.synbio.2026.01.006

Figure Lengend Snippet: Evaluation of exogenous xylose utilization pathways and library-based strain selection. (A) Schematic comparison of the endogenous XI pathway with the Dahms and Weimberg pathways; (B) Design of pathway plasmid libraries and RBS variants controlling expression of key genes for Dahms and Weimberg pathways. The Weimberg library plasmid carries XylA , XylX , and XylB from C. crescentus , while the Dahms library plasmid contains XylB from C. crescentus . The helper plasmid harbors xylC from C. crescentus and the endogenous yjhG from E. coli . RBS sequences were designed with 32 mutations, enabling gene expression levels ranging from 4 to 57,523 au; (C) Growth and succinate production of four representative ESC7 derivatives (ESC7-W1, ESC7-W2, ESC7-D1, ESC7-D2), which were randomly selected from the Weimberg (W1, W2) or Dahms (D1, D2) pathway libraries, compared with ESC6 (XI pathway); (D) Fermentation performance of the same four ESC7 clones carrying the helper plasmid (harboring XylC and yjhG ), compared with ESC6; (E) Validation of pathway combinations in the ESC6 background using the same four representative plasmids, integrating XI with Dahms/Weimberg routes and help plasmid; (F) Screening of library colonies identified six optimal variants, which were reconstructed in ESC6 and evaluated for succinate production from glucose–xylose mixtures. All experimental data were performed in triplicate, and error bars represent the standard deviation. Statistical analysis was performed using a two-tailed Student's t -test (∗∗∗ p < 0.001).

Article Snippet: In this study, we systematically engineered E. coli C600 (ATCC 23724) [ ], a strain with efficient and low-energy xylose transport, as the chassis for succinate production from lignocellulosic sugars.

Techniques: Selection, Comparison, Plasmid Preparation, Expressing, Gene Expression, Clone Assay, Biomarker Discovery, Standard Deviation, Two Tailed Test

Journal: Journal of Structural Biology: X

Article Title: Salt bridge disruption in colicin Ib channel-forming domain enhances membrane translocation and bactericidal activity

doi: 10.1016/j.yjsbx.2026.100144

Figure Lengend Snippet: E. coli viability after the treatments of full-length ColIb and salt bridge variants using spot assay and CFU analysis. E. coli ATCC8739 treated with full-length WT ColIb or salt bridge variants, in the a, c absence and b, d presence of the iron chelator, 2,2′ bipyridine (100 μM), were 10-fold serially diluted and spotted. The groups treated with the protein buffer were included as a negative control. The bacterial cell viabilities treated with 0.1 nM and 0.01 nM of protein samples are compared in b . Data represent the mean ± S.D. with n = 3 independent experimental replicates. Statistical analyses were assessed using a one-way ANOVA in GraphPad Prism. * p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001, **** p ≤ 0.0001, n.s., not significant.

Article Snippet: Since the above experimental results demonstrated that disrupting the electrostatic interactions in the C-domain leads to a more loosely packed tertiary structure, which may reduce the unfolding energy required for translocation through CirA and facilitate membrane insertion, we sought to characterize the antibacterial activity by monitoring the viability of E. coli ATCC 8739 treated with full-length ColIb and its salt bridge variants ( , ).

Techniques: Spot Test, Negative Control

Journal: Journal of Structural Biology: X

Article Title: Salt bridge disruption in colicin Ib channel-forming domain enhances membrane translocation and bactericidal activity

doi: 10.1016/j.yjsbx.2026.100144

Figure Lengend Snippet: Bactericidal activity of the WT ColIb C-domain and salt bridge variants using the spot-on-lawn antimicrobial assay. Three-fold serially diluted a , b isolated ColIb C-domain and variants, and c , d full-length ColIb were spotted on the lawn of E. coli ATCC8739. The WT ColIb C-domain and variants were purified at pH 6.0 ( a , b left) and pH 4.5 ( a , b right) for spotting. The C-domain-truncated ColIb variant (TR) was pre-spotted on the plate before spotting b the ColIb C-domain and variants, and d full-length ColIb. Refer to Methods for details.

Article Snippet: Since the above experimental results demonstrated that disrupting the electrostatic interactions in the C-domain leads to a more loosely packed tertiary structure, which may reduce the unfolding energy required for translocation through CirA and facilitate membrane insertion, we sought to characterize the antibacterial activity by monitoring the viability of E. coli ATCC 8739 treated with full-length ColIb and its salt bridge variants ( , ).

Techniques: Activity Assay, Isolation, Purification, Variant Assay