Journal: iScience

Article Title: Engineering Escherichia coli for polyethylene terephthalate powder biodegradation via recoding of an outer membrane protein

doi: 10.1016/j.isci.2025.114621

Figure Lengend Snippet: In vivo accumulation of PET degradation products by genome-rewired E . coli cultured with PET powder (A) Concentrations of degradation products generated during in vivo cultivation of strain S3 in the presence of pPET (solid lines, primary axis) and the growth of strains S3 and control S1 during this experiment (dotted lines, secondary axis). Cultures (10 mL) were grown in 50 mL Falcon tubes for 192 h in M9 medium supplemented with 0.1 mg mL −1 ampicillin at 37°C and 200 rpm, with an initial OD 600 nm of 0.1 and a pPET concentration of 5.0 mg mL −1 . To induce growth via EG utilization, 1 mM isopropyl β-D-1-thiogalactopyranoside (IPTG) and 0.1 mg mL −1 glycerol were added. We would like to note that in our previous work, strains expressing only the recoded PETase-like protein (LsrB m ) or only the EG-metabolizing genes did not grow, confirming their inability to use EG as a carbon source. These controls were therefore not repeated here; instead, strain S1, which carries both heterologous EG-metabolizing genes and the recoded periplasmic LsrB m , was used as the main control, as it can hydrolyze nanometric PET particles but not PET powder, as shown in this study. (B) Concentrations of degradation products generated during in vivo cultivation of strain S3 in the presence of different concentrations of pPET. Reactions were performed in 2-mL Eppendorf tubes using 500 μL of culture (OD 600 nm of 0.1) in M9 medium supplemented with 0.1 mg mL −1 ampicillin, 1 mM IPTG, 0.1 mg mL −1 glycerol, and different concentrations of pPET (5, 10, 20, and 30 mg mL −1 ) at 37°C and 1,200 rpm. (A and B) Absorbance in (A) was quantified spectrophotometrically, and the degradation products in (A and B) were quantified using HPLC, as detailed in . The values represent the means of three biological replicates ( n = 3), with the means and standard deviations (SDs) shown. Unprocessed data are available in D and S1F.

Article Snippet: In brief, selected E . coli BL21 (DE3) clones were grown at 37°C on LB agar plates (ThermoFisher Scientific, MA, USA; ref. 22700041) supplemented with 0.1 mg mL -1 ampicillin (ThermoFisher Scientific; ref. BP1760).

Techniques: In Vivo, Cell Culture, Generated, Control, Concentration Assay, Expressing

Journal: Life Metabolism

Article Title: Propionic acid secreted by Akkermansia muciniphila alleviates hepatic fibrosis by antioxidant regulation across the gut–liver axis

doi: 10.1093/lifemeta/loaf036

Figure Lengend Snippet: AKK alleviates liver fibrosis in mice by improving propionic acid metabolism. (a) Body weight of animals recorded weekly during the experimental period. (b) Liver index ( n = 6). (c–f) Serum content of ALT (c), AST (d), γ-GT (e), and ALP (f) ( n = 6). (g) Representative images of H&E, Masson, and Sirius Red staining (scale bar = 25 μm) in the liver ( n = 6). (h and i) Liver collagen deposition index ( n = 6). (j) Fibrosis-related markers such as TIMP-1, α-SMA, and Col1α1 and TGF-β1 protein expression assayed by western blotting. (k) Propionic acid levels in the livers, feces, and plasma of mice ( n = 6). (l) Gene expression of Slc52a1 and Slc52a2 in mice ( n = 6). Data are presented as the mean ± SEM. Statistical significance was determined using ANOVA for multiple-group comparisons. CCl 4 -induced hepatic fibrosis (CCl 4 ), ABX + CCl 4 , or a combination of ABX + CCl 4 plus AKK (ABX + CCl 4 + AKK ) were used to assess liver metabolomics and the indicated assays. ** P < 0.01, *** P < 0.05, compared with the CCl 4 group. # P < 0.05, ## P < 0.01, compared with the ABX + CCl 4 group. $ P < 0.05, compared with the CCl 4 + AKK group.

Article Snippet: To induce the ABX model, mice with hepatic fibrosis were orally administered an ABX mixture consisting of ampicillin (0.2 g/L, MedChemExpress, CAS# HY-B0522), vancomycin (0.2 g/L, MedChemExpress, CAS# HY-B0671), neomycin sulfate (0.2 g/L, MedChemExpress, CAS# HY-B0470), and metronidazole (0.2 g/L, MedChemExpress, CAS# HY-B0318) for 1 week before the 8th week.

Techniques: Staining, Expressing, Western Blot, Clinical Proteomics, Gene Expression