Journal: Metabolites

Article Title: Identification of Quinone Degradation as a Triggering Event for Intense Pulsed Light-Elicited Metabolic Changes in Escherichia coli by Metabolomic Fingerprinting

doi: 10.3390/metabo11020102

Figure Lengend Snippet: Effects of IPL on E. coli growth and morphology. ( A ) Plate counts of E. coli after the IPL treatments. The linear regression between Log-transformed CFU and the IPL treatment time ( t ) yielded an equation of Log(CFU) = −0.1882 t + 8.688 with r 2 = 0.94. The control and IPL-treated E. coli cells were examined by TEM imaging: ( B ) control; ( C ) 5 s (a dead cell is marked by the red arrow); ( D ) 10 s; ( E ) 15 s; and ( F ) 20 s. Scale bars = 1.0 μm.

Article Snippet: E. coli strain K-12 W3110 (ATCC 27325) was chosen as the surrogate of food-borne pathogens to examine the IPL-elicited bacteriostatic and bactericidal effects.

Techniques: Transformation Assay, Control, Imaging

Journal: Metabolites

Article Title: Identification of Quinone Degradation as a Triggering Event for Intense Pulsed Light-Elicited Metabolic Changes in Escherichia coli by Metabolomic Fingerprinting

doi: 10.3390/metabo11020102

Figure Lengend Snippet: Modeling of IPL-elicited changes in the E. coli metabolome. Pooled data from the LC-MS analysis of organic and aqueous extracts of E. coli cells were processed by principal components analysis (PCA). ( A ) Scores plot of the PCA model. The samples in the same treatment group ( n = 4) are circled. A scores plot containing three quality control (QC) samples is presented in . ( B ) Loadings plot of the PCA model. The labeled markers (I–XIX) are the identified metabolites that contribute to the separation of sample groups. Their identities are listed in . ( C ) Heatmap from the clustering analysis of IPL-responsive markers (I–XIX). PE, phosphatidylethanolamine; CMGSH, S -carboxymethyl-glutathione; UMP, uridine monophosphate; AMP, adenosine monophosphate; G3P, glycerol 3-phosphate; UQH 2 -8, ubiquinol-8; MK-8, menaquinone-8; UQ-8, ubiquinone-8; R5P, ribose 5-phosphate.

Article Snippet: E. coli strain K-12 W3110 (ATCC 27325) was chosen as the surrogate of food-borne pathogens to examine the IPL-elicited bacteriostatic and bactericidal effects.

Techniques: Liquid Chromatography with Mass Spectroscopy, Control, Labeling

Journal: Metabolites

Article Title: Identification of Quinone Degradation as a Triggering Event for Intense Pulsed Light-Elicited Metabolic Changes in Escherichia coli by Metabolomic Fingerprinting

doi: 10.3390/metabo11020102

Figure Lengend Snippet: Detection and identities of IPL-responsive metabolites in the E. coli metabolome. The metabolite markers were detected in four different modes, including positive-mode detection of protonated metabolites ([M + H] + ) in aqueous extracts, negative-mode detection of deprotonated metabolites ([M − H] − ) in aqueous extracts, positive-model detection of dansylated metabolites ([M + DC] + ) in aqueous extracts, and positive-mode detection of both protonated ([M + H] + ) and ammonium ([M + NH 4 ] + ) adducts in lipid extracts.

Article Snippet: E. coli strain K-12 W3110 (ATCC 27325) was chosen as the surrogate of food-borne pathogens to examine the IPL-elicited bacteriostatic and bactericidal effects.

Techniques:

Journal: Metabolites

Article Title: Identification of Quinone Degradation as a Triggering Event for Intense Pulsed Light-Elicited Metabolic Changes in Escherichia coli by Metabolomic Fingerprinting

doi: 10.3390/metabo11020102

Figure Lengend Snippet: Influences of IPL treatment on membrane lipids. ( A ) Representative chromatographs on membrane phospholipids and quinones in the organic fractions of control and IPL-treated E. coli (20 s). The relative abundances of lipid markers across all the samples were compared by arbitrarily setting the average of the treatment group with the highest relative abundances as 1: ( B ) menaquinone-8 (IX); ( C ) ubiquinol-8 (VIII); ( D ) ubiquinone-8 (X); ( E ) PE(14:0/16:0) (XII); ( F ) PE(16:0/17:0Cyclo) (V); and ( G ) PE(16:0/19:0Cyclo) (XI). Different letters (a and b) indicate significant differences ( p < 0.05) between timepoints.

Article Snippet: E. coli strain K-12 W3110 (ATCC 27325) was chosen as the surrogate of food-borne pathogens to examine the IPL-elicited bacteriostatic and bactericidal effects.

Techniques: Membrane, Control

Journal: Metabolites

Article Title: Identification of Quinone Degradation as a Triggering Event for Intense Pulsed Light-Elicited Metabolic Changes in Escherichia coli by Metabolomic Fingerprinting

doi: 10.3390/metabo11020102

Figure Lengend Snippet: Influences of IPL treatment on cytoplasmic metabolites. ( A ) Representative chromatographs on amino acid metabolites in the aqueous fractions of control and IPL-treated E. coli (20 s). These metabolites were detected via dansyl chloride derivatization. d 5 -TRP ( d 5 -tryptophan) was the internal standard in amino acid analysis and had stable signals across all the samples. ( B ) Representative chromatographs on hydrophilic metabolites in the aqueous fractions of control and IPL-treated E. coli (20 s). These metabolites were detected in the negative ionization mode without derivatization. The relative abundances of cytoplasmic metabolite markers across all the samples were compared by arbitrarily setting the average of the treatment group with the highest relative abundances as 1. The peak of NAD + is included in the chromatograph for its relative stable signals across all the samples: ( C ) glutamate; ( D ) N -acetylcadaverine; ( E ) N -acetylputrescine; ( F ) valine; ( G ) histidine; ( H ) GSH, glutathione; ( I ) CMGSH, S-carboxymethyl-glutathione; ( J ) UMP, uridine monophosphate; ( K ) AMP, adenosine monophosphate; ( L ) phosphoric acid; ( M ) G3P, glycerol 3-phosphate; ( N ) R5P, ribose 5-phosphate; and ( O ) N -acetylspermidine. Different letters (a–d) indicate significant differences ( p < 0.05) between timepoints.

Article Snippet: E. coli strain K-12 W3110 (ATCC 27325) was chosen as the surrogate of food-borne pathogens to examine the IPL-elicited bacteriostatic and bactericidal effects.

Techniques: Control

Journal: Metabolites

Article Title: Identification of Quinone Degradation as a Triggering Event for Intense Pulsed Light-Elicited Metabolic Changes in Escherichia coli by Metabolomic Fingerprinting

doi: 10.3390/metabo11020102

Figure Lengend Snippet: Summary of IPL-elicited morphological and metabolic changes in E. coli . IPL covers ultraviolet (UV), visible, and infrared (IR) light. IPL-treated E. coli cells underwent changes in size, shape, and structures, especially in the nucleoid. Metabolic changes occurred in the inner plasma membrane, cytoplasm, and nucleoid of E. coli after the IPL treatments, affecting the metabolites in ETC, oxidative stress, Embden–Meyerhof–Parnas glycolytic pathway (EMP), pentose phosphate pathway (PPP), amino acid, and nucleotide metabolism. Among them, the degradation of quinone electron carriers, especially the depletion of MK-8, is the earliest and most dramatic metabolic event induced by the IPL.

Article Snippet: E. coli strain K-12 W3110 (ATCC 27325) was chosen as the surrogate of food-borne pathogens to examine the IPL-elicited bacteriostatic and bactericidal effects.

Techniques: Clinical Proteomics, Membrane