WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14627/6
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Article Metabolic Responses to Benzoic Acid Stress and Glutamine Transport-Dependent Vulnerabilities in Escherichia Coli Revealed by NMR Metabolomics(Springer, 2026) Yuksektepe, Ecem; Elgin, Emine Sonay; Onat-Tasdelen, Kadriye Aslihan; Chae, Young Kee; Dogu, Eralp; Catav, Sukru Serter; Ozturkel-Kabakas, HaticeBenzoic acid (BA) is a widely used weak organic acid preservative with antimicrobial activity, yet the metabolic basis of its antibacterial action and the determinants of bacterial sensitivity remain incompletely understood. Here we combined growth assays with H-1 NMR metabolomics to characterize BA-induced metabolic responses in Escherichia coli BW25113 and to examine metabolic changes associated with impaired glutamine transport. Wild-type BW25113 and its BA-sensitive isogenic Delta glnP mutant, lacking the membrane-bound glutamine permease of the high-affinity GlnHPQ transport system, were exposed to sublethal BA concentrations. BA slowed growth and significantly altered the levels of 42 metabolites in the wild-type and 38 in Delta glnP, with the mutant showing stronger growth inhibition and reduced BA tolerance. Both strains exhibited metabolic changes consistent with cellular responses to oxidative and acid stress, including alterations in central carbon metabolism, lysine degradation, cysteine and methionine metabolism, pyrimidine metabolism, and one-carbon pool by folate. However, several metabolic responses differed between the two strains. In wild-type cells, BA exposure was associated with changes in glycerolipid metabolism, glycerophospholipid metabolism, nicotinate and nicotinamide metabolism, lysine biosynthesis, glycine, serine and threonine metabolism, and purine metabolism. In contrast, Delta glnP cells showed distinct alterations in D-amino acid metabolism, arginine biosynthesis, and other carbon fixation pathways. In addition, the mutant displayed substantial baseline differences relative to the wild-type, including altered nucleotide and amino acid pools. Together, these results indicate that both BA exposure and deletion of glnP induce broad metabolic adjustments in Escherichia coli. Loss of glnP is associated with distinct metabolic states and altered responses to BA stress, highlighting the importance of glutamine transport in adaptation to weak organic acid stress.Article Citation - WoS: 1Citation - Scopus: 1A Comparative Study of Biochemical, Antimicrobial Effects and Phytochemical Composition Analysis of Glycyrrhiza Glabra L. Varieties Root Extracts(Marmara University, 2025) Sen, Ali; Servı, Hüseyın; Barak, Timur Hakan; Tekin, Fethullah; Şener, Azize; Marzi, Mahdi; Gülmez, GizemPlants are the significant global interest as alternative treatment sources with their biologically activecompounds. This study compares the chemical composition and the antioxidant, antidiabetic, and antimicrobialproperties of ethanol extracts of G. glabra L. two different varieties from different regions. The phytochemicalcompositions was determined using GC-MS. Additionaly, total phenolic (TPC), flavonoid (TFC) and triterpene (TTC)contents were determined. Glycyrrhizic acid contents were analysed by HPLC. G. glabra var. glandulifera (GF1) showedthe highest antioxidant activity. All extracts had strong antidiabetic effects, besides GF1 showing the highest effect. TheMIC values was determined against 8 bacterial and 1 yeast strain and values ranged from 2.500 to 0.500; 2.500 to 0.714;2.500 to 0.714 for G. glabra var. glabra (GB), GF1, G. glabra var. glandulifera (GF2) respectively. Phytochemical studies haveshown that TPC was 100.60±5.06, 127.90±0.30, 69.01±0.30 mg GAE /g extract; TFC was 80.07±0.15, 25.35±0.0, 16.58±0.31mg KE/g and TTC was 217.30±6.05,172.40±2.17, 126.30±4.50 mg OE/g extract for GB, GF1, GF2, respectively. GF1 inparticular has the highest glycyrrhizic acid content. This study will contribute to the creation of new treatment strategiesand potential therapeutic agents in addition to the use of G. glabra L. in traditional treatments. Our study is also apreliminary study for future studies.