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Wang XT, Ma BG. Spatial Chromosome Organization and Adaptation of Escherichia coli under Heat Stress. Microorganisms 2024; 12:1229. [PMID: 38930611 PMCID: PMC11205535 DOI: 10.3390/microorganisms12061229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/14/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024] Open
Abstract
The spatial organization of bacterial chromosomes is crucial for cellular functions. It remains unclear how bacterial chromosomes adapt to high-temperature stress. This study delves into the 3D genome architecture and transcriptomic responses of Escherichia coli under heat-stress conditions to unravel the intricate interplay between the chromosome structure and environmental cues. By examining the role of macrodomains, chromosome interaction domains (CIDs), and nucleoid-associated proteins (NAPs), this work unveils the dynamic changes in chromosome conformation and gene expression patterns induced by high-temperature stress. It was observed that, under heat stress, the short-range interaction frequency of the chromosomes decreased, while the long-range interaction frequency of the Ter macrodomain increased. Furthermore, two metrics, namely, Global Compactness (GC) and Local Compactness (LC), were devised to measure and compare the compactness of the chromosomes based on their 3D structure models. The findings in this work shed light on the molecular mechanisms underlying thermal adaptation and chromosomal organization in bacterial cells, offering valuable insights into the complex inter-relationships between environmental stimuli and genomic responses.
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Affiliation(s)
| | - Bin-Guang Ma
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China;
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Xu Y, Guan X, Wang S. Synergistic bactericidal mechanisms of RF energy simultaneously combined with cinnamon essential oil or epsilon-polylysine against Salmonella revealed at cellular and metabolic levels. Int J Food Microbiol 2024; 408:110447. [PMID: 37907022 DOI: 10.1016/j.ijfoodmicro.2023.110447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/13/2023] [Accepted: 10/11/2023] [Indexed: 11/02/2023]
Abstract
Radio frequency (RF) heating and antimicrobials are considered to be effective methods for inactivating food pathogens. This study explored the bactericidal effects against Salmonella of RF heating combined with two kinds of natural antimicrobials possessing different hydrophobic properties and their synergistic bactericidal mechanisms. Results showed that RF heating caused sublethal damage to bacterial cells and enhanced the interaction of cells and antimicrobials, leading to synergistic bactericidal effects of the simultaneous combination of RF heating and antimicrobials. The combination of RF heating and ε-polylysine (ε-PL) further promoted cell morphological alteration, raised membrane permeability, intracellular adenosine triphosphate (ATP) leakage and intracellular reactive oxygen species (ROS) accumulation compared to individual treatment. The simultaneous combination of RF heating and cinnamon essential oil nanoemulsion (CEON) also further enhanced membrane permeability and ROS accumulation compared to individual treatment, but impacts were less than those in the combination of RF heating and ε-PL. The major synergistic bactericidal mechanism of RF heating and CEON was significantly inhibiting intracellular ATP synthesis. The untargeted metabolomics analysis revealed that the combined treatments enhanced disturbances to multiple intracellular metabolisms compared to individual treatment, thus leading to synergistic bactericidal effects against Salmonella. These results provide an in-depth understanding of the synergistic bactericidal mechanisms of the combination of RF heating and natural antimicrobials from cellular and metabolic levels.
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Affiliation(s)
- Yuanmei Xu
- College of Biological and Food Engineering, Changshu Institute of Technology, 99 South Third Ring Road, Changshu 215500, China
| | - Xiangyu Guan
- College of Food Science and Engineering, Shandong Agricultural University, Taian 271018, China
| | - Shaojin Wang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China; Washington State University, Department of Biological Systems Engineering, Pullman, WA 99164-6120, USA.
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Wang Y, Chen Z, Zhao F, Yang H. Metabolome shifts triggered by chlorine sanitisation induce Escherichia coli on fresh produce into the viable but nonculturable state. Food Res Int 2023; 171:113084. [PMID: 37330837 DOI: 10.1016/j.foodres.2023.113084] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/19/2023]
Abstract
Facing the increasing occurrence of "big six" Escherichia coli outbreaks linked to fresh produce, chlorine-based sanitisers are widely used for fresh produce decontamination in recent years. However, latest finding that chlorine may induce E. coli cells into a viable not nonculturable (VBNC) state is bringing a new challenge to the fresh produce industry. VBNC cells are undetectable by the plate count test, and yet they retain pathogenicity and are more antibiotic-resistant than culturable cells. As a result, their eradication is critical to ensure the safety of fresh produce. Understanding VBNC cells at the metabolic level may provide a breakthrough for their eradication. Therefore, this study was carried out to collect the VBNC pathogenic E. coli (O26:H11, O121:H19, and O157:H7) cells from chlorine-treated pea sprouts and characterise them using NMR-based metabolomics. From the globally increased metabolite contents detected in the VBNC E. coli cells as compared to the culturable cells, mechanisms underlying E. coli's VBNC induction were elucidated. These include rendering the energy generation scheme to become more compatible with the lowered energy needs, disaggregating protein aggregates to release amino acids for osmoprotection and later resuscitation, as well as increasing cAMP content to downregulate RpoS. These identified metabolic characteristics can inspire future development of targeted measures for VBNC E. coli cell inhibition. Our methods can also be applied to other pathogens to help lower the risk of overall foodborne diseases.
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Affiliation(s)
- Yue Wang
- Department of Food Science and Technology, National University of Singapore, Singapore 117542, Singapore.
| | - Zihui Chen
- Department of Food Science and Technology, National University of Singapore, Singapore 117542, Singapore
| | - Fengnian Zhao
- Department of Food Science and Technology, National University of Singapore, Singapore 117542, Singapore
| | - Hongshun Yang
- Shaoxing Key Laboratory of Traditional Fermentation Food and Human Health, Jiangnan University (Shaoxing) Industrial Technology Research Institute, Zhejiang, 312000, China.
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Le Y, Lou X, Yu C, Guo C, He Y, Lu Y, Yang H. Integrated metabolomics analysis of Lactobacillus in fermented milk with fish gelatin hydrolysate in different degrees of hydrolysis. Food Chem 2023; 408:135232. [PMID: 36566542 DOI: 10.1016/j.foodchem.2022.135232] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
Dual-platform metabolomics combined with multivariate data analysis was used to investigate the effects of adding fish gelatin (FGH) at different degrees of hydrolysis (DH) on the growth and metabolic pathways of different species of Lactobacillus in fermented milk. The results showed that the promotion effect of FGH on Lactobacillus was related to the species of probiotics. The corresponding metabolic pathways also changed, with the promotion of Lactobacillus by FGH mainly regulated through amino acid metabolism, lipid metabolism, and nucleotide metabolism pathways. The excess DH inhibited the growth of L. paracasei by adjusting its metabolic state through reducing nucleotide requirements, allocating protein resources, and adopting a stress response. In conclusion, this study revealed the effectiveness of dual-platform metabolomics in explaining the metabolic mechanisms of probiotics, providing theoretical support and a scientific basis for the development of functional fermented foods.
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Affiliation(s)
- Yi Le
- Department of Food Science and Technology, National University of Singapore, 117542, Singapore
| | - Xiaowei Lou
- Department of Food Science and Technology, National University of Singapore, 117542, Singapore; National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Suzhou, Jiangsu 215123, China
| | - Chengwei Yu
- Department of Food Science and Technology, National University of Singapore, 117542, Singapore; School of Health, Jiangxi Normal University, Nanchang, Jiangxi 330022, China
| | - Chenxi Guo
- Department of Food Science and Technology, National University of Singapore, 117542, Singapore
| | - Yun He
- Department of Food Science and Technology, National University of Singapore, 117542, Singapore; National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Suzhou, Jiangsu 215123, China
| | - Yuyun Lu
- Department of Food Science and Technology, National University of Singapore, 117542, Singapore
| | - Hongshun Yang
- Department of Food Science and Technology, National University of Singapore, 117542, Singapore; National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Suzhou, Jiangsu 215123, China.
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Ma Y, Xu D, Xu X. The effect of wheat flour treated with superheated steam on the microstructure and rheological behaviors of batter and cake quality. J FOOD PROCESS ENG 2023. [DOI: 10.1111/jfpe.14273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Yongshuai Ma
- School of Food Science and Technology Jiangnan University Wuxi People's Republic of China
| | - Dan Xu
- School of Food Science and Technology Jiangnan University Wuxi People's Republic of China
- State Key Laboratory of Food Science and Technology Jiangnan University Wuxi People's Republic of China
| | - Xueming Xu
- School of Food Science and Technology Jiangnan University Wuxi People's Republic of China
- State Key Laboratory of Food Science and Technology Jiangnan University Wuxi People's Republic of China
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Wang Y, Yang H. Metabolomics elucidating the effect of water activity on the thermal resistance of Salmonella in wheat flour. Food Res Int 2022; 162:112203. [DOI: 10.1016/j.foodres.2022.112203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 11/12/2022] [Accepted: 11/15/2022] [Indexed: 11/21/2022]
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Dual-Species Biofilms Formed by Escherichia coli and Salmonella Enhance Chlorine Tolerance. Appl Environ Microbiol 2022; 88:e0148222. [PMID: 36300924 PMCID: PMC9680634 DOI: 10.1128/aem.01482-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Outbreaks of
Escherichia coli
and
Salmonella
in food might be associated with the cross-contamination of biofilms on food-contact surfaces. The knowledge of the sanitization of mono-species biofilm on the food-contact surface is well established, while mixed-species biofilm occurs more naturally, which could profoundly affect the efficacy of sanitizer.
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Wang Y, Gao X, Yang H. Integrated metabolomics of "big six" Escherichia coli on pea sprouts to organic acid treatments. Food Res Int 2022; 157:111354. [PMID: 35761617 DOI: 10.1016/j.foodres.2022.111354] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/27/2022] [Accepted: 05/06/2022] [Indexed: 11/17/2022]
Abstract
Naturally occurring organic acids (OAs) have demonstrated satisfactory effects in inhibiting common pathogens on fresh produce; however, their effectiveness on "big six" Escherichia coli serotypes, comprised of E. coli O26:H11, O45:H2, O103:H11, O111, O121:H19 and O145, remained unaddressed. Regarding this, using nuclear magnetic resonance (NMR) spectroscopy and ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS), the sanitising efficacy and the underlying antimicrobial mechanisms of 10-min treatments with 0.2 mol/L ascorbic acid (AA), citric acid (CA) and malic acid (MA) against the "big six" strains on pea sprouts were thoroughly investigated in this study. Despite the varying antimicrobial efficacy (AA: 0.12-0.99, CA: 0.36-1.72, MA: 0.75-3.28 log CFU/g reductions), the three OAs induced consistent metabolic changes in the E. coli strains, particularly in the metabolism of membrane lipids, nucleotide derivatives and amino acids. Comparing all strains, the most OA-resistant strain, O26 (0.36-1.12 log CFU/g reductions), had the largest total amino acids accumulated to resist osmotic stress; its ulteriorly suppressed cell activity further strengthened its endurance. In contrast, the lowest OA-resistance of O121 (0.99-3.28 log CFU/g reductions) might be explained by the depletion of putrescine, an oxidative stress regulator. Overall, the study sheds light on the effectiveness of a dual-platform metabolomics investigation in elucidating the metabolic responses of "big six" E. coli to OAs. The manifested antimicrobial effects of OAs, especially MA, together with the underlying metabolic perturbations detected in the "big six" strains, provided scientific basis for applying OA treatments to future fresh produce sanitisation.
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Affiliation(s)
- Yue Wang
- Department of Food Science and Technology, National University of Singapore, Singapore 117542, Singapore; National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Suzhou, Jiangsu 215123, PR China
| | - Xianfu Gao
- Shanghai Profleader Biotech Co., Ltd, Jiading District, Shanghai 201805, PR China
| | - Hongshun Yang
- Department of Food Science and Technology, National University of Singapore, Singapore 117542, Singapore; National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Suzhou, Jiangsu 215123, PR China.
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