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Hu X, Wang X, Ren H, Li C, Zhang B, Shi R, Wang Y, Lu S, Li Y, Lu Q, Liu Z, Hu P. Preliminary Study of the Characterization of the Viable but Noncultivable State of Yersinia enterocolitica Induced by Chloride and UV Irradiation. Microorganisms 2024; 12:1778. [PMID: 39338453 PMCID: PMC11434376 DOI: 10.3390/microorganisms12091778] [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: 08/08/2024] [Revised: 08/19/2024] [Accepted: 08/24/2024] [Indexed: 09/30/2024] Open
Abstract
The viable but non-culturable (VBNC) state is a survival strategy for many foodborne pathogens under adverse conditions. Yersinia enterocolitica (Y. enterocolitica) as a kind of primary foodborne pathogen, and it is crucial to investigate its survival strategies and potential risks in the food chain. In this study, the effectiveness of ultraviolet (UV) irradiation and chlorine treatment in disinfecting the foodborne pathogen Y. enterocolitica was investigated. The results indicated that both UV irradiation and chlorine treatment can induce the VBNC state in Y. enterocolitica. The bacteria completely lost culturability after being treated with 25 mg/L of NaClO for 30 min and a UV dose of 100 mJ/cm². The number of culturable and viable cells were detected using plate counting and a combination of fluorescein and propidium iodide (live/dead cells). Further research found that these VBNC cells exhibited reduced intracellular Adenosine Triphosphate (ATP) levels, and increased levels of reactive oxygen species (ROS) compared to non-induced cells. Morphologically, the cells changed from a rod shape to a shorter, coccobacillary shape with small vacuoles forming at the edges, indicating structural changes. Both condition-induced VBNC-state cells were able to resuscitate in tryptic soy broth (TSB) medium supplemented with Tween 80, sodium pyruvate, and glucose. These findings contribute to a better understanding of the survival mechanisms of Y. enterocolitica in the environment and are of significant importance for the development of effective disinfection strategies.
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Affiliation(s)
- Xueyu Hu
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Xiaoxu Wang
- Institute of Special Animal and Plant Sciences of Chinese Academy of Agricultural Sciences, Changchun 130112, China
| | - Honglin Ren
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Chengwei Li
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Bo Zhang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Ruoran Shi
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Yuzhu Wang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Shiying Lu
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Yansong Li
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Qiang Lu
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Zengshan Liu
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Pan Hu
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China
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Li L, Bae S. Quantitative detection and survival analysis of VBNC Salmonella Typhimurium in flour using droplet digital PCR and DNA-intercalating dyes. Microbiol Spectr 2024; 12:e0024924. [PMID: 38975767 PMCID: PMC11302299 DOI: 10.1128/spectrum.00249-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 05/13/2024] [Indexed: 07/09/2024] Open
Abstract
The difficulty in detecting viable but non-culturable (VBNC) Salmonella by culture-dependent methods poses a risk to food safety. In our study, we applied a viability test to Salmonella following a lethal treatment and to flour samples inoculated with Salmonella to evaluate the effectiveness of viability polymerase chain reaction (PCR). Our findings revealed that the combination of both ddPCR and qPCR with those DNA-intercalating dyes could quantify viable cells at low concentrations when the plate counting method failed to detect them post-inactivation. Prolonged UV exposure did not induce cell membrane disruption, as confirmed with PMA-ddPCR, with insignificant differences in gene copies. However, samples exposed to DyeTox13 and DyeTox13 + EMA showed lower gene copy numbers, implying that enzymatic activity was decreased by UV exposure duration. In addition, temperature-dependent survival in flour revealed uniform decay rates and D values (time required for a 1 log reduction) of DNA in untreated samples across various temperatures. By contrast, different decay rates were observed with DNA-intercalating dyes (DyeTox13 and DyeTox13 + EMA), showing faster metabolic activity loss at higher temperatures in flour. The decay rates and D values, determined through plate counting and those DNA-intercalating dyes, indicated the potential presence of VBNC Salmonella. A strong correlation between DyeTox13 dyes and the plate counting method suggested DyeTox13 as a rapid alternative for detecting Salmonella in flour. The ddPCR with DNA-intercalating dyes could effectively evaluate Salmonella viability, facilitating more precise monitoring of VBNC in food. IMPORTANCE Salmonella, a major foodborne pathogen, poses significant risks, particularly to vulnerable groups like infants, older people, and the immunocompromised. Accurate detection is vital for public health and food safety, given its potential to cause severe and life-threatening symptoms. Our study demonstrated digital polymerase chain reaction (ddPCR) with DNA-intercalating dyes for identifying the different physiological statuses of Salmonella. Also, the application of ddPCR with DNA-intercalating dyes offers quantification of viable cells post-disinfection as an alternative method in food. Utilizing ddPCR and DNA-intercalating dyes, we enhanced the detection of VBNC Salmonella, a form often undetectable by conventional methods. This innovative approach could significantly improve the precision and efficiency of detection for viable Salmonella. By providing deeper insights into its transmission potential, our method is a critical tool in preventing outbreaks and ensuring the safety of food products. This research contributes substantially to global efforts in controlling foodborne illnesses and safeguarding public health.
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Affiliation(s)
- Liyan Li
- Department of Civil and Environmental Engineering, College of Design and Engineering, National University of Singapore, Singapore, Singapore
| | - Sungwoo Bae
- Department of Civil and Environmental Engineering, College of Design and Engineering, National University of Singapore, Singapore, Singapore
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3
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Pîndaru AM, Măruțescu L, Popa M, Chifiriuc MC. A Label-Free Optical Flow Cytometry Based-Method for Rapid Assay of Disinfectants' Bactericidal Activity. Int J Mol Sci 2024; 25:7158. [PMID: 39000264 PMCID: PMC11241575 DOI: 10.3390/ijms25137158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 07/16/2024] Open
Abstract
Selecting the appropriate disinfectant to control and prevent healthcare-associated infections (HAIs) is a challenging task for environmental health experts due to the large number of available disinfectant products. This study aimed to develop a label-free flow cytometry (FCM) method for the rapid evaluation of bactericidal activity and to compare its efficacy with that of standard qualitative/quantitative suspension tests. The bactericidal efficiency of eight commercial disinfectants containing quaternary ammonium compounds (QACs) was evaluated against four strains recommended by EN 13727 (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus hirae) and four multidrug-resistant pathogens. The proposed FCM protocol measures changes in scattered light and counts following disinfectant exposure, neutralization, and culture steps. Unlike other available FCM-based methods, this approach does not rely on autofluorescence measurements, impedance cytometry, or fluorescent dyes. The FCM scattered light signals revealed both decreased count rates and morphological changes after treatment with minimum inhibitory concentrations (MICs) and higher concentrations for all tested bacteria. The results from the FCM measurements showed excellent correlation with those from standard assays, providing a rapid tool for monitoring the susceptibility profile of clinical, multidrug-resistant pathogens to chemical disinfectants, which could support infection prevention and control procedures for healthcare environments. This label-free FCM protocol offers a novel and rapid tool for environmental health experts, aiding in the optimization of disinfectant selection for the prevention and control of HAIs.
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Affiliation(s)
- Andreea Maria Pîndaru
- Department of Botany and Microbiology, Faculty of Biology, University of Bucharest, 91-95 Splaiul Independentei, 050095 Bucharest, Romania; (A.M.P.); (M.C.C.)
| | - Luminița Măruțescu
- Department of Botany and Microbiology, Faculty of Biology, University of Bucharest, 91-95 Splaiul Independentei, 050095 Bucharest, Romania; (A.M.P.); (M.C.C.)
- Research Institute of University of Bucharest, University of Bucharest, 050663 Bucharest, Romania;
| | - Marcela Popa
- Research Institute of University of Bucharest, University of Bucharest, 050663 Bucharest, Romania;
| | - Mariana Carmen Chifiriuc
- Department of Botany and Microbiology, Faculty of Biology, University of Bucharest, 91-95 Splaiul Independentei, 050095 Bucharest, Romania; (A.M.P.); (M.C.C.)
- Research Institute of University of Bucharest, University of Bucharest, 050663 Bucharest, Romania;
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Reem A, Almansoob S, Senan AM, Kumar Raj A, Shah R, Kumar Shrewastwa M, Kumal JPP. Pseudomonas aeruginosa and related antibiotic resistance genes as indicators for wastewater treatment. Heliyon 2024; 10:e29798. [PMID: 38694026 PMCID: PMC11058306 DOI: 10.1016/j.heliyon.2024.e29798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 04/13/2024] [Accepted: 04/15/2024] [Indexed: 05/03/2024] Open
Abstract
This review aims to examine the existence of Pseudomonas aeruginosa (P. aeruginosa) and their antibiotic resistance genes (ARGs) in aquatic settings and the alternative treatment ways. P. aeruginosa in a various aquatic environment have been identified as contaminants with impacts on human health and the environment. P. aeruginosa resistance to multiple antibiotics, such as sulfamethoxazole, ciprofloxacin, quinolone, trimethoprim, tetracycline, vancomycin, as well as specific antibiotic resistance genes including sul1, qnrs, blaVIM, blaTEM, blaCTX, blaAIM-1, tetA, ampC, blaVIM. The development of resistance can occur naturally, through mutations, or via horizontal gene transfer facilitated by sterilizing agents. In addition, an overview of the current knowledge on inactivation of Pseudomonas aeruginosa and ARG and the mechanisms of action of various disinfection processes in water and wastewater (UV chlorine processes, catalytic oxidation, Fenton reaction, and ozonation) is given. An overview of the effects of nanotechnology and the resulting wetlands is also given.
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Affiliation(s)
- Alariqi Reem
- Medical Laboratory Department, Faculty of Medical Sciences, Amran University, Yemen
| | - Siham Almansoob
- International department, Changsha medical university, Changsha, Hunan, 410000, China
| | - Ahmed M. Senan
- Department of Basic Pharmaceutical Sciences, Faculty of Pharmacy, Suleyman Demirel University, Isparta, 32260, Turkey
| | - Aditya Kumar Raj
- Department of Physiology, National Medical College, Birgunj, Nepal
| | - Rajesh Shah
- Department of Microbiology, Nepalgunj Medical College, Chisapani, Banke, Nepal
| | - Mukesh Kumar Shrewastwa
- Department of Biochemistry, Nepalgunj Medical College, Kohalpur, Banke, Nepal
- Department of Biochemistry (IMS & SUM hospital), SOA, deemed to be University, Bhubaneswar, India
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Gao Y, Guo T, Shi W, Lu C, Song Y, Hou Y, Liu W, Guo J. Multifaceted synergistic facilitation mechanism of conductive polymers in promoting selenite bioreduction and biological detoxification. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132470. [PMID: 37683341 DOI: 10.1016/j.jhazmat.2023.132470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/21/2023] [Accepted: 09/01/2023] [Indexed: 09/10/2023]
Abstract
Here, polypyrrole (PPY) was first used to the bioreduction of toxic selenite, while the acceleration effect and mechanism were explored. Experiment results suggested that PPY could enhance the selenite bioreduction from 0.42 to 1.04 mg/(L·h). The tests of electrochemical analysis and cytochrome c (cyt-c) content confirmed that PPY promoted the intracellular/intracellular electron transfer of Shewanella oneidensis·MR-1 in selenite bioreduction process. The enhancement of metabolic activity by PPY contributed to biological detoxification, which was manifested in the increased extracellular polymeric substances (EPS), adenosine triphosphate (ATP), electron transfer system activity (ETSA), membrane permeability and enzyme activity. Transcriptome analysis of DEGs, KEGG pathway enrichment and GO functional classification verified that the environmental adaptability of Shewanella oneidensis·MR-1 was enhanced with the addition of PPY. The transmission electron microscopy (TEM) images indicated that PPY promoted the biosynthesis of selenium nanoparticles (SeNPs), which was beneficial to reduce cell damage. Combined with the above results, a multifaceted synergistic facilitation mechanism based on "conductive cross-linking network" was elaborated from electron transfer, microbial metabolism and environmental adaptability. This study shed light the effect of conductive polymers (CPs) on selenite bioreduction and provided new insights into the bioremediation of toxic pollutants.
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Affiliation(s)
- Ying Gao
- School of Environmental and Municipal Engineering, Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Tingting Guo
- School of Civil Engineering and Architecture, Taizhou University, Taizhou 318000, China
| | - Wenda Shi
- School of Environmental and Municipal Engineering, Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Caicai Lu
- Experimental and practical innovation education center, Beijing Normal University, Jinfeng Road 18, Zhuhai 519000, China
| | - Yuanyuan Song
- School of Environmental and Municipal Engineering, Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Yanan Hou
- School of Environmental and Municipal Engineering, Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China
| | - Wenli Liu
- School of Civil Engineering and Architecture, Taizhou University, Taizhou 318000, China
| | - Jianbo Guo
- School of Civil Engineering and Architecture, Taizhou University, Taizhou 318000, China.
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Chen J, Wang Q, Wu Y, Wu Y, Sun Y, Ding Y, Wei Z, Manickam S, Pan S, Yang J, Tao Y. Ultrasound-assisted fermentation of ginkgo kernel juice by Lactiplantibacillus plantarum: Microbial response and juice composition development. ULTRASONICS SONOCHEMISTRY 2023; 99:106587. [PMID: 37683418 PMCID: PMC10495669 DOI: 10.1016/j.ultsonch.2023.106587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/30/2023] [Accepted: 09/03/2023] [Indexed: 09/10/2023]
Abstract
This study is aimed to explore the feasibility of ultrasound on enhancing the fermentation properties of ginkgo kernel juice by Lactiplantibacillus plantarum Y2. Specifically, ultrasound at 20 kHz and different intensities (mild ultrasound intensity-84.42 W/L, moderate ultrasound intensity-115.50 W/L, high ultrasound intensity-173.88 W/L) with a pulse mode were applied to facilitate the fermentation process. The number of viable cells of Lactiplantibacillus plantarum Y2 increased by 5.06, 5.05 and 2.19% in the sonicated groups at 173.88, 115.50 and 84.42 W/L, compared with the non-sonicated juice after 24-h fermentation. Furthermore, mild intensity ultrasonication improved the permeability of the cell membrane, which is beneficial for the metabolism of phenolics, amino acids and organic acids. Ultrasonication increased in-vitro antioxidant activity of fermented ginkgo kernel juice by promoting the metabolism of phenolic acids, such as ferulic acid, chlorogenic and caffeic acids. At the end of fermentation, the sonicated group at 84.42 W/L has the maximum consumptions of total sugars and proteins (increased by 12.52 and 18.73%). Moreover, the reduction rate of the poison material 4'-O-methylpyridoxine (MPN) in ginkgo kernel juice increased by more than 16.40% with ultrasound treatment at 173.88 W/L after the fermentation for 48 h. Overall, ultrasound can improve the metabolizations of Lactobacillus plantarum and reduce the toxic substances, which promoted the nutritional value and flavors of ginkgo kernel juice.
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Affiliation(s)
- Jinling Chen
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Qiqi Wang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Yuting Wu
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Yue Wu
- Sonochemistry Group, School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Yue Sun
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Yunfei Ding
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Zhen Wei
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Sivakumar Manickam
- Department of Petroleum and Chemical Engineering, Faculty of Engineering, Universiti Teknologi Brunei, Bandar Seri Begawan BE1410, Brunei Darussalam
| | - Saikun Pan
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Jie Yang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China.
| | - Yang Tao
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
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Ding N, Li Z, Jiang L, Liu H, Zhang Y, Sun Y. Kinetics and mechanisms of bacteria disinfection by performic acid in wastewater: In comparison with peracetic acid and sodium hypochlorite. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 878:162606. [PMID: 36906014 DOI: 10.1016/j.scitotenv.2023.162606] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 05/13/2023]
Abstract
Performic acid (PFA) has been increasingly used in wastewater disinfection due to its strong oxidizing ability and few disinfection byproducts. However, its disinfection pathways and mechanisms towards pathogenic bacteria disinfection are poorly understood. In this study, E. coli, S. aureus, and B. subtilis were inactivated using sodium hypochlorite (NaClO), PFA, and peracetic acid (PAA) in simulated turbid water and municipal secondary effluent. Cell culture-based plate counting showed that E. coli and S. aureus were extremely susceptible to NaClO and PFA and achieved a 4-log inactivation at CTs ≤ 1 mg/L·min with an initial disinfectant concentration of 0.3 mg/L. B. subtilis was much more resistant. At the initial disinfectant dose of 7.5 mg/L, PFA required CTs of 3-13 mg/L·min to achieve a 4-log inactivation. Turbidity negatively affected the disinfection. In the secondary effluent, the CTs required for PFA to achieve a 4-log inactivation of E. coli and B. subtilis were 6-12 times higher than those required in simulated turbid water, and a 4-log inactivation of S. aureus could not be achieved. PAA showed a much weaker disinfection ability than the other two disinfectants. The reaction pathways of E. coli inactivation by PFA included both direct and indirect reactions, in which the PFA molecule accounted for 73 %, and ·OH and peroxide radicals accounted for 20 % and 6 %, respectively. During PFA disinfection, E. coli cells were severely disintegrated, while the S. aureus cell exteriors remained mostly intact. B. subtilis was the least affected. Compared with cell culture-based analysis, the inactivation detected by flow cytometry was significantly lower. Viable but non-culturable bacteria after disinfection were believed to be primarily responsible for this inconsistency. This study suggested that PFA was able to control regular bacteria in wastewater, but it should be used with caution when treating recalcitrant pathogens.
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Affiliation(s)
- Ning Ding
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, China; Key Laboratory of Cleaner Production and Comprehensive Utilization of Resources, China National Light Industry, Beijing Technology and Business University, Beijing, China
| | - Ziwei Li
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, China
| | - Lin Jiang
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, China
| | - Hong Liu
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Jiangsu Province, China
| | - Yanping Zhang
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, China; Key Laboratory of Cleaner Production and Comprehensive Utilization of Resources, China National Light Industry, Beijing Technology and Business University, Beijing, China
| | - Yingxue Sun
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, China; Key Laboratory of Cleaner Production and Comprehensive Utilization of Resources, China National Light Industry, Beijing Technology and Business University, Beijing, China.
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Juárez-Jiménez B, Fenice M, Pasqualetti M, Muñoz-Palazon B, Correa-Galeote D, Braconcini M, Gorrasi S. Flow Cytometric Investigation of Salinicola halophilus S28 Physiological Response Provides Solid Evidence for Its Uncommon and High Ability to Face Salt-Stress Conditions. MICROBIOLOGY RESEARCH 2023. [DOI: 10.3390/microbiolres14020034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
Abstract
In a previous work, some bacterial strains isolated from the Saline di Tarquinia marine salterns (Viterbo, Italy) showed very unusual growth profiles in relation to temperature and salinity variations when grown in solid media. In particular, Salinicola halophilus S28 showed optimal or suboptimal growth in a very wide range of NaCl concentrations, suggesting a great coping ability with salinity variations. These intriguing outcomes did not fit with the general Salinicola halophilus description as a moderately halophilic species. Therefore, this study profiles the actual physiological status of S28 cells subjected to different NaCl concentrations to provide evidence for the actual coping ability of strain S28 with broad salinity variations. Flow cytometry was selected as the evaluation method to study the physiological status of bacterial cells subjected to different salinity levels, monitoring the strain response at different growth phases over 72 h. Strain S28 showed maximal growth at 8% NaCl; however, it grew very well with no statistically significant differences at all salinity conditions (4–24% NaCl). Flow cytometric results provided clear evidence of its actual and strong ability to face increasing salinity, revealing a good physiological response up to 24% of NaCl. In addition, strain S28 showed very similar cell physiological status at all salinity levels, as also indicated by the flat growth profile revealed in the range of 4–24% NaCl. This is the first study regarding the physiological response during the growth of halophilic bacteria under different conditions of salinity via flow cytometry. This technique represents an effective tool for the investigation of the physiological status of each cell, even if it is somehow underrated and underused by microbiologists for this purpose.
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Affiliation(s)
- Belén Juárez-Jiménez
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Andalucía, Spain
| | - Massimiliano Fenice
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Largo Università snc, 01100 Viterbo, Italy
- Laboratory of Applied Marine Microbiology, CoNISMa, University of Tuscia, Largo Università snc, 01100 Viterbo, Italy
| | - Marcella Pasqualetti
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Largo Università snc, 01100 Viterbo, Italy
- Laboratory of Ecology of Marine Fungi, CoNISMa, University of Tuscia, Largo Università snc, 01100 Viterbo, Italy
| | - Barbara Muñoz-Palazon
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Andalucía, Spain
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Largo Università snc, 01100 Viterbo, Italy
| | - David Correa-Galeote
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Andalucía, Spain
| | - Martina Braconcini
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Largo Università snc, 01100 Viterbo, Italy
| | - Susanna Gorrasi
- Department of Ecological and Biological Sciences (DEB), University of Tuscia, Largo Università snc, 01100 Viterbo, Italy
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Mohanty SR, Mahawar H, Bajpai A, Dubey G, Parmar R, Atoliya N, Devi MH, Singh AB, Jain D, Patra A, Kollah B. Methylotroph bacteria and cellular metabolite carotenoid alleviate ultraviolet radiation-driven abiotic stress in plants. Front Microbiol 2023; 13:899268. [PMID: 36687662 PMCID: PMC9853530 DOI: 10.3389/fmicb.2022.899268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 09/30/2022] [Indexed: 01/07/2023] Open
Abstract
Increasing UV radiation in the atmosphere due to the depletion of ozone layer is emerging abiotic stress for agriculture. Although plants have evolved to adapt to UV radiation through different mechanisms, but the role of phyllosphere microorganisms in counteracting UV radiation is not well studied. The current experiment was undertaken to evaluate the role of phyllosphere Methylobacteria and its metabolite in the alleviation of abiotic stress rendered by ultraviolet (UV) radiation. A potential pink pigmenting methylotroph bacterium was isolated from the phylloplane of the rice plant (oryzae sativa). The 16S rRNA gene sequence of the bacterium was homologous to the Methylobacter sp. The isolate referred to as Methylobacter sp N39, produced beta-carotene at a rate (μg ml-1 d-1) of 0.45-3.09. Biosynthesis of beta-carotene was stimulated by brief exposure to UV for 10 min per 2 days. Carotenoid biosynthesis was predicted as y = 3.09 × incubation period + 22.151 (r 2 = 0.90). The carotenoid extract of N39 protected E. coli from UV radiation by declining its death rate from 14.67% min-1 to 4.30% min-1 under UV radiation. Application of N39 cells and carotenoid extract also protected rhizobium (Bradyrhizobium japonicum) cells from UV radiation. Scanning electron microscopy indicated that the carotenoid extracts protected E. coli cells from UV radiation. Foliar application of either N39 cells or carotenoid extract enhanced the plant's (Pigeon pea) resistance to UV irradiation. This study highlight that Methylobacter sp N39 and its carotenoid extract can be explored to manage UV radiation stress in agriculture.
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Affiliation(s)
- Santosh Ranjan Mohanty
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India,*Correspondence: Santosh Ranjan Mohanty, ,
| | - Himanshu Mahawar
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India,ICAR -s Directorate of Weed Research, Jabalpur, Madhya Pradesh, India,Himanshu Mahawar,
| | - Apekcha Bajpai
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India
| | - Garima Dubey
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India
| | - Rakesh Parmar
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India
| | - Nagvanti Atoliya
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India
| | | | | | - Devendra Jain
- Department of Molecular Biology and Biotechnology, Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India
| | - Ashok Patra
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India
| | - Bharati Kollah
- ICAR-Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India,Bharati Kollah, ,
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10
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Yang J, Sun Y, Chen J, Cheng Y, Zhang H, Gao T, Xu F, Pan S, Tao Y, Lu J. Fermentation of ginkgo biloba kernel juice using Lactobacillus plantarum Y2 from the ginkgo peel: Fermentation characteristics and evolution of phenolic profiles, antioxidant activities in vitro, and volatile flavor compounds. Front Nutr 2022; 9:1025080. [PMID: 36386957 PMCID: PMC9649921 DOI: 10.3389/fnut.2022.1025080] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 10/13/2022] [Indexed: 09/10/2023] Open
Abstract
In this study, a strain of Lactobacillus plantarum Y2 was isolated from the ginkgo peel, and showed adequate adaptation to the ginkgo biloba kernel juice. After 48 h of fermentation, the number of viable cells in the stable growth phase was remained at 10.0 Log CFU/mL, while the content of total organic acid increased by 5.86%. Phenolic substances were significantly enriched, and the content of total phenolic substances increased by 9.72%, and the content of total flavonoids after fermentation exceeded 55.33 mg/L, which was 3.6 times that of the unfermented ginkgo juice. The total relative content of volatile flavor compounds increased by 125.48%, and 24 new volatile flavor substances were produced. The content of total sugar, total protein, and total free amino acid decreased to 44.85, 67.51, and 6.88%, respectively. Meanwhile, more than 82.25% of 4'-O-methylpyridoxine was degraded by lactic acid fermentation, and the final concentration in ginkgo biloba kernel juice was lower than 41.53 mg/L. In addition, the antioxidant and antibacterial activities of fermented ginkgo biloba kernel juice were significantly enhanced. These results showed that LAB fermentation could effectively improve the nutritional value and safety of ginkgo biloba kernel juice.
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Affiliation(s)
- Jie Yang
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Yue Sun
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Jinling Chen
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Yu Cheng
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Haoran Zhang
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Tengqi Gao
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Feng Xu
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Saikun Pan
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
| | - Yang Tao
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Jing Lu
- Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China
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11
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Changes in physiological states of Salmonella Typhimurium measured by qPCR with PMA and DyeTox13 Green Azide after pasteurization and UV treatment. Appl Microbiol Biotechnol 2022; 106:2739-2750. [PMID: 35262785 DOI: 10.1007/s00253-022-11850-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 01/17/2022] [Accepted: 02/26/2022] [Indexed: 11/02/2022]
Abstract
Diarrheal diseases caused by Salmonella pose a major threat to public health, and assessment of bacterial viability is critical in determining the safety of food and drinking water after disinfection. Viability PCR could overcome the limitations of traditional culture-dependent methods for a more accurate assessment of the viability of a microbial sample. In this study, the physiological changes in Salmonella Typhimurium induced by pasteurization and UV treatment were evaluated using a culture-based method, RT-qPCR, and viability PCR. The plate count results showed no culturable S. Typhimurium after the pasteurization and UV treatments, while viability PCR with propidium monoazide (PMA) and DyeTox13-qPCR indicated that the membrane integrity of S. Typhimurium remained intact with no metabolic activity. The RT-qPCR results demonstrated that invasion protein (invA) was detectable in UV-treated cells even though the log2-fold change ranged from - 2.13 to - 5.53 for PMA treatment. However, the catalytic activity gene purE was under the detection limit after UV treatment, indicating that most Salmonella entered metabolically inactive status after UV disinfection. Also, viability PCRs were tested with artificially contaminated eggs to determine physiological status on actual food matrices. DyeTox13-qPCR methods showed that most Salmonella lost their metabolic activity but retained membrane integrity after UV disinfection. RT-qPCR may not determine the physiological status of Salmonella after UV disinfection because mRNA could be detectable in UV-treated cells depending on the choice of target gene. Viability PCR demonstrated potential for rapid and specific detection of pathogens with physiological states such as membrane integrity and metabolic activity.Key Points• Membrane integrity of Salmonella remained intact with no metabolic activity after UV.• mRNA could be detectable in UV-treated cells depending on the choice of target gene.• Viability PCR could rapidly detect specific pathogens with their physiological states.
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