1
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Lindeque JZ. Targeted analysis of organic acids with GC-MS/MS: Challenges and prospects. Anal Biochem 2024; 694:115620. [PMID: 39029642 DOI: 10.1016/j.ab.2024.115620] [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: 02/26/2024] [Revised: 07/01/2024] [Accepted: 07/13/2024] [Indexed: 07/21/2024]
Abstract
GC-MS/MS combines the superior chromatographic resolution of GC with the specific and sensitive detection of tandem MS. On paper, it is an ideal system for the routine analyses of organic acids, yet very few studies have used and published such methods. This is likely due to several challenges highlighted in this communication. Briefly, the combination of EI ionization with MRM detection provides arguably insufficient specificity when targeting organic acids. Moreover, the narrow peaks generally produced by GC can lead to inaccurate quantification when the mass spectrometer's cycle time is too long. Potential solutions to these problems are discussed.
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Affiliation(s)
- Jeremie Zander Lindeque
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, 11 Hoffman Street, Potchefstroom, 2531, South Africa.
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2
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Yoon JH, Oh MS, Lee SY. Effectiveness of organic acids for inactivating pathogenic bacteria inoculated in laboratory media and foods: an updated minireview. Food Sci Biotechnol 2024; 33:2715-2728. [PMID: 39184989 PMCID: PMC11339227 DOI: 10.1007/s10068-024-01618-9] [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: 03/04/2024] [Revised: 05/16/2024] [Accepted: 05/23/2024] [Indexed: 08/27/2024] Open
Abstract
Food processing industries commonly employ organic acids (OAAs) to determine bacterial contamination in acidified and fermented foods. OAAs are believed to possess potent antimicrobial properties by permeating cell membranes, altering proton and anion concentrations in the cytoplasm due to their lipophilic undissociated forms. The bacteriostatic or bactericidal effects of OAAs are influenced by various factors including microbial physiology, environmental pH, and acid dissociation ratios. Despite their utility, the precise mechanisms underlying OAA-mediated inhibition of pathogenic bacteria remain incompletely understood. Therefore, the objectives of this review are to compile a selected area of researches that focus on the current propensity of different OAAs for inactivating food-borne pathogens, and then to present a theoretical insight on the use of OAAs to prevent and control pathogenic bacteria present in acidic/acidified foods and their mode of mechanisms.
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Affiliation(s)
- Jae-Hyun Yoon
- Department of Food and Nutrition, Sunchon National University, 235 Jungang-Ro, Suncheon-Si, Jeollanam-Do 57922 Republic of Korea
| | - Min-Seok Oh
- Department of Food and Nutrition, Chung-Ang University, 4726 Seodong-Dearo, Anseong Si, Gyeonggi-Do 17546 Republic of Korea
| | - Sun-Young Lee
- Department of Food and Nutrition, Chung-Ang University, 4726 Seodong-Dearo, Anseong Si, Gyeonggi-Do 17546 Republic of Korea
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3
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Moiseenko KV, Glazunova OA, Fedorova TV. Fermentation of Rice, Oat, and Wheat Flour by Pure Cultures of Common Starter Lactic Acid Bacteria: Growth Dynamics, Sensory Evaluation, and Functional Properties. Foods 2024; 13:2414. [PMID: 39123605 PMCID: PMC11312058 DOI: 10.3390/foods13152414] [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: 06/13/2024] [Revised: 07/17/2024] [Accepted: 07/26/2024] [Indexed: 08/12/2024] Open
Abstract
Recent consumer demand for non-dairy alternatives has forced many manufacturers to turn their attention to cereal-based non-alcoholic fermented products. In contrast to fermented dairy products, there is no defined and standardized starter culture for manufacturing cereal-based products. Since spontaneous fermentation is rarely suitable for large-scale commercial production, it is not surprising that manufacturers have started to adopt centuries-known dairy starters based on lactic acid bacteria (LABs) for the fermentation of cereals. However, little is known about the fermentation processes of cereals with these starters. In this study, we combined various analytical tools in order to understand how the most common starter cultures of LABs affect the most common types of cereals during fermentation. Specifically, 3% suspensions of rice, oat, and wheat flour were fermented by the pure cultures of 16 LAB strains belonging to five LAB species-Lacticaseibacillus paracasei, Lactobacillus delbrueckii, Lactobacillus helveticus, Streptococcus thermophilus, and Lactococcus lactis. The fermentation process was described in terms of culture growth and changes in the pH, reducing sugars, starch, free proteins, and free phenolic compounds. The organoleptic and rheological features of the obtained fermented products were characterized, and their functional properties, such as their antioxidant capacity and angiotensin-converting enzyme inhibitory activity, were determined.
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Affiliation(s)
- Konstantin V. Moiseenko
- A. N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Leninsky Ave. 33/2, Moscow 119071, Russia; (O.A.G.); (T.V.F.)
| | - Olga A. Glazunova
- A. N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Leninsky Ave. 33/2, Moscow 119071, Russia; (O.A.G.); (T.V.F.)
| | - Tatyana V. Fedorova
- A. N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Leninsky Ave. 33/2, Moscow 119071, Russia; (O.A.G.); (T.V.F.)
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4
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Pagano C, Ceccarini MR, Marinelli A, Imbriano A, Beccari T, Primavilla S, Valiani A, Ricci M, Perioli L. Development and characterization of an emulgel based on a snail slime useful for dermatological applications. Int J Pharm 2024; 660:124337. [PMID: 38885774 DOI: 10.1016/j.ijpharm.2024.124337] [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: 02/28/2024] [Revised: 06/10/2024] [Accepted: 06/11/2024] [Indexed: 06/20/2024]
Abstract
Snail slime is an interesting material for effective dermatological use (e.g. wounds). Its properties are stricly connected to the origin. In this paper a snail slime, deriving from the species Helix aspersa Muller and obtained from a company, was deeply characterized and then properly formulated. The slime, obtained by Donatella Veroni method, was firstly submitted to NMR analysis in order to evaluate the chemical composition. The main molecules found are glycolate and allantoin, well known for their activities in wound healing promotion. In vitro experiments performed on keratinocytes, revealed the snail slime ability to promote cellular well-being. Moreover, the microbiological analysis showed high activity against many strains involved in wounds infections such as gram+ (e.g. S. aureus, S. pyogenes), gram- (e.g. P. aeruginosa, E. coli) and the yeast C. albicans. The effect on skin elasticity was evaluated as well by the instrument Cutometer® dualMPA580. The snail slime was then formulated as hydrophilic gel, using a combination of corn starch and sodium hyaluronate as polymers, then used as external water phase of an O/W emulgel. The formulation is physically stable and easily spreadable and demonstrated antimicrobial activity as observed for slime alone, suggesting its suitability to be used for wound treatment.
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Affiliation(s)
- Cinzia Pagano
- Department of Pharmaceutical Sciences, University of Perugia, via del Liceo 1, 06123 Perugia, Italy.
| | - Maria Rachele Ceccarini
- Department of Pharmaceutical Sciences, University of Perugia, via del Liceo 1, 06123 Perugia, Italy
| | - Alessia Marinelli
- Department of Pharmaceutical Sciences, University of Perugia, via del Liceo 1, 06123 Perugia, Italy
| | - Anna Imbriano
- Department of Pharmaceutical Sciences, University of Perugia, via del Liceo 1, 06123 Perugia, Italy
| | - Tommaso Beccari
- Department of Pharmaceutical Sciences, University of Perugia, via del Liceo 1, 06123 Perugia, Italy
| | - Sara Primavilla
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche "Togo Rosati", Via Salvemini 1, 06126 Perugia, Italy
| | - Andrea Valiani
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche "Togo Rosati", Via Salvemini 1, 06126 Perugia, Italy
| | - Maurizio Ricci
- Department of Pharmaceutical Sciences, University of Perugia, via del Liceo 1, 06123 Perugia, Italy
| | - Luana Perioli
- Department of Pharmaceutical Sciences, University of Perugia, via del Liceo 1, 06123 Perugia, Italy
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5
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Gavriil A, Giannenas I, Skandamis PN. A current insight into Salmonella's inducible acid resistance. Crit Rev Food Sci Nutr 2024:1-21. [PMID: 39014992 DOI: 10.1080/10408398.2024.2373387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
Salmonella is a diverse and ubiquitous group of bacteria and a major zoonotic pathogen implicated in several foodborne disease outbreaks worldwide. With more than 2500 distinct serotypes, this pathogen has evolved to survive in a wide spectrum of environments and across multiple hosts. The primary and most common source of transmission is through contaminated food or water. Although the main sources have been primarily linked to animal-related food products, outbreaks due to the consumption of contaminated plant-related food products have increased in the last few years. The perceived ability of Salmonella to trigger defensive mechanisms following pre-exposure to sublethal acid conditions, namely acid adaptation, has renewed a decade-long attention. The impact of acid adaptation on the subsequent resistance against lethal factors of the same or multiple stresses has been underscored by multiple studies. Α plethora of studies have been published, aiming to outline the factors that- alone or in combination- can impact this phenomenon and to unravel the complex networking mechanisms underlying its induction. This review aims to provide a current and updated insight into the factors and mechanisms that rule this phenomenon.
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Affiliation(s)
- Alkmini Gavriil
- Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, Athens, Greece
- Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
| | - Ilias Giannenas
- School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Panagiotis N Skandamis
- Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
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Jiang B, Liu J, Wang J, Zhao G, Zhao Z. Adaptive Evolution for the Efficient Production of High-Quality d-Lactic Acid Using Engineered Klebsiella pneumoniae. Microorganisms 2024; 12:1167. [PMID: 38930549 PMCID: PMC11205318 DOI: 10.3390/microorganisms12061167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 05/31/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
d-Lactic acid serves as a pivotal platform chemical in the production of poly d-lactic acid (PDLA) and other value-added products. This compound can be synthesized by certain bacteria, including Klebsiella pneumoniae. However, industrial-scale lactic acid production in Klebsiella pneumoniae faces challenges due to growth inhibition caused by lactic acid stress, which acts as a bottleneck in commercial microbial fermentation processes. To address this, we employed a combination of evolutionary and genetic engineering approaches to create an improved Klebsiella pneumoniae strain with enhanced lactic acid tolerance and production. In flask fermentation experiments, the engineered strain achieved an impressive accumulation of 19.56 g/L d-lactic acid, representing the highest production yield observed in Klebsiella pneumoniae to date. Consequently, this strain holds significant promise for applications in industrial bioprocessing. Notably, our genome sequencing and experimental analyses revealed a novel correlation between UTP-glucose-1-phosphate uridylyltransferase GalU and lactic acid resistance in Klebsiella pneumoniae. Further research is warranted to explore the potential of targeting GalU for enhancing d-lactic acid production.
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Affiliation(s)
- Bo Jiang
- State Key Laboratory of Microbial Technology and Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (B.J.); (J.L.); (J.W.)
| | - Jiezheng Liu
- State Key Laboratory of Microbial Technology and Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (B.J.); (J.L.); (J.W.)
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingnan Wang
- State Key Laboratory of Microbial Technology and Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (B.J.); (J.L.); (J.W.)
| | - Guang Zhao
- State Key Laboratory of Microbial Technology and Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (B.J.); (J.L.); (J.W.)
| | - Zhe Zhao
- State Key Laboratory of Microbial Technology and Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (B.J.); (J.L.); (J.W.)
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Warsi OM, Upterworth LM, Breidenstein A, Lustig U, Mikkelsen K, Nagy T, Szatmari D, Ingmer H, Andersson DI. Staphylococcus aureus mutants resistant to the feed-additive monensin show increased virulence and altered purine metabolism. mBio 2024; 15:e0315523. [PMID: 38214510 PMCID: PMC10865815 DOI: 10.1128/mbio.03155-23] [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: 11/28/2023] [Accepted: 12/01/2023] [Indexed: 01/13/2024] Open
Abstract
Ionophores are antibacterial compounds that affect bacterial growth by changing intracellular concentrations of the essential cations, sodium and potassium. They are extensively used in animal husbandry to increase productivity and reduce infectious diseases, but our understanding of the potential for and effects of resistance development to ionophores is poorly known. Thus, given their widespread global usage, it is important to determine the potential negative consequences of ionophore use on human and animal health. In this study, we demonstrate that exposure to the ionophore monensin can select for resistant mutants in the human and animal pathogen Staphylococcus aureus, with a majority of the resistant mutants showing increased growth rates in vitro and/or in mice. Whole-genome sequencing and proteomic analysis of the resistant mutants show that the resistance phenotype is associated with de-repression of de novo purine synthesis, which could be achieved through mutations in different transcriptional regulators including mutations in the gene purR, the repressor of the purine de novo synthesis pathway. This study shows that mutants with reduced susceptibility to the ionophore monensin can be readily selected and highlights an unexplored link between ionophore resistance, purine metabolism, and fitness in pathogenic bacteria.IMPORTANCEThis study demonstrates a novel link between ionophore resistance, purine metabolism, and virulence/fitness in the key human and animal pathogen Staphylococcus aureus. The results show that mutants with reduced susceptibility to the commonly used ionophore monensin can be readily selected and that the reduced susceptibility observed is associated with an increased expression of the de novo purine synthesis pathway. This study increases our understanding of the impact of the use of animal feed additives on both human and veterinary medicine.
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Affiliation(s)
- Omar M. Warsi
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Lina M. Upterworth
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Kiel University, Kiel, Germany
| | - Annika Breidenstein
- Department of Medical Chemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Ulrika Lustig
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Kasper Mikkelsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tamás Nagy
- Department of Laboratory Medicine, Medical School, University of Pécs, Pécs, Hungary
| | - Dávid Szatmari
- Department of Biophysics, Medical School, University of Pécs, Pécs, Hungary
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dan I. Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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8
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Song Q, Gao B, Zhang S, Hu C. Adopting the "Missile boats-Aircraft carrier" strategy via human-contact friendly oxidized starch to achieve rapid-sustainably antibacterial paperboards. Int J Biol Macromol 2024; 259:129066. [PMID: 38158062 DOI: 10.1016/j.ijbiomac.2023.129066] [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: 09/11/2023] [Revised: 12/14/2023] [Accepted: 12/25/2023] [Indexed: 01/03/2024]
Abstract
Polysaccharide-based antibacterial agents have received tremendous attention for the facile fabrication, low toxicity, and high compatibility with carbohydrate polymers. However, the antimicrobial mechanism, activity, and cytotoxicity for human-contact paperboards of oxidized starch (OST) with high carboxyl content, has not been explored. Herein, OST-27- 75 with 27- 75 wt% carboxyl contents were fabricated by H2O2 and coated on paperboards. Strikingly, OST-55 coating layer (16 g/m2) did not exfoliate from paperboard and possessed the rapid-sustainable antibacterial performance against Staphylococcus aureus and Escherichia coli. The soluble and insoluble components of OST-55 (OST55-S: OST55-IS mass ratio = 1: 2.1) presented different antimicrobial features and herein they were characterized by GC-MS, FT-IR, H-NMR, XRD, bacteriostatic activities, biofilm formation inhibition and intracellular constituent leakage to survey the antibacterial mechanism. The results revealed OST55-S displayed an amorphous structure and possessed superior antibacterial activity against S. aureus (MIC = 4 mg/mL) and E. coli (MIC = 8 mg/mL). Distinctively, OST55-S could rapidly ionize [H+] like "missile boats" from small molecule saccharides, while OST55-IS polyelectrolyte could continuously and slowly release for [H+] like an "aircraft carrier" to inhibit biofilm formation and disrupt cell structure. Eventually, the "Missile boats-Aircraft carrier" strategy provided a green methodology to fabricate polymeric antibacterial agents and expanded the use of cellulose-based materials.
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Affiliation(s)
- Qiaowei Song
- Packaging Engineering Institute, Jinan University, Qianshan Road 206, Zhuhai, Guangdong 519070, China
| | - Bingbing Gao
- School of Mechanical and Automotive Engineering, South China University of Technology, No. 381 Wushan Road, Tianhe District, Guangzhou 510640, China
| | - Shuidong Zhang
- School of Mechanical and Automotive Engineering, South China University of Technology, No. 381 Wushan Road, Tianhe District, Guangzhou 510640, China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China.
| | - Changying Hu
- Packaging Engineering Institute, Jinan University, Qianshan Road 206, Zhuhai, Guangdong 519070, China; Department of Food Science & Engineering, Jinan University, Huangpu West Avenue 601, Guangzhou City 510632, Guangdong, China..
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9
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Panda S, Jayasinghe YP, Shinde DD, Bueno E, Stastny A, Bertrand BP, Chaudhari SS, Kielian T, Cava F, Ronning DR, Thomas VC. Staphylococcus aureus counters organic acid anion-mediated inhibition of peptidoglycan cross-linking through robust alanine racemase activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.15.575639. [PMID: 38293037 PMCID: PMC10827132 DOI: 10.1101/2024.01.15.575639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Weak organic acids are commonly found in host niches colonized by bacteria, and they can inhibit bacterial growth as the environment becomes acidic. This inhibition is often attributed to the toxicity resulting from the accumulation of high concentrations of organic anions in the cytosol, which disrupts cellular homeostasis. However, the precise cellular targets that organic anions poison and the mechanisms used to counter organic anion intoxication in bacteria have not been elucidated. Here, we utilize acetic acid, a weak organic acid abundantly found in the gut to investigate its impact on the growth of Staphylococcus aureus. We demonstrate that acetate anions bind to and inhibit d-alanyl-d-alanine ligase (Ddl) activity in S. aureus. Ddl inhibition reduces intracellular d-alanyl-d-alanine (d-Ala-d-Ala) levels, compromising staphylococcal peptidoglycan cross-linking and cell wall integrity. To overcome the effects of acetate-mediated Ddl inhibition, S. aureus maintains a high intracellular d-Ala pool through alanine racemase (Alr1) activity and additionally limits the flux of d-Ala to d-glutamate by controlling d-alanine aminotransferase (Dat) activity. Surprisingly, the modus operandi of acetate intoxication in S. aureus is common to multiple biologically relevant weak organic acids indicating that Ddl is a conserved target of small organic anions. These findings suggest that S. aureus may have evolved to maintain high intracellular d-Ala concentrations, partly to counter organic anion intoxication.
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Affiliation(s)
- Sasmita Panda
- Center for Staphylococcal Research, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5900, USA
| | - Yahani P Jayasinghe
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Dhananjay D Shinde
- Center for Staphylococcal Research, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5900, USA
| | - Emilio Bueno
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Center for Microbial Research (UCMR), Department of Molecular Biology, Umeå University, Umea SE-90187, Sweden
| | - Amanda Stastny
- Center for Staphylococcal Research, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5900, USA
| | - Blake P Bertrand
- Center for Staphylococcal Research, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5900, USA
| | - Sujata S Chaudhari
- Center for Staphylococcal Research, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5900, USA
| | - Tammy Kielian
- Center for Staphylococcal Research, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5900, USA
| | - Felipe Cava
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Center for Microbial Research (UCMR), Department of Molecular Biology, Umeå University, Umea SE-90187, Sweden
| | - Donald R Ronning
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Vinai C Thomas
- Center for Staphylococcal Research, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-5900, USA
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10
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Redko V, Wolska L, Potrykus M, Olkowska E, Cieszyńska-Semenowicz M, Tankiewicz M. Environmental impacts of 5-year plastic waste deposition on municipal waste landfills: A follow-up study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167710. [PMID: 37832682 DOI: 10.1016/j.scitotenv.2023.167710] [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: 06/28/2023] [Revised: 08/14/2023] [Accepted: 10/07/2023] [Indexed: 10/15/2023]
Abstract
Depositing plastic waste has long been a prevalent method of utilization, persisting today. Plastic waste within municipal waste landfills (MWL) undergoes diverse (bio-)degradation processes, which may be a potential source of chemicals and microorganisms harmful to the environment and human health. Soil and air samples were collected from modern MWL to identify environmental contamination caused by 5 years of plastic (bio-)degradation. The pH of soil samples was higher than in the reference area (RA), which was possibly caused by alterations in soil anionic composition detected with ion chromatography. The presence of plastic additives with a toxic potential was detected in soil samples by gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). With the use of thermal desorption and GC - MS, hazardous substances (phthalic anhydride, phenylmaleic anhydride, ethylbenzene, xylene) with a known impact on the human endocrine system were also detected. The number of microorganisms, both fungi, and bacteria, was highly increased in soil and air in the MWL as compared to the RA. The soil collected in the MWL area appeared to be phytotoxic, and inhibited seed germination (Phytotoxkit FTM bioassay), while acute toxicity Microtox® bioassay showed a hormetic effect towards Aliivibrio fischeri. Obtained results exhibited massive soil and air contamination, with both chemical substances and microorganisms while plastic waste undergoes (bio-)degradation. It may contribute to serious environmental contamination and pose a threat to human health.
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Affiliation(s)
- Vladyslav Redko
- Division of Environmental Toxicology, Faculty of Health Sciences with Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Debowa 23 A, 80-204 Gdansk, Poland.
| | - Lidia Wolska
- Division of Environmental Toxicology, Faculty of Health Sciences with Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Debowa 23 A, 80-204 Gdansk, Poland.
| | - Marta Potrykus
- Division of Environmental Toxicology, Faculty of Health Sciences with Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Debowa 23 A, 80-204 Gdansk, Poland.
| | - Ewa Olkowska
- Division of Environmental Toxicology, Faculty of Health Sciences with Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Debowa 23 A, 80-204 Gdansk, Poland.
| | - Monika Cieszyńska-Semenowicz
- Division of Environmental Toxicology, Faculty of Health Sciences with Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Debowa 23 A, 80-204 Gdansk, Poland.
| | - Maciej Tankiewicz
- Division of Environmental Toxicology, Faculty of Health Sciences with Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Debowa 23 A, 80-204 Gdansk, Poland.
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11
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Hartono S, Meijerink MFA, Abee T, Smid EJ, van Mastrigt O. The stressostat: A novel approach in adaptive laboratory evolution to improve end-product resistance. N Biotechnol 2023; 78:123-130. [PMID: 37879567 DOI: 10.1016/j.nbt.2023.10.010] [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: 04/03/2023] [Revised: 09/18/2023] [Accepted: 10/22/2023] [Indexed: 10/27/2023]
Abstract
End-product inhibition in pH-controlled batch cultures, is the major limiting factor for bacterial biomass formation in the starter culture industry as well as in many other biotechnological processes. Adaptive laboratory evolution (ALE) has emerged over the past decades as a powerful tool for phenotype optimization, but none of the existing ALE methods could select for improved end-product resistance. Therefore, we developed the stressostat (STress Resistance Evolution in Substrate Surplus) as a novel continuous ALE method. Stressostat cultivation applies end-product concentrations as constant evolutionary pressure on microorganisms in the presence of substrate surplus. In this study, we improved the lactate resistance of Lactococcus lactis FM03P in 35 days of stressostat cultivations. The lactate concentrations increased over time from 530 to 675 mM, indicating the successful selection for variants with improved lactate resistance. Thirty-four variants were isolated and grouped into four clusters based on their growth rates at high lactate concentrations. In the high-throughput screening without pH control, most isolated variants could grow at high lactate concentrations (870-928 mM), while the wild type was completely inhibited. The variants grew slower than wild type at low lactate media indicating possible evolutionary trade-off. However, in pH-controlled batch cultivations, most variants produced more biomass than the wild type. In conclusion, stressostat cultivation is a valuable method to obtain L. lactis variants with improved end-product resistance and further characterization is needed to elucidate underlying resistance mechanisms and potential industrial applications.
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Affiliation(s)
- Sylviani Hartono
- Food Microbiology, Wageningen University & Research, P.O. Box 17, 6700AA Wageningen, the Netherlands
| | - Marlisa F A Meijerink
- Food Microbiology, Wageningen University & Research, P.O. Box 17, 6700AA Wageningen, the Netherlands
| | - Tjakko Abee
- Food Microbiology, Wageningen University & Research, P.O. Box 17, 6700AA Wageningen, the Netherlands
| | - Eddy J Smid
- Food Microbiology, Wageningen University & Research, P.O. Box 17, 6700AA Wageningen, the Netherlands
| | - Oscar van Mastrigt
- Food Microbiology, Wageningen University & Research, P.O. Box 17, 6700AA Wageningen, the Netherlands.
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12
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Roasto M, Mäesaar M, Püssa T, Anton D, Rätsep R, Elias T, Jortikka S, Pärna M, Kapp K, Tepper M, Kerner K, Meremäe K. The Effect of Fruit and Berry Pomaces on the Growth Dynamics of Microorganisms and Sensory Properties of Marinated Rainbow Trout. Microorganisms 2023; 11:2960. [PMID: 38138104 PMCID: PMC10745767 DOI: 10.3390/microorganisms11122960] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/04/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023] Open
Abstract
Plant pomaces in suitable forms (powders, extracts) can be used in foods of animal origin to increase the nutritional value and safety of these foods. In the present study, water extracts of apple, black currant, rhubarb and tomato pomaces were used in fish marinade solutions to evaluate their effect on the growth dynamics of microorganisms and the growth potential of Listeria monocytogenes by challenge testing. The results showed that mesophilic aerobic microorganisms, Pseudomonas spp., yeasts and moulds remained at acceptable levels throughout the predetermined storage period. The challenge test results showed that the overall growth potential of L. monocytogenes in all marinated rainbow trout samples remained at ≤0.5 log10 cfu/g during the study period, and none of the marinated fish samples supported the growth of L. monocytogenes. In addition, the effect of fruit and berry pomaces on the sensory properties of marinated rainbow trout samples was evaluated. The results revealed that it is possible to effectively use fruit and berry pomaces in marinated fish products, ensuring food safety, high microbiological quality, acceptable sensory characteristics and a sufficiently long shelf life of the products.
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Affiliation(s)
- Mati Roasto
- Chair of Veterinary Biomedicine and Food Hygiene, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 56/3, 51006 Tartu, Estonia; (M.M.); (T.P.); (D.A.); (T.E.); (S.J.); (K.M.)
| | - Mihkel Mäesaar
- Chair of Veterinary Biomedicine and Food Hygiene, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 56/3, 51006 Tartu, Estonia; (M.M.); (T.P.); (D.A.); (T.E.); (S.J.); (K.M.)
| | - Tõnu Püssa
- Chair of Veterinary Biomedicine and Food Hygiene, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 56/3, 51006 Tartu, Estonia; (M.M.); (T.P.); (D.A.); (T.E.); (S.J.); (K.M.)
| | - Dea Anton
- Chair of Veterinary Biomedicine and Food Hygiene, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 56/3, 51006 Tartu, Estonia; (M.M.); (T.P.); (D.A.); (T.E.); (S.J.); (K.M.)
| | - Reelika Rätsep
- Polli Horticultural Research Centre, Chair of Horticulture, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Uus 2, 69108 Polli, Estonia;
| | - Terje Elias
- Chair of Veterinary Biomedicine and Food Hygiene, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 56/3, 51006 Tartu, Estonia; (M.M.); (T.P.); (D.A.); (T.E.); (S.J.); (K.M.)
| | - Salli Jortikka
- Chair of Veterinary Biomedicine and Food Hygiene, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 56/3, 51006 Tartu, Estonia; (M.M.); (T.P.); (D.A.); (T.E.); (S.J.); (K.M.)
| | - Merilin Pärna
- Chair of Food Science and Technology, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 56/5, 51006 Tartu, Estonia; (M.P.); (M.T.); (K.K.)
| | - Karmen Kapp
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E, P.O. Box 56, FI-00014 Helsinki, Finland;
| | - Marek Tepper
- Chair of Food Science and Technology, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 56/5, 51006 Tartu, Estonia; (M.P.); (M.T.); (K.K.)
| | - Kristi Kerner
- Chair of Food Science and Technology, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 56/5, 51006 Tartu, Estonia; (M.P.); (M.T.); (K.K.)
| | - Kadrin Meremäe
- Chair of Veterinary Biomedicine and Food Hygiene, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi 56/3, 51006 Tartu, Estonia; (M.M.); (T.P.); (D.A.); (T.E.); (S.J.); (K.M.)
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13
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Song K, Chen L, Suo N, Kong X, Li J, Wang T, Song L, Cheng M, Guo X, Huang Z, Huang Z, Yang Y, Tian X, Choo SW. Whole-transcriptome analysis reveals mechanisms underlying antibacterial activity and biofilm inhibition by a malic acid combination (MAC) in Pseudomonas aeruginosa. PeerJ 2023; 11:e16476. [PMID: 38084141 PMCID: PMC10710775 DOI: 10.7717/peerj.16476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 10/26/2023] [Indexed: 12/18/2023] Open
Abstract
Background Pseudomonas aeruginosa is a highly prevalent bacterial species known for its ability to cause various infections and its remarkable adaptability and biofilm-forming capabilities. In earlier work, we conducted research involving the screening of 33 metabolites obtained from a commercial source against two prevalent bacterial strains, Escherichia coli and Staphylococcus aureus. Through screening assays, we discovered a novel malic acid combination (MAC) consisting of malic acid, citric acid, glycine, and hippuric acid, which displayed significant inhibitory effects. However, the precise underlying mechanism and the potential impact of the MAC on bacterial biofilm formation remain unknown and warrant further investigation. Methods To determine the antibacterial effectiveness of the MAC against Pseudomonas aeruginosa, we conducted minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques were employed to observe bacterial morphology and biofilm formation. We further performed a biofilm inhibition assay to assess the effect of the MAC on biofilm formation. Whole-transcriptome sequencing and bioinformatics analysis were employed to elucidate the antibacterial mechanism of the MAC. Additionally, the expression levels of differentially expressed genes were validated using the real-time PCR approach. Results Our findings demonstrated the antibacterial activity of the MAC against P. aeruginosa. SEM analysis revealed that the MAC can induce morphological changes in bacterial cells. The biofilm assay showed that the MAC could reduce biofilm formation. Whole-transcriptome analysis revealed 1093 differentially expressed genes consisting of 659 upregulated genes and 434 downregulated genes, in response to the MAC treatment. Mechanistically, the MAC inhibited P. aeruginosa growth by targeting metabolic processes, secretion system, signal transduction, and cell membrane functions, thereby potentially compromising the survival of this human pathogen. This study provides valuable insights into the antibacterial and antibiofilm activities of the MAC, a synergistic and cost-effective malic acid combination, which holds promise as a potential therapeutic drug cocktail for treating human infectious diseases in the future.
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Affiliation(s)
- Kunping Song
- Wenzhou-Kean University, College of Science, Mathematics and Technology, Wenzhou, Zhejiang, China
| | - Li Chen
- Universiti Malaya, Institute of Biological Sciences, Faculty of Science, Kuala Lumpur, Kuala Lumpur, Malaysia
| | - Nanhua Suo
- Wenzhou-Kean University, College of Science, Mathematics and Technology, Wenzhou, Zhejiang, China
| | - Xinyi Kong
- Wenzhou-Kean University, College of Science, Mathematics and Technology, Wenzhou, Zhejiang, China
| | - Juexi Li
- Wenzhou-Kean University, College of Science, Mathematics and Technology, Wenzhou, Zhejiang, China
| | - Tianyu Wang
- Wenzhou-Kean University, College of Science, Mathematics and Technology, Wenzhou, Zhejiang, China
| | - Lanni Song
- Wenzhou-Kean University, Wenzhou Municipal Key Laboratory for Applied Biomedical and Biopharmaceutical Informatics, Wenzhou, Zhejiang, China
| | - Mengwei Cheng
- Wenzhou-Kean University, Wenzhou Municipal Key Laboratory for Applied Biomedical and Biopharmaceutical Informatics, Wenzhou, Zhejiang, China
| | - Xindian Guo
- Wenzhou No.2 Foreign Language School, Wenzhou, Zhejiang, China
| | - Zhenghe Huang
- Wenzhou No.2 Foreign Language School, Wenzhou, Zhejiang, China
| | - Zichen Huang
- Wenzhou No.2 Foreign Language School, Wenzhou, Zhejiang, China
| | - Yixin Yang
- Wenzhou-Kean University, College of Science, Mathematics and Technology, Wenzhou, Zhejiang, China
- Wenzhou-Kean University, Wenzhou Municipal Key Laboratory for Applied Biomedical and Biopharmaceutical Informatics, Wenzhou, Zhejiang, China
- Wenzhou-Kean University, Zhejiang Bioinformatics International Science and Technology Cooperation Center, Wenzhou, Zhejiang, China
| | - Xuechen Tian
- Wenzhou-Kean University, Wenzhou Municipal Key Laboratory for Applied Biomedical and Biopharmaceutical Informatics, Wenzhou, Zhejiang, China
- Wenzhou-Kean University, Zhejiang Bioinformatics International Science and Technology Cooperation Center, Wenzhou, Zhejiang, China
| | - Siew Woh Choo
- Wenzhou-Kean University, College of Science, Mathematics and Technology, Wenzhou, Zhejiang, China
- Wenzhou-Kean University, Wenzhou Municipal Key Laboratory for Applied Biomedical and Biopharmaceutical Informatics, Wenzhou, Zhejiang, China
- Wenzhou-Kean University, Zhejiang Bioinformatics International Science and Technology Cooperation Center, Wenzhou, Zhejiang, China
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14
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Bendig T, Ulmer A, Luzia L, Müller S, Sahle S, Bergmann FT, Lösch M, Erdemann F, Zeidan AA, Mendoza SN, Teusink B, Takors R, Kummer U, Figueiredo AS. The pH-dependent lactose metabolism of Lactobacillus delbrueckii subsp. bulgaricus: An integrative view through a mechanistic computational model. J Biotechnol 2023; 374:90-100. [PMID: 37572793 DOI: 10.1016/j.jbiotec.2023.08.001] [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: 02/09/2023] [Revised: 07/20/2023] [Accepted: 08/07/2023] [Indexed: 08/14/2023]
Abstract
The fermentation process of milk to yoghurt using Lactobacillus delbrueckii subsp. bulgaricus in co-culture with Streptococcus thermophilus is hallmarked by the breakdown of lactose to organic acids such as lactate. This leads to a substantial decrease in pH - both in the medium, as well as cytosolic. The latter impairs metabolic activities due to the pH-dependence of enzymes, which compromises microbial growth. To quantitatively elucidate the impact of the acidification on metabolism of L. bulgaricus in an integrated way, we have developed a proton-dependent computational model of lactose metabolism and casein degradation based on experimental data. The model accounts for the influence of pH on enzyme activities as well as cellular growth and proliferation of the bacterial population. We used a machine learning approach to quantify the cell volume throughout fermentation. Simulation results show a decrease in metabolic flux with acidification of the cytosol. Additionally, the validated model predicts a similar metabolic behaviour within a wide range of non-limiting substrate concentrations. This computational model provides a deeper understanding of the intricate relationships between metabolic activity and acidification and paves the way for further optimization of yoghurt production under industrial settings.
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Affiliation(s)
- Tamara Bendig
- BioQuant, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Andreas Ulmer
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Laura Luzia
- Systems Biology Lab, Vrije Universiteit, Amsterdam, the Netherlands
| | - Susanne Müller
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Sven Sahle
- BioQuant, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Frank T Bergmann
- BioQuant, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany
| | - Maren Lösch
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Florian Erdemann
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Ahmad A Zeidan
- Systems Biology, R&D Discovery, Chr. Hansen A/S, Hørsholm, Denmark
| | | | - Bas Teusink
- Systems Biology Lab, Vrije Universiteit, Amsterdam, the Netherlands
| | - Ralf Takors
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Ursula Kummer
- BioQuant, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany.
| | - Ana Sofia Figueiredo
- BioQuant, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany.
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15
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Jyung S, Kang JW, Kang DH. Inactivation of Listeria monocytogenes through the synergistic interaction between plasma-activated water and organic acid. Food Res Int 2023; 167:112687. [PMID: 37087257 DOI: 10.1016/j.foodres.2023.112687] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/24/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023]
Abstract
This study observed that when plasma-activated water (PAW) was combined with organic acid, it showed a synergistic inactivation effect on Listeria monocytogenes, which is highly resistant to PAW. When comparing various organic acids, lactic acid (LA) showed the greatest synergistic effect, followed by malic acid (MA), citric acid (CA), and acetic acid (AA), whereas propionic acid (PA) did not show a synergistic effect. Organic acid lowered the activity of ROS defense enzymes (catalase, superoxide dismutase) by reducing intracellular pH (pHi), which induced the increase in the accumulation of ROS of PAW within the cell. In the end, the synergistic inactivation effect appeared as the increased occurrence of oxidative damage when organic acid was combined as a series of preceding causes. In this case, LA with the greatest ability to lower the pH induced the greatest synergistic effect, suggesting that LA is the best candidate to be combined with PAW. As a result of observing changes in inactivation activity for L. monocytogenes of PAW combined with 1.0% LA while storing at - 80, -20, 4, 25, & 37 °C for 30 days, respectively, it was confirmed that the lower the temperature, the lower the activity loss during the storage period, and that it had an activity of 3.72 log reduction based on 10 min treatment when stored at - 80 °C for 30 days. Application of PAW combined with 1.0% LA stored at - 80 °C for 30 days to mackerel inoculated with L. monocytogenes in ice form resulted in a decrease of 4.53 log after 120 min treatment, without changing the quality of mackerel. These results suggest that combining LA with PAW can be an effective control strategy for L. monocytogenes with high resistance to PAW, and can be effectively utilized, even in ice form.
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16
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Toomik E, Rood L, Bowman JP, Kocharunchitt C. Microbial spoilage mechanisms of vacuum-packed lamb meat: A review. Int J Food Microbiol 2023; 387:110056. [PMID: 36563532 DOI: 10.1016/j.ijfoodmicro.2022.110056] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/04/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
Lamb meat is an important export commodity, however chilled vacuum-packed (VP) lamb has approximately half the shelf-life of beef under the same storage conditions. This makes the industry more vulnerable to financial losses due to long shipping times and unexpected spoilage. Understanding the spoilage mechanisms of chilled VP lamb in relation to VP beef is important for developing effective strategies to extend the shelf-life of lamb. This review has discussed various key factors (i.e., pH, fat, and presence of bone) that have effects on microbial spoilage of VP lamb contributing to its shorter shelf-life relative to VP beef. A range of bacterial organisms and their metabolisms in relevance to lamb spoilage are also discussed. The data gap in the literature regarding the potential mechanisms of spoilage in VP red meat is highlighted. This review has provided the current understanding of key factors affecting the shelf-life of VP lamb relative to VP beef. It has also identified key areas of research to further understand the spoilage mechanisms of VP lamb. These include investigating the potential influence of fat and bone (including bone marrow) on the shelf-life, as well as assessing changes in the meat metabolome as the spoilage microbial community is developing using an integrated approach. Such new knowledge would aid the development of effective approaches to extend the shelf-life of VP lamb.
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Affiliation(s)
- Elerin Toomik
- Centre for Food Safety and Innovation, Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 54, Hobart, TAS 7001, Australia.
| | - Laura Rood
- Centre for Food Safety and Innovation, Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 54, Hobart, TAS 7001, Australia
| | - John P Bowman
- Centre for Food Safety and Innovation, Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 54, Hobart, TAS 7001, Australia
| | - Chawalit Kocharunchitt
- Centre for Food Safety and Innovation, Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 54, Hobart, TAS 7001, Australia
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17
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Redding M, Bolten S, Gu G, Luo Y, Micallef SA, Millner P, Nou X. Growth and inactivation of Listeria monocytogenes in sterile extracts of fruits and vegetables: Impact of the intrinsic factors pH, sugar and organic acid content. Int J Food Microbiol 2023; 386:110043. [PMID: 36495819 DOI: 10.1016/j.ijfoodmicro.2022.110043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/15/2022] [Accepted: 11/26/2022] [Indexed: 12/04/2022]
Abstract
Intrinsic characteristics of fresh produce, such as pH, water activity, acid content and nutrient availability are critical factors in determining the survival and growth of Listeria monocytogenes (Lm). In this study, sterile fresh produce juice was used to analyze Lm growth potential among 14 different commodities and to identify physicochemical characteristics in those juices that affect Lm growth. Significant growth of Lm was observed in juices with pH ≥5.6 and low acidity (0.04-0.07 % titratable acidity (TA)) (cantaloupe, carrot, celery, green pepper, parsley, and romaine lettuce), slight reduction of Lm was observed in juices with pH 4.1 (tomato) and pH 3.9 (mango), and no Lm counts were recovered from juices with pH ≤3.8 and high acidity (0.28-1.17 % TA) (apple, blueberry, grape, peach, and pineapple). Although these acidic fruit juices possessed a high sugar content, the pH and acidity of produce juice seemed to be the primary determinants for Lm growth. The neutralization of acidic juices (i.e., Fuji and Gala apple, blueberry, grape, mango, pineapple, peach, and tomato) enabled Lm growth at 37 °C in all juices except for Gala apple and peach. Strong decline in Lm populations in Gala apple, grape and peach juices might be linked to sensitivity to organic acids, such as malic acid. Furthermore, Lm populations significantly decreased in pH-neutral (7.6) cauliflower juice, suggesting that potential antilisterial substances may play a role in Lm decline in cauliflower juice.
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Affiliation(s)
- Marina Redding
- USDA Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD 20705, USA
| | - Samantha Bolten
- USDA Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD 20705, USA; Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| | - Ganyu Gu
- USDA Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD 20705, USA
| | - Yaguang Luo
- USDA Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD 20705, USA
| | - Shirley A Micallef
- Department of Plant Science and Landscape Architecture, Centre for Food Safety and Security Systems, University of Maryland, College Park, MD 20742, USA
| | - Patricia Millner
- USDA Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD 20705, USA
| | - Xiangwu Nou
- USDA Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD 20705, USA.
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18
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Wang J, Kong K, Guo C, Yin G, Meng S, Lan L, Luo L, Song Y. Cultureless enumeration of live bacteria in urinary tract infection by single-cell Raman spectroscopy. Front Microbiol 2023; 14:1144607. [PMID: 37032883 PMCID: PMC10076591 DOI: 10.3389/fmicb.2023.1144607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 03/06/2023] [Indexed: 04/11/2023] Open
Abstract
Urinary tract infections (UTIs) are the most common outpatient infections. Obtaining the concentration of live pathogens in the sample is crucial for the treatment. Still, the enumeration depends on urine culture and plate counting, which requires days of turn-around time (TAT). Single-cell Raman spectra combined with deuterium isotope probing (Raman-DIP) has been proven to identify the metabolic-active bacteria with high accuracy but is not able to reveal the number of live pathogens due to bacteria replication during the Raman-DIP process. In this study, we established a new approach of using sodium acetate to inhibit the replication of the pathogen and applying Raman-DIP to identify the active single cells. By combining microscopic image stitching and recognition, we could further improve the efficiency of the new method. Validation of the new method on nine artificial urine samples indicated that the exact number of live pathogens obtained with Raman-DIP is consistent with plate-counting while shortening the TAT from 18 h to within 3 h, and the potential of applying Raman-DIP for pathogen enumeration in clinics is promising.
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Affiliation(s)
- Jingkai Wang
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
| | - Kang Kong
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
- Department of Chemistry, College of Sciences, Shanghai University, Shanghai, China
| | - Chen Guo
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
- Division of Life Sciences and Medicine, School of Biomedical Engineering (Suzhou), University of Science and Technology of China, Suzhou, China
| | - Guangyao Yin
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
| | - Siyu Meng
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
| | - Lu Lan
- VibroniX, Inc., Suzhou, China
| | - Liqiang Luo
- Department of Chemistry, College of Sciences, Shanghai University, Shanghai, China
| | - Yizhi Song
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
- Division of Life Sciences and Medicine, School of Biomedical Engineering (Suzhou), University of Science and Technology of China, Suzhou, China
- Chongqing Guoke Medical Technology Development Co., Ltd., Chongqing, China
- *Correspondence: Yizhi Song,
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19
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Shakil MH, Trisha AT, Rahman M, Talukdar S, Kobun R, Huda N, Zzaman W. Nitrites in Cured Meats, Health Risk Issues, Alternatives to Nitrites: A Review. Foods 2022; 11:3355. [PMID: 36359973 PMCID: PMC9654915 DOI: 10.3390/foods11213355] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/28/2022] [Accepted: 10/15/2022] [Indexed: 09/10/2023] Open
Abstract
Nitrite is one of the most widely used curing ingredients in meat industries. Nitrites have numerous useful applications in cured meats and a vital component in giving cured meats their unique characteristics, such as their pink color and savory flavor. Nitrites are used to suppress the oxidation of lipid and protein in meat products and to limit the growth of pathogenic microorganisms such as Clostridium botulinum. Synthetic nitrite is frequently utilized for curing due to its low expenses and easier applications to meat. However, it is linked to the production of nitrosamines, which has raised several health concerns among consumers regarding its usage in meat products. Consumer desire for healthier meat products prepared with natural nitrite sources has increased due to a rising awareness regarding the application of synthetic nitrites. However, it is important to understand the various activities of nitrite in meat curing for developing novel substitutes of nitrites. This review emphasizes on the effects of nitrite usage in meat and highlights the role of nitrite in the production of carcinogenic nitrosamines as well as possible nitrite substitutes from natural resources explored also.
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Affiliation(s)
- Mynul Hasan Shakil
- Department of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
| | - Anuva Talukder Trisha
- Department of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
| | - Mizanur Rahman
- Department of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
| | - Suvro Talukdar
- Department of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
| | - Rovina Kobun
- Faculty of Food Science and Nutrition, Universiti Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
| | - Nurul Huda
- Faculty of Food Science and Nutrition, Universiti Malaysia Sabah, Kota Kinabalu 88400, Sabah, Malaysia
| | - Wahidu Zzaman
- Department of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
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20
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Antimicrobial Functionalization of Prolamine-Silica Hybrid Coatings with Fumaric Acid for Food Packaging Materials and Their Biocompatibility. Antibiotics (Basel) 2022; 11:antibiotics11091259. [PMID: 36140038 PMCID: PMC9495839 DOI: 10.3390/antibiotics11091259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/10/2022] [Accepted: 09/10/2022] [Indexed: 11/16/2022] Open
Abstract
The interest of the food packaging industry in biodegradable, recyclable, and functional materials has steadily increased in recent years. The use of hydrogels in the food sector holds great potential for use in packaging systems or as carriers for bioactive substances. The synthesis of an oxygen barrier coating of prolaminic silica material and antimicrobial functionalization with fumaric acid for packaging materials described here is an elegant way to meet these requirements. The developed material achieved a significant antimicrobial activity against Escherichia coli and Staphylococcus aureus, two common clinical pathogens. Another pre-requisite of such materials is a high biocompatibility, which can be assessed using human cell models, to help ensure consumer safety. The biocompatibility was determined by luminescence adenosine triphosphate and photometric lactate dehydrogenase assays. No cytotoxic effects on human keratinocytes in vitro were found for the test materials.
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21
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Ghoshal M, Chuang S, Zhang Y, McLandsborough L. Efficacy of Acidified Oils against Salmonella in Low-Moisture Environments. Appl Environ Microbiol 2022; 88:e0093522. [PMID: 35938829 PMCID: PMC9397106 DOI: 10.1128/aem.00935-22] [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: 06/08/2022] [Accepted: 07/08/2022] [Indexed: 11/20/2022] Open
Abstract
When processing low-moisture, high-fat foods such as peanut butter and nuts, water-based sanitization is unsuitable due to the immiscible nature of water and fats. Dry sanitization mainly uses flammable compounds such as isopropanol, requiring equipment cooling before application. The use of oils to deliver antimicrobials against foodborne pathogens enables the use of elevated temperatures, thus eliminating processing downtimes associated with dry sanitization. This study delivered organic acids and medium-chain fatty acids (100, 250, and 500 mM) in peanut oil against Salmonella enterica serovar Enteritidis desiccated at 75% relative humidity (RH). Acetic acid in peanut oil (AO) at 45°C was the most effective food-grade acid, causing a 4.4-log reduction in S. Enteritidis at 500 mM. AO caused cellular injury and was effective against a variety of S. Enteritidis strains. Confocal microscopy demonstrated that cells treated with 50 mM and 250 mM AO had significant membrane damage and reduced cellular respiration compared to untreated controls. Treatment efficacy increased with the increase in acid concentration, treatment duration, and treatment temperature from 20 to 45°C. Transmission electron microscopy after treatment with 100 and 250 mM AO revealed membrane ruffling and leakage in cell membranes, especially at 45°C. Reduction of the RH to 33% during desiccation of S. Enteritidis caused a decrease in AO efficacy compared to that at 75% RH, while at a higher RH of 90%, there was an increase in the efficacy of AO. Acidified oils can serve as robust, cost-effective replacements for dry-sanitation methods and improve safety of low moisture foods. IMPORTANCE Currently, dry sanitization products used during food processing often contain flammable compounds which require processing to stop and equipment to cool before application. This leads to processing downtimes and consequently, economic losses. This challenge is compounded by exposure to dryness which frequently renders Salmonella resistant to heat and different antimicrobials. Thus, the development of heat-tolerant oil-based antimicrobial compounds is a novel approach for sanitizing in low-moisture (dry) environments such as those found in peanut butter, tree nuts, and chocolate manufacturing. This study shows that acidified oils, especially acetic acid in peanut oil at elevated temperatures (45°C), was highly effective against desiccated Salmonella. Acidified oils have the potential to replace dry sanitizers, increasing the frequency of sanitization, leading to an improvement in food safety.
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Affiliation(s)
- Mrinalini Ghoshal
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Shihyu Chuang
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts, USA
| | - Ying Zhang
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China
| | - Lynne McLandsborough
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts, USA
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22
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Metabolic Phenotyping of Marine Heterotrophs on Refactored Media Reveals Diverse Metabolic Adaptations and Lifestyle Strategies. mSystems 2022; 7:e0007022. [PMID: 35856685 PMCID: PMC9426600 DOI: 10.1128/msystems.00070-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial communities, through their metabolism, drive carbon cycling in marine environments. These complex communities are composed of many different microorganisms including heterotrophic bacteria, each with its own nutritional needs and metabolic capabilities. Yet, models of ecosystem processes typically treat heterotrophic bacteria as a “black box,” which does not resolve metabolic heterogeneity nor address ecologically important processes such as the successive modification of different types of organic matter. Here we directly address the heterogeneity of metabolism by characterizing the carbon source utilization preferences of 63 heterotrophic bacteria representative of several major marine clades. By systematically growing these bacteria on 10 media containing specific subsets of carbon sources found in marine biomass, we obtained a phenotypic fingerprint that we used to explore the relationship between metabolic preferences and phylogenetic or genomic features. At the class level, these bacteria display broadly conserved patterns of preference for different carbon sources. Despite these broad taxonomic trends, growth profiles correlate poorly with phylogenetic distance or genome-wide gene content. However, metabolic preferences are strongly predicted by a handful of key enzymes that preferentially belong to a few enriched metabolic pathways, such as those involved in glyoxylate metabolism and biofilm formation. We find that enriched pathways point to enzymes directly involved in the metabolism of the corresponding carbon source and suggest potential associations between metabolic preferences and other ecologically relevant traits. The availability of systematic phenotypes across multiple synthetic media constitutes a valuable resource for future quantitative modeling efforts and systematic studies of interspecies interactions. IMPORTANCE Half of the Earth’s annual primary production is carried out by phytoplankton in the surface ocean. However, this metabolic activity is heavily impacted by heterotrophic bacteria, which dominate the transformation of organic matter released from phytoplankton. Here, we characterize the diversity of metabolic preferences across many representative heterotrophs by systematically growing them on different fractions of dissolved organic carbon. Our analysis suggests that different clades of bacteria have substantially distinct preferences for specific carbon sources, in a way that cannot be simply mapped onto phylogeny. These preferences are associated with the presence of specific genes and pathways, reflecting an association between metabolic capabilities and ecological lifestyles. In addition to helping understand the importance of heterotrophs under different conditions, the phenotypic fingerprint we obtained can help build higher resolution quantitative models of global microbial activity and biogeochemical cycles in the oceans.
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Changes on some quality characteristics of jujube juice with enzymatic hydrolysis prior to Lactobacillus plantarum fermentation. JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2022. [DOI: 10.1007/s11694-022-01426-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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24
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25
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Branson SR, Broadbent JR, Carpenter CE. Internal pH and Acid Anion Accumulation in Listeria monocytogenes and Escherichia coli Exposed to Lactic or Acetic Acids at Mildly Acidic pH. Front Microbiol 2022; 12:803271. [PMID: 35281309 PMCID: PMC8908002 DOI: 10.3389/fmicb.2021.803271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/20/2021] [Indexed: 12/19/2022] Open
Abstract
Organic acids are widely employed in the food industry to control growth of microbial pathogens such as Listeria monocytogenes and Escherichia coli. There is substantial evidence that intracellular accumulation of acid anions is a major inhibitor to cell viability, and that some bacteria are able to combat the toxic effects of anion accumulation via their ability to continue active metabolism at a lower intracellular pH (pHi). This study followed the accumulation of acid anion into the cell pellet and parallel changes in pHi in two human pathogenic strains of L. monocytogenes (N1-227 and R2-499) and in E. coli O157:H7 after exposure to sub-bacteriostatic levels of lactic and acetic acids at mildly acidic pH 6. The methodology employed in these studies included independent measures of pHi and intracellular anion accumulation. For the latter work, cells were pelleted through bromododecane to strip off extracellular water and solutes. Listeria strains accumulated 1.5-fold acetate or 2.5-fold lactate as compared to the external environment while mounting a defense against anion accumulation that included up to a 1-unit pHi drop from 7.5 to 6.5 for strain R2-499. E. coli accumulated 2.5-fold acetate but not lactate and apparently made use of combat mechanisms other than lowering pHi not explored in this study. Inulin was employed to estimate the fractional volume of cell pellet present as intracellular space. That intracellular fraction was 0.24 for E. coli, which infers that acid accumulation into the intercellular space was minimally 4 × that measured for the entire pellet. An intercellular fraction of pellet was not measurable for strains of L. monocytogenes. The data also bring into question the efficacy across bacterial species of the common, but confounding, practice of using intracellular anion accumulation as a measure of pHi, and vice versa.
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Affiliation(s)
- Savannah R Branson
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
| | - Jeff R Broadbent
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
| | - Charles E Carpenter
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
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26
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Chin JHC, Samian MR, Normi YM. Characterization of polyhydroxyalkanoate production capacity, composition and weight synthesized by Burkholderia cepacia JC-1 from various carbon sources. Heliyon 2022; 8:e09174. [PMID: 35368536 PMCID: PMC8971576 DOI: 10.1016/j.heliyon.2022.e09174] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/27/2021] [Accepted: 03/17/2022] [Indexed: 12/17/2022] Open
Abstract
Polyhydroxyalkanoates (PHA) are microbial polymers that have received widespread attention in recent decades as potential alternatives to some petrochemical-based plastics. However, widespread use of PHA is often impeded by its cost of production. Therefore, the search for and systematic investigation of versatile microbial PHA producers capable of using various carbon sources, even in the form of animal fats, for PHA biosynthesis is desirable. This study highlights the PHA production capacity, monomer composition and molecular weight synthesized by Burkholderia cepacia JC-1, a locally isolated strain from soil, from various carbon sources. In the category of simple sugars and plant oils, the use of glucose and palm oil at C:N ratio of 40 resulted in the highest accumulation of 52 wt% and 36 wt% poly(3-hydroxybutyrate) [P(3HB)] homopolymer and dry cell weight of 2.56 g/L and 3.17 g/L, respectively. Interestingly, B. cepacia JC-1 was able to directly utilize animal-derived lipid in the form of crude and extracted chicken fat, resulting in appreciable dry cell weight and PHA contents of up to 3.19 g/L and 47 wt% respectively, surpassing even that of palm oil in the group of triglycerides as substrates. The presence of antibiotics (streptomycin) in cultivation medium did not significantly affect cell growth and polymer production. The supply of sodium pentanoate as a co-substrate resulted in the incorporation of 3-hydroxyvalerate (3HV) monomer at fractions up to 37 mol%. The molecular weight of polymers produced from glucose, palm oil and chicken fat were in the range of 991–2118 kDa, higher than some reported studies involving native strains. The results from this study form an important basis for possible improvements in using B. cepacia JC-1 and crude chicken fats in solid form for PHA production in the future.
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Affiliation(s)
- Julian Hock-Chye Chin
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia
| | - Mohd Razip Samian
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia
| | - Yahaya M Normi
- Enzyme and Microbial Technology (EMTech) Research Center, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.,Department of Cell and Molecular Biology, Faculty of Biotechnology and Bimolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
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27
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Bai J, Wu Y, Bu Q, Zhong K, Gao H. Comparative study on antibacterial mechanism of shikimic acid and quinic acid against Staphylococcus aureus through transcriptomic and metabolomic approaches. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2021.112441] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Sun R, Vermeulen A, Devlieghere F. Modeling the combined effect of temperature, pH, acetic and lactic acid concentrations on the growth/no growth interface of acid-tolerant Bacillus spores. Int J Food Microbiol 2021; 360:109419. [PMID: 34600755 DOI: 10.1016/j.ijfoodmicro.2021.109419] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 08/05/2021] [Accepted: 09/19/2021] [Indexed: 11/16/2022]
Abstract
The application of minimal processing technologies has led to increased spoilage incidents in low-acid pasteurized sauces due to the outgrowth of acid-tolerant spore-forming spoilage bacteria (ATSSB). Controlling the germination and subsequent growth of ATSSB spores is vital to enhance the ambient storage stability of pasteurized sauces. This study developed and validated a set of growth/no growth (G/NG) models for spores of two ATSSB strains (Bacillus velezensis and Bacillus subtilis subsp. subtilis) isolated from pasteurized sauces. The G/NG data at two levels of temperature (22 and 30 °C) were collected in Nutrient Broth (aw = 0.98 adjusted with NaCl) by a full factorial design with five equidistant levels of pH (4.4-5.6), four concentrations of total acetic acid (0.0-0.3% (w/w)), and four concentrations of total lactic acid (0.00-1.00% (w/w)). The growth, starting from heat-treated (10 min 80 °C) spores, of each strain was assessed under 160 combinations by regular optical density measurements during three months. Twelve replicates were made for each combination. The developed models demonstrate that without organic acids even the lowest pH (4.4) allows a high growth possibility of the ATSSB spores, while acetic and lactic acids exhibit a significant antibacterial activity, which can be enhanced at decreased pH. The growth starting from B. subtilis spores can be inhibited for at least three months with 1.0% (w/w) total lactic acid in the water phase at both temperatures, which was not the case for B. velezensis, while 0.3% acetic acid achieves a full inhibition on both strains at 22 °C. With a combination of 0.3% acetic acid and 0.7% lactic acid, no growth should occur in the investigated range. This research is one of the first studies exploring the feasibility of ambient storage for low-acid pasteurized sauces eliminating preservatives such as benzoic and sorbic acids, and proves the synergistic effect of decreased pH and the presence of acetic and lactic acids on inhibiting bacterial growth from ATSSB spores.
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Affiliation(s)
- Rongxue Sun
- FMFP, Research Unit of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
| | - An Vermeulen
- FMFP, Research Unit of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Frank Devlieghere
- FMFP, Research Unit of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
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Novel strategies of essential oils, chitosan, and nano- chitosan for inhibition of multi-drug resistant: E. coli O157:H7 and Listeria monocytogenes. Saudi J Biol Sci 2021; 29:2582-2590. [PMID: 35531141 PMCID: PMC9073063 DOI: 10.1016/j.sjbs.2021.12.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/25/2021] [Accepted: 12/14/2021] [Indexed: 11/21/2022] Open
Abstract
Despite the wide range of available antibiotics, food borne bacteria demonstrate a huge spectrum of resistance. The current study aims to use natural components such as essential oils (EOs), chitosan, and nano-chitosan that have very influential antibacterial properties with novel technologies like chitosan solution/film loaded with EOs against multi-drug resistant bacteria. Two strains of Escherichia coli O157:H7 and three strains of Listeria monocytogenes were used to estimate antibiotics resistance. Ten EOs and their mixture, chitosan, nano-chitosan, chitosan plus EO solutions, and biodegradable chitosan film enriched with EOs were tested as antibacterial agents against pathogenic bacterial strains. Results showed that E. coli O157:H7 51,659 and L. monocytogenes 19,116 relatively exhibited considerable resistance to more than one single antibiotic. Turmeric, cumin, pepper black, and marjoram did not show any inhibition zone against L. monocytogenes; Whereas, clove, thyme, cinnamon, and garlic EOs exhibited high antibacterial activity against L. monocytogenes with minimum inhibitory concentration (MIC) of 250–400 μl 100−1 ml and against E. coli O157:H7 with an MIC of 350–500 μl 100−1 ml, respectively. Among combinations, clove, and thyme EOs showed the highest antibacterial activity against E. coli O157:H7 with MIC of 170 μl 100−1 ml, and the combination of cinnamon and clove EOs showed the strongest antibacterial activity against L. monocytogenes with an MIC of 120 μl 100−1 ml. Both chitosan and nano-chitosan showed a promising potential as an antibacterial agent against pathogenic bacteria as their MICs were relatively lower against L. monocytogenes than for E. coli O157:H7. Chitosan combined with each of cinnamon, clove, and thyme oil have a more effective antibacterial activity against L. monocytogenes and E. coli O157:H7 than the mixture of oils alone. Furthermore, the use of either chitosan solution or biodegradable chitosan film loaded with a combination of clove and thyme EOs had the strongest antibacterial activity against L. monocytogenes and E. coli O157:H7. However, chitosan film without EOs did not exhibit an inhibition zone against the tested bacterial strains.
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The challenges and prospects of Escherichia coli as an organic acid production host under acid stress. Appl Microbiol Biotechnol 2021; 105:8091-8107. [PMID: 34617140 DOI: 10.1007/s00253-021-11577-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Organic acids have a wide range of applications and have attracted the attention of many industries, and their large-scale applications have led fermentation production to low-cost development. Among them, the microbial fermentation method, especially using Escherichia coli as the production host, has the advantages of fast growth and low energy consumption, and has gradually shown better advantages and prospects in organic acid fermentation production. IMPORTANCE However, when the opportunity comes, the acidified environment caused by the acid products accumulated during the fermentation process also challenges E. coli. The acid sensitivity of E. coli is a core problem that needs to be solved urgently. The addition of neutralizers in traditional operations led to the emergence of osmotic stress inadvertently, the addition of strong acid substances to recover products in the salt state not only increases production costs, but the discharged sewage is also harmful to the environment. ELABORATION This article summarizes the current status of the application of E. coli in the production of organic acids, and based on the impact of acid stress on the physiological state of cells and the impact of industrial production profits, put forward some new conjectures that can make up for the deficiencies in existing research and application. IMPLICATION At this point, the diversified transformation of E. coli has become a chassis microbe that is more suitable for industrial fermentation, enhancing industrial application value. KEY POINTS • E. coli is a potential host for high value-added organic acids production. • Classify the damage mechanism and coping strategies of E. coli when stimulated by acid molecules. • Multi-dimensional expansion tools are needed to create acid-resistant E. coli chassis.
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31
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Physiology and antioxidant activity of Pediococcus pentosaceus R1 and Lactobacillus fermentum R6 in response to lactic acid stress. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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32
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Camesasca L, de Mattos JA, Vila E, Cebreiros F, Lareo C. Lactic acid production by Carnobacterium sp. isolated from a maritime Antarctic lake using eucalyptus enzymatic hydrolysate. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2021; 31:e00643. [PMID: 34168965 PMCID: PMC8209079 DOI: 10.1016/j.btre.2021.e00643] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 06/02/2021] [Accepted: 06/06/2021] [Indexed: 11/25/2022]
Abstract
Carnobacterium sp., a lactic acid bacterium isolated from a maritime Antarctic lake, was evaluated for lactic acid production from a lignocellulosic hydrolysate. Eucalyptus sawdust, a residue from pulp and paper industries, was subjected to alkaline pretreatment to enhance its enzymatic hydrolysis. Fermentations were performed without and with pH control using eucalyptus enzymatic hydrolysate containing a mixture of glucose and xylose sugars. The sugars were successfully converted into lactic acid in 24 h, resulting in 7.6 g/L of lactic acid and a product yield of 0.50 g/g for pH controlled at 6.5. Fed-batch fermentation performed at a controlled pH of 6.5 improved both the lactic acid production (30 g/L) and the biomass growth (4.2 g/L). l-lactic acid optical purity higher than 95 % was obtained. These results demonstrated the potential usage of Carnobacterium sp in l-lactic acid production from eucalyptus.
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Affiliation(s)
- Laura Camesasca
- Departamento de Bioingeniería, Facultad de Ingeniería, Universidad de la República, Julio Herrera y Reissig 565, CP 11300, Montevideo, Uruguay
| | - Juan Andrés de Mattos
- Departamento de Bioingeniería, Facultad de Ingeniería, Universidad de la República, Julio Herrera y Reissig 565, CP 11300, Montevideo, Uruguay
| | - Eugenia Vila
- Departamento de Bioingeniería, Facultad de Ingeniería, Universidad de la República, Julio Herrera y Reissig 565, CP 11300, Montevideo, Uruguay
| | - Florencia Cebreiros
- Departamento de Bioingeniería, Facultad de Ingeniería, Universidad de la República, Julio Herrera y Reissig 565, CP 11300, Montevideo, Uruguay
| | - Claudia Lareo
- Departamento de Bioingeniería, Facultad de Ingeniería, Universidad de la República, Julio Herrera y Reissig 565, CP 11300, Montevideo, Uruguay
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Li M, Carpenter CE, Broadbent JR. Organic Acid Exposure Enhances Virulence in Some Listeria monocytogenes Strains Using the Galleria mellonella Infection Model. Front Microbiol 2021; 12:675241. [PMID: 34295317 PMCID: PMC8290484 DOI: 10.3389/fmicb.2021.675241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 06/14/2021] [Indexed: 01/01/2023] Open
Abstract
Prior research has suggested that the use of organic acids in the food industry may unintentionally enhance pathogenicity of Listeria monocytogenes strain N1-227 and R2-499. This study explored the connection between habituation to L-lactic acid or acetic acid and virulence in L. monocytogenes strains N1-227 and R2-499 using selected gene expression analysis and the in vivo Galleria mellonella wax worm model for infection. Expression of transcription factors (sigB and prfA) and genes related to acid resistance (gadD2, gadD3, and arcA) and bile resistance (bsh and bilE) or to virulence (inlA, inlB, hly, plcA, plcB, uhpT, and actA) was investigated by quantitative real-time PCR (qRT-PCR), while in vivo virulence was assessed by following the lethal time to 50% population mortality (LT50) of G. mellonella larvae after injection of untreated and habituated L. monocytogenes. Twenty minutes of habituation to the organic acids at pH 6.0 significantly increased expression of key acid and bile stress response genes in both strains, while expression of virulence genes was strain-dependent. The expression of transcription factor sigB was strain-dependent and there was no significant change in the expression of transcription factor prfA in both strains. Habituation to acid increased virulence of both strains as evidenced by decreased LT50 of G. mellonella larvae injected with Listeria habituated to either acid. In summary, habituation of both L. monocytogenes strains to organic acids up-regulated expression of several stress and virulence genes and concurrently increased virulence as measured using the G. mellonella model.
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Affiliation(s)
- Minghao Li
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
| | - Charles E Carpenter
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
| | - Jeff R Broadbent
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
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Wang S, Tian R, Liu B, Wang H, Liu J, Li C, Li M, Evivie SE, Li B. Effects of carbon concentration, oxygen, and controlled pH on the engineering strain Lactiplantibacillus casei E1 in the production of bioethanol from sugarcane molasses. AMB Express 2021; 11:95. [PMID: 34176008 PMCID: PMC8236424 DOI: 10.1186/s13568-021-01257-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 06/16/2021] [Indexed: 01/28/2023] Open
Abstract
Sugarcane molasses are considered a potential source for bioethanol's commercial production because of its availability and low market price. It contains high concentrations of fermentable sugars that can be directly metabolized by microbial fermentation. Heterofermentative lactic acid bacteria, especially Lactiplantibacillus casei, have a high potential to be a biocatalyst in ethanol production that they are characterized by strong abilities of carbohydrate metabolism, ethanol synthesis, and high alcohol tolerance. This study aimed to evaluate the feasibility of producing ethanol by Lactiplantibacillus casei used the ethanologen engineering strain L. casei E1 as a starter culture and cane molasses as substrate medium. The effects of environmental factors on the metabolism of L. casei E1 were analyzed by high-performance liquid chromatography (HPLC) system, and the gene expression of key enzymes in carbon source metabolism was detected using quantitative real-time PCR (RT-qPCR). Results showed that the strain could grow well, ferment sugar quickly in cane molasses. By fermenting this bacterium anaerobically at 37 °C for 36 h incubation in 5 °BX molasses when the fermenter's pH was controlled at 6.0, ethanol yield reached 13.77 g/L, and carbohydrate utilization percentage was 78.60%. RT-qPCR results verified the strain preferentially ferment glucose and fructose of molasses to ethanol at the molecular level. In addition, the metabolism of sugars, especially fructose, would be inhibited by elevating acidity. Our findings support the theoretical basis for exploring Lactic acid bacteria as a starter culture for converting sugarcane molasses into ethanol.
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Affiliation(s)
- Song Wang
- Food College, Northeast Agricultural University, Harbin, 150030, China
- Shandong Yuwang Ecological Food Industry Co., Ltd, Dezhou, 251200, Shandong, China
| | - Ran Tian
- Food College, Northeast Agricultural University, Harbin, 150030, China
| | - Buwei Liu
- Food College, Northeast Agricultural University, Harbin, 150030, China
| | - Hongcai Wang
- Shandong Yuwang Ecological Food Industry Co., Ltd, Dezhou, 251200, Shandong, China
| | - Jun Liu
- Shandong Yuwang Ecological Food Industry Co., Ltd, Dezhou, 251200, Shandong, China
| | - Chenghui Li
- Shandong Yuwang Ecological Food Industry Co., Ltd, Dezhou, 251200, Shandong, China
| | - Mingyue Li
- Shandong Yuwang Ecological Food Industry Co., Ltd, Dezhou, 251200, Shandong, China
| | - Smith Etareri Evivie
- Food College, Northeast Agricultural University, Harbin, 150030, China
- Department of Animal Science, Faculty of Agriculture, University of Benin, Benin City, 300001, Nigeria
- Department of Food Science and Human Nutrition, Faculty of Agriculture, University of Benin, Benin City, 300001, Nigeria
| | - Bailiang Li
- Food College, Northeast Agricultural University, Harbin, 150030, China.
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Postharvest quality of orange fruit as influenced by salicylic acid, acetic acid, and carboxymethyl cellulose coating. JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2021. [DOI: 10.1007/s11694-021-00966-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Unravelling the Molecular Mechanisms Underlying the Protective Effect of Lactate on the High-Pressure Resistance of Listeria monocytogenes. Biomolecules 2021; 11:biom11050677. [PMID: 33946460 PMCID: PMC8147161 DOI: 10.3390/biom11050677] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 04/16/2021] [Accepted: 04/27/2021] [Indexed: 12/22/2022] Open
Abstract
Formulations with lactate as an antimicrobial and high-pressure processing (HPP) as a lethal treatment are combined strategies used to control L. monocytogenes in cooked meat products. Previous studies have shown that when HPP is applied in products with lactate, the inactivation of L. monocytogenes is lower than that without lactate. The purpose of the present work was to identify the molecular mechanisms underlying the piezo-protection effect of lactate. Two L. monocytogenes strains (CTC1034 and EGDe) were independently inoculated in a cooked ham model medium without and with 2.8% potassium lactate. Samples were pressurized at 400 MPa for 10 min at 10 °C. Samples were subjected to RNA extraction, and a shotgun transcriptome sequencing was performed. The short exposure of L. monocytogenes cells to lactate through its inoculation in a cooked ham model with lactate 1h before HPP promoted a shift in the pathogen’s central metabolism, favoring the metabolism of propanediol and ethanolamine together with the synthesis of the B12 cofactor. Moreover, the results suggest an activated methyl cycle that would promote modifications in membrane properties resulting in an enhanced resistance of the pathogen to HPP. This study provides insights on the mechanisms developed by L. monocytogenes in response to lactate and/or HPP and sheds light on the understanding of the piezo-protective effect of lactate.
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Health Promoting Properties of Cereal Vinegars. Foods 2021; 10:foods10020344. [PMID: 33562762 PMCID: PMC7914830 DOI: 10.3390/foods10020344] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 01/19/2023] Open
Abstract
Vinegar has been used for its health promoting properties since antiquity. Nowadays, these properties are investigated, scientifically documented, and highlighted. The health benefits of vinegar have been associated with the presence of a variety of bioactive components such as acetic acid and other organic acids, phenolic compounds, amino acids, carotenoids, phytosterols, vitamins, minerals, and alkaloids, etc. These components are known to induce responses in the human body, such as antioxidant, antidiabetic, antimicrobial, antitumor, antiobesity, antihypertensive, and anti-inflammatory effects. The diversity and levels of bioactive components in vinegars depend on the raw material and the production method used. Cereal vinegars, which are more common in the Asia-Pacific region, are usually made from rice, although other cereals, such as millet, sorghum, barley, malt, wheat, corn, rye, oats, bran and chaff, are also used. A variety of bioactive components, such as organic acids, polyphenols, amino acids, vitamins, minerals, alkaloids, melanoidins, butenolides, and specific compounds such as γ-oryzanol, tetramethylpyrazine, γ-aminobutyric acid, etc., have been associated with the health properties of cereal vinegars. In this work, the bioactive components and the related health effects of cereal vinegars are reviewed, and the most recent scientific literature is presented and discussed.
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Donatti Leão Alvarenga P, Mileib Vasconcelos C, de São José JFB. Application of Ultrasound Combined with Acetic Acid and Peracetic Acid: Microbiological and Physicochemical Quality of Strawberries. Molecules 2020; 26:molecules26010016. [PMID: 33375142 PMCID: PMC7792923 DOI: 10.3390/molecules26010016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/17/2020] [Accepted: 08/21/2020] [Indexed: 11/16/2022] Open
Abstract
This work evaluated the application of organic acids (acetic and peracetic acid) and ultrasound as alternative sanitization methods for improving the microbiological and physicochemical qualities of strawberries. A reduction of up to 2.48 log CFU/g aerobic mesophiles and between 0.89 and 1.45 log CFU/g coliforms at 35 °C was found. For molds and yeasts, significant differences occurred with different treatments and storage time (p < 0.05). Ultrasound treatments in combination with peracetic acid and acetic acid allowed a decimal reduction in molds and yeasts (p < 0.05). All evaluated treatments promoted a significant reduction in the Escherichia coli count (p < 0.05). Scanning electron microscopy revealed fragmented E. coli cells due to treatment with acetic acid and ultrasound. Storage time significantly affected pH, total titratable acidity, total soluble solids and the ratio of the total titratable acidity to the total soluble solids (p < 0.05). Anthocyanin content did not change with treatment or time and generally averaged 13.47 mg anthocyanin/100 g of strawberries on fresh matter. Mass loss was not significantly affected by the applied treatments (p > 0.05). The combination of ultrasound and peracetic acid may be an alternative to chlorine-based compounds to ensure microbiological safety without causing significant changes in the physicochemical characteristics of strawberries.
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Affiliation(s)
- Priscila Donatti Leão Alvarenga
- Postgraduate Program in Nutrition and Health, Federal University of Espírito Santo, Marechal Campos Avenue, Vitória, Espírito Santo 28630, Brazil;
| | - Christiane Mileib Vasconcelos
- Food Biotechnology Laboratory, Vila Velha University, Comissário José Dantas de Melo Avenue, Vila Velha, Espírito Santo 28630, Brazil;
| | - Jackline Freitas Brilhante de São José
- Department of Integrated Health Education, Federal University of Espírito Santo, Marechal Campos Avenue, Vitória, Espírito Santo 28630, Brazil
- Correspondence: ; Tel.: +55–27–3335–7223
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Nath S, Sinha A, Singha YS, Dey A, Bhattacharjee N, Deb B. Prevalence of antibiotic-resistant, toxic metal-tolerant and biofilm-forming bacteria in hospital surroundings. Environ Anal Health Toxicol 2020; 35:e2020018. [PMID: 32979903 PMCID: PMC7656160 DOI: 10.5620/eaht.2020018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 08/31/2020] [Indexed: 01/26/2023] Open
Abstract
The emergence and rapid spread of antibiotic-resistant bacteria due to unethical and non-scientific disposal of hospital wastes and clinical by-products caused an alarming environmental concern and associated public health risks. The present study aims to assess the co-selection of antibiotic resistance and heavy metal tolerance by bacteria isolated from hospital effluents. These isolates were also tested for hemolytic activity, pH-tolerance, thermal inactivation, auto-aggregation, cell-surface hydrophobicity and interaction with other bacteria. The study reports the prevalence of antibiotic-resistant and heavy metal tolerant bacteria in clinical effluents and water samples. Most of these isolates were resistant to vancomycin, clindamycin, ampicillin, rifampicin, penicillin-G, methicillin and cefdinir, and evidenced the production of extended-spectrum β-lactamase enzyme. Toxic metals such as cadmium, copper, iron, lead and zinc also exert a selection pressure towards antibiotic resistance. Pseudomonas aeruginosa strain GCC_19W3, Bacillus sp. strain GCC_19S2 and Achromobacter spanius strain GCC_SB1 showed β-hemolysis, evidenced by the complete breakdown of the red blood cells. Highest auto-aggregation was exhibited by Bacillus sp. strain GCC_19S2; whereas, maximum cell-surface hydrophobicity was displayed by P. aeruginosa strain GCC_19W1. Antagonistic activity by Stenotrophomonas maltophilia strain GCC_19W2, P. aeruginosa strain GCC_19W3 and strains of Achromobacter restricts the growth of other microorganisms by producing some bactericidal substances. The study emphasises undertaking safety measures for the disposal of clinical effluents directly into the environment. The study suggests adopting necessary measures and regulations to restrict the spread of emerging pathogens within the hospital biome and community, which if unnoticed, might pose a significant clinical challenge.
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Affiliation(s)
- Soumitra Nath
- Department of Biotechnology, Gurucharan College, Silchar, Assam, India
- Bioinformatics Centre, Gurucharan College, Silchar, Assam, India
- Institutional Biotech Hub, Gurucharan College, Silchar, Assam, India
| | - Ahana Sinha
- Department of Biotechnology, Gurucharan College, Silchar, Assam, India
| | | | - Ankita Dey
- Department of Biotechnology, Gurucharan College, Silchar, Assam, India
| | | | - Bibhas Deb
- Department of Biotechnology, Gurucharan College, Silchar, Assam, India
- Bioinformatics Centre, Gurucharan College, Silchar, Assam, India
- Institutional Biotech Hub, Gurucharan College, Silchar, Assam, India
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Palachum W, Choorit W, Manurakchinakorn S, Chisti Y. Guava pulp fermentation and processing to a vitamin B12‐enriched product. J FOOD PROCESS PRES 2020. [DOI: 10.1111/jfpp.14566] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wilawan Palachum
- School of Allied Health Sciences Walailak University Tasala Thailand
| | - Wanna Choorit
- School of Agricultural Technology Walailak University Tasala Thailand
- Biomass and Oil Palm Center of Excellence Walailak University Tasala Thailand
| | | | - Yusuf Chisti
- School of Engineering Massey University Palmerston North New Zealand
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Transforming kinetic model into a stochastic inactivation model: Statistical evaluation of stochastic inactivation of individual cells in a bacterial population. Food Microbiol 2020; 91:103508. [PMID: 32539982 DOI: 10.1016/j.fm.2020.103508] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/01/2020] [Accepted: 04/01/2020] [Indexed: 11/22/2022]
Abstract
Kinetic models performing point estimation are effective in predicting the bacterial behavior. However, the large variation of bacterial behavior appearing in a small number of cells, i.e. equal or less than 102 cells, cannot be expressed by point estimation. We aimed to predict the variation of Escherichia coli O157:H7 behavior during inactivation in acidified tryptone soy broth (pH3.0) through Monte Carlo simulation and evaluated the accuracy of the developed model. Weibullian fitted parameters were estimated from the kinetic survival data of E. coli O157:H7 with an initial cell number of 105. A Monte Carlo simulation (100 replication) based on the obtained Weibullian parameters and the Poisson distribution of initial cell numbers successfully predicted the results of 50 replications of bacterial inactivation with initial cell numbers of 101, 102, and 103 cells. The accuracy of the simulation revealed that more than 83% of the observed survivors were within predicted range in all condition. 90% of the distribution in survivors with initial cells less than 100 is equivalent to a Poisson distribution. This calculation transforms the traditional microbial kinetic model into probabilistic model, which can handle bacteria number as discrete probability distribution. The probabilistic approach would utilize traditional kinetic model towards exposure assessment.
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Liu Y, Zhu L, Dong P, Liang R, Mao Y, Yang X, Zhang Y, Luo X. Acid Tolerance Response of Listeria monocytogenes in Various External pHs with Different Concentrations of Lactic Acid. Foodborne Pathog Dis 2020; 17:253-261. [PMID: 31738578 DOI: 10.1089/fpd.2019.2730] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This study evaluated the acid tolerance response (ATR) of two strains of Listeria monocytogenes (serotype 1/2a and 4b) and one strain of Listeria innocua under different mildly acid conditions. Cells were incubated in combinations of three concentrations of lactic acid medium (3, 4.75, and 15 mM) and three external pH's (pHex 5.0, 6.0, and 6.5), plus, a HCl control, and a blank control (pH 7.4). Results showed that lactic acid induced lower log reduction of all three strains when challenged in severe acid conditions (pH 3.0) after being habituated at a pHex of 5.5 or 6.0 until the log phase, compared with a pHex of 6.5 or the two controls. This indicates that when the pHex was either 5.5 or 6.0 this induced a higher ATR of the strains, which may be caused by the ability of the strains to retain intracellular pH (pHi) homeostasis with pHi maintained in the range of 7.4-7.9. It was also found that a pHex of 5.5 resulted in the highest pHi of the strains across all incubated conditions, which indicates that the pHi may play an important role in the induction of ATR when Listeria cells are habituated in lactic acid, and if the higher pHi can be maintained, the ATR would be stronger. The concentration of lactic acid per se has no significant effect on ATR, which it is proposed was due to the pHi homeostasis maintained within the cells. However, the difference in ATR among three strains was also significant, which cannot be explained by the stable pHi of all tested strains. Therefore, other underlying mechanisms to mediate ATR under different conditions need to be explored in further studies.
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Affiliation(s)
- Yunge Liu
- Lab of Beef Processing and Quality Control, College of Food Science and Engineering, Shandong Agricultural University, Tai'an, People's Republic of China
- National R&D Center for Beef Processing Technology, Tai'an, People's Republic of China
| | - Lixian Zhu
- Lab of Beef Processing and Quality Control, College of Food Science and Engineering, Shandong Agricultural University, Tai'an, People's Republic of China
- National R&D Center for Beef Processing Technology, Tai'an, People's Republic of China
| | - Pengcheng Dong
- Lab of Beef Processing and Quality Control, College of Food Science and Engineering, Shandong Agricultural University, Tai'an, People's Republic of China
- National R&D Center for Beef Processing Technology, Tai'an, People's Republic of China
| | - Rongrong Liang
- Lab of Beef Processing and Quality Control, College of Food Science and Engineering, Shandong Agricultural University, Tai'an, People's Republic of China
- National R&D Center for Beef Processing Technology, Tai'an, People's Republic of China
| | - Yanwei Mao
- Lab of Beef Processing and Quality Control, College of Food Science and Engineering, Shandong Agricultural University, Tai'an, People's Republic of China
- National R&D Center for Beef Processing Technology, Tai'an, People's Republic of China
| | - Xiaoyin Yang
- Lab of Beef Processing and Quality Control, College of Food Science and Engineering, Shandong Agricultural University, Tai'an, People's Republic of China
- National R&D Center for Beef Processing Technology, Tai'an, People's Republic of China
| | - Yimin Zhang
- Lab of Beef Processing and Quality Control, College of Food Science and Engineering, Shandong Agricultural University, Tai'an, People's Republic of China
- National R&D Center for Beef Processing Technology, Tai'an, People's Republic of China
| | - Xin Luo
- Lab of Beef Processing and Quality Control, College of Food Science and Engineering, Shandong Agricultural University, Tai'an, People's Republic of China
- National R&D Center for Beef Processing Technology, Tai'an, People's Republic of China
- Jiangsu Synergetic Innovation Center of Meat Production and Processing Quality and Safety Control, Nanjing, People's Republic of China
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Beier RC, Byrd JA, Caldwell D, Andrews K, Crippen TL, Anderson RC, Nisbet DJ. Inhibition and Interactions of Campylobacter jejuni from Broiler Chicken Houses with Organic Acids. Microorganisms 2019; 7:E223. [PMID: 31366094 PMCID: PMC6722939 DOI: 10.3390/microorganisms7080223] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/19/2019] [Accepted: 07/27/2019] [Indexed: 12/11/2022] Open
Abstract
Campylobacter jejuni is a bacterium that causes major diarrheal disease worldwide and is also one of the top five foodborne pathogens encountered in the United States. Poultry is a major source of C. jejuni, and a high-risk factor for contracting campylobacteriosis. Organic acids are used in the United States during food animal processing for removal of bacterial contamination from animal carcasses. Six organic acids were evaluated in inhibition studies of 96 C. jejuni strains obtained from shoe covers used in broiler chicken houses at different poultry farms in several states by determining the susceptibilities of the C. jejuni strains, along with the pH values at the molar minimum inhibitory concentrations (MICMs). The undissociated and dissociated organic acid concentrations were calculated at the MICMs with the Henderson-Hasselbalch equation. The results for the 96 C. jejuni strains were treated similarly for each different organic acid. Campylobacter jejuni inhibition did correlate with the dissociated organic acids, but did not correlate with pH or with the undissociated organic acids. When the concentrations of dissociated organic acids decreased, the C. jejuni strains were not disinfected. A carcass wash using organic acids should have the concentration of dissociated acid species carefully controlled. It is suggested to maintain a dissociated acid concentration for propionic, l-lactic, formic, citric, butyric, and acetic acids at 24, 40, 36, 21, 23, and 25 mM, respectively, and at these dissociated organic acid levels an acid wash would be expected to remove or inhibit 97% or more of the C. jejuni bacteria studied here. However, studies must be undertaken to confirm that the suggested concentrations of dissociated organic acids are adequate to remove C. jejuni bacteria in the field vs. the laboratory. Due to propionate, l-lactate, formate, butyrate, and acetate being utilized by C. jejuni, these organic acids may not be appropriate for use as a carcass wash to remove C. jejuni surface contamination. Of all tested organic acids, dissociated citric acid was the most efficient at inhibiting C. jejuni.
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Affiliation(s)
- Ross C Beier
- United States Department of Agriculture, Agricultural Research Service, Southern Plains Agricultural Research Center, Food and Feed Safety Research Unit, College Station, TX 77845-4988, USA.
| | - J Allen Byrd
- United States Department of Agriculture, Agricultural Research Service, Southern Plains Agricultural Research Center, Food and Feed Safety Research Unit, College Station, TX 77845-4988, USA
| | - Denise Caldwell
- United States Department of Agriculture, Agricultural Research Service, Southern Plains Agricultural Research Center, Food and Feed Safety Research Unit, College Station, TX 77845-4988, USA
| | - Kathleen Andrews
- United States Department of Agriculture, Agricultural Research Service, Southern Plains Agricultural Research Center, Food and Feed Safety Research Unit, College Station, TX 77845-4988, USA
| | - Tawni L Crippen
- United States Department of Agriculture, Agricultural Research Service, Southern Plains Agricultural Research Center, Food and Feed Safety Research Unit, College Station, TX 77845-4988, USA
| | - Robin C Anderson
- United States Department of Agriculture, Agricultural Research Service, Southern Plains Agricultural Research Center, Food and Feed Safety Research Unit, College Station, TX 77845-4988, USA
| | - David J Nisbet
- United States Department of Agriculture, Agricultural Research Service, Southern Plains Agricultural Research Center, Food and Feed Safety Research Unit, College Station, TX 77845-4988, USA
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Pinhal S, Ropers D, Geiselmann J, de Jong H. Acetate Metabolism and the Inhibition of Bacterial Growth by Acetate. J Bacteriol 2019; 201:e00147-19. [PMID: 30988035 PMCID: PMC6560135 DOI: 10.1128/jb.00147-19] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 03/26/2019] [Indexed: 11/24/2022] Open
Abstract
During aerobic growth on glucose, Escherichia coli excretes acetate, a mechanism called "overflow metabolism." At high concentrations, the secreted acetate inhibits growth. Several mechanisms have been proposed for explaining this phenomenon, but a thorough analysis is hampered by the diversity of experimental conditions and strains used in these studies. Here, we describe the construction of a set of isogenic strains that remove different parts of the metabolic network involved in acetate metabolism. Analysis of these strains reveals that (i) high concentrations of acetate in the medium inhibit growth without significantly perturbing central metabolism; (ii) growth inhibition persists even when acetate assimilation is completely blocked; and (iii) regulatory interactions mediated by acetyl-phosphate play a small but significant role in growth inhibition by acetate. The major contribution to growth inhibition by acetate may originate in systemic effects like the uncoupling effect of organic acids or the perturbation of the anion composition of the cell, as previously proposed. Our data suggest, however, that under the conditions considered here, the uncoupling effect plays only a limited role.IMPORTANCE High concentrations of organic acids such as acetate inhibit growth of Escherichia coli and other bacteria. This phenomenon is of interest for understanding bacterial physiology but is also of practical relevance. Growth inhibition by organic acids underlies food preservation and causes problems during high-density fermentation in biotechnology. What causes this phenomenon? Classical explanations invoke the uncoupling effect of acetate and the establishment of an anion imbalance. Here, we propose and investigate an alternative hypothesis: the perturbation of acetate metabolism due to the inflow of excess acetate. We find that this perturbation accounts for 20% of the growth-inhibitory effect through a modification of the acetyl phosphate concentration. Moreover, we argue that our observations are not expected based on uncoupling alone.
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Affiliation(s)
- Stéphane Pinhal
- Univ. Grenoble Alpes, CNRS, Laboratoire Interdisciplinaire de Physique, Grenoble, France
| | | | - Johannes Geiselmann
- Univ. Grenoble Alpes, CNRS, Laboratoire Interdisciplinaire de Physique, Grenoble, France
- Univ. Grenoble Alpes, Inria, Grenoble, France
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Bushell FML, Tonner PD, Jabbari S, Schmid AK, Lund PA. Synergistic Impacts of Organic Acids and pH on Growth of Pseudomonas aeruginosa: A Comparison of Parametric and Bayesian Non-parametric Methods to Model Growth. Front Microbiol 2019; 9:3196. [PMID: 30671033 PMCID: PMC6331447 DOI: 10.3389/fmicb.2018.03196] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 12/10/2018] [Indexed: 01/05/2023] Open
Abstract
Different weak organic acids have significant potential as topical treatments for wounds infected by opportunistic pathogens that are recalcitrant to standard treatments. These acids have long been used as bacteriostatic compounds in the food industry, and in some cases are already being used in the clinic. The effects of different organic acids vary with pH, concentration, and the specific organic acid used, but no studies to date on any opportunistic pathogens have examined the detailed interactions between these key variables in a controlled and systematic way. We have therefore comprehensively evaluated the effects of several different weak organic acids on growth of the opportunistic pathogen Pseudomonas aeruginosa. We used a semi-automated plate reader to generate growth profiles for two different strains (model laboratory strain PAO1 and clinical isolate PA1054 from a hospital burns unit) in a range of organic acids at different concentrations and pH, with a high level of replication for a total of 162,960 data points. We then compared two different modeling approaches for the interpretation of this time-resolved dataset: parametric logistic regression (with or without a component to include lag phase) vs. non-parametric Gaussian process (GP) regression. Because GP makes no prior assumptions about the nature of the growth, this method proved to be superior in cases where growth did not follow a standard sigmoid functional form, as is common when bacteria grow under stress. Acetic, propionic and butyric acids were all more detrimental to growth than the other acids tested, and although PA1054 grew better than PAO1 under non-stress conditions, this difference largely disappeared as the levels of stress increased. As expected from knowledge of how organic acids behave, their effect was significantly enhanced in combination with low pH, with this interaction being greatest in the case of propionic acid. Our approach lends itself to the characterization of combinatorial interactions between stressors, especially in cases where their impacts on growth render logistic growth models unsuitable.
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Affiliation(s)
- Francesca M. L. Bushell
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Peter D. Tonner
- Department of Biology, Duke University, Durham, NC, United States
- Statistical Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD, United States
| | - Sara Jabbari
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
- School of Mathematics, University of Birmingham, Birmingham, United Kingdom
| | - Amy K. Schmid
- Department of Biology, Duke University, Durham, NC, United States
- Center for Genomics and Computational Biology, Duke University, Durham, NC, United States
| | - Peter A. Lund
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
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Wang J, Tao D, Wang S, Li C, Li Y, Zheng F, Wu Z. Disinfection of lettuce using organic acids: an ecological analysis using 16S rRNA sequencing. RSC Adv 2019; 9:17514-17520. [PMID: 35519892 PMCID: PMC9064555 DOI: 10.1039/c9ra03290h] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 05/23/2019] [Indexed: 12/15/2022] Open
Abstract
Comparing disinfection efficacies of same type sanitizer using a combined microbial reduction/16S rRNA analysis strategy.
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Affiliation(s)
- Jiayi Wang
- College of Food Science
- Shenyang Agricultural University
- Shenyang
- China
| | - Dongbing Tao
- College of Food Science
- Shenyang Agricultural University
- Shenyang
- China
| | - Shan Wang
- College of Food Science
- Shenyang Agricultural University
- Shenyang
- China
| | - Chen Li
- College of Food Science
- Shenyang Agricultural University
- Shenyang
- China
| | - Yanru Li
- College of Food Science
- Shenyang Agricultural University
- Shenyang
- China
| | - Fenge Zheng
- Shenyang Product Quality Supervision and Inspection Institute
- Shenyang
- China
| | - Zhaoxia Wu
- College of Food Science
- Shenyang Agricultural University
- Shenyang
- China
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Kang JH, Song KB. Combined effect of a positively charged cinnamon leaf oil emulsion and organic acid on the inactivation of Listeria monocytogenes inoculated on fresh-cut Treviso leaves. Food Microbiol 2018; 76:146-153. [PMID: 30166135 DOI: 10.1016/j.fm.2018.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 04/09/2018] [Accepted: 05/14/2018] [Indexed: 11/17/2022]
Affiliation(s)
- Ji-Hoon Kang
- Department of Food Science and Technology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Kyung Bin Song
- Department of Food Science and Technology, Chungnam National University, Daejeon 34134, Republic of Korea.
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Hamid H, Shi HQ, Ma GY, Fan Y, Li WX, Zhao LH, Zhang JY, Ji C, Ma QG. Influence of acidified drinking water on growth performance and gastrointestinal function of broilers. Poult Sci 2018; 97:3601-3609. [PMID: 29860532 DOI: 10.3382/ps/pey212] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/28/2018] [Indexed: 11/20/2022] Open
Abstract
The ban on the use of antibiotic feed additives as growth promoters compelled the researchers for exploring the future utility of other alternatives. This experiment was designed to evaluate the effect of acidified drinking water on growth performance, gastrointestinal pH, digestive enzymes, intestinal histomorphology, and cecum microbial counting of the broiler chicken. A total of 540 one-day-old male broilers (Arbor Acre) were randomly assigned to 5 treatments, with 6 replicates of 18 chicks per replicate. Broilers received diets and water as follows: NC (negative control, basal diet, normal water), PC (positive control, basal diet + 8 ppm colistin sulfate + 8 ppm enduracidin, normal water), A1 (basal diet, continuous supply of acidified water during whole experiment period), A2 (basal diet, intermittent acidification of water during 0 to 14 d, 22 to 28 d, and 36 to 42 d), and A3 [basal diet, intermittent acidification of water (24 h/d from 0 to 14 d and from 10:00 am to 4:00 pm on d 15 to 42)]. During the entire period, the acidified groups (A1, A2, and A3) and PC group showed improve on weight gain, average daily gain and feed conversion ratio compared to NC group (P < 0.05). The pH in crop, proventriculus and ileum at 43 d declined by 0.04, 1.03, 1.23; 0.55, 0.69, 0.70; and 0.63, 0.74, 1.21 in A1, A2, and A3 group, respectively. There was a significant decline of lipase activity in the PC and acidified groups compared to NC group. The A2 group had higher villus height in jejunum than NC group. The PC and acidified groups reduced (P < 0.05) the total aerobic bacteria count of cecum when contrasted to NC group. Therefore, we conclude that acidified drinking water can improve growth performance, compensate for gastric acidity, and control pathogenic bacteria in broilers and may be considered as a potential alternative to improve production parameters. Discontinuous supply of acidified water had the same or even better influence on broilers compared to continuous supply.
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Affiliation(s)
- H Hamid
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - H Q Shi
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - G Y Ma
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Y Fan
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - W X Li
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - L H Zhao
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - J Y Zhang
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - C Ji
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Q G Ma
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China
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Butler JL, Dhowlaghar N, Kim T, Smith BS, Campano SG, Schilling MW. Utilization of Buffered Vinegar to Inhibit the Growth of Listeria monocytogenes on Marinated and Cooked Chicken Breast. MEAT AND MUSCLE BIOLOGY 2018. [DOI: 10.22175/mmb2018.03.0002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The objective of this experiment was to evaluate the efficacy of adding buffered vinegar to RTE broiler breast meat to inhibit Listeria monocytogenes growth on cooked broiler breast meat. Broiler breast fillets were vacuum-tumbled with a 15% solution (over green weight) for 30 min with a marinade consisting of different concentrations of dry vinegar (DV) or liquid vinegar (LV; 0%, 0.4, 0.6, and 0.8% DV, and 1.5% LV), 1.0% sodium chloride on a total raw product basis (RPB), 0.4% sodium tripolyphosphate on a RPB and water. After marinating, the chicken was cooked to an internal temperature of 77°C. The top and bottom of each piece of broiler breast meat (200 g) was surface inoculated with 1 mL of ∼5 log CFU/g of a 3 strain mixture of L. monocytogenes such that there was a target concentration of 3 log CFU/g L. monocytogenes on each chicken breast. Each chicken breast was then placed into individual packages that had the headspace exchanged for a modified atmosphere (95% CO2, 5% O2) and stored at refrigeration temperature (2°C ± 2°C) for 0 to 60 d and sampled at 5 d intervals. No differences in L. monocytogenes counts existed among buffered vinegar treatments at any storage time. At storage times from 35 to 60 d, broiler breast meat that was treated with buffered vinegar had fewer L. monocytogenes counts (P < 0.05) than the untreated broiler breast meat and continued to control L. monocytogenes growth through 60 d of storage. Additionally, the chicken treated with 0.8% DV and 1.5% LV had 2.0 log CFU/g or less L. monocytogenes counts after 60 d of storage.
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Affiliation(s)
- James L. Butler
- Mississippi State University Department of Food Science, Nutrition and Health Promotion
| | - Nitin Dhowlaghar
- Mississippi State University Department of Food Science, Nutrition and Health Promotion
| | - Taejo Kim
- University of Wisconsin–Stout Department of Food and Nutrition
| | | | | | - M. Wes Schilling
- Mississippi State University Department of Food Science, Nutrition and Health Promotion
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