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The Impact of Low-Temperature Inactivation of Protease AprX from Pseudomonas on Its Proteolytic Capacity and Specificity: A Peptidomic Study. DAIRY 2023. [DOI: 10.3390/dairy4010011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The destabilization of UHT milk during its shelf life can be promoted by the residual proteolytic activity attributed to the protease AprX from Pseudomonas. To better understand the hydrolysis patterns of AprX, and to evaluate the feasibility of using low-temperature inactivation (LTI) for AprX, the release of peptides through AprX activity on milk proteins was examined using an LC-MS/MS-based peptidomic analysis. Milk samples were either directly incubated to be hydrolyzed by AprX, or preheated under LTI conditions (60 °C for 15 min) and then incubated. Peptides and parent proteins (the proteins from which the peptides originated) were identified and quantified. The peptides were mapped and the cleavage frequency of amino acids in the P1/P1′ positions was analyzed, after which the influence of LTI and the potential bitterness of the formed peptides were determined. Our results showed that a total of 2488 peptides were identified from 48 parent proteins, with the most abundant peptides originating from κ-casein and β-casein. AprX may also non-specifically hydrolyze other proteins in milk. Except for decreasing the bitterness potential in skim UHT milk, LTI did not significantly reduce the AprX-induced hydrolysis of milk proteins. Therefore, the inactivation of AprX by LTI may not be feasible in UHT milk production.
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2
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Peptidomic Fingerprints of Stored UHT Milk Inoculated with Protease Extracts from Different Pseudomonas Strains Relative to aprX Expression and Visible Spoilage. DAIRY 2023. [DOI: 10.3390/dairy4010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Lately, concern about the protease AprX produced by Pseudomonas has increased in the dairy industry due to its ability to survive UHT treatment and spoil UHT milk. Efficient prediction methods for UHT milk spoilage are currently lacking, mainly due to high diversity in proteolytic potential between Pseudomonas strains. The present study aimed to gain more insight into the variability between Pseudomonas strains regarding proteolytic potential by comparing their proteolytic capability with their aprX expression levels and differences in peptide formation. The variability in aprX expression levels in four Pseudomonas strains were related to physical stability, milk proteolysis and peptidomic cleavage patterns of milk proteins in a storage experiment of UHT milk inoculated with protease extracellular extracts and stored for 45 days at 20 °C. A positive relationship was observed between the relative expression of aprX and milk proteolysis during storage, with the strain Pseudomonas panacis DSM 18529 showing the highest level in both parameters. This strain was the only strain to show visual gelation, which occurred after 21 days. The peptide formation analysis showed a similar protein hydrolysis pattern between strains and high hydrolysis of αs1-caseins during long-term spoilage putatively due to the activity of AprX was observed.
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3
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Potential spoilage of extended shelf-life (ESL) milk by Bacillus subtilis and Bacillus velezensis. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2021.112487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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4
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Quintieri L, Caputo L, Brasca M, Fanelli F. Recent Advances in the Mechanisms and Regulation of QS in Dairy Spoilage by Pseudomonas spp. Foods 2021; 10:3088. [PMID: 34945641 PMCID: PMC8701193 DOI: 10.3390/foods10123088] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 11/28/2021] [Accepted: 12/08/2021] [Indexed: 11/16/2022] Open
Abstract
Food spoilage is a serious issue dramatically impacting the worldwide need to counteract food insecurity. Despite the very expensive application of low temperatures, the proper conservation of fresh dairy products is continuously threatened at different stages of production and commercialization by psychrotrophic populations mainly belonging to the Pseudomonas genus. These bacteria cause discolouration, loss of structure, and off-flavours, with fatal implications on the quality and shelf-life of products. While the effects of pseudomonad decay have been widely reported, the mechanisms responsible for the activation and regulation of spoilage pathways are still poorly explored. Recently, molecule signals and regulators involved in quorum sensing (QS), such as homoserine lactones, the luxR/luxI system, hdtS, and psoR, have been detected in spoiled products and bacterial spoiler species; this evidence suggests the role of bacterial cross talk in dairy spoilage and paves the way towards the search for novel preservation strategies based on QS inhibition. The aim of this review was to investigate the advancements achieved by the application of omic approaches in deciphering the molecular mechanisms controlled by QS systems in pseudomonads, by focusing on the regulators and metabolic pathways responsible for spoilage of fresh dairy products. In addition, due the ability of pseudomonads to quickly spread in the environment as biofilm communities, which may also include pathogenic and multidrug-resistant (MDR) species, the risk derived from the gaps in clearly defined and regulated sanitization actions is underlined.
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Affiliation(s)
- Laura Quintieri
- Institute of Sciences of Food Production, National Research Council of Italy, 70126 Bari, Italy; (L.C.); (F.F.)
| | - Leonardo Caputo
- Institute of Sciences of Food Production, National Research Council of Italy, 70126 Bari, Italy; (L.C.); (F.F.)
| | - Milena Brasca
- Institute of Sciences of Food Production, National Research Council of Italy, 20133 Milan, Italy;
| | - Francesca Fanelli
- Institute of Sciences of Food Production, National Research Council of Italy, 70126 Bari, Italy; (L.C.); (F.F.)
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5
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Wang G, Qing li, Tang W, Ma F, Wang H, Xu X, Qiu W. AprD is important for extracellular proteolytic activity, physicochemical properties and spoilage potential in meat-borne Pseudomonas fragi. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.107868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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6
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Morandi S, Pica V, Masotti F, Cattaneo S, Brasca M, De Noni I, Silvetti T. Proteolytic Traits of Psychrotrophic Bacteria Potentially Causative of Sterilized Milk Instability: Genotypic, Phenotypic and Peptidomic Insight. Foods 2021; 10:foods10050934. [PMID: 33923137 PMCID: PMC8145555 DOI: 10.3390/foods10050934] [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: 03/23/2021] [Revised: 04/15/2021] [Accepted: 04/22/2021] [Indexed: 11/16/2022] Open
Abstract
The proteolytic traits of the psychrotrophic strains Pseudomonas poae LP5, Pseudomonas fluorescens LPF3, Chryseobacterium joostei LPR1, Pseudomonas fulva PS1, Citrobacter freundii PS37, Hafnia alvei PS46, and Serratia marcescens PS92 were initially investigated by phenotypic and genotypic approaches. Six strains elicited extracellular proteolytic activity, and five expressed the thermostable AprX or (likely) Ser1 enzymes. Then, the strains were inoculated (104 CFU/mL) in microfiltered pasteurized milk and kept at 4 °C for five days. All of the strains reached 108 CFU/mL at the end of storage and five produced thermostable extracellular proteolytic enzymes. The freshly inoculated samples and the corresponding samples at 108 CFU/mL were batch-sterilized (131 °C, 30 s) and kept at 45 °C up to 100 days. The former samples did not gel until the end of incubation, whereas the latter, containing P. poae, P. fluorescens, C. joostei, C. freundii, and S. marcescens, gelled within a few days of incubation. The thermostable proteolytic activity of strains affected the peptidomic profile, and specific proteolyzed zones of β-CN were recognized in the gelled samples. Overall, the results confirm some proteolytic traits of psychrotrophic Pseudomonas spp. strains and provide additional insights on the proteolytic activity of psychrotrophic bacteria potentially responsible for sterilized milk destabilization.
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Affiliation(s)
- Stefano Morandi
- National Research Council, Institute of Sciences of Food Production, Via G. Celoria 2, 20133 Milan, Italy; (S.M.); (M.B.); (T.S.)
| | - Valentina Pica
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Via G. Celoria 2, 20133 Milan, Italy; (V.P.); (F.M.); (S.C.)
| | - Fabio Masotti
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Via G. Celoria 2, 20133 Milan, Italy; (V.P.); (F.M.); (S.C.)
| | - Stefano Cattaneo
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Via G. Celoria 2, 20133 Milan, Italy; (V.P.); (F.M.); (S.C.)
| | - Milena Brasca
- National Research Council, Institute of Sciences of Food Production, Via G. Celoria 2, 20133 Milan, Italy; (S.M.); (M.B.); (T.S.)
| | - Ivano De Noni
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Via G. Celoria 2, 20133 Milan, Italy; (V.P.); (F.M.); (S.C.)
- Correspondence:
| | - Tiziana Silvetti
- National Research Council, Institute of Sciences of Food Production, Via G. Celoria 2, 20133 Milan, Italy; (S.M.); (M.B.); (T.S.)
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7
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Verhegghe M, De Block J, Heyndrickx M, Van Coillie E, Van Poucke C, Duquenne B. Application of LC‐HRMS identified marker peptides in an LC‐MS/MS method for detection and quantification of heat‐resistant proteolytic activity in raw milk. INT J DAIRY TECHNOL 2020. [DOI: 10.1111/1471-0307.12754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Marijke Verhegghe
- Technology and Food Science Unit Flanders Research Institute for Agriculture, Fisheries and Food (ILVO) Brusselsesteenweg 370 Melle9090Belgium
| | - Jan De Block
- Technology and Food Science Unit Flanders Research Institute for Agriculture, Fisheries and Food (ILVO) Brusselsesteenweg 370 Melle9090Belgium
| | - Marc Heyndrickx
- Technology and Food Science Unit Flanders Research Institute for Agriculture, Fisheries and Food (ILVO) Brusselsesteenweg 370 Melle9090Belgium
- Department of Pathology, Bacteriology and Avian Diseases Faculty of Veterinary Medicine Ghent University Salisburylaan 133 Merelbeke9820Belgium
| | - Els Van Coillie
- Technology and Food Science Unit Flanders Research Institute for Agriculture, Fisheries and Food (ILVO) Brusselsesteenweg 370 Melle9090Belgium
| | - Christof Van Poucke
- Technology and Food Science Unit Flanders Research Institute for Agriculture, Fisheries and Food (ILVO) Brusselsesteenweg 370 Melle9090Belgium
| | - Barbara Duquenne
- Technology and Food Science Unit Flanders Research Institute for Agriculture, Fisheries and Food (ILVO) Brusselsesteenweg 370 Melle9090Belgium
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8
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Yuan L, Wang N, Sadiq FA, He G. RNA sequencing reveals the involvement of quorum sensing in dairy spoilage caused by psychrotrophic bacteria. Lebensm Wiss Technol 2020. [DOI: 10.1016/j.lwt.2020.109384] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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Milk fat influences proteolytic enzyme activity of dairy Pseudomonas species. Int J Food Microbiol 2020; 320:108543. [PMID: 32028204 DOI: 10.1016/j.ijfoodmicro.2020.108543] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 01/07/2020] [Accepted: 01/27/2020] [Indexed: 11/21/2022]
Abstract
This study investigated the effect of growth conditions on proteolytic activity of six Pseudomonas strains, (Pseudomonas fragi DZ1, Pseudomonas koreensis DZ138, Pseudomonas rhodesiae DZ351, Pseudomonas fluorescens DZ390, Pseudomonas synxantha DZ832 and Pseudomonas lundensis DZ845), isolated from raw milk. The proteolytic activity of all Pseudomonas strains in dairy media (skim milk and whole milk) was significantly higher (p < 0.05) than in non-dairy media (TSB), with most activity from Pseudomonas grown in whole milk. The proteolytic activity from P. lundensis DZ845 grown in TSB with the addition of 5% (w/v) butter was higher than other dairy ingredients added to TSB and the amount of proteolytic activity increased with increasing concentrations of butter (from 5 to 15%). P. rhodesiae DZ351 showed little proteolytic activity in all TSB supplemented with dairy ingredients. Only four of the six strains produced one protease of 47 kDa when grown in TSB. However, all six strains were able to produce at least one type of proteases in milk medium. For P. lundensis DZ845, a 12% casein zymography gel revealed that the presence of butter could induce proteolytic activity. This is the first study showing the effect of milk fat (butter) on the proteolytic activity of Pseudomonas. This highlights the greater vulnerability of whole milk compared to skim milk to proteolytic activity.
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10
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11
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Li T, Wang D, Ren L, Mei Y, Ding T, Li Q, Chen H, Li J. Involvement of Exogenous N-Acyl-Homoserine Lactones in Spoilage Potential of Pseudomonas fluorescens Isolated From Refrigerated Turbot. Front Microbiol 2019; 10:2716. [PMID: 31849873 PMCID: PMC6895499 DOI: 10.3389/fmicb.2019.02716] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/08/2019] [Indexed: 01/18/2023] Open
Abstract
Some bacteria can modulate their spoilage potential by responding to environmental signaling molecules via the quorum sensing (QS) system. However, the ability of Pseudomonas fluorescens, the specific spoilage organism (SSO) of turbot, to response to environmental signaling molecules remains unclear. This study investigated the effects of six synthetic N-acyl homoserine lactones (AHLs) on typical behaviors mediated by QS in P. fluorescens, such as biofilm formation and extracellular protease activity. Total volatile basic nitrogen (TVB-N) was used as a spoilage indicator to evaluate quality changes in AHL-treated turbot filets during storage. The results confirm the enhancing effect of environmental AHLs on QS-dependent factors of P. fluorescens and quality deterioration of turbot filets, with C4-HSL and C14-HSL being the most effective. Moreover, the content decrease of exogenous AHLs was also validated by gas chromatography–mass spectrometry analysis. Further, changes in rhlR transcription levels in P. fluorescens suggest that this bacterium can sense environmental AHLs. Finally, molecular docking analysis demonstrates the potential interactions of RhlR protein with various exogenous AHLs. These findings strongly implicate environmental AHLs in turbot spoilage caused by P. fluorescens, suggesting preservation of turbot should not exclusively consider the elimination of SSO-secreted AHLs.
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Affiliation(s)
- Tingting Li
- Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Dalian Minzu University, Dalian, China
| | - Dangfeng Wang
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
| | - Likun Ren
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
| | - Yongchao Mei
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
| | - Ting Ding
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Qiuying Li
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
| | - Haitao Chen
- Beijing Key Laboratory of Flavor Chemistry, Beijing Technology and Business University, Beijing, China
| | - Jianrong Li
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
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12
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Li T, Wang D, Ren L, Mei Y, Ding T, Li Q, Chen H, Li J. Involvement of Exogenous N-Acyl-Homoserine Lactones in Spoilage Potential of Pseudomonas fluorescens Isolated From Refrigerated Turbot. Front Microbiol 2019; 10:2716. [PMID: 31849873 DOI: 10.3389/fmicb.2019.0271610.3389/fmicb.2019.02716.s001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/08/2019] [Indexed: 05/28/2023] Open
Abstract
Some bacteria can modulate their spoilage potential by responding to environmental signaling molecules via the quorum sensing (QS) system. However, the ability of Pseudomonas fluorescens, the specific spoilage organism (SSO) of turbot, to response to environmental signaling molecules remains unclear. This study investigated the effects of six synthetic N-acyl homoserine lactones (AHLs) on typical behaviors mediated by QS in P. fluorescens, such as biofilm formation and extracellular protease activity. Total volatile basic nitrogen (TVB-N) was used as a spoilage indicator to evaluate quality changes in AHL-treated turbot filets during storage. The results confirm the enhancing effect of environmental AHLs on QS-dependent factors of P. fluorescens and quality deterioration of turbot filets, with C4-HSL and C14-HSL being the most effective. Moreover, the content decrease of exogenous AHLs was also validated by gas chromatography-mass spectrometry analysis. Further, changes in rhlR transcription levels in P. fluorescens suggest that this bacterium can sense environmental AHLs. Finally, molecular docking analysis demonstrates the potential interactions of RhlR protein with various exogenous AHLs. These findings strongly implicate environmental AHLs in turbot spoilage caused by P. fluorescens, suggesting preservation of turbot should not exclusively consider the elimination of SSO-secreted AHLs.
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Affiliation(s)
- Tingting Li
- Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Dalian Minzu University, Dalian, China
| | - Dangfeng Wang
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
| | - Likun Ren
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
| | - Yongchao Mei
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
| | - Ting Ding
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
- School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Qiuying Li
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
| | - Haitao Chen
- Beijing Key Laboratory of Flavor Chemistry, Beijing Technology and Business University, Beijing, China
| | - Jianrong Li
- College of Food Science and Technology, Bohai University, National and Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, Jinzhou, China
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13
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García-Cano I, Rocha-Mendoza D, Ortega-Anaya J, Wang K, Kosmerl E, Jiménez-Flores R. Lactic acid bacteria isolated from dairy products as potential producers of lipolytic, proteolytic and antibacterial proteins. Appl Microbiol Biotechnol 2019; 103:5243-5257. [PMID: 31030287 PMCID: PMC6570704 DOI: 10.1007/s00253-019-09844-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/08/2019] [Accepted: 04/10/2019] [Indexed: 01/21/2023]
Abstract
Regular consumption of fermented dairy products helps maintain a healthy microbiota and prevent gut dysbiosis-linked diseases. The lactic acid bacteria (LAB) present in food enhance the digestibility of proteins, moderate the release of fatty acids, and support human health through inhabiting the gastrointestinal tract. These desirable properties of LAB are attributed, in part, to their metabolic processes involving enzymes such as lipases, proteases, and antibacterial proteins. The LAB strains presenting higher enzymatic activities may offer improved functionality for applications in foods. The first aim of this work was to isolate and identify LAB from diverse dairy products and select those with enhanced enzymatic activities. Secondly, this work aimed to investigate the subcellular organization and identity of these enzymes after semi-purification. Out of the total 137 LAB strains isolated and screened, 50.3% and 61.3% of the strains exhibited lipolytic and proteolytic activities, respectively. Seven strains displaying high enzymatic activities were selected and further characterized for the cellular organization of their lipases, proteases, and antibacterial proteins. The lipolytic and proteolytic activities were exhibited predominantly in the extracellular fraction; whereas, the antibacterial activities were found in various cellular fractions and were capable of inhibiting common undesirable microorganisms in foods. In total, two lipases, seven proteases, and three antibacterial proteins were identified by LC-MS/MS. Characterization of LAB strains with high enzymatic activity has potential biotechnological significance in fermentative processes and in human health as they may improve the physicochemical characteristics of foods and displace strains with weaker enzymatic activities in the human gut microbiota.
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Affiliation(s)
- Israel García-Cano
- Department of Food Science and Technology, Parker Food Science and Technology Building, The Ohio State University, Columbus, OH, 43210, USA
| | - Diana Rocha-Mendoza
- Department of Food Science and Technology, Parker Food Science and Technology Building, The Ohio State University, Columbus, OH, 43210, USA
| | - Joana Ortega-Anaya
- Department of Food Science and Technology, Parker Food Science and Technology Building, The Ohio State University, Columbus, OH, 43210, USA
| | - Karen Wang
- Department of Food Science and Technology, Parker Food Science and Technology Building, The Ohio State University, Columbus, OH, 43210, USA
| | - Erica Kosmerl
- Department of Food Science and Technology, Parker Food Science and Technology Building, The Ohio State University, Columbus, OH, 43210, USA
| | - Rafael Jiménez-Flores
- Department of Food Science and Technology, Parker Food Science and Technology Building, The Ohio State University, Columbus, OH, 43210, USA.
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14
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Zhang C, Bijl E, Svensson B, Hettinga K. The Extracellular Protease AprX fromPseudomonasand its Spoilage Potential for UHT Milk: A Review. Compr Rev Food Sci Food Saf 2019; 18:834-852. [DOI: 10.1111/1541-4337.12452] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 03/06/2019] [Accepted: 03/10/2019] [Indexed: 01/10/2023]
Affiliation(s)
- Chunyue Zhang
- Dairy Science and Technology, Food Quality and Design GroupWageningen Univ. and Research P.O. Box 17 6700 AA Wageningen the Netherlands
| | - Etske Bijl
- Dairy Science and Technology, Food Quality and Design GroupWageningen Univ. and Research P.O. Box 17 6700 AA Wageningen the Netherlands
| | - Birgitta Svensson
- Tetra Pak Processing Systems ABRuben Rausings gata 221 86 Lund Sweden
| | - Kasper Hettinga
- Dairy Science and Technology, Food Quality and Design GroupWageningen Univ. and Research P.O. Box 17 6700 AA Wageningen the Netherlands
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15
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D'Incecco P, Brasca M, Rosi V, Morandi S, Ferranti P, Picariello G, Pellegrino L. Bacterial proteolysis of casein leading to UHT milk gelation: An applicative study. Food Chem 2019; 292:217-226. [PMID: 31054668 DOI: 10.1016/j.foodchem.2019.04.066] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/11/2019] [Accepted: 04/16/2019] [Indexed: 01/22/2023]
Abstract
Heat-stable peptidases released in refrigerated raw milk by psychrotrophic bacteria are responsible for UHT milk gelation. K-casein-derived caseinomacropeptides, identified by mass spectrometry, were constantly detected in gelled milk by capillary electrophoresis. Strains of Pseudomonas fluorescens, Ps. poae and Chryseobacterium joostei, selected among aprX-positive strains from raw milk, were incubated in milk up to 6 days at 4 °C before sterilization (98 °C/4 min). Samples were then stored at 25 or 40 °C, visually observed for gelation, and analysed for presence of caseinomacropeptides throughout 90 days of storage. Depending on cold pre-incubation time, caseinomacropeptides accumulated well before gelation onset in milk stored at 25 °C. Caseinomacropeptides were successively degraded, especially in milk stored at 40 °C, due to extensive proteolysis, and an abundant sediment developed instead of a gel. The caseinomacropeptides are here presented as an early indicator of UHT milk gelation and a mechanism explaining this phenomenon is proposed.
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Affiliation(s)
- Paolo D'Incecco
- Department of Food, Environmental and Nutritional Sciences, University of Milano, Milan, Italy
| | - Milena Brasca
- Institute of Sciences of Food Production, National Research Council of Italy (ISPA-CNR), Milan, Italy
| | - Veronica Rosi
- Department of Food, Environmental and Nutritional Sciences, University of Milano, Milan, Italy
| | - Stefano Morandi
- Institute of Sciences of Food Production, National Research Council of Italy (ISPA-CNR), Milan, Italy
| | - Pasquale Ferranti
- Department of Agricultural Sciences, University of Naples Federico II, Naples, Italy; Institute of Food Science and Technology, National Research Council of Italy (ISA-CNR), Avellino, Italy
| | - Gianluca Picariello
- Institute of Food Science and Technology, National Research Council of Italy (ISA-CNR), Avellino, Italy
| | - Luisa Pellegrino
- Department of Food, Environmental and Nutritional Sciences, University of Milano, Milan, Italy.
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16
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Volk V, Glück C, Leptihn S, Ewert J, Stressler T, Fischer L. Two Heat Resistant Endopeptidases from Pseudomonas Species with Destabilizing Potential during Milk Storage. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:905-915. [PMID: 30585481 DOI: 10.1021/acs.jafc.8b04802] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In the current study, the extracellular endopeptidases from Pseudomonas lundensis and Pseudomonas proteolytica were investigated. The amino acid sequence identity between both endopeptidases is 68%. Both endopeptidases were purified to homogeneity and partially characterized. They were classified as metallopeptidases with a maximum activity at pH 10.0 ( P. lundensis) or 8.5 ( P. proteolytica) at 35 °C. Both remained active in skim milk with 39.7 ± 2.4% and 24.5 ± 3.3%, respectively, of the initial enzyme activity after UHT processing (138 °C for 20 s), indicating the relevance for milk destabilization. The transition points in buffer were determined at 50 °C ( P. lundensis) and 43 °C ( P. proteolytica) using circular dichroism spectroscopy. The loss of the secondary structure at different temperatures was correlated with residual peptidase activities after heat treatment. The ability to destabilize UHT milk was proven by supplementation of skim milk with endopeptidase and storage for 4 weeks.
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Affiliation(s)
| | | | - Sebastian Leptihn
- Institute of Microbiology, Department of Microbiology , University of Hohenheim , Garbenstrasse 30 , 70599 Stuttgart , Germany
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Lampugnani C, Was MZ, Montanhini MTM, Nero LA, Bersot LDS. Quantification of psychrotrophic bacteria and molecular identification of Pseudomonas fluorescens in refrigerated raw milk. ARQUIVOS DO INSTITUTO BIOLÓGICO 2019. [DOI: 10.1590/1808-1657001212018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
ABSTRACT In this study, we investigated the contamination of refrigerated raw milk produced in the western region of Paraná, southern Brazil, with psychrotrophic microorganisms, aiming to assay the proteolytic activity of the isolates and to identify Pseudomonas fluorescens, the main proteolytic species associated with the spoilage of milk products. Raw milk samples from 50 dairy farms were submitted to the counting of psychrotrophic microorganisms, being the microbiota characterized by its mesophilic behavior and proteolytic capacity, besides molecular identification of P. fluorescens. Of the samples evaluated, 94% had psychrotrophic counts ranging from 3 to 7.1 log CFU mL-1, and 48.5% of these showed mesophilic behavior. Of the isolates, 48.0% had proteolytic activity in at least one evaluated temperature (21 and 30°C), and 39.3% had proteolytic activity in both temperatures. Among the 61 isolates submitted to molecular identification by polymerase chain reaction (PCR), 86.8% contained the expression of the 16S gene characteristic for P. fluorescens. In this study, we demonstrated that P. fluorescens is the most prevalent psychrotrophic bacteria species in raw refrigerated milk and their proteolytic ability poses high risks to the dairy industry.
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Ribeiro Júnior JC, Teider Junior PI, Oliveira AL, Rios EA, Tamanini R, Beloti V. Proteolytic and lipolytic potential of Pseudomonas spp. from goat and bovine raw milk. PESQUISA VETERINÁRIA BRASILEIRA 2018. [DOI: 10.1590/1678-5150-pvb-5645] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
ABSTRACT: Pseudomonas, the main genus of gram-negative microorganisms isolated from milk, is psychrotrophic, biofilm-forming, and thermo-resistant deteriorating enzyme producers. The aim of this study was to quantify Pseudomonas spp. in goat’s and cow’s milk produced in the Paraná state, Brazil, to evaluate the deteriorating activity of the isolates at mesophilic and psychrotrophic conditions and to identify, at the species level, the isolates with alkaline metalloprotease (aprX gene) production potential. Microbiological, biochemical and molecular methods were used for isolating, confirming and identifying of isolates. The mean counts were 1.6 (±6.3)x104 and 0.89(±3)x102 CFU/mL for goat and bovine milk samples, respectively, immediately after milking. Of the Pseudomonas colonies isolated from goat milk (n=60), 91.7% showed proteolytic potential when incubated at 35°C/48 h and 80% at 7°C/10 days, and lipolytic potential was observed in 95% of the isolates incubated in mesophilic and 78.3% at refrigeration conditions. From the isolates of bovine milk (n=20), 35% showed proteolytic activity only when incubated at 35°C/48 h, and lipolytic potential was observed in 25% of the isolates incubated at 7°C/10d and 35°C/48h. It was observed that 83.3% and 25% of the isolates genetically confirmed as Pseudomonas spp. of goat and bovine milk showed the potential for alkaline metalloprotease production, with the species P. azotoformans, P. koreensis, P. gessardii, P. monteilii and P. lurida being the most frequent in goat milk and P. aeruginosa the only species identified in cow milk.
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Xin L, Zhang L, Meng Z, Lin K, Zhang S, Han X, Yi H, Cui Y. Development of a novel loop-mediated isothermal amplification assay for the detection of lipolytic Pseudomonas fluorescens in raw cow milk from north China. J Dairy Sci 2017; 100:7802-7811. [PMID: 28780114 DOI: 10.3168/jds.2017-12740] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 06/17/2017] [Indexed: 01/23/2023]
Abstract
Lipases secreted by psychrotrophic bacteria are known to be heat resistant and can remain active even after the thermal processing of milk products. Such enzymes are able to destabilize the quality of milk products by causing a rancid flavor. Rapid detection of a small amount of heat-resistant lipase-producing psychrotrophic bacteria is crucial for reducing their adverse effects on milk quality. In this study, we established and optimized a novel loop-mediated isothermal amplification (LAMP) assay for the detection of Pseudomonas fluorescens in raw cow milk, as the most frequently reported heat-resistant lipase-producing bacterial species. Pseudomonas fluorescens-specific DNA primers for LAMP were designed based on the lipase gene sequence. Reaction conditions of the LAMP assay were tested and optimized. The detection limit of the optimized LAMP assay was found to be lower than that of a conventional PCR-based method. In pure culture, the detection limit of the LAMP assay was found to be 4.8 × 101 cfu/reaction of the template DNA, whereas the detection limit of the PCR method was 4.8 × 102 cfu/reaction. Evaluation of the performance of the method in P. fluorescens-contaminated pasteurized cow milk revealed a detection limit of 7.4 × 101 cfu/reaction, which was 102 lower than that of the PCR-based method. If further developed, the LAMP assay could offer a favorable on-farm alternative to existing technologies for the detection of psychotrophic bacterial contamination of milk, enabling improved quality control of milk and milk products.
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Affiliation(s)
- Liang Xin
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Lanwei Zhang
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China; College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
| | - Zhaoxu Meng
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Kai Lin
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Shuang Zhang
- Food College, Northeast Agricultural University, Harbin 150030, China
| | - Xue Han
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - HuaXi Yi
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
| | - Yanhua Cui
- Department of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China
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Machado SG, Baglinière F, Marchand S, Van Coillie E, Vanetti MCD, De Block J, Heyndrickx M. The Biodiversity of the Microbiota Producing Heat-Resistant Enzymes Responsible for Spoilage in Processed Bovine Milk and Dairy Products. Front Microbiol 2017; 8:302. [PMID: 28298906 PMCID: PMC5331058 DOI: 10.3389/fmicb.2017.00302] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/14/2017] [Indexed: 12/28/2022] Open
Abstract
Raw bovine milk is highly nutritious as well as pH-neutral, providing the ideal conditions for microbial growth. The microbiota of raw milk is diverse and originates from several sources of contamination including the external udder surface, milking equipment, air, water, feed, grass, feces, and soil. Many bacterial and fungal species can be found in raw milk. The autochthonous microbiota of raw milk immediately after milking generally comprises lactic acid bacteria such as Lactococcus, Lactobacillus, Streptococcus, and Leuconostoc species, which are technologically important for the dairy industry, although they do occasionally cause spoilage of dairy products. Differences in milking practices and storage conditions on each continent, country and region result in variable microbial population structures in raw milk. Raw milk is usually stored at cold temperatures, e.g., about 4°C before processing to reduce the growth of most bacteria. However, psychrotrophic bacteria can proliferate and contribute to spoilage of ultra-high temperature (UHT) treated and sterilized milk and other dairy products with a long shelf life due to their ability to produce extracellular heat resistant enzymes such as peptidases and lipases. Worldwide, species of Pseudomonas, with the ability to produce these spoilage enzymes, are the most common contaminants isolated from cold raw milk although other genera such as Serratia are also reported as important milk spoilers, while for others more research is needed on the heat resistance of the spoilage enzymes produced. The residual activity of extracellular enzymes after high heat treatment may lead to technological problems (off flavors, physico-chemical instability) during the shelf life of milk and dairy products. This review covers the contamination patterns of cold raw milk in several parts of the world, the growth potential of psychrotrophic bacteria, their ability to produce extracellular heat-resistant enzymes and the consequences for dairy products with a long shelf life. This problem is of increasing importance because of the large worldwide trade in fluid milk and milk powder.
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Affiliation(s)
- Solimar G Machado
- Instituto Federal do Norte de Minas Gerais - Campus Salinas Salinas, Brazil
| | | | - Sophie Marchand
- Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fischeries and Food (ILVO) Melle, Belgium
| | - Els Van Coillie
- Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fischeries and Food (ILVO) Melle, Belgium
| | - Maria C D Vanetti
- Department of Microbiology, Universidade Federal de Viçosa Viçosa, Brazil
| | - Jan De Block
- Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fischeries and Food (ILVO) Melle, Belgium
| | - Marc Heyndrickx
- Technology and Food Science Unit, Flanders Research Institute for Agriculture, Fischeries and Food (ILVO)Melle, Belgium; Department of Pathology, Bacteriology and Poultry Diseases, Ghent UniversityMerelbeke, Belgium
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