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Chang G, Li Q, Wang T, Zhang B, Wu W, Lv C, Sun T, Zhou T, Zheng W, Wang Y, Wang X. Characterization of Pseudomonas spp. contamination and in situ spoilage potential in pasteurized milk production process. Food Res Int 2024; 188:114463. [PMID: 38823831 DOI: 10.1016/j.foodres.2024.114463] [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: 03/07/2024] [Revised: 04/27/2024] [Accepted: 05/01/2024] [Indexed: 06/03/2024]
Abstract
To investigate the prevalence of Pseudomonas in the pasteurized milk production process and its effect on milk quality, 106 strains of Pseudomonas were isolated from the pasteurized milk production process of a milk production plant in Shaanxi Province, China. The protease, lipase and biofilm-producing capacities of the 106 Pseudomonas strains were evaluated, and the spoilage enzyme activities of their metabolites were assessed by simulating temperature incubation in the refrigerated (7 °C) and transport environment (25 °C) segments and thermal treatments of pasteurization (75 °C, 5 min) and ultra-high temperature sterilization (121 °C, 15 s). A phylogenetic tree was drawn based on 16S rDNA gene sequencing and the top 5 strains were selected as representative strains to identify their in situ spoilage potential by examining their growth potential and ability to hydrolyze proteins and lipids in milk using growth curves, pH, whiteness, Zeta-potential, lipid oxidation, SDS-PAGE and volatile flavor compounds. The results showed that half and more of the isolated Pseudomonas had spoilage enzyme production and biofilm capacity, and the spoilage enzyme activity of metabolites was affected by the culture temperature and sterilization method, but ultra-high temperature sterilization could not completely eliminate the enzyme activity. The growth of Pseudomonas lundensis and Pseudomonas qingdaonensis was less affected by temperature and time, and the hydrolytic capacity of extracellular protease and lipase secreted by Pseudomonas lurida was the strongest, which had the greatest effect on milk quality. Therefore, it is crucial to identify the key contamination links of Pseudomonas, the main bacteria responsible for milk spoilage, and the influence of environmental factors on its deterioration.
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Affiliation(s)
- Guanhong Chang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Qianhong Li
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Ting Wang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Bozheng Zhang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Wendi Wu
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Chunyang Lv
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Tongzhuo Sun
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Ting Zhou
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Wanxiang Zheng
- Department of Urology, Xijing Hospital, Fourth Military Medical University, 127 Changle West Road, Xi'an, Shaanxi, China
| | - Yeru Wang
- National Center for Food Safety Risk Assessment, Beijing, China.
| | - Xin Wang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China.
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Dacres H, Weihs F, Wang J, Anderson A, Trowell SC. Bioluminescence resonance energy transfer biosensor for measuring activity of a protease secreted by Pseudomonas fluorescens growing in milk. Anal Chim Acta 2023; 1270:341401. [PMID: 37311608 DOI: 10.1016/j.aca.2023.341401] [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: 11/07/2022] [Revised: 05/18/2023] [Accepted: 05/20/2023] [Indexed: 06/15/2023]
Abstract
Bacterial proteases are sporadic contributors to milk spoilage, reducing the quality of ultra-heat treated (UHT) milk and other dairy products. Current methods for measuring bacterial protease activity in milk are insensitive and too slow to be used in routine testing in dairy processing plants. We have designed a novel bioluminescence resonance energy transfer (BRET)-based biosensor to measure the activity of proteases secreted by bacteria in milk. The BRET-based biosensor is highly selective for bacterial protease activity compared with other proteases tested, notably including plasmin, which is abundant in milk. It incorporates a novel peptide linker that is selectively cleaved by P. fluorescens AprX proteases. The peptide linker is flanked by green fluorescent protein (GFP2) at the N-terminus and a variant Renilla luciferase (RLuc2) at the C-terminus. Complete cleavage of the linker by bacterial proteases from Pseudomonas fluorescens strain 65, leads to a 95% decrease in the BRET ratio. We applied an azocasein-based calibration method to the AprX biosensor using standard international enzyme activity units. In a 10-min assay, the detection limit for AprX protease activity in buffer was equivalent to 40 pg/mL (≈0.8 pM, 22 μU/mL) and 100 pg/mL (≈2pM, 54 μU/mL) in 50% (v/v) full fat milk. The EC50 values were 1.1 ± 0.3 ng/mL (87 μU/mL) and 6.8 ± 0.2 ng/mL (540 μU/mL), respectively. The biosensor was approximately 800x more sensitive than the established FITC-Casein method in a 2-h assay, the shortest feasible time for the latter method. The protease biosensor is sensitive and fast enough to be used in production settings. It is suitable for measuring bacterial protease activity in raw and processed milk, to inform efforts to mitigate the effects of heat-stable bacterial proteases and maximise the shelf-life of dairy products.
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Affiliation(s)
- H Dacres
- CSIRO Health & Biosecurity, Food Innovation Centre, 671 Sneydes Road, Werribee, VIC, 3030, Australia
| | - F Weihs
- PPB Technology Pty Ltd, PO Box 265, Erindale Centre, ACT, 2903, Australia; CSIRO Health & Biosecurity, Canberra, ACT, 2601, Australia.
| | - J Wang
- CSIRO Health & Biosecurity, Canberra, ACT, 2601, Australia
| | - A Anderson
- CSIRO Health & Biosecurity, Canberra, ACT, 2601, Australia
| | - S C Trowell
- PPB Technology Pty Ltd, PO Box 265, Erindale Centre, ACT, 2903, Australia; CSIRO Health & Biosecurity, Canberra, ACT, 2601, Australia
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Aguilera-Toro M, Kragh ML, Thomasen AV, Piccini V, Rauh V, Xiao Y, Wiking L, Poulsen NA, Hansen LT, Larsen LB. Proteolytic activity and heat resistance of the protease AprX from Pseudomonas in relation to genotypic characteristics. Int J Food Microbiol 2023; 391-393:110147. [PMID: 36848797 DOI: 10.1016/j.ijfoodmicro.2023.110147] [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: 11/18/2022] [Revised: 02/15/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023]
Abstract
AprX is an alkaline metalloprotease produced by Pseudomonas spp. and encoded by its initial gene of the aprX-lipA operon. The intrinsic diversity among Pseudomonas spp. regarding their proteolytic activity is the main challenge for the development of accurate methods for spoilage prediction of ultra-high temperature (UHT) treated milk in the dairy industry. In the present study, 56 Pseudomonas strains were characterized by assessing their proteolytic activity in milk before and after lab-scale UHT treatment. From these, 24 strains were selected based on their proteolytic activity for whole genome sequencing (WGS) to identify common genotypic characteristics that correlated with the observed variations in proteolytic activity. Four groups (A1, A2, B and N) were determined based on operon aprX-lipA sequence similarities. These alignment groups were observed to significantly influence the proteolytic activity of the strains, with an average proteolytic activity of A1 > A2 > B > N. The lab-scale UHT treatment did not significantly influence their proteolytic activity, indicating a high thermal stability of proteases among strains. Amino acid sequence variation of biologically-relevant motifs in the AprX sequence, namely the Zn2+-binding motif at the catalytic domain and the C-terminal type I secretion signaling mechanism, were found to be highly conserved within alignment groups. These motifs could serve as future potential genetic biomarkers for determination of alignment groups and thereby strain spoilage potential.
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Affiliation(s)
| | - Martin Laage Kragh
- Technical University of Denmark, Food Microbiology and Hygiene Research Group, Denmark
| | | | | | | | - Yinghua Xiao
- Arla Innovation Center, Arla Foods Amba, Denmark
| | - Lars Wiking
- Department of Food Science, Aarhus University, Denmark
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Maggio F, Serio A, Rossi C, Purgatorio C, Buccioni F, Chaves- López C, Paparella A. Effectiveness of essential oils against dual-species biofilm of <em>Listeria monocytogenes</em> and <em>Pseudomonas fluorescens</em> in a Ricotta-based model system. Ital J Food Saf 2023; 12:11048. [PMID: 37064519 PMCID: PMC10102963 DOI: 10.4081/ijfs.2023.11048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 02/13/2023] [Indexed: 03/11/2023] Open
Abstract
Biofilms represent an evolutionary form of life, which translates from life in free-living cells to a community lifestyle. In natural habitats, biofilms are a multispecies complex, where synergies or antagonisms can be established. For example, Listeria monocytogenes and Pseudomonas fluorescens are associated with a dual-species biofilm that is widespread in dairy plants. In food plants, multiple strategies are devised to control biofilms, including natural compounds such as essential oils (EOs). In this respect, this study evaluated the effectiveness of Thymbra capitata (L.) Cav. EO and Cinnamomum zeylanicum (CEO) against a dual-species biofilm of L. monocytogenes and P. fluorescens, mimicking dairy process conditions. Based on Minimum Inhibitory Concentrations results, the EOs concentration (10 µL/mL) was chosen for the antibiofilm assay at 12°C on polystyrene (PS), and stainless steel surfaces for 168 h, using a Ricotta-based model system as culture medium. Biofilm biomass was assessed by crystal violet staining, and the planktonic and sessile cells were quantified in terms of Log CFU/cm2. Results showed that CEO displayed the greatest antibiofilm activity, reducing significantly (P<0.05) P. fluorescens and L. monocytogenes sessile cells of about 2.5 and 2.8 Log CFU/cm2 after 72 h, respectively. However, L. monocytogenes gained the protection of P. fluorescens, evading CEO treatment and showing a minimal sessile cell reduction of 0.7 Log CFU/cm2 after 72 h. Considering the outcome of this study, CEO might have promising perspectives for applications in dairy facilities.
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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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6
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Potential application of non-thermal atmospheric plasma in reducing the activity of Pseudomonas-secreted proteases in milk. Int Dairy J 2021. [DOI: 10.1016/j.idairyj.2021.105078] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Porcellato D, Smistad M, Bombelli A, Abdelghani A, Jørgensen HJ, Skeie SB. Longitudinal Study of the Bulk Tank Milk Microbiota Reveals Major Temporal Shifts in Composition. Front Microbiol 2021; 12:616429. [PMID: 33708181 PMCID: PMC7940241 DOI: 10.3389/fmicb.2021.616429] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 02/04/2021] [Indexed: 01/04/2023] Open
Abstract
Introduction of microbial contaminations in the dairy value chain starts at the farm level and the initial microbial composition may severely affect the production of high-quality dairy products. Therefore, understanding the farm-to-farm variation and longitudinal shifts in the composition of the bulk tank milk microbiota is fundamental to increase the quality and reduce the spoilage and waste of milk and dairy products. In this study, we performed a double experiment to study long- and short-term longitudinal shifts in microbial composition using 16S rRNA gene amplicon sequencing. We analyzed milk from 37 farms, that had also been investigated two years earlier, to understand the stability and overall microbial changes over a longer time span. In addition, we sampled bulk tank milk from five farms every 1–2 weeks for up to 7 months to observe short-term changes in microbial composition. We demonstrated that a persistent and farm-specific microbiota is found in bulk tank milk and that changes in composition within the same farm are mostly driven by bacterial genera associated with mastitis (e.g., Staphylococcus and Streptococcus). On a long-term, we detected that major shift in milk microbiota were not correlated with farm settings, such as milking system, number of cows and quality of the milk but other factors, such as weather and feeding, may have had a greater impact on the main shifts in composition of the bulk tank milk microbiota. Our results provide new information regarding the ecology of raw milk microbiota at the farm level.
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Affiliation(s)
- Davide Porcellato
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, NMBU, Ås, Norway
| | - Marit Smistad
- Norwegian Veterinary Institute, Oslo, Norway.,TINE SA, Oslo, Norway
| | - Alberto Bombelli
- Department of Agrotechnology and Food Science, Wageningen University and Research, Wageningen, Netherlands
| | - Ahmed Abdelghani
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, NMBU, Ås, Norway
| | - Hannah Joan Jørgensen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, NMBU, Ås, Norway
| | - Siv B Skeie
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, NMBU, Ås, Norway
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Maggio F, Rossi C, Chaves-López C, Serio A, Valbonetti L, Pomilio F, Chiavaroli AP, Paparella A. Interactions between L. monocytogenes and P. fluorescens in Dual-Species Biofilms under Simulated Dairy Processing Conditions. Foods 2021; 10:foods10010176. [PMID: 33467189 PMCID: PMC7829993 DOI: 10.3390/foods10010176] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/07/2021] [Accepted: 01/14/2021] [Indexed: 12/13/2022] Open
Abstract
In dairy processing environments, many bacterial species adhere and form biofilms on surfaces and equipment, leading to foodborne illness and food spoilage. Among them, Listeria monocytogenes and Pseudomonas spp. could be present in mixed-species biofilms. This study aimed to evaluate the interactions between L. monocytogenes and P. fluorescens in biofilms simulating dairy processing conditions, as well as the capability of P. fluorescens in co-culture to produce the blue pigment in a Ricotta-based model system. The biofilm-forming capability of single- and mixed-cultures was evaluated on polystyrene (PS) and stainless steel (SS) surfaces at 12 °C for 168 h. The biofilm biomass was measured, the planktonic and sessile cells and the carbohydrates in biofilms were quantified. The biofilms were also observed through Confocal Laser Scanning Microscopy analysis. Results showed that only P. fluorescens was able to form biofilms on PS. Moreover, in dual-species biofilms at the end of the incubation time (168 h at 12 °C), a lower biomass compared to P. fluorescens mono-species was observed on PS. On SS, the biofilm cell population of L. monocytogenes was higher in the dual-species than in mono-species, particularly after 48 h. Carbohydrates quantity in the dual-species system was higher than in mono-species and was revealed also at 168 h. The production of blue pigment by P. fluorescens was revealed both in single- and co-culture after 72 h of incubation (12 °C). This work highlights the interactions between the two species, under the experimental conditions studied in the present research, which can influence biofilm formation (biomass and sessile cells) but not the capability of P. fluorescens to produce blue pigment.
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Affiliation(s)
- Francesca Maggio
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via R. Balzarini 1, 64100 Teramo, Italy; (F.M.); (C.R.); (C.C.-L.); (A.S.); (L.V.); (A.P.C.)
| | - Chiara Rossi
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via R. Balzarini 1, 64100 Teramo, Italy; (F.M.); (C.R.); (C.C.-L.); (A.S.); (L.V.); (A.P.C.)
| | - Clemencia Chaves-López
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via R. Balzarini 1, 64100 Teramo, Italy; (F.M.); (C.R.); (C.C.-L.); (A.S.); (L.V.); (A.P.C.)
| | - Annalisa Serio
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via R. Balzarini 1, 64100 Teramo, Italy; (F.M.); (C.R.); (C.C.-L.); (A.S.); (L.V.); (A.P.C.)
| | - Luca Valbonetti
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via R. Balzarini 1, 64100 Teramo, Italy; (F.M.); (C.R.); (C.C.-L.); (A.S.); (L.V.); (A.P.C.)
| | - Francesco Pomilio
- Food Hygiene Unit, NRL for L. monocytogenes, Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise “G. Caporale”, 64100 Teramo, Italy;
| | - Alessio Pio Chiavaroli
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via R. Balzarini 1, 64100 Teramo, Italy; (F.M.); (C.R.); (C.C.-L.); (A.S.); (L.V.); (A.P.C.)
| | - Antonello Paparella
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via R. Balzarini 1, 64100 Teramo, Italy; (F.M.); (C.R.); (C.C.-L.); (A.S.); (L.V.); (A.P.C.)
- Correspondence: ; Tel.: +39-0861-266944
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RAMOS GLDPA, NASCIMENTO JDS. Pseudomonas SP. in uninspected raw goat’s milk in Rio de Janeiro, Brazil. FOOD SCIENCE AND TECHNOLOGY 2020. [DOI: 10.1590/fst.21719] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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10
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Identification, phylogenetic characterisation and proteolytic activity quantification of high biofilm-forming Pseudomonas fluorescens group bacterial strains isolated from cold raw milk. Int Dairy J 2020. [DOI: 10.1016/j.idairyj.2020.104787] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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11
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Paludetti LF, O'Callaghan TF, Sheehan JJ, Gleeson D, Kelly AL. Effect of Pseudomonas fluorescens proteases on the quality of Cheddar cheese. J Dairy Sci 2020; 103:7865-7878. [PMID: 32600766 DOI: 10.3168/jds.2019-18043] [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: 12/11/2019] [Accepted: 04/10/2020] [Indexed: 12/31/2022]
Abstract
The objective of this study was to investigate the effect of adding different levels of a thermoresistant protease produced by a Pseudomonas fluorescens strain to milk on the manufacture and quality of Cheddar cheese. Fresh raw milk was collected, standardized, and pasteurized at 72°C for 15 s, and the enzyme was added to give a protease activity of 0.15 or 0.60 U/L (treatments P1 and P4, respectively), while one sample had no enzyme added (control). Milk was stored at 4°C for 48 h and Cheddar cheese was manufactured after 0 and 48 h of storage. Results indicated that the protease was active in milk during 48 h of storage; however, its effect on milk composition was minimal. The protein that was preferentially hydrolyzed by the protease over storage was β-casein, followed by κ-casein. The mean cheese yield and recovery of fat and protein obtained for all cheeses were not affected by protease activity. The protease showed low activity during cheese manufacture, possibly because of unfavorable conditions, including low pH. One of the factors that might have influenced protease activity was the pH of the curd (approximately 6.55 after acidification and 5.35 at milling), which was lower than that at which the enzyme would have optimum activity (pH 7 to 9). Consequently, the composition, pH, patterns of proteolysis, and hardness of all cheeses produced were similar and in accordance with values expected for that type of cheese, independently of the protease activity level. However, slight increases in proteolysis were observed in P4 cheeses and produced using milk stored for 48 h. Both the P1 and P4 cheeses had higher concentrations of free amino acids (FAA) compared with the control, whereas urea-PAGE electrophoretograms indicated a greater breakdown of caseins in the P4 cheese samples, which may be related to possible increases in numbers of proteolytic bacteria in milk during storage. Therefore, the thermoresistant psychrotrophic bacterial protease(s) tested in this study may affect the manufacture or quality of Cheddar cheese during ripening to a relatively limited extent. However, controlling initial levels of proteolytic bacteria in raw milk remains essential, because proteolysis affects the development of flavor and texture in cheese.
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Affiliation(s)
- Lizandra F Paludetti
- Teagasc Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, P61 C996 County Cork, Ireland; School of Food and Nutritional Sciences, University College Cork, T12 K8AF County Cork, Ireland
| | - Tom F O'Callaghan
- Teagasc Food Research Centre, Moorepark, Fermoy, P61 C996 County Cork, Ireland
| | - Jeremiah J Sheehan
- Teagasc Food Research Centre, Moorepark, Fermoy, P61 C996 County Cork, Ireland.
| | - David Gleeson
- Teagasc Animal & Grassland Research and Innovation Centre, Moorepark, Fermoy, P61 C996 County Cork, Ireland
| | - Alan L Kelly
- School of Food and Nutritional Sciences, University College Cork, T12 K8AF County Cork, Ireland
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Maier C, Huptas C, von Neubeck M, Scherer S, Wenning M, Lücking G. Genetic Organization of the aprX-lipA2 Operon Affects the Proteolytic Potential of Pseudomonas Species in Milk. Front Microbiol 2020; 11:1190. [PMID: 32587583 PMCID: PMC7298200 DOI: 10.3389/fmicb.2020.01190] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 05/11/2020] [Indexed: 11/30/2022] Open
Abstract
Psychrotolerant Pseudomonas species are a main cause of proteolytic spoilage of ultra-high temperature (UHT) milk products due to the secretion of the heat-resistant metallopeptidase AprX, which is encoded by the first gene of the aprX-lipA2 operon. While the proteolytic property has been characterized for many different Pseudomonas isolates, the underlying aprX-lipA2 gene organization was only described for a few strains so far. In this study, the phylogenomic analysis of 185 Pseudomonas type strains revealed that the presence of aprX is strongly associated to a monophylum composed of 81 species, of which 83% carried the aprX locus. Furthermore, almost all type strains of known milk-relevant species were shown to be members of the three monophyletic groups P. fluorescens, P. gessardii, and P. fragi. In total, 22 different types of aprX-lipA2 genetic organizations were identified in the genus, whereby 31% of the species tested carried the type 1 operon structure consisting of eight genes (aprXIDEF prtAB lipA2). Other genetic structures differed from type 1 mainly in the presence and location of genes coding for two lipases (lipA1 and lipA2) and putative autotransporters (prtA and prtB). The peptidase activity of 129 strains, as determined on skim milk agar and in UHT-milk, correlated largely with different aprX-lipA2 gene compositions. Particularly, isolates harboring the type 1 operon were highly proteolytic, while strains with other operon types, especially ones lacking prtA and prtB, exhibited significantly lower peptidase activities. In conclusion, the phylogenomic position and the aprX-lipA2 gene organization specify the proteolytic potential of Pseudomonas isolates. In addition, however, an interplay of several environmental factors and intrinsic traits influences production and activity of AprX, leading to strain-specific proteolytic phenotypes.
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Affiliation(s)
- Christopher Maier
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Christopher Huptas
- Lehrstuhl für Mikrobielle Ökologie, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Mario von Neubeck
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Siegfried Scherer
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
- Lehrstuhl für Mikrobielle Ökologie, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Mareike Wenning
- Bavarian Health and Food Safety Authority (LGL), Oberschleißheim, Germany
| | - Genia Lücking
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
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Spoilage potential of a heat-stable lipase produced by Serratia liquefaciens isolated from cold raw milk. Lebensm Wiss Technol 2020. [DOI: 10.1016/j.lwt.2020.109289] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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14
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Paludetti LF, Kelly AL, Gleeson D. Effect of thermoresistant protease of Pseudomonas fluorescens on rennet coagulation properties and proteolysis of milk. J Dairy Sci 2020; 103:4043-4055. [PMID: 32147268 DOI: 10.3168/jds.2019-17771] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 12/26/2019] [Indexed: 01/05/2023]
Abstract
This study aimed to investigate the effect of different activity levels of a thermoresistant protease, produced by Pseudomonas fluorescens (ATCC 17556), on the cheesemaking properties of milk and proteolysis levels. Sterilized reconstituted skim milk powder was inoculated with the bacteria, and after incubation, centrifuged to obtain a supernatant-containing protease. Raw milk was collected and inoculated to obtain a protease activity of 0.15, 0.60, and 1.5 U/L of milk (treatments P1, P4, and P10, respectively). One sample was not inoculated (control) and noninoculated supernatant was added to a fifth sample to be used as a negative control. Samples were stored at 4°C for 72 h. After 0, 48, and 72 h, the rennet coagulation properties and proteolysis levels were assessed. The protease produced was thermoresistant, as no significant differences were observed in the activity in the pasteurized (72°C for 15 s) and nonpasteurized supernatants. The chromatograms and electrophoretograms indicated that the protease preferably hydrolyzed κ-casein and β-casein, and levels of proteolysis increased with added protease activity over storage time. The hydrolysis of αS-caseins and major whey proteins increased considerably in P10 milk samples. At 0 h, the increase in the level of protease activity decreased the rennet coagulation time (RCT, min) of the samples, possibly due to synergistic proteolysis of κ-casein into para-κ-casein. However, over prolonged storage, hydrolysis of β-casein and αS-casein increased in P4 and P10 samples. The RCT of P4 samples increased over time and the coagulum became softer, whereas P10 samples did not coagulate after 48 h of storage. In contrast, the RCT of P1 samples decreased over time and a firmer coagulum was obtained, possibly due to a lower rate of hydrolysis of β-casein and αS-casein. Increased levels of protease could result in further hydrolysis of caseins, affecting the processability of milk over storage time.
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Affiliation(s)
- Lizandra F Paludetti
- Teagasc, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, County Cork P61 C996, Ireland; School of Food and Nutritional Sciences, University College Cork, County Cork T12 K8AF, Ireland
| | - Alan L Kelly
- School of Food and Nutritional Sciences, University College Cork, County Cork T12 K8AF, Ireland
| | - David Gleeson
- Teagasc, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, County Cork P61 C996, Ireland.
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Salwan R, Sharma V, Kasana RC, Gulati A. Bioprospecting Psychrotrophic Bacteria for Serine-Type Proteases from the Cold Areas of Western Himalayas. Curr Microbiol 2020; 77:795-806. [PMID: 31919673 DOI: 10.1007/s00284-020-01876-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 01/03/2020] [Indexed: 11/28/2022]
Abstract
The aim of present study was to analyze the prevalence of protease diversity among psychrotrophic bacteria in Lahaul and Spiti of the Western Himalayas. A total of 459 bacteria were screened and protease activity was observed in 150 isolates at 5 °C. Furthermore, 55 isolates showed protease activity up to pH 10 at 5 °C. Based on the hydrolytic zone, 22 isolates were selected for protease quantification. The protease activity varied from 58-377 U mL-1 at 10 °C, 49-396 U mL-1 at 28 °C and 31-407 U mL-1 at 37 °C. Similarly, protease activity ranged from 36-353 U mL-1 at pH 7, 40-306 U mL-1 at pH 9 and 33-304 U mL-1 at pH 10. The isolates were identified based on 16S rRNA gene sequencing and showed phylogenetic relationship to Arthrobacter belonging to the class Actinobacteria, Bacillus, Exiguobacterium, Paenibacillus, and Planomicrobium to Bacilli, and Pseudomonas, Serratia, and Stenotrophomonas to Gammaproteobacteria. Zymogram analysis revealed variations in protease isoforms ranging from 20 to 250 kDa which were strongly inhibited in the presence of phenylmethylsulfonyl fluoride, thus indicated serine-type nature. The extensive number of serine proteases among these bacteria was confirmed by annotating genomes of the reported genera for prevalence of protease isoforms. The properties of proteases including low-temperature activity with alkaline stability and detergent compatibility suggested their suitability as bio-additives in laundry.
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Affiliation(s)
- Richa Salwan
- Academy of Scientific and Innovative Research, New Delhi, India. .,CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, India. .,College of Horticulture and Forestry (Dr. YSP-University of Horticulture and Forestry), Neri, Hamirpur, Himachal Pradesh, 177 001, India.
| | - Vivek Sharma
- CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, India.,University Centre for Research and Development, Chandigarh University, Gharuan, Mohali (PB.), India
| | - Ramesh Chand Kasana
- Academy of Scientific and Innovative Research, New Delhi, India.,CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, India.,Central Arid Zone Research Institute, Jodhpur, 342 003, India
| | - Arvind Gulati
- Academy of Scientific and Innovative Research, New Delhi, India.,CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, India
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16
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Pseudomonas fluorescens: a potential food spoiler and challenges and advances in its detection. ANN MICROBIOL 2019. [DOI: 10.1007/s13213-019-01501-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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Lauer Cruz K, de Souza da Motta A. Characterization of biofilm production by Pseudomonas fluorescens isolated from refrigerated raw buffalo milk. Journal of Food Science and Technology 2019; 56:4595-4604. [PMID: 31686691 DOI: 10.1007/s13197-019-03924-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 06/28/2019] [Accepted: 07/03/2019] [Indexed: 12/13/2022]
Abstract
Pseudomonas fluorescens can often be isolated from refrigerated raw milk. Two strains of P. fluorescens PL5.4 and PL7.1, isolated from raw buffalo milk, were evaluated for their proteolytic capacity, exopolysaccharide production and biofilm production. Proteolytic activity was observed in both strains. The P. fluorescens PL5.4 strain presented fluorescence in the presence of calcofluor, indicating exopolysaccharide production. Both strains were able to produce biofilm at 7 °C for 72 h. For the biofilm production test on stainless steel, adherent cell counts of up to 7.1, 7.3 and 8.8 log CFU/cm2 at 7, 23 and 30 °C were obtained. Through scanning electron microscopy, it was possible to observe the biofilm produced by the P. fluorescens PL5.4 strain. Proper cleaning and disinfection practices in order are important to reduce bacterial contamination and extend the useful life of raw material and its derivatives.
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Affiliation(s)
- Karine Lauer Cruz
- Instituto de Ciências Básicas da Saúde, Microbiology Department, Immunology and Parasitology, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, Sala 216, Porto Alegre, 90050-170 Brazil
| | - Amanda de Souza da Motta
- Instituto de Ciências Básicas da Saúde, Microbiology Department, Immunology and Parasitology, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, Sala 216, Porto Alegre, 90050-170 Brazil
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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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Martins ML, Pinto UM, Riedel K, Vanetti MCD. Quorum Sensing and Spoilage Potential of Psychrotrophic Enterobacteriaceae Isolated from Milk. BIOMED RESEARCH INTERNATIONAL 2018; 2018:2723157. [PMID: 30426005 PMCID: PMC6217898 DOI: 10.1155/2018/2723157] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 09/25/2018] [Accepted: 10/02/2018] [Indexed: 12/03/2022]
Abstract
The 16S rDNA of six psychrotrophic Enterobacteriaceae isolated from cold raw milk were sequenced and the isolate 039 was identified as Pantoea sp., isolates 059, 068, and 071 were identified as Hafnia alvei, 067 was identified as Enterobacter sp., and 099 was identified as Aeromonas hydrophila. They presented different spoilage potentials in milk with A. hydrophila 099 being the most deteriorative. Only Pantoea sp. 039 was not able to induce the quorum sensing monitor strains of acyl homoserine lactones (AHLs). The halI gene, which encodes the AHL synthase in H. alvei, was identified in the isolates 059, 067, 068, and 071. After initial sequencing characterization and cloning, this gene showed its function by the heterologous synthesis of N-hexanoyl-DL-homoserine lactone and N-3-oxohexanoyl-L-homoserine lactone in Escherichia coli. In addition to producing AHLs, A. hydrophila 099 produced AI-2 in higher level than the assay's positive control Vibrio harveyi BB120. Therefore, Enterobacteriaceae strains isolated from cooled raw milk produce a rich array of signaling molecules that may influence bacterial traits in the milk environment.
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Affiliation(s)
- Maurilio Lopes Martins
- Department of Food Science and Technology, Federal Institute of Southeast of Minas Gerais, 36180-000 Rio Pomba, MG, Brazil
| | - Uelinton Manoel Pinto
- Food Research Center, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, 05508-000 São Paulo, SP, Brazil
| | - Katharina Riedel
- Institute of Microbiology, Ernst-Moritz-Arndt University of Greifswald, 17489, Germany
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Pinto Júnior WR, Joaquim LO, Pereira PR, Cristianini M, Del Aguila EM, Paschoalin VMF. Effect of high isostatic pressure on the peptidase activity and viability of Pseudomonas fragi isolated from a dairy processing plant. Int Dairy J 2017. [DOI: 10.1016/j.idairyj.2017.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Xin L, Zhang L, Meng Z, Di W, Han X, Yi H, Cui Y. Lipolytic psychrotrophic bacteria and lipase heat-resistant property in bovine raw milk of North China. J FOOD PROCESS PRES 2017. [DOI: 10.1111/jfpp.13289] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Liang Xin
- School of Chemistry and Chemical Engineering; Harbin Institute of Technology; Harbin 150090 China
| | - Lanwei Zhang
- School of Chemistry and Chemical Engineering; Harbin Institute of Technology; Harbin 150090 China
- College of Food Science and Engineering; Ocean University of China; Qingdao 266003 China
| | - Zhaoxu Meng
- School of Chemistry and Chemical Engineering; Harbin Institute of Technology; Harbin 150090 China
| | - Wei Di
- School of Chemistry and Chemical Engineering; Harbin Institute of Technology; Harbin 150090 China
| | - Xue Han
- School of Chemistry and Chemical 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
- School of Chemistry and Chemical 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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Baglinière F, Salgado RL, Salgado CA, Vanetti MCD. Biochemical Characterization of an Extracellular Heat-Stable Protease fromSerratia liquefaciensIsolated from Raw Milk. J Food Sci 2017; 82:952-959. [DOI: 10.1111/1750-3841.13660] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 01/04/2017] [Accepted: 01/23/2017] [Indexed: 11/27/2022]
Affiliation(s)
- François Baglinière
- Dept. of Microbiology; Federal Univ. of Viçosa; Viçosa MG 36.570-900 Brazil
- CAPES Foundation; Ministry of Education of Brazil; Brasília DF 70.040-020 Brazil
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Stuknytė M, Decimo M, Colzani M, Silvetti T, Brasca M, Cattaneo S, Aldini G, De Noni I. Extracellular thermostable proteolytic activity of the milk spoilage bacterium Pseudomonas fluorescens PS19 on bovine caseins. J Dairy Sci 2016; 99:4188-4195. [DOI: 10.3168/jds.2016-10894] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 02/09/2016] [Indexed: 11/19/2022]
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25
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Quorum sensing regulated phenotypes in Aeromonas hydrophila ATCC 7966 deficient in AHL production. ANN MICROBIOL 2016. [DOI: 10.1007/s13213-016-1196-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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