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Horstmann G, Schäfer J, Rosenberger M, Seitl I, Hinrichs J, Fischer L. The behavior of cathepsin D during milk processing and its contribution to bitterness in a model fresh cheese. J Dairy Sci 2023:S0022-0302(23)00300-4. [PMID: 37268572 DOI: 10.3168/jds.2022-22914] [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: 10/16/2022] [Accepted: 01/29/2023] [Indexed: 06/04/2023]
Abstract
The bovine endopeptidase cathepsin D was investigated regarding its temperature-dependent inactivation and ability to form bitter peptides within a spiked model fresh cheese. Cathepsin D was found to be more susceptible than other milk endogenous peptidases to temperature treatments in skim milk. Inactivation kinetics revealed decimal reduction times of 5.6 min to 10 s in a temperature range from 60 to 80°C. High temperature and ultra-high temperature (UHT) treatments from 90 to 140°C completely inactivated cathepsin D within 5 s. A residual cathepsin D activity of around 20% was detected under pasteurization conditions (72°C for 20 s). Therefore, investigations were done to estimate the effect of residual cathepsin D activity on taste in a model fresh cheese. The UHT-treated skim milk was spiked with cathepsin D and acidified with glucono-δ-lactone to produce a model fresh cheese. A trained bitter-sensitive panel was not able to distinguish cathepsin D-spiked model fresh cheeses from the control model fresh cheeses in a triangle test. Model fresh cheese samples were also analyzed for known bitter peptides derived from casein fractions using a HPLC-tandem mass spectrometry (MS) approach. In accordance with the sensory evaluation, the MS analyses revealed that the bitter peptides investigated within the cathepsin D-spiked model fresh cheese were not found or were below the limit of detection. Even though cathepsin D may be present during the fermentation of pasteurized milk, it does not seem to be responsible for bitter peptide formation from milk proteins on its own.
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Affiliation(s)
- Gudrun Horstmann
- Department of Biotechnology and Enzyme Science, University of Hohenheim, Institute of Food Science and Biotechnology, Garbenstrasse 25, 70599 Stuttgart, Germany
| | - Johannes Schäfer
- Department of Soft Matter Science and Dairy Technology, University of Hohenheim, Institute of Food Science and Biotechnology, Garbenstrasse 21, 70599 Stuttgart, Germany
| | - Melanie Rosenberger
- Department of Soft Matter Science and Dairy Technology, University of Hohenheim, Institute of Food Science and Biotechnology, Garbenstrasse 21, 70599 Stuttgart, Germany
| | - Ines Seitl
- Department of Biotechnology and Enzyme Science, University of Hohenheim, Institute of Food Science and Biotechnology, Garbenstrasse 25, 70599 Stuttgart, Germany
| | - Jörg Hinrichs
- Department of Soft Matter Science and Dairy Technology, University of Hohenheim, Institute of Food Science and Biotechnology, Garbenstrasse 21, 70599 Stuttgart, Germany
| | - Lutz Fischer
- Department of Biotechnology and Enzyme Science, University of Hohenheim, Institute of Food Science and Biotechnology, Garbenstrasse 25, 70599 Stuttgart, Germany.
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2
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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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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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4
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Du B, Meng L, Liu H, Zheng N, Zhang Y, Zhao S, Li M, Wang J. Diversity and proteolytic activity of Pseudomonas species isolated from raw cow milk samples across China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156382. [PMID: 35660435 DOI: 10.1016/j.scitotenv.2022.156382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 05/27/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Pseudomonas spp. are common microorganisms from cold-storage raw milk, and protease secreted by Pseudomonas spp. can cause the deterioration of stored milk. However, analyses of Pseudomonas spp. diversity and proteolytic activity in raw milk from different regions of China have not been extensively examined. With this aim, the diversity and proteolytic activity of Pseudomonas isolated from 25 raw cow milk samples from Inner Mongolia, Heilongjiang, Gansu, Henan, Anhui, Jiangsu, Chongqing and Hunan of China in different seasons were evaluated by PCR targeting 16S rDNA and rpoD, as well as TNBS method, respectively. A total of 116 Pseudomonas isolates from 25 raw cow milk samples were identified at the species level, including P. fluorescens, P. veronii, P. psychrophila, P. lundensis, P. lactis, P. azotoformans, P. granadensis, P. lurida, P. rhizosphaerae, P. rhodesiae and P. extremorientalis. P. fluorescens accounted for 75.8% of the total. Of all 116 Pseudomonas isolates, 68.9% of them displayed proteolytic activity at 4 °C, 81.9% at 10 °C and 85.3% at 25 °C, respectively. The aprX gene encoded a secreted and heat-resistant metalloprotease that was present in 60.3% of the Pseudomonas isolates tested. The proteases showed residual activity ranged from 73 ± 4% to 84 ± 7% residual activity after the heat treatment at 72 °C for 15 s and 62 ± 3% to 74 ± 2% after the heat treatment at 132 °C for 4 s. This is the first report to compare Pseudomonas spp. diversity and proteolytic activity at species levels in raw milk from different regions of China. The results of this study provide valuable data about the diversity and spoilage potential of Pseudomonas species in raw milk and the thermal resistance of the proteases. Therefore, these findings provide a reference for the importance to prevent Pseudomonas spp. contamination of raw cow milk to ensure the quality and safety of milk and dairy products.
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Affiliation(s)
- Bingyao Du
- Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China; Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Lu Meng
- Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huimin Liu
- Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Nan Zheng
- Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yangdong Zhang
- Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Shengguo Zhao
- Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Ming Li
- Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jiaqi Wang
- Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
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Bacterial Composition and Interactions in Raw Milk and Teat Skin of Dairy Cows. FERMENTATION 2022. [DOI: 10.3390/fermentation8050235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The microbiota in raw milk plays an important role in the health of dairy cows and the safety of dairy products, which might be influenced by that in teat skin. However, the microbiota composition in raw milk and teat skin, as well as the bacterial interaction between the two adjacent spatial locations, remains elusive. Here, we investigated the composition, diversity, and co-occurrence network of the bacterial communities in raw milk and on teat skin, as well as the shift of bacterial communities during the teat bath using 469 samples from 156 individual cows. We observed that raw milk and teat skin harbored significantly different bacterial communities according to an assessment of the genera numbers (p < 0.05) and PCoA analysis (ANOSIM p < 0.05). The microbiota in raw milk was dominated by Proteobacteria (58.5% in relative abundance) at the phylum level and by Pseudomonas (51.2%) at the genus level, while that in teat skin was dominated by Firmicutes (46.9%) at the phylum level and by Pseudomonas (11.0%) at the genus level. We observed a massive difference between the bacterial subnetworks in raw milk and teat, and the bacterial abundance in these two adjacent spatial locations was positively correlated (p < 0.05). Using Bayesian algorithms, we identified that 92.1% of bacteria in raw milk were transferred from teat skin, while 63.6% of bacteria on teat skin were transferred from raw milk. Moreover, microbiota composition in teat skin could be affected by the teat bath with iodine disinfectant, which tended to be more similar to that in raw milk after the teat bath (p < 0.05), while the abundance of the dominant genus Pseudomonas significantly increased (p < 0.05). These findings expand our knowledge on the microbiota composition in teat skin and raw milk, as well as the interaction between these two adjacent spatial locations.
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Sguazzi G, Mickleburgh HL, Ghignone S, Voyron S, Renò F, Migliario M, Sellitto F, Lovisolo F, Camurani G, Ogbanga N, Gino S, Procopio N. Microbial DNA in human nucleic acid extracts: Recoverability of the microbiome in DNA extracts stored frozen long-term and its potential and ethical implications for forensic investigation. Forensic Sci Int Genet 2022; 59:102686. [PMID: 35338895 DOI: 10.1016/j.fsigen.2022.102686] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 11/28/2022]
Abstract
Human DNA samples can remain unaltered for years and preserve important genetic information for forensic investigations. In fact, besides human genetic information, these extracts potentially contain additional valuable information: microbiome signatures. Forensic microbiology is rapidly becoming a significant tool for estimating post-mortem interval (PMI), and establishing cause of death and personal identity. To date, the possibility to recover unaltered microbiome signatures from human DNA extracts has not been proven. This study examines the microbiome signatures within human DNA extracts obtained from six cadavers with different PMIs, which were stored frozen for 5-16 years. Results demonstrated that the microbiome can be co-extracted with human DNA using forensic kits designed to extract the human host's DNA from different tissues and fluids during decomposition. We compared the microbial communities identified in these samples with microbial DNA recovered from two human cadavers donated to the Forensic Anthropology Center at Texas State University (FACTS) during multiple decomposition stages, to examine whether the microbial signatures recovered from "old" (up to 16 years) extracts are consistent with those identified in recently extracted microbial DNA samples. The V4 region of 16 S rRNA gene was amplified and sequenced using Illumina MiSeq for all DNA extracts. The results obtained from the human DNA extracts were compared with each other and with the microbial DNA from the FACTS samples. Overall, we found that the presence of specific microbial taxa depends on the decomposition stage, the type of tissue, and the depositional environment. We found no indications of contamination in the microbial signatures, or any alterations attributable to the long-term frozen storage of the extracts, demonstrating that older human DNA extracts are a reliable source of such microbial signatures. No shared Core Microbiome (CM) was identified amongst the total 18 samples, but we identified certain species in association with the different decomposition stages, offering potential for the use of microbial signatures co-extracted with human DNA samples for PMI estimation in future. Unveiling the new significance of older human DNA extracts brings with it important ethical-legal considerations. Currently, there are no shared legal frameworks governing the long-term storage and use of human DNA extracts obtained from crime scene evidence for additional research purposes. It is therefore important to create common protocols on the storage of biological material collected at crime scenes. We review existing legislation and guidelines, and identify some important limitations for the further development and application of forensic microbiomics.
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Affiliation(s)
- Giulia Sguazzi
- Department of Health Science, University of Piemonte Orientale, via Solaroli 17, 28100 Novara, Italy; CRIMEDIM - Center for Research and Training in Disaster Medicine, Humanitarian Aid and Global Health, Università del Piemonte Orientale, Via Lanino, 1-28100 Novara, Italy
| | - Hayley L Mickleburgh
- Department of Cultural Sciences, Linnaeus University, Växjö, Sweden; Forensic Anthropology Center, Texas State University, San Marcos, TX, USA
| | - Stefano Ghignone
- Institute for Sustainable Plant Protection (IPSP) - Turin Unit - National Research Council (CNR), 1-10125 Turin, Italy
| | - Samuele Voyron
- Institute for Sustainable Plant Protection (IPSP) - Turin Unit - National Research Council (CNR), 1-10125 Turin, Italy; Department of Life Sciences and Systems Biology, University of Torino, V.le P.A. Mattioli 25, 10125 Turin, Italy
| | - Filippo Renò
- Department of Health Science, University of Piemonte Orientale, via Solaroli 17, 28100 Novara, Italy
| | - Mario Migliario
- Department of Translational Medicine, University of Piemonte Orientale, via Solaroli 17, 28100 Novara, Italy
| | - Federica Sellitto
- Forensic Science Research Group, Faculty of Health and Life Sciences, Applied Sciences, Northumbria University, NE1 8ST, Newcastle Upon Tyne, UK
| | - Flavia Lovisolo
- Department of Health Science, University of Piemonte Orientale, via Solaroli 17, 28100 Novara, Italy
| | - Giulia Camurani
- Department of Health Science, University of Piemonte Orientale, via Solaroli 17, 28100 Novara, Italy
| | - Nengi Ogbanga
- Forensic Science Research Group, Faculty of Health and Life Sciences, Applied Sciences, Northumbria University, NE1 8ST, Newcastle Upon Tyne, UK
| | - Sarah Gino
- Department of Health Science, University of Piemonte Orientale, via Solaroli 17, 28100 Novara, Italy
| | - Noemi Procopio
- Forensic Anthropology Center, Texas State University, San Marcos, TX, USA; Forensic Science Research Group, Faculty of Health and Life Sciences, Applied Sciences, Northumbria University, NE1 8ST, Newcastle Upon Tyne, UK.
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7
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Wang Y, Sun J, Deng Y, Tu Y, Niu H, Cai W, Han X. Whey protein influences the production and activity of extracellular protease from Pseudomonas fluorescens W3. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2021.112865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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8
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Eisner MD. Direct and indirect heating of milk – A technological perspective beyond time–temperature profiles. Int Dairy J 2021. [DOI: 10.1016/j.idairyj.2021.105145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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9
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Treinen C, Magosch O, Hoffmann M, Klausmann P, Würtz B, Pfannstiel J, Morabbi Heravi K, Lilge L, Hausmann R, Henkel M. Modeling the time course of ComX: towards molecular process control for Bacillus wild-type cultivations. AMB Express 2021; 11:144. [PMID: 34714452 PMCID: PMC8556439 DOI: 10.1186/s13568-021-01306-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/19/2021] [Indexed: 11/30/2022] Open
Abstract
Wild-type cultivations are of invaluable relevance for industrial biotechnology when it comes to the agricultural or food sector. Here, genetic engineering is hardly applicable due to legal barriers and consumer’s demand for GMO-free products. An important pillar for wild-type cultivations displays the genus Bacillus. One of the challenges for Bacillus cultivations is the global ComX-dependent quorum sensing system. Here, molecular process control can serve as a tool to optimize the production process without genetic engineering. To realize this approach, quantitative knowledge of the mechanism is essential, which, however, is often available only to a limited extent. The presented work provides a case study based on the production of cyclic lipopeptide surfactin, whose expression is in dependence of ComX, using natural producer B. subtilis DSM 10 T. First, a surfactin reference process with 40 g/L of glucose was performed as batch fermentation in a pilot scale bioreactor system to gain novel insights into kinetic behavior of ComX in relation to surfactin production. Interestingly, the specific surfactin productivity did not increase linearly with ComX activity. The data were then used to derive a mathematic model for the time course of ComX in dependence of existing biomass, biomass growth as well as a putative ComX-specific protease. The newly adapted model was validated and transferred to other batch fermentations, employing 20 and 60 g/L glucose. The applied approach can serve as a model system for molecular process control strategies, which can thus be extended to other quorum sensing dependent wild-type cultivations.
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Scudino H, Guimarães JT, Cabral L, Centurion VB, Gomes A, Orsi AS, Cunha RL, Sant’Ana AS, Cruz AG. Raw milk processing by high‐intensity ultrasound and conventional heat treatments: Microbial profile by amplicon sequencing and physical stability during storage. INT J DAIRY TECHNOL 2021. [DOI: 10.1111/1471-0307.12819] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Hugo Scudino
- Department of Food Technology Faculty of Veterinary Fluminense Federal University Niterói RJ Brazil
| | - Jonas T Guimarães
- Department of Food Technology Faculty of Veterinary Fluminense Federal University Niterói RJ Brazil
| | - Lucélia Cabral
- Department of General and Applied Biology Institute of Biosciences São Paulo State University (UNESP) Rio Claro SP Brazil
| | - Victor Borin Centurion
- Microbial Resources Division (DRM), Research Center for Chemistry Biology and Agriculture (CPQBA) University of Campinas Campinas SP Brazil
| | - Andresa Gomes
- Department of Food Engineering and Technology Faculty of Food Engineering University of Campinas Campinas SP Brazil
| | - Arthur S Orsi
- Department of Food Technology Faculty of Veterinary Fluminense Federal University Niterói RJ Brazil
- Department of Food Science and Nutrition Faculty of Food Engineering University of Campinas Campinas SP Brazil
| | - Rosiane L Cunha
- Department of Food Engineering and Technology Faculty of Food Engineering University of Campinas Campinas SP Brazil
| | - Anderson S Sant’Ana
- Department of Food Science and Nutrition Faculty of Food Engineering University of Campinas Campinas SP Brazil
| | - Adriano G Cruz
- Department of Food Federal Institute of Science and Technology of Rio de Janeiro Rio de Janeiro RJ Brazil
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11
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Lilge L, Vahidinasab M, Adiek I, Becker P, Kuppusamy Nesamani C, Treinen C, Hoffmann M, Morabbi Heravi K, Henkel M, Hausmann R. Expression of degQ gene and its effect on lipopeptide production as well as formation of secretory proteases in Bacillus subtilis strains. Microbiologyopen 2021; 10:e1241. [PMID: 34713601 PMCID: PMC8515880 DOI: 10.1002/mbo3.1241] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 09/16/2021] [Accepted: 09/16/2021] [Indexed: 11/12/2022] Open
Abstract
Bacillus subtilis is described as a promising production strain for lipopeptides. In the case of B. subtilis strains JABs24 and DSM10T , surfactin and plipastatin are produced. Lipopeptide formation is controlled, among others, by the DegU response regulator. The activating phospho-transfer by the DegS sensor kinase is stimulated by the pleiotropic regulator DegQ, resulting in enhanced DegU activation. In B. subtilis 168, a point mutation in the degQ promoter region leads to a reduction in gene expression. Corresponding reporter strains showed a 14-fold reduced expression. This effect on degQ expression and the associated impact on lipopeptide formation was examined for B. subtilis JABs24, a lipopeptide-producing derivative of strain 168, and B. subtilis wild-type strain DSM10T , which has a native degQ expression. Based on the stimulatory effects of the DegU regulator on secretory protease formation, the impact of degQ expression on extracellular protease activity was additionally investigated. To follow the impact of degQ, a deletion mutant was constructed for DSM10T , while a natively expressed degQ version was integrated into strain JABs24. This allowed strain-specific quantification of the stimulatory effect of degQ expression on plipastatin and the negative effect on surfactin production in strains JABs24 and DSM10T . While an unaffected degQ expression reduced surfactin production in JABs24 by about 25%, a sixfold increase in plipastatin was observed. In contrast, degQ deletion in DSM10T increased surfactin titer by threefold but decreased plipastatin production by fivefold. In addition, although significant differences in extracellular protease activity were detected, no decrease in plipastatin and surfactin produced during cultivation was observed.
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Affiliation(s)
- Lars Lilge
- Department of Bioprocess Engineering (150k)Institute of Food Science and Biotechnology (150)University of HohenheimStuttgartGermany
| | - Maliheh Vahidinasab
- Department of Bioprocess Engineering (150k)Institute of Food Science and Biotechnology (150)University of HohenheimStuttgartGermany
| | - Isabel Adiek
- Department of Bioprocess Engineering (150k)Institute of Food Science and Biotechnology (150)University of HohenheimStuttgartGermany
| | - Philipp Becker
- Department of Bioprocess Engineering (150k)Institute of Food Science and Biotechnology (150)University of HohenheimStuttgartGermany
| | - Chanthiya Kuppusamy Nesamani
- Department of Bioprocess Engineering (150k)Institute of Food Science and Biotechnology (150)University of HohenheimStuttgartGermany
| | - Chantal Treinen
- Department of Bioprocess Engineering (150k)Institute of Food Science and Biotechnology (150)University of HohenheimStuttgartGermany
| | - Mareen Hoffmann
- Department of Bioprocess Engineering (150k)Institute of Food Science and Biotechnology (150)University of HohenheimStuttgartGermany
| | - Kambiz Morabbi Heravi
- Department of Bioprocess Engineering (150k)Institute of Food Science and Biotechnology (150)University of HohenheimStuttgartGermany
| | - Marius Henkel
- Department of Bioprocess Engineering (150k)Institute of Food Science and Biotechnology (150)University of HohenheimStuttgartGermany
| | - Rudolf Hausmann
- Department of Bioprocess Engineering (150k)Institute of Food Science and Biotechnology (150)University of HohenheimStuttgartGermany
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12
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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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13
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Volk V, Graw N, Stressler T, Fischer L. An indirect ELISA system for the detection of heat-stable Pseudomonas endopeptidases (AprX) in milk. J Dairy Sci 2021; 104:5185-5196. [PMID: 33663848 DOI: 10.3168/jds.2020-19790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/30/2020] [Indexed: 11/19/2022]
Abstract
Heat-stable endopeptidases in raw milk, especially the alkaline metallopeptidase AprX secreted by Pseudomonas spp., are a well-known challenge for the dairy industry. They can withstand UHT treatment and may cause quality defects over the shelf life of milk products. Therefore, we established an indirect ELISA for the detection of Pseudomonas AprX in milk. We developed a 2-step sample treatment for milk contaminated with AprX to avoid the interference of milk proteins with the detection system. First, casein micelles were destabilized by the detraction of Ca2+ using trisodium citrate; then, AprX was concentrated 10-fold using hydrophobic interaction chromatography. The recovery of AprX in spiked milk samples after the 2-step treatment was 43 ± 0.1%. Specific antibodies for purified AprX from Pseudomonas lactis were produced to establish the ELISA. Western blot experiments showed that the binding affinity of these antibodies depended on the sequence homology of the AprX from P. lactis and several other Pseudomonas spp. The indirect ELISA, which was completed in 6 to 7 h, had a limit of detection of 21.0 ng mL-1 and a limit of quantification of 25.7 ng mL-1. Milk proteins or milk endogenous peptidases were not detected by the antibodies. The ELISA had high precision, with a CV between 0.2 and 0.8% measured on the same day (intraday) and 5.6 and 6.8% measured on 5 separate days (interday). Milk samples were spiked with different AprX activity levels [7.5-150 nkat Na-caseinate/o-phthalaldehyde (OPA) mL-1] and evaluated by ELISA. The recovery of the ELISA was 92.3 ± 1.6 to 105 ± 4.7%. The lowest AprX activity quantifiable in the spiked milk samples was 500 pkat Na-caseinate/OPA mL-1. The proof of concept to detect heat-stable Pseudomonas AprX in milk by ELISA was established.
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Affiliation(s)
- Veronika Volk
- Department of Biotechnology and Enzyme Science, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 25, 70599 Stuttgart, Germany
| | - Nicole Graw
- Department of Biotechnology and Enzyme Science, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 25, 70599 Stuttgart, Germany
| | - Timo Stressler
- Department of Biotechnology and Enzyme Science, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 25, 70599 Stuttgart, Germany
| | - Lutz Fischer
- Department of Biotechnology and Enzyme Science, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 25, 70599 Stuttgart, Germany.
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14
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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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15
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Fritz B, Schäfer K, März M, Wahl S, Ziemssen F, Egert M. Eye-Catching Microbes-Polyphasic Analysis of the Microbiota on Microscope Oculars Verifies Their Role as Fomites. J Clin Med 2020; 9:jcm9051572. [PMID: 32455878 PMCID: PMC7290821 DOI: 10.3390/jcm9051572] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 11/16/2022] Open
Abstract
Microscopes are used in virtually every biological and medical laboratory. Previous cultivation-based studies have suggested that direct contact with microscope eyepieces increases the risk of eye infections. To obtain a deeper insight into the microbiota on oculars, we analysed 10 recently used university microscopes. Their left oculars were used for a cultivation-based approach, while the right oculars served for massive gene sequencing. After cleaning with isopropyl alcohol, the oculars were re-sampled and analysed again. All oculars were found to be contaminated with bacteria, with a maximum load of 1.7 × 103 CFU cm-2. MALDI Biotyping revealed mainly Cutibacterium (68%), Staphylococcus (14%) and Brevibacterium (10%), with the most abundant species being Cutibacterium acnes (13%) and Staphylococcus capitis (6%). Cleaning reduced the microbial load by up to 2 log scales. Within 10 uncleaned and 5 cleaned samples, 1480 ASVs were assigned to 10 phyla and 262 genera. The dominant genera before cleaning were Cutibacterium (78%), Paracoccus (13%), Pseudomonas (2%) and Acinetobacter (1%). The bacteriota composition on the cleaned oculars was similar; however, it probably largely represented dead bacteria. In summary, used oculars were significantly contaminated with skin and environmental bacteria, including potential pathogens. Regular cleaning is highly recommended to prevent eye and skin infections.
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Affiliation(s)
- Birgit Fritz
- Faculty of Medical and Life Sciences, Institute of Precision Medicine, Microbiology and Hygiene Group, Furtwangen University, Jakob-Kienzle-Strasse 17, 78054 Villingen-Schwenningen, Germany; (B.F.); (K.S.); (M.M.)
| | - Karin Schäfer
- Faculty of Medical and Life Sciences, Institute of Precision Medicine, Microbiology and Hygiene Group, Furtwangen University, Jakob-Kienzle-Strasse 17, 78054 Villingen-Schwenningen, Germany; (B.F.); (K.S.); (M.M.)
| | - Melanie März
- Faculty of Medical and Life Sciences, Institute of Precision Medicine, Microbiology and Hygiene Group, Furtwangen University, Jakob-Kienzle-Strasse 17, 78054 Villingen-Schwenningen, Germany; (B.F.); (K.S.); (M.M.)
| | - Siegfried Wahl
- Carl Zeiss Vision International GmbH, Turnstrasse 27, 73430 Aalen, Germany;
- Institute for Ophthalmic Research, Eberhard-Karls University, Elfriede-Aulhorn-Strasse 7, 72076 Tuebingen, Germany
| | - Focke Ziemssen
- Center for Ophthalmology, Eberhard-Karls University, Elfriede-Aulhorn-Strasse 7, 72076 Tuebingen, Germany;
| | - Markus Egert
- Faculty of Medical and Life Sciences, Institute of Precision Medicine, Microbiology and Hygiene Group, Furtwangen University, Jakob-Kienzle-Strasse 17, 78054 Villingen-Schwenningen, Germany; (B.F.); (K.S.); (M.M.)
- Correspondence: ; Tel.: +49-7720-307-4554
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16
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Yuan L, Sadiq FA, Burmølle M, Wang NI, He G. Insights into Psychrotrophic Bacteria in Raw Milk: A Review. J Food Prot 2019; 82:1148-1159. [PMID: 31225978 DOI: 10.4315/0362-028x.jfp-19-032] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
HIGHLIGHTS Levels of psychrotrophic bacteria in raw milk are affected by to habitats and farm hygiene. Biofilms formed by psychrotrophic bacteria are persistent sources of contamination. Heat-stable enzymes produced by psychrotrophic bacteria compromise product quality. Various strategies are available for controlling dairy spoilage caused by psychrotrophic bacteria.
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Affiliation(s)
- Lei Yuan
- 1 College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, People's Republic of China.,2 Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen 2100, Denmark
| | - Faizan A Sadiq
- 3 School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Mette Burmølle
- 2 Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen 2100, Denmark
| | - N I Wang
- 1 College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Guoqing He
- 1 College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, People's Republic of China
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17
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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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18
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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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19
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Anema SG. Age Gelation, Sedimentation, and Creaming in UHT Milk: A Review. Compr Rev Food Sci Food Saf 2018; 18:140-166. [PMID: 33337027 DOI: 10.1111/1541-4337.12407] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 10/11/2018] [Accepted: 10/14/2018] [Indexed: 11/30/2022]
Abstract
Demand for ultra-high-temperature (UHT) milk and milk protein-based beverages is growing. UHT milk is microbiologically stable. However, on storage, a number of chemical and physical changes occur and these can reduce the quality of the milk. These changes can be sufficiently undesirable so as to limit acceptance or shelf life of the milk. The most severe changes in UHT milk during storage are age gelation, with an irreversible three-dimensional protein network forming throughout, excessive sedimentation with a compact layer of protein-enriched material forming rapidly at the bottom of the pack, and creaming with excessive fat accumulating at the top. For age gelation, it is known that at least two mechanisms can lead to gelation during storage. One mechanism involves proteolytic degradation of the proteins through heat-stable indigenous or exogenous enzymes, destabilizing milk and ultimately forming a gel. The other mechanism is referred to as a physico-chemical mechanism. Several factors are known to affect the physico-chemical age gelation, such as milk/protein concentration, heat load during processing (direct compared with indirect UHT processes), and milk composition. Similar factors to age gelation are known to affect sedimentation. There are relatively few studies on the creaming of UHT milk during storage, suggesting that this defect is less common or less detrimental compared with gelation and sedimentation. This review focuses on the current state of knowledge of age gelation, sedimentation, and creaming of UHT milks during storage, providing a critical evaluation of the available literature and, based on this, mechanisms for age gelation and sedimentation are proposed.
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Affiliation(s)
- Skelte G Anema
- Fonterra Research and Development Centre, Private Bag 11029, Dairy Farm Road, Palmerston North, 4442, New Zealand.,Riddet Inst., Massey Univ., Private Bag 11222, Palmerston North, 4442, New Zealand
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20
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Yuan L, Sadiq FA, Liu TJ, Li Y, Gu JS, Yang HY, He GQ. Spoilage potential of psychrotrophic bacteria isolated from raw milk and the thermo-stability of their enzymes. J Zhejiang Univ Sci B 2018; 19:630-642. [PMID: 30070086 DOI: 10.1631/jzus.b1700352] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The storage and transportation of raw milk at low temperatures promote the growth of psychrotrophic bacteria and the production of thermo-stable enzymes, which pose great threats to the quality and shelf-life of dairy products. Though many studies have been carried out on the spoilage potential of psychrotrophic bacteria and the thermo-stabilities of the enzymes they produce, further detailed studies are needed to devise an effective strategy to avoid dairy spoilage. The purpose of this study was to explore the spoilage potential of psychrotrophic bacteria from Chinese raw milk samples at both room temperature (28 °C) and refrigerated temperature (7 °C). Species of Yersinia, Pseudomonas, Serratia, and Chryseobacterium showed high proteolytic activity. The highest proteolytic activity was shown by Yersinia intermedia followed by Pseudomonas fluorescens (d). Lipolytic activity was high in isolates of Acinetobacter, and the highest in Acinetobacter guillouiae. Certain isolates showed positive β-galactosidase and phospholipase activity. Strains belonging to the same species sometimes showed markedly different phenotypic characteristics. Proteases and lipases produced by psychrotrophic bacteria retained activity after heat treatment at 70, 80, or 90 °C, and proteases appeared to be more heat-stable than lipases. For these reasons, thermo-stable spoilage enzymes produced by a high number of psychrotrophic bacterial isolates from raw milk are of major concern to the dairy industry. The results of this study provide valuable data about the spoilage potential of bacterial strains in raw milk and the thermal resistance of the enzymes they produce.
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Affiliation(s)
- Lei Yuan
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Faizan A Sadiq
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Tong-Jie Liu
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Yang Li
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Jing-Si Gu
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Huan-Yi Yang
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Guo-Qing He
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
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21
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Yuan L, Sadiq FA, Burmølle M, Liu T, He G. Insights into Bacterial Milk Spoilage with Particular Emphasis on the Roles of Heat-Stable Enzymes, Biofilms, and Quorum Sensing. J Food Prot 2018; 81:1651-1660. [PMID: 30207500 DOI: 10.4315/0362-028x.jfp-18-094] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Milk spoilage caused by psychrotrophic bacteria and their heat-stable enzymes is a serious challenge for the dairy industry. In many studies, spoilage has been explored based on the simplistic view of undesirable enzymes produced by planktonic cells. Recently, biofilms and quorum sensing (QS) have been suggested as important factors in the deterioration of milk, which opens new avenues for investigation of the processes and challenges. Production and heat stability of enzymes are enhanced in biofilms, mainly because of inherent differences in physiological states and protective shielding by extracellular polymeric substances. QS plays a key role in modulating expression of hydrolytic enzymes and biofilm formation. To date, few studies have been conducted to investigate the complex interplays of enzyme production, biofilm formation, and QS. This review provides novel insights into milk spoilage with particular emphasis on the roles of biofilms and QS and summarizes potential effective strategies for controlling the spoilage of milk.
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Affiliation(s)
- Lei Yuan
- 1 College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, People's Republic of China; and
| | - Faizan A Sadiq
- 1 College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, People's Republic of China; and
| | - Mette Burmølle
- 2 Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen 2100, Denmark
| | - Tongjie Liu
- 1 College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, People's Republic of China; and
| | - Guoqing He
- 1 College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, People's Republic of China; and
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22
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Meng L, Liu H, Dong L, Zheng N, Xing M, Zhang Y, Zhao S, Wang J. Identification and proteolytic activity quantification of Pseudomonas spp. isolated from different raw milks at storage temperatures. J Dairy Sci 2018; 101:2897-2905. [DOI: 10.3168/jds.2017-13617] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/16/2017] [Indexed: 12/16/2022]
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23
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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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24
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Heat stability of indigenous milk plasmin and proteases from Pseudomonas: A challenge in the production of ultra-high temperature milk products. Int Dairy J 2016. [DOI: 10.1016/j.idairyj.2016.06.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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25
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Stoeckel M, Lidolt M, Achberger V, Glück C, Krewinkel M, Stressler T, von Neubeck M, Wenning M, Scherer S, Fischer L, Hinrichs J. Growth of Pseudomonas weihenstephanensis, Pseudomonas proteolytica and Pseudomonas sp. in raw milk: Impact of residual heat-stable enzyme activity on stability of UHT milk during shelf-life. Int Dairy J 2016. [DOI: 10.1016/j.idairyj.2016.02.045] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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26
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Glück C, Rentschler E, Krewinkel M, Merz M, von Neubeck M, Wenning M, Scherer S, Stoeckel M, Hinrichs J, Stressler T, Fischer L. Thermostability of peptidases secreted by microorganisms associated with raw milk. Int Dairy J 2016. [DOI: 10.1016/j.idairyj.2016.01.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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27
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Stressler T, Ewert J, Eisele T, Fischer L. Cross-linked enzyme aggregates (CLEAs) of PepX and PepN – production, partial characterization and application of combi-CLEAs for milk protein hydrolysis. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2015. [DOI: 10.1016/j.bcab.2015.11.002] [Citation(s) in RCA: 15] [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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28
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A Sensitive and Robust Method for Direct Determination of Lipolytic Activity in Natural Milk Environment. FOOD ANAL METHOD 2015. [DOI: 10.1007/s12161-015-0233-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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