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Hongchao D, Ma L, Xu Z, Soteyome T, Yuan L, Yang Z, Jiao XA. Invited review: Role of Bacillus licheniformis in the dairy industry- friends or foes? J Dairy Sci 2024:S0022-0302(24)00904-4. [PMID: 38851582 DOI: 10.3168/jds.2024-24826] [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: 02/25/2024] [Accepted: 05/07/2024] [Indexed: 06/10/2024]
Abstract
Bacillus licheniformis is one of the major spore-forming bacteria with great genotypic diversity in raw milk, dairy ingredients, final dairy products, and is found throughout the dairy processing continuum. Though being widely used as a probiotic strain, this species also serves as a potential risk in the dairy industry based on its roles in foodborne illness and dairy spoilage. Biofilm formation of B. licheniformis in combined with the heat resistance of its spores, make it impossible to prevent the presence of B. licheniformis in final dairy products by traditional cleaning and disinfection procedures. Despite the extensive efforts on the identification of B. licheniformis from various dairy samples, no reviews have been reported on both hazard and benefits of this spore-former. This review discusses the prevalence of B. licheniformis from raw milk to commercial dairy products, biofilm formation and spoilage potential of B. licheniformis, and its potential prevention methods. In addition, the potential benefits of B. licheniformis in the dairy industry were also summarized.
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Affiliation(s)
- Dai Hongchao
- School of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu, 225127 China; Jiangsu Key Laboratory of Zoonoses, Yangzhou, Jiangsu, 225009 China
| | - Lili Ma
- School of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu, 225127 China
| | - Zhenbo Xu
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Engineering Research Center of Starch and Vegetable Protein Processing Ministry of Education, South China University of Technology, Guangzhou 510640, China; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Home Economics Technology, Rajamangala University of Technology Phra Nakhon, Bangkok, Thailand
| | - Thanapop Soteyome
- Home Economics Technology, Rajamangala University of Technology Phra Nakhon, Bangkok, Thailand
| | - Lei Yuan
- School of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu, 225127 China; Jiangsu Key Laboratory of Zoonoses, Yangzhou, Jiangsu, 225009 China.
| | - Zhenquan Yang
- School of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu, 225127 China
| | - Xin-An Jiao
- Jiangsu Key Laboratory of Zoonoses, Yangzhou, Jiangsu, 225009 China
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Chincha AAIA, Marone MP, Pia AKR, Freire L, Amorim-Neto DP, Carazzolle MF, Sant'Ana AS. Phenotypic, genotypic, and resistome of mesophilic spore-forming bacteria isolated from pasteurized liquid whole egg. Food Res Int 2024; 184:114215. [PMID: 38609213 DOI: 10.1016/j.foodres.2024.114215] [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: 10/17/2023] [Revised: 02/22/2024] [Accepted: 03/06/2024] [Indexed: 04/14/2024]
Abstract
The production of whole-liquid eggs is of significant economic and nutritional importance. This study aimed to assess the phenotypic and genotypic diversity of mesophilic aerobic spore-forming bacteria (n = 200) isolated from pasteurized whole liquid egg and liquid egg yolk. The majority of the isolates were identified as belonging to the genera Bacillus (86 %), followed by Brevibacillus (10 %) and Lysinibacillus (4 %). For the phenotypic characterization, isolates were subjected to various heat shocks, with the most significant reductions observed at 80 °C/30 min and 90 °C/10 min for isolates recovered from raw materials. On the other hand, the decrease was similar for isolates recovered from raw material and final product at 100 °C/5 min and 110 °C/5 min. Genotypic genes related to heat resistance (cdnL, spoVAD, dacB, clpC, dnaK, and yitF/Tn1546) were examined for genotypic characterization. The dnaK gene showed a positive correlation with the highest thermal condition tested (110 °C/5 min), while 100 °C/5 min had the highest number of positively correlated genes (clpC, cdnL, yitF/Tn1546, and spoVAD). Whole Genome Sequencing of four strains revealed genes related to sporulation, structure formation, initiation and regulation, stress response, and DNA repair in vegetative cells. The findings of this study indicate that these mesophilic aerobic spore-forming bacteria may adopt several strategies to persist through the process and reach the final product. As the inactivation of these microorganisms during egg processing is challenging, preventing raw materials contamination and their establishment in processing premises must be reinforced.
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Affiliation(s)
- Alexandra A I A Chincha
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Marina P Marone
- Laboratory of Genomics and BioEnergy, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas, Campinas, SP, Brazil
| | - Arthur K R Pia
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Luisa Freire
- Faculty of Pharmaceutical Sciences, Food and Nutrition, Federal University of Mato Grosso do Sul. Campo Grande, Mato Grosso do Sul, Brazil
| | - Dionisio P Amorim-Neto
- Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Marcelo F Carazzolle
- Laboratory of Genomics and BioEnergy, Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas, Campinas, SP, Brazil; Center for Computing and Engineering Sciences, 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.
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Fan L, Dai H, Zhou W, Yuan L, Yang J, Yang Z, Jiao XA. Unraveling the significance of calcium as a biofilm promotion signal for Bacillus licheniformis strains isolated from dairy products. Food Res Int 2024; 182:114145. [PMID: 38519175 DOI: 10.1016/j.foodres.2024.114145] [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: 12/08/2023] [Revised: 02/15/2024] [Accepted: 02/17/2024] [Indexed: 03/24/2024]
Abstract
Bacillus licheniformis, a quick and strong biofilm former, is served as a persistent microbial contamination in the dairy industry. Its biofilm formation process is usually regulated by environmental factors including the divalent cation Ca2+. This work aims to investigate how different concentrations of Ca2+ change biofilm-related phenotypes (bacterial motility, biofilm-forming capacity, biofilm structures, and EPS production) of dairy B. licheniformis strains. The Ca2+ ions dependent regulation mechanism for B. licheniformis biofilm formation was further investigated by RNA-sequencing analysis. Results revealed that supplementation of Ca2+ increased B. licheniformis biofilm formation in a dose-dependent way, and enhanced average coverage and thickness of biofilms with complex structures were observed by confocal laser scanning microscopy. Bacterial mobility of B. licheniformis was increased by the supplementation of Ca2+ except the swarming ability at 20 mM of Ca2+. The addition of Ca2+ decreased the contents of polysaccharides but promoted proteins production in EPS, and the ratio of proteins/polysaccharides content was significantly enhanced with increasing Ca2+ concentrations. RNA-sequencing results clearly indicated the variation in regulating biofilm formation under different Ca2+ concentrations, as 939 (671 upregulated and 268 downregulated) and 951 genes (581 upregulated and 370 downregulated) in B. licheniformis BL2-11 were induced by 10 and 20 mM of Ca2+, respectively. Differential genes were annotated in various KEGG pathways, including flagellar assembly, two-component system, quorum sensing, ABC transporters, and related carbohydrate and amino acid metabolism pathways. Collectively, the results unravel the significance of Ca2+ as a biofilm-promoting signal for B. licheniformis in the dairy industry.
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Affiliation(s)
- Luyao Fan
- College of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China
| | - Hongchao Dai
- College of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China
| | - Wenyuan Zhou
- College of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China
| | - Lei Yuan
- College of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China; Key Laboratory of Dairy Science (Northeast Agricultural University), Ministry of Education, Harbin, Heilongjiang 150030, China; Jiangsu Key Laboratory of Zoonoses, Yangzhou, Jiangsu 225009, China.
| | - Jia Yang
- Yangzhou Institute for Food and Drug Control, Yangzhou, Jiangsu 225106, China
| | - Zhenquan Yang
- College of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China
| | - Xin-An Jiao
- Jiangsu Key Laboratory of Zoonoses, Yangzhou, Jiangsu 225009, China
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Sadiq FA, De Reu K, Steenackers H, Van de Walle A, Burmølle M, Heyndrickx M. Dynamic social interactions and keystone species shape the diversity and stability of mixed-species biofilms - an example from dairy isolates. ISME COMMUNICATIONS 2023; 3:118. [PMID: 37968339 PMCID: PMC10651889 DOI: 10.1038/s43705-023-00328-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 10/28/2023] [Accepted: 11/02/2023] [Indexed: 11/17/2023]
Abstract
Identifying interspecies interactions in mixed-species biofilms is a key challenge in microbial ecology and is of paramount importance given that interactions govern community functionality and stability. We previously reported a bacterial four-species biofilm model comprising Stenotrophomonas rhizophila, Bacillus licheniformis, Microbacterium lacticum, and Calidifontibacter indicus that were isolated from the surface of a dairy pasteuriser after cleaning and disinfection. These bacteria produced 3.13-fold more biofilm mass compared to the sum of biofilm masses in monoculture. The present study confirms that the observed community synergy results from dynamic social interactions, encompassing commensalism, exploitation, and amensalism. M. lacticum appears to be the keystone species as it increased the growth of all other species that led to the synergy in biofilm mass. Interactions among the other three species (in the absence of M. lacticum) also contributed towards the synergy in biofilm mass. Biofilm inducing effects of bacterial cell-free-supernatants were observed for some combinations, revealing the nature of the observed synergy, and addition of additional species to dual-species combinations confirmed the presence of higher-order interactions within the biofilm community. Our findings provide understanding of bacterial interactions in biofilms which can be used as an interaction-mediated approach for cultivating, engineering, and designing synthetic bacterial communities.
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Affiliation(s)
- Faizan Ahmed Sadiq
- Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Technology and Food Science Unit, Brusselsesteenweg 370, 9090, Melle, Belgium.
| | - Koen De Reu
- Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Technology and Food Science Unit, Brusselsesteenweg 370, 9090, Melle, Belgium
| | - Hans Steenackers
- Centre of Microbial and Plant Genetics (CMPG), Department of Microbial and Molecular Systems, KU Leuven, Kasteelpark Arenberg 20, 3001, Leuven, Belgium
| | - Ann Van de Walle
- Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Technology and Food Science Unit, Brusselsesteenweg 370, 9090, Melle, Belgium
| | - Mette Burmølle
- Section of Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
| | - Marc Heyndrickx
- Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Technology and Food Science Unit, Brusselsesteenweg 370, 9090, Melle, Belgium.
- Ghent University, Department of Pathobiology, Pharmacology and Zoological Medicine, Salisburylaan 133, B-9820, Merelbeke, Belgium.
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Sulieman AME, Abdallah EM, Alanazi NA, Ed-Dra A, Jamal A, Idriss H, Alshammari AS, Shommo SAM. Spices as Sustainable Food Preservatives: A Comprehensive Review of Their Antimicrobial Potential. Pharmaceuticals (Basel) 2023; 16:1451. [PMID: 37895922 PMCID: PMC10610427 DOI: 10.3390/ph16101451] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/09/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023] Open
Abstract
Throughout history, spices have been employed for their pharmaceutical attributes and as a culinary enhancement. The food industry widely employs artificial preservatives to retard the deterioration induced by microbial proliferation, enzymatic processes, and oxidative reactions. Nevertheless, the utilization of these synthetic preservatives in food products has given rise to significant apprehension among consumers, primarily stemming from the potential health risks that they pose. These risks encompass a spectrum of adverse effects, including but not limited to gastrointestinal disorders, the disruption of gut microbiota, allergic reactions, respiratory complications, and concerns regarding their carcinogenic properties. Consequently, consumers are displaying an increasing reluctance to purchase preserved food items that contain such additives. Spices, known for their antimicrobial value, are investigated for their potential as food preservatives. The review assesses 25 spice types for their inherent antimicrobial properties and their applicability in inhibiting various foodborne microorganisms and suggests further future investigations regarding their use as possible natural food preservatives that could offer safer, more sustainable methods for extending shelf life. Future research should delve deeper into the use of natural antimicrobials, such as spices, to not only replace synthetic preservatives but also optimize their application in food safety and shelf-life extension. Moreover, there is a need for continuous innovation in encapsulation technologies for antimicrobial agents. Developing cost-effective and efficient methods, along with scaling up production processes, will be crucial to competing with traditional antimicrobial options in terms of both efficacy and affordability.
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Affiliation(s)
- Abdel Moneim E. Sulieman
- Department of Biology, College of Science, University of Ha’il, Ha’il 55473, Saudi Arabia; (N.A.A.); (A.J.)
| | - Emad M. Abdallah
- Department of Science Laboratories, College of Science and Arts, Qassim University, Ar Rass 51921, Saudi Arabia
| | - Naimah Asid Alanazi
- Department of Biology, College of Science, University of Ha’il, Ha’il 55473, Saudi Arabia; (N.A.A.); (A.J.)
| | - Abdelaziz Ed-Dra
- Laboratory of Engineering and Applied Technologies, Higher School of Technology, M’ghila Campus, Sultan Moulay Slimane University, Beni Mellal 23000, Morocco;
| | - Arshad Jamal
- Department of Biology, College of Science, University of Ha’il, Ha’il 55473, Saudi Arabia; (N.A.A.); (A.J.)
| | - Hajo Idriss
- Department of Physics, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia;
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Malek F. Flow of spore-forming bacteria between suppliers of dairy powders and users in some developing countries: challenges and perspectives. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2023; 60:2132-2142. [PMID: 37273561 PMCID: PMC10232714 DOI: 10.1007/s13197-022-05495-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 04/07/2022] [Accepted: 05/19/2022] [Indexed: 06/06/2023]
Abstract
Abstract Spore-forming bacteria are common contaminants of milk powder and processing lines and a major concern for the dairy industry. This dairy-associated microflora was studied extensively and well characterized in developed countries (exporters of milk powder), compared to developing countries (importers). Thereby, the quality issues affecting dairy powders and derived products are not fully controlled in developing countries. That is the case in Algeria, where recombined or reconstituted pasteurized milk is of low quality, reduced shelf-life, and the related dairies faced recurrent contaminations due to spores and biofilms. The transfer of spore-forming bacteria from exporters of dairy powders to importers in developing countries is an interesting topic, not thoroughly investigated. In addition, milk powder-based products are growing worldwide and their attributes, processes and technologies need to be better understood and controlled. This review analyzes issues affecting milk powder quality, based on few studies from developing countries in comparison with current knowledge, and emphasis on the case in Algeria. It provides information on how spore-forming bacteria and their biofilms affect the quality and shelf-life of recombined pasteurized milk produced in Algeria and compromise hygiene conditions in local dairy plants. Challenges and perspectives for better management of spore transfer from exporters of dairy powders to importers in developing countries are thereby outlined. Highlights The presence of spore-forming bacteria in milk powder is a serious safety issue.Spores are not well known, characterized and controlled in importers from developing countries.Spores cause recurrent contamination of pasteurized milk and biofilm issues in Algerian dairies.Challenges are how to reduce the flow of spores in milk powder trade.Perspectives on identification targeting predominant spores and improvement of biofilm removal.
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Affiliation(s)
- Fadila Malek
- Department of Biology, Faculty SNV-STU, University of Tlemcen, 13000 Tlemcen, Algeria
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7
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Peng Z, Li Y, Yan L, Yang S, Yang D. Correlation Analysis of Microbial Contamination and Alkaline Phosphatase Activity in Raw Milk and Dairy Products. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:1825. [PMID: 36767192 PMCID: PMC9915017 DOI: 10.3390/ijerph20031825] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/10/2023] [Accepted: 01/15/2023] [Indexed: 06/18/2023]
Abstract
Microbial contamination in raw milk and dairy products can detrimentally affect product quality and human health. In this study, the aerobic plate count, aerobic Bacillus abundance, thermophilic aerobic Bacillus abundance, and alkaline phosphatase activity were determined in 435 raw milk, 451 pasteurized milk, and 617 sterilized milk samples collected from 13 Chinese provinces (or municipalities). Approximately 9.89% and 2.22% of raw milk and pasteurized milk samples exceeded the threshold values for the aerobic plate count, respectively. The proportions of aerobic Bacillus in raw milk, pasteurized milk, and sterilized milk were 54.02%, 14.41%, and 1.30%, respectively. The proportions of thermophilic aerobic Bacillus species were 7.36% in raw milk and 4.88% in pasteurized milk samples, and no bacteria were counted in sterilized milk. Approximately 36.18% of raw milk samples contained >500,000 mU/L of alkaline phosphatase activity, while 9.71% of pasteurized milk samples contained >350 mU/L. For raw milk, there was a positive correlation between the aerobic plate count, the aerobic Bacillus abundance, and the alkaline phosphatase activity, and there was a positive correlation between the aerobic Bacillus abundance, the thermophilic aerobic Bacillus count, and the alkaline phosphatase activity. For pasteurized milk, there was a positive correlation between the aerobic plate count, the aerobic Bacillus abundance, and the thermophilic aerobic Bacillus count; however, the alkaline phosphatase activity had a negative correlation with the aerobic plate count, the aerobic Bacillus abundance, and the thermophilic aerobic Bacillus abundance. These results facilitate the awareness of public health safety issues and the involvement of dairy product regulatory agencies in China.
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Radwan AA, Darwesh OM, Emam MT, Mohamed KA, Shady HMA. A combined treatment of Proteinase K and biosynthesized ZnO-NPs for eradication of dairy biofilm of sporeformers. AIMS Microbiol 2022; 8:507-527. [PMID: 36694584 PMCID: PMC9834087 DOI: 10.3934/microbiol.2022033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 11/24/2022] [Accepted: 11/30/2022] [Indexed: 12/29/2022] Open
Abstract
Biofilms of sporeformers found in the dairy industry are the major contaminants during processing, as they withstand heat and chemical treatment that are used to control microbes. The present work is aimed to remove these resistant forms of bacterial community (biofilm) present in dairy production lines using ecofriendly agents based on proteinase K (Prot-K) coupled with Zinc oxide nanoparticles (ZnO-NPs). Some metal/metal oxide (Ag, CuO and ZnO) NPs were prepared microbially, and ZnO-NPs were characterized as the most effective ones among them. The produced ZnO-NPs were 15-25 nm in size with spherical shape, and FTIR analysis confirmed the presence of proteins and alkanes surrounding particles as capping agents. Application of Prot-K for eradication (removal) of a model biofilm of mixed sporeformers on food-grade stainless steel resulted in an 83% reduction in the absorbance of crystal violet-stained biofilm. When Prot-K was mixed with the biosynthesized NPs ZnO_G240, the reduction increased to 99.19%. This finding could contribute to an efficient cleaning approach combined with CIP to remove the recalcitrant biofilms in dairy production lines.
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Affiliation(s)
- Ahmed A. Radwan
- Genetics and Cytology Dept., National Research Centre (NRC), Cairo, 12622, Egypt
| | - Osama M. Darwesh
- Agricultural Microbiology Dept., National Research Centre (NRC), Cairo, 12622, Egypt,* Correspondence: , ; Tel: +201155265558
| | - Maha T. Emam
- Genetics and Cytology Dept., National Research Centre (NRC), Cairo, 12622, Egypt
| | - Karima A. Mohamed
- Genetics and Cytology Dept., National Research Centre (NRC), Cairo, 12622, Egypt
| | - Hala M. Abu Shady
- Microbiology Dept., Faculty of Science, Ain-Shams University Cairo, Egypt
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Yuan L, Fan L, Liu S, Sant'Ana AS, Zhang Y, Zhou W, Zheng X, He G, Yang Z, Jiao X. Bacterial community analysis of infant foods obtained from Chinese markets by combining culture-dependent and high-throughput sequence methods. Food Res Int 2022; 162:112060. [DOI: 10.1016/j.foodres.2022.112060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 09/23/2022] [Accepted: 10/07/2022] [Indexed: 11/04/2022]
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Pal N, Sinha S, Shivani, Chakraborty M. A review on bacterial and archaeal thermostable sulfur oxidoreductases (SORS)-an insight into the biochemical, molecular and in-silico structural comparative analysis of a neglected thermostable enzyme of industrial significance. Arch Microbiol 2022; 204:655. [PMID: 36175582 DOI: 10.1007/s00203-022-03256-3] [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: 03/08/2022] [Revised: 09/08/2022] [Accepted: 09/12/2022] [Indexed: 11/02/2022]
Abstract
Diverse thermophilic microorganisms with the potential to withstand extreme physiological conditions have long been investigated and explored for human commercial benefit. Thermozymes with distinct functional and structural properties isolated from these thermophiles are known to have high thermostability without significant loss of specific enzyme activity. Thermophiles isolated and characterised from the thermophilic ecological niche of India are well documented. There is a plethora of work in the literature emphasising its industrial significance. However, in-depth knowledge of the thermophilic oxidoreductase group of enzymes (Oxizymes) is restricted. Sulfur Oxygenase Reductases or Sulfur Oxygen-Reductases (SORs) are a group of thermophilic oxizymes reported predominantly from thermophilic and mesophilic archaea and bacteria, which catalyse oxygen-dependent disproportionation reactions of elemental sulfur, producing sulfite, thiosulfate, and sulphide. There have been few reports on isolated and characterised SORs from the Indian geothermal niche. The review article will highlight the SORs reported till date with a concise overview of different archaeal and bacterial species producing the enzymes. Based on the literature available till date, characteristics including physico-chemical properties, amino acid sequence homology, conserved motifs and their 3D structure comparison have been discussed. In-silico sequence and structure level preliminary comparative analysis of various SORs has also been discussed. However, a few SORs whose structural information is not reported in the protein data bank have been modelled to enrich our analysis.
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Affiliation(s)
- Nirmalya Pal
- University Institute of Biotechnology, Chandigarh University, Gharuan, Mohali, Punjab, 140413, India
| | - Sanjana Sinha
- NMR Micro-Imaging and Spectroscopy Laboratory, Centre for Cellular and Molecular Biology, Uppal Rd, IICT Colony, Habsiguda, Hyderabad, 500007, Telangana, India
| | - Shivani
- University Institute of Biotechnology, Chandigarh University, Gharuan, Mohali, Punjab, 140413, India
| | - Mitun Chakraborty
- Department of Biotechnology Engineering and Food Technology, University Institute of Engineering, Chandigarh University, Gharuan, Mohali, Punjab, 140413, India.
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Wedel C, Atamer Z, Dettling A, Wenning M, Scherer S, Hinrichs J. Towards low-spore milk powders: A review on microbiological challenges of dairy powder production with focus on aerobic mesophilic and thermophilic spores. Int Dairy J 2022. [DOI: 10.1016/j.idairyj.2021.105252] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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12
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Kumar M, Tierney J, Wilkinson M. Enzymatic Disruption of Biofilms During Cheese Manufacturing: A Mini Review. Front Microbiol 2021; 12:791061. [PMID: 34975813 PMCID: PMC8716882 DOI: 10.3389/fmicb.2021.791061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/18/2021] [Indexed: 11/13/2022] Open
Abstract
Bacteria are capable of colonizing industrial processing surfaces creating biofilms on them which may adversely affect the quality and safety of products. Traditional cleaning-in-place (CIP) treatments using caustic and nitric acid solutions have been known to exhibit variable efficiency in eliminating biofilm bacteria. Here, we introduce enzymes as an alternative to traditional CIP treatments and discuss their mechanism of action against bacterial biofilms in cheese manufacturing. In addition, we discuss research gaps namely thermal stability, substrate specificity and residual activity of enzymes that may play a vital role in the selection of enzymes with optimal effectiveness against multi species biofilms. The outcome of this mini review will aid in the development of a novel and sustainable enzyme-based CIP treatment during cheese manufacturing in the future.
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Affiliation(s)
- Murali Kumar
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
- *Correspondence: Murali Kumar,
| | | | - Martin Wilkinson
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
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13
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Sun R, Vermeulen A, Devlieghere F. Modeling the combined effect of temperature, pH, acetic and lactic acid concentrations on the growth/no growth interface of acid-tolerant Bacillus spores. Int J Food Microbiol 2021; 360:109419. [PMID: 34600755 DOI: 10.1016/j.ijfoodmicro.2021.109419] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 08/05/2021] [Accepted: 09/19/2021] [Indexed: 11/16/2022]
Abstract
The application of minimal processing technologies has led to increased spoilage incidents in low-acid pasteurized sauces due to the outgrowth of acid-tolerant spore-forming spoilage bacteria (ATSSB). Controlling the germination and subsequent growth of ATSSB spores is vital to enhance the ambient storage stability of pasteurized sauces. This study developed and validated a set of growth/no growth (G/NG) models for spores of two ATSSB strains (Bacillus velezensis and Bacillus subtilis subsp. subtilis) isolated from pasteurized sauces. The G/NG data at two levels of temperature (22 and 30 °C) were collected in Nutrient Broth (aw = 0.98 adjusted with NaCl) by a full factorial design with five equidistant levels of pH (4.4-5.6), four concentrations of total acetic acid (0.0-0.3% (w/w)), and four concentrations of total lactic acid (0.00-1.00% (w/w)). The growth, starting from heat-treated (10 min 80 °C) spores, of each strain was assessed under 160 combinations by regular optical density measurements during three months. Twelve replicates were made for each combination. The developed models demonstrate that without organic acids even the lowest pH (4.4) allows a high growth possibility of the ATSSB spores, while acetic and lactic acids exhibit a significant antibacterial activity, which can be enhanced at decreased pH. The growth starting from B. subtilis spores can be inhibited for at least three months with 1.0% (w/w) total lactic acid in the water phase at both temperatures, which was not the case for B. velezensis, while 0.3% acetic acid achieves a full inhibition on both strains at 22 °C. With a combination of 0.3% acetic acid and 0.7% lactic acid, no growth should occur in the investigated range. This research is one of the first studies exploring the feasibility of ambient storage for low-acid pasteurized sauces eliminating preservatives such as benzoic and sorbic acids, and proves the synergistic effect of decreased pH and the presence of acetic and lactic acids on inhibiting bacterial growth from ATSSB spores.
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Affiliation(s)
- Rongxue Sun
- FMFP, Research Unit of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
| | - An Vermeulen
- FMFP, Research Unit of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Frank Devlieghere
- FMFP, Research Unit of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
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14
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Wang N, Jin Y, He G, Yuan L. Intraspecific and interspecific extracellular metabolites remodel biofilms formed by thermophilic spoilage bacteria. J Appl Microbiol 2021; 133:2096-2106. [PMID: 34689405 DOI: 10.1111/jam.15338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/24/2021] [Accepted: 10/17/2021] [Indexed: 11/30/2022]
Abstract
AIMS Thermophilic spoilage bacteria and their biofilms formed during milk powder processing posed threats to safety and quality of dairy products. This research aims to understand more about the bacterial behaviours and their social models in biofilms. METHODS AND RESULTS Interactional effects from both extracellular metabolites and co-culture on biofilms formation of the contaminating thermophilic bacteria were determined. The results showed that strong biofilm formers always had high AI-2 activities, including Geobacillus stearothermophilus gs1, Bacillus licheniformis bl1 and Thermoactinomyces vulgaris tv1. Metabolites from themself or other species altered their biofilm biomass detected by crystal violet staining. Dual-species cultures observed by confocal laser scanning microscope indicated either synergistic or inhibitory effects between B. circulans bc1 and G. stearothermophilus gs1, as well as B. licheniformis bl1 and G. stearothermophilus gs1. Fourier transform infrared spectrometry results revealed the significant diversities in polysaccharides of the biofilm matrix. CONCLUSIONS Cell communication played an important role on biofilm formation in the complex microbial community. Intraspecific and interspecific extracellular metabolites influenced collective bacterial behaviours under mixed circumstances. SIGNIFICANCE AND IMPACT OF STUDY This research provided evidences on cell communication and biofilm formation of thermophilic bacteria in dairy industry.
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Affiliation(s)
- Ni Wang
- School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, China
| | - Yujie Jin
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China
| | - Guoqing He
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China
| | - Lei Yuan
- College of Food Science and Engineering, Yangzhou University, Yangzhou, China
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15
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16
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Sadiq FA, Flint S. Dairy strains of Anoxybacillus flavithermus inhibit lipase production by Geobacillus stearothermophilus. Int Dairy J 2021. [DOI: 10.1016/j.idairyj.2021.104996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Alonso VPP, de Oliveira Morais J, Kabuki DY. Incidence of Bacillus cereus, Bacillus sporothermodurans and Geobacillus stearothermophilus in ultra-high temperature milk and biofilm formation capacity of isolates. Int J Food Microbiol 2021; 354:109318. [PMID: 34246014 DOI: 10.1016/j.ijfoodmicro.2021.109318] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 06/02/2021] [Accepted: 06/19/2021] [Indexed: 12/19/2022]
Abstract
The presence of mesophilic and thermophilic spore-forming bacteria in UHT milk, as well as biofilm formation in dairy plants, are concerning. The current study explored the spore-forming bacilli diversity in 100 samples of UHT milk (skimmed and whole). Through this work, a total of 239 isolates from UHT milk samples were obtained. B. cereus s.s. was isolated from 7 samples, B. sporothermodurans from 19 and, G. stearothermophilus from 25 samples. Genes encoding hemolysin (HBL), and non-hemolytic (NHE) enterotoxins were detected in B. cereus s.s. isolates. All isolates of B. cereus s.s. (12) B. sporothermodurans (38), and G. stearothermophilus (47) were selected to verify the ability of biofilm formation in microtiter plates. The results showed all isolates could form biofilms. The OD595 values of biofilm formation varied between 0.14 and 1.04 for B. cereus, 0.20 to 1.87 for B. sporothermodurans, and 0.49 to 2.77 for G. stearothermophilus. The data highlights that the dairy industry needs to reinforce control in the initial quality of the raw material and in CIP cleaning procedures; avoiding biofilm formation and consequently a persistent microbiota in processing plants, which can shelter pathogenic species such as B. cereus s.s.
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Affiliation(s)
- Vanessa Pereira Perez Alonso
- Department of Food Science and Nutrition, School of Food Engineering, State University of Campinas, Campinas, SP, Brazil.
| | - Jéssica de Oliveira Morais
- Department of Food Science and Nutrition, School of Food Engineering, State University of Campinas, Campinas, SP, Brazil
| | - Dirce Yorika Kabuki
- Department of Food Science and Nutrition, School of Food Engineering, State University of Campinas, Campinas, SP, Brazil
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18
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Karaca B, Buzrul S, Cihan AC. Mathematical Models for the Biofilm Formation of Geobacillus and Anoxybacillus on Stainless Steel Surface in Whole Milk. Food Sci Anim Resour 2021; 41:288-299. [PMID: 33987549 PMCID: PMC8115000 DOI: 10.5851/kosfa.2020.e100] [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: 09/29/2020] [Revised: 10/28/2020] [Accepted: 12/15/2020] [Indexed: 11/16/2022] Open
Abstract
Biofilm formation of Geobacillus thermodenitrificans,
Geobacillus thermoglucosidans and Anoxybacillus
flavithermus in milk on stainless steel were monitored at
55°C, 60°C, and 65°C for various incubation times. Although
species of Geobacillus showed a rapid response and produced
biofilm within 4 h on stainless steel, a delay (lag time) was observed for
Anoxybacillus. A hyperbolic equation and a hyperbolic
equation with lag could be used to describe the biofilm formation of
Geobacillus and Anoxybacillus,
respectively. The highest biofilm formation amount was obtained at 60°C
for both Geobacillus and Anoxybacillus.
However, the biofilm formation rates indicated that the lowest rates of
formation were obtained at 60°C for Geobacillus.
Moreover, biofilm formation rates of G. thermodenitrificans
(1.2–1.6 Log10CFU/mL·h) were higher than G.
thermoglucosidans (0.4–0.7 Log10CFU/mL·h).
Although A. flavithermus had the highest formation rate values
(2.7–3.6 Log10CFU/mL·h), this was attained after the
lag period (4 or 5 h). This study revealed that modeling could be used to
describe the biofilm formation of thermophilic bacilli in milk.
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Affiliation(s)
- Basar Karaca
- Department of Biology, Ankara University, Ankara, Turkey
| | - Sencer Buzrul
- Department of Food Engineering, Konya Food and Agriculture University, Konya, Turkey
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19
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Kumar M, Flint S, Palmer J, Plieger P. A comparison of the spore heat resistance of dairy isolates of Geobacillus stearothermophilus obtained using a CDC biofilm reactor and a sporulating medium. Int Dairy J 2021. [DOI: 10.1016/j.idairyj.2021.105000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Beldie AA, Moraru CI. Forward osmosis concentration of milk: Product quality and processing considerations. J Dairy Sci 2021; 104:7522-7533. [PMID: 33865601 DOI: 10.3168/jds.2020-20019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 02/28/2021] [Indexed: 11/19/2022]
Abstract
Concentration of milk in the dairy industry is typically achieved by thermal evaporation or reverse osmosis (RO). Heat concentration is energy intensive and leads to cooked flavor and color changes in the final product, and RO is affected by fouling, which limits the final achievable concentration of the product. The main objective of this work was to evaluate forward osmosis (FO) as an alternative method for concentrating milk. The effects of fat content and temperature on the process were evaluated, and the physicochemical properties and sensory qualities of the final product were assessed. Commercially pasteurized skim and whole milk samples were concentrated at 4, 15, and 25°C using a benchtop FO unit. The FO process was assessed by monitoring water flux and product concentration. The color of the milk concentrates was also evaluated. A sensory panel compared the FO concentrated and thermally concentrated milks, diluted to single strength, with high temperature, short time pasteurized milk. The FO experimental runs were conducted in triplicate, and data were analyzed by single-factor ANOVA. Water flux during FO decreased with time under all processing conditions. Higher temperatures led to faster concentration and higher concentration factors for both skim and whole milk. After 5.75 h of FO processing, the concentration factors achieved for skim milk were 2.68 ± 0.08 at 25°C, 2.68 ± 0.09 at 15°C, and 2.36 ± 0.08 at 4°C. For whole milk, after 5.75 h of FO processing, concentration factors of 2.32 ± 0.12 at 25°C, 2.12 ± 0.36 at 15°C, and 1.91 ± 0.15 at 4°C were obtained. Overall, maximum concentration levels of 40.15% total solids for skim milk and 40.94% total solids for whole milk were achieved. Additionally, a triangle sensory test showed no significant differences between regular milk and FO concentrated milk diluted to single strength. This work shows that FO is a viable nonthermal processing method for concentrating milk, but some technical challenges need to be overcome to facilitate commercial utilization.
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Affiliation(s)
| | - Carmen I Moraru
- Department of Food Science, Cornell University, Ithaca, NY 14853.
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21
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McHugh AJ, Yap M, Crispie F, Feehily C, Hill C, Cotter PD. Microbiome-based environmental monitoring of a dairy processing facility highlights the challenges associated with low microbial-load samples. NPJ Sci Food 2021; 5:4. [PMID: 33589631 PMCID: PMC7884712 DOI: 10.1038/s41538-021-00087-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 01/13/2021] [Indexed: 01/01/2023] Open
Abstract
Efficient and accurate identification of microorganisms throughout the food chain can potentially allow the identification of sources of contamination and the timely implementation of control measures. High throughput DNA sequencing represents a potential means through which microbial monitoring can be enhanced. While Illumina sequencing platforms are most typically used, newer portable platforms, such as the Oxford Nanopore Technologies (ONT) MinION, offer the potential for rapid analysis of food chain microbiomes. Initial assessment of the ability of rapid MinION-based sequencing to identify microbes within a simple mock metagenomic mixture is performed. Subsequently, we compare the performance of both ONT and Illumina sequencing for environmental monitoring of an active food processing facility. Overall, ONT MinION sequencing provides accurate classification to species level, comparable to Illumina-derived outputs. However, while the MinION-based approach provides a means of easy library preparations and portability, the high concentrations of DNA needed is a limiting factor.
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Affiliation(s)
- Aoife J McHugh
- Food Bioscience Department, Teagasc Food Research Centre, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
| | - Min Yap
- Food Bioscience Department, Teagasc Food Research Centre, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
| | - Fiona Crispie
- Food Bioscience Department, Teagasc Food Research Centre, Cork, Ireland.,APC Microbiome Ireland, Cork, Ireland
| | - Conor Feehily
- Food Bioscience Department, Teagasc Food Research Centre, Cork, Ireland.,APC Microbiome Ireland, Cork, Ireland
| | - Colin Hill
- School of Microbiology, University College Cork, Cork, Ireland.,APC Microbiome Ireland, Cork, Ireland
| | - Paul D Cotter
- Food Bioscience Department, Teagasc Food Research Centre, Cork, Ireland. .,APC Microbiome Ireland, Cork, Ireland.
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22
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Graf B, Hehnke S, Neuwirth M, Hinrichs J. Continuous microwave heating to inactivate thermophilic spores in heating-sensitive skim milk concentrate. Int Dairy J 2021. [DOI: 10.1016/j.idairyj.2020.104894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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23
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Murphy SI, Kent D, Skeens J, Wiedmann M, Martin NH. A standard set of testing methods reliably enumerates spores across commercial milk powders. J Dairy Sci 2020; 104:2615-2631. [PMID: 33358815 DOI: 10.3168/jds.2020-19313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 10/01/2020] [Indexed: 11/19/2022]
Abstract
Contamination of dairy powders with sporeforming bacteria is a concern for dairy processors who wish to penetrate markets with stringent spore count specifications (e.g., infant powders). Despite instituted specifications, no standard methodology is used for spore testing across the dairy industry. Instead, a variety of spore enumeration methods are in use, varying primarily by heat-shock treatments, plating method, recovery medium, and incubation temperature. Importantly, testing the same product using different methodologies leads to differences in spore count outcomes, which is a major issue for those required to meet specifications. As such, we set out to identify method(s) to recommend for standardized milk powder spore testing. To this end, 10 commercial milk powders were evaluated using methods varying by (1) heat treatment (e.g., 80°C/12 min), (2) plating method (e.g., spread plating), (3) medium type (e.g., plate count milk agar), and (4) incubation time and temperature combinations (e.g., 32°C for 48 h). The resulting data set included a total of 48 methods. With this data set, we used a stepwise process to identify optimal method(s) that would explain a high proportion of variance in spore count outcomes and would be practical to implement across the dairy industry. Ultimately, spore pasteurized mesophilic spore count (80°C/12 min, incubated at 32°C for 48 h), highly heat resistant thermophilic spore count (100°C/30 min, incubated at 55°C for 48 h), and specially thermoresistant spore enumeration (106°C/30 min, incubated at 55°C for 48 h) spread plating on plate count milk agar were identified as the optimal method set for reliable enumeration of spores in milk powders. Subsequently, we assessed different powder sampling strategies as a way to reduce variation in powder spore testing outcomes using our recommended method set. Results indicated that 33-g composite sampling may reduce variation in spore testing outcomes for highly heat resistant thermophilic spore count over 11-g and 33-g discrete sampling, whereas there was no significant difference across sampling strategies for specially thermoresistant spore enumeration or spore pasteurized mesophilic spore count. Finally, an interlaboratory study using our recommended method set and a modified method set (using tryptic soy agar with 1% starch) among both university and industry laboratories showed increased variation in spore count outcomes within milk powders, which not only was due to natural variation in powders but also was hypothesized to be due to technical errors, highlighting the need for specialized training for technicians who perform spore testing on milk powders. Overall, this study addresses challenges to milk powder spore testing and recommends a method set for standardized spore testing for implementation across the dairy industry.
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Affiliation(s)
- S I Murphy
- Milk Quality Improvement Program, Department of Food Science, Cornell University, Ithaca, NY 14853
| | - D Kent
- Milk Quality Improvement Program, Department of Food Science, Cornell University, Ithaca, NY 14853
| | - J Skeens
- Milk Quality Improvement Program, Department of Food Science, Cornell University, Ithaca, NY 14853
| | - M Wiedmann
- Milk Quality Improvement Program, Department of Food Science, Cornell University, Ithaca, NY 14853
| | - N H Martin
- Milk Quality Improvement Program, Department of Food Science, Cornell University, Ithaca, NY 14853.
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24
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Mathot AG, Postollec F, Leguerinel I. Bacterial spores in spices and dried herbs: The risks for processed food. Compr Rev Food Sci Food Saf 2020; 20:840-862. [DOI: 10.1111/1541-4337.12690] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 11/15/2020] [Accepted: 11/20/2020] [Indexed: 11/26/2022]
Affiliation(s)
- Anne Gabrielle Mathot
- Université de Brest, Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne Quimper France
| | | | - Ivan Leguerinel
- Université de Brest, Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne Quimper France
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25
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Wang N, Gao J, Yuan L, Jin Y, He G. Metabolomics profiling during biofilm development of Bacillus licheniformis isolated from milk powder. Int J Food Microbiol 2020; 337:108939. [PMID: 33160113 DOI: 10.1016/j.ijfoodmicro.2020.108939] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 10/23/2022]
Abstract
Bacillus licheniformis is a major source of microbial contamination to dairy industry, and biofilm formation by this spoilage bacterium aggravates the safety issues. Especially for milk powder manufactures, the evaporation process at temperatures between 50 °C and 70 °C before spray drying, is a critical control point against thermophilic bacteria multiplication. In our study, metabolomics analysis was performed to investigate dynamic changes of the metabolites and their roles during process of biofilm development of B. licheniformis at 55 °C for 24 h. Amino acid metabolism was quite active, with cooperation from lipid metabolism, carbohydrate metabolism and nucleotide metabolism. Amino acid biosynthesis provided significant contributions especially during early biofilm development from 8 to 12 h. Metabolites involved in specific pathways of arginine biosynthetic, galactose metabolism and sphingolipid metabolism played a crucial role in building biofilm. This work provided new insights into dynamic metabolic alternations and a comprehensive network during B. licheniformis biofilm development, which will extend the knowledge on the metabolic process of biofilm formation by B. licheniformis. The results are helpful in creating better environmental hygiene in dairy processing and new strategies for ensuring quality of dairy products.
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Affiliation(s)
- Ni Wang
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Jie Gao
- College of Food Science and Technology, Hebei Agriculture University, Baoding 071000, China
| | - Lei Yuan
- College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, China
| | - Yujie Jin
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China
| | - Guoqing He
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.
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26
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New experimental set-up for testing microwave technology to continuously heat fouling-sensitive food products like milk concentrates. INNOV FOOD SCI EMERG 2020. [DOI: 10.1016/j.ifset.2020.102453] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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27
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Soni A, Smith J, Archer R, Gardner A, Tong K, Brightwell G. Development of Bacterial Spore Pouches as a Tool to Evaluate the Sterilization Efficiency-A Case Study with Microwave Sterilization Using Clostridium sporogenes and Geobacillus stearothermophilus. Foods 2020; 9:E1342. [PMID: 32977443 PMCID: PMC7598248 DOI: 10.3390/foods9101342] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/18/2020] [Accepted: 09/20/2020] [Indexed: 11/16/2022] Open
Abstract
In this study, novel spore pouches were developed using mashed potato as a food model inoculated with either Geobacillus stearothermophilus or Clostridium sporogenes spores. These spore pouches were used to evaluate the sterilization efficiency of Coaxially induced microwave pasteurization and sterilization (CiMPAS) as a case study. CiMPAS technology combines microwave energy (915 MHz) along with hot water immersion to sterilize food in polymeric packages. The spore pouches were placed at pre-determined specific locations, especially cold spots in each food tray before being processed using two regimes (R-121 and R-65), which consisted of 121 °C and 65 °C at 12 and 22 kW, respectively, followed by recovery and enumeration of the surviving spores. To identify cold spots or the location for inoculation, mashed potato was spiked with Maillard precursors and processed through CiMPAS, followed by measurement of lightness values (*L-values). Inactivation equivalent to of 1-2 Log CFU/g and >6 Log CFU/g for Geobacillus stearothermophilus and Clostridium sporogenes spores, respectively was obtained on the cold spots using R-121, which comprised of a total processing time of 64.2 min. Whereas, inactivation of <1 and 2-3 Log CFU/g for G. stearothermophilus and C. sporogenes spores, respectively on the cold spots was obtained using R-65 (total processing time of 68.3 min), whereas inactivation of 1-3 Log CFU/g of C. sporogenes spores was obtained on the sides of the tray. The results were reproducible across three processing replicates for each regime and inactivation at the specific locations were clearly distinguishable. The study indicated a strong potential to use spore pouches as a tool for validation studies of microwave-induced sterilization.
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Affiliation(s)
- Aswathi Soni
- Food Assurance, AgResearch, Palmerston North 4410, New Zealand; (A.G.); (G.B.)
| | - Jeremy Smith
- School of Food & Advanced Technology, Massey University, Palmerston North 4410, New Zealand; (J.S.); (R.A.); (K.T.)
| | - Richard Archer
- School of Food & Advanced Technology, Massey University, Palmerston North 4410, New Zealand; (J.S.); (R.A.); (K.T.)
| | - Amanda Gardner
- Food Assurance, AgResearch, Palmerston North 4410, New Zealand; (A.G.); (G.B.)
| | - Kris Tong
- School of Food & Advanced Technology, Massey University, Palmerston North 4410, New Zealand; (J.S.); (R.A.); (K.T.)
| | - Gale Brightwell
- Food Assurance, AgResearch, Palmerston North 4410, New Zealand; (A.G.); (G.B.)
- New Zealand Food Safety Science Research Centre, Palmerston North 4410, New Zealand
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28
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Wang N, Sadiq FA, Li S, He G, Yuan L. Tandem mass tag-based quantitative proteomics reveals the regulators in biofilm formation and biofilm control of Bacillus licheniformis. Food Control 2020. [DOI: 10.1016/j.foodcont.2019.107029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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29
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Thermally induced milk fouling: Survival of thermophilic spore formers and potential of contamination. Int Dairy J 2020. [DOI: 10.1016/j.idairyj.2019.104582] [Citation(s) in RCA: 5] [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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30
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Deshpande VK, Walsh MK. Effect of thermosonication in a batch system on the survival of spore‐forming bacteria. INT J DAIRY TECHNOL 2020. [DOI: 10.1111/1471-0307.12685] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Vidita K Deshpande
- Department of Nutrition, Dietetics, and Food Sciences Utah State University 8700 Old Main Hill 84322‐8700 Logan Utah USA
| | - Marie K Walsh
- Department of Nutrition, Dietetics, and Food Sciences Utah State University 8700 Old Main Hill 84322‐8700 Logan Utah USA
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31
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Inhibitory effect of Lactobacillus plantarum metabolites against biofilm formation by Bacillus licheniformis isolated from milk powder products. Food Control 2019. [DOI: 10.1016/j.foodcont.2019.106721] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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32
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Dettling A, Doll E, Wedel C, Hinrichs J, Scherer S, Wenning M. Accurate quantification of thermophilic spores in dairy powders. Int Dairy J 2019. [DOI: 10.1016/j.idairyj.2019.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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33
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Li F, Hunt K, Van Hoorde K, Butler F, Jordan K, Tobin JT. Occurrence and identification of spore-forming bacteria in skim-milk powders. Int Dairy J 2019. [DOI: 10.1016/j.idairyj.2019.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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34
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Wedel C, Wenning M, Dettling A, Scherer S, Hinrichs J. Resistance of thermophilic spore formers isolated from milk and whey products towards cleaning-in-place conditions: Influence of pH, temperature and milk residues. Food Microbiol 2019; 83:150-158. [DOI: 10.1016/j.fm.2019.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 04/29/2019] [Accepted: 05/04/2019] [Indexed: 01/04/2023]
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35
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Kumar M, Flint SH, Palmer J, Plieger PG, Waterland M. The effect of phosphate on the heat resistance of spores of dairy isolates of Geobacillus stearothermophilus. Int J Food Microbiol 2019; 309:108334. [PMID: 31520893 DOI: 10.1016/j.ijfoodmicro.2019.108334] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 08/15/2019] [Accepted: 09/01/2019] [Indexed: 10/26/2022]
Abstract
In this study, we show that phosphate decreases the spore heat resistance by accelerating the rate of loss of cations from spores. Heat resistance of spores of Geobacillus stearothermophilus A1, D1, P3 and ATCC 12980 were determined in distilled water containing varying concentrations (0.1, 1 and 2% w/v) of di‑sodium phosphate. The average decimal reduction times (D value) for strains A1, D1, P3 and ATCC 12980 in distilled water were 5.8, 6.8, 5.7 and 9 min at 110 °C respectively. On the addition of 0.1, 1 and 2% w/v of di‑sodium phosphate, the average D110 values of all the strains in distilled water were lowered by 50, 61 and 70% respectively. Addition of 0.05% w/v of Na-EDTA to distilled water resulted in lowering of the average D110 value of all the strains by 55%. Heat resistance of spores of A1, D1, P3 and ATCC 12980 was found to be associated with the Dipicolinic Acid (DPA) content whose concentrations were 0.25, 0.30, 0.27 and 1.6 pg per spore respectively. Analysis by atomic absorption spectroscopy revealed that the phosphate present in the heating medium causes excess release of calcium from spores with 2% w/v phosphate being highly effective, thus confirming the chelating effect of phosphate. This study provides insight into the heat resistance and the increased heat sensitivity of spores of G. stearothermophilus A1, D1 and P3 in the presence of phosphate, which can be used in the design of Cleaning in Place (CIP) systems involving phosphate based cleaning agents to combat biofilms and spores in the dairy industry.
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Affiliation(s)
- M Kumar
- Massey Institute of Food Science and Technology, Massey University, Palmerston North 4442, New Zealand
| | - S H Flint
- Massey Institute of Food Science and Technology, Massey University, Palmerston North 4442, New Zealand.
| | - J Palmer
- Massey Institute of Food Science and Technology, Massey University, Palmerston North 4442, New Zealand
| | - P G Plieger
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - M Waterland
- School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
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Pereira APM, Stelari HA, Carlin F, Sant’Ana AS. Inactivation kinetics of Bacillus cereus and Geobacillus stearothermophilus spores through roasting of cocoa beans and nibs. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2019.05.063] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Viable and Total Bacterial Populations Undergo Equipment- and Time-Dependent Shifts during Milk Processing. Appl Environ Microbiol 2019; 85:AEM.00270-19. [PMID: 31028031 DOI: 10.1128/aem.00270-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/24/2019] [Indexed: 12/13/2022] Open
Abstract
We set out to identify the viable and total bacterial content in milk as it passes through a large-scale, dairy product manufacturing plant for pasteurization, concentration, separation, blending, and storage prior to cheese manufacture. A total of 142 milk samples were collected from up to 10 pieces of equipment for a period spanning 21 h on two collection dates in the spring and late summer of 2014. Bacterial composition in the milk was determined by 16S rRNA marker gene, high-throughput DNA sequencing. Milk samples from the late summer were paired such that half were treated with propidium monoazide (PMA) to enrich for viable cells prior to quantification by PCR and identification by DNA sequence analysis. Streptococcus had the highest median relative abundance across all sampling sites within the facility on both sampling dates. The proportions of Anoxybacillus, Thermus, Lactococcus, Lactobacillus, Micrococcaceae, and Pseudomonas were also elevated in some samples. Viable cells detected by PMA treatment showed that Turicibacter was enriched after high-temperature short-time pasteurization, whereas proportions of Staphylococcus were significantly reduced. Using clean-in-place (CIP) times as a reference point, Bacillus, Pseudomonas, and Anoxybacillus were found in high relative proportions in several recently cleaned silos (<19 h since CIP). At later times (>19 h after CIP), 10 of 11 silos containing elevated viable cell numbers were enriched in Acinetobacter and/or Lactococcus These results show the tremendous point-to-point and sample-dependent variations in bacterial composition in milk during processing.IMPORTANCE Milk undergoes sustained contact with the built environment during processing into finished dairy products. This contact has the potential to influence the introduction, viability, and growth of microorganisms within the milk. Currently, the population dynamics of bacteria in milk undergoing processing are not well understood. Therefore, we measured for total and viable bacterial composition and cell numbers in milk over time and at different processing points in a cheese manufacturing facility in California. Our results provide new perspectives on the dramatic variations in microbial populations in milk during processing even over short amounts of time. Although some of the changes in the milk microbiota were predictable (e.g., reduced viable cell numbers after pasteurization), other findings could not be easily foreseen based on knowledge of bacteria contained in raw milk or when the equipment was last cleaned. This information is important for predicting and controlling microbial spoilage contaminants in dairy products.
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Eijlander RT, van Hekezen R, Bienvenue A, Girard V, Hoornstra E, Johnson NB, Meyer R, Wagendorp A, Walker DC, Wells‐Bennik MHJ. Spores in dairy – new insights in detection, enumeration and risk assessment. INT J DAIRY TECHNOL 2019. [DOI: 10.1111/1471-0307.12586] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | - Erik Hoornstra
- Laboratory & Quality Services FrieslandCampina Leeuwarden The Netherlands
| | | | - Rolf Meyer
- Nestec Ltd. Nestlé Research & Development Konolfingen 3510 Switzerland
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Pia AKR, Pereira APM, Costa RA, Alvarenga VO, Freire L, Carlin F, Sant'Ana AS. The fate of Bacillus cereus and Geobacillus stearothermophilus during alkalization of cocoa as affected by alkali concentration and use of pre-roasted nibs. Food Microbiol 2019; 82:99-106. [PMID: 31027825 DOI: 10.1016/j.fm.2019.01.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 01/20/2019] [Accepted: 01/21/2019] [Indexed: 11/26/2022]
Abstract
Alkalization is a step of cocoa processing and consists of the use of alkali and high temperature to improve the sensorial and technological qualities of cocoa. Intense food processing can select spores, which can compromise safety and quality of the final product. Thus, the aim of this study was to evaluate the fate of B. cereus and G. stearothermophilus spores during the alkalization of pre-roasted (Pr) nibs (held at 120 °C) and unroasted (Ur) nibs (held at 90 °C) using potassium carbonate (0, 2, 4 and 6% w/w). In all conditions, log-linear inactivation kinetics with a tail was observed. The inactivation rate (kmax) for B. cereus varied from 0.065 to 1.67 min-1, whereas the kmax for G. stearothermophilus varied from 0.012 to 0.063 min-1. For both microorganisms, the lowest kmax values were observed during Ur nibs alkalization. The carbonate concentration increase promoted kmax values reduction. The highest tail values were observed for G. stearothermophilus in Ur nibs alkalization, reaching 3.04 log spores/g. Tail formation and low kmax values indicated that cocoa alkalization does not cause significant reductions on bacterial spore population. Therefore, the microbiological control should be primarily ensured by the raw material quality and by avoiding recontamination in the cocoa chain.
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Affiliation(s)
- Arthur K R Pia
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil
| | - Ana P M Pereira
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil
| | - Ramon A Costa
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil
| | - Verônica O Alvarenga
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil
| | - Luisa Freire
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil
| | - Frédéric Carlin
- UMR408 SQPOV "Sécurité et Qualité des Produits d'Origine Végétale", INRA Avignon Université, 84000, Avignon, France
| | - Anderson S Sant'Ana
- Department of Food Science, Faculty of Food Engineering, University of Campinas, Campinas, Brazil.
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Cho TJ, Rhee MS. Underrecognized niche of spore-forming bacilli as a nitrite-producer isolated from the processing lines and end-products of powdered infant formula. Food Microbiol 2018; 80:50-61. [PMID: 30704596 DOI: 10.1016/j.fm.2018.12.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/20/2018] [Accepted: 12/21/2018] [Indexed: 01/14/2023]
Abstract
Although nitrite in powdered milk formula (PIF) is a recognized health risk for infants, the presence of nitrite in PIF has only been investigated as a chemical contaminant during the inspection of end-products. The risk posed by microbial sources of nitrite during the PIF manufacturing process has not been considered. This is the first study to report the taxonomy and physiological characteristics of nitrite-producing bacteria isolated from PIF processing environments. All isolates identified as nitrite-producers (133 out of 501 strains collected over four years) from work-in-process and end-products of PIF were spore-forming bacilli. Nitrite-producing metabolism under PIF processing conditions was found in not only thermophilic isolates (3 Bacillus, 60 Geobacillus from 63 strains; 100%) but also in mesophilic isolates (65 Bacillus, 1 Anoxybacillus from 70 strains; 65.7%). Geobacillus was the only highly heat-resistant sporeformer and vigorous nitrite-producer exhibiting dramatic increases in nitrite over short periods of incubation (a maximum value within 3 h). High conversions of nitrate to nitrite (up to 88.8%) was also observed, highlighting bacteria as a key source of nitrite in PIF processing lines. Further research into the diversity of metabolic activity observed in this study can facilitate specialized management of nitrite-producers in PIF processing lines.
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Affiliation(s)
- Tae Jin Cho
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, South Korea
| | - Min Suk Rhee
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, South Korea.
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41
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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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Survival variability of 12 strains of Bacillus cereus yielded to spray drying of whole milk. Int J Food Microbiol 2018; 286:80-89. [DOI: 10.1016/j.ijfoodmicro.2018.07.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 07/09/2018] [Accepted: 07/16/2018] [Indexed: 11/20/2022]
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Daqu Fermentation Selects for Heat-Resistant Enterobacteriaceae and Bacilli. Appl Environ Microbiol 2018; 84:AEM.01483-18. [PMID: 30120119 DOI: 10.1128/aem.01483-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 08/15/2018] [Indexed: 11/20/2022] Open
Abstract
Daqu is a spontaneous solid-state cereal fermentation used as saccharification and starter culture in Chinese vinegar and liquor production. The evolution of microbiota in this spontaneous fermentation is controlled by the temperature profile, which reaches temperatures from 50 to 65°C for several days. Despite these high temperatures, mesophilic Enterobacteriaceae (including Cronobacter) and bacilli are present throughout Daqu fermentation. This study aimed to determine whether Daqu spontaneous solid-state fermentation selects for heat-resistant variants of these organisms. Heat resistance in Enterobacteriaceae is mediated by the locus of heat resistance (LHR). One LHR-positive strain of Kosakonia cowanii was identified in Daqu, and it exhibited higher heat resistance than the LHR-negative K. cowanii isolated from malted oats. Heat resistance in Bacillus endospores is mediated by the spoVA 2mob operon. Out of 10 Daqu isolates of the species Bacillus licheniformis, Brevibacillus parabrevis, Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus velezensis, 5 did not contain spoVA 2mob, 3 contained one copy, and 2 contained two copies. The presence and copy number of the spoVA 2mob operon increased the resistance of spores to treatment with 110°C. To confirm the selection of LHR- and spoVA 2mob-positive strains during Daqu fermentation, the copy numbers of these genetic elements in Daqu samples were quantified by quantitative PCR (qPCR). The abundance of LHR and the spoVA 2mob operon in community DNA relative to that of total bacterial 16S rRNA genes increased 3-fold and 5-fold, respectively, during processing. In conclusion, culture-dependent and culture-independent analyses suggest that Daqu fermentation selects for heat-resistant Enterobacteriaceae and bacilli.IMPORTANCE Daqu fermentations select for mobile genetic elements conferring heat resistance in Enterobacteriaceae and bacilli. The locus of heat resistance (LHR), a genomic island conferring heat resistance in Enterobacteriaceae, and the spoVA 2mob operon, conferring heat resistance on bacterial endospores, were enriched 3- to 5-fold during Daqu fermentation and maturation. It is therefore remarkable that the LHR and the spoVA 2mob operon are accumulated in the same food fermentation. The presence of heat-resistant Kosakonia spp. and Bacillus spp. in Daqu is not of concern for food safety; however, both genomic islands are mobile and transferable to pathogenic bacteria or toxin-producing bacteria by horizontal gene transfer. The identification of the LHR and the spoVA 2mob operon as indicators of fitness of Enterobacteriaceae and bacilli in Daqu fermentation provides insights into environmental sources of heat-resistant organisms that may contaminate the food supply.
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44
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Microbiota of milk powders and the heat resistance and spoilage potential of aerobic spore-forming bacteria. Int Dairy J 2018. [DOI: 10.1016/j.idairyj.2018.06.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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45
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Cho TJ, Kim HW, Kim NH, Park SM, Kwon JI, Kim YJ, Lee KW, Rhee MS. New insights into the thermophilic spore-formers in powdered infant formula: Implications of changes in microbial composition during manufacture. Food Control 2018. [DOI: 10.1016/j.foodcont.2018.05.036] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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46
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Sadek ZI, Abdel-Rahman MA, Azab MS, Darwesh OM, Hassan MS. Microbiological evaluation of infant foods quality and molecular detection of Bacillus cereus toxins relating genes. Toxicol Rep 2018; 5:871-877. [PMID: 30167378 PMCID: PMC6111046 DOI: 10.1016/j.toxrep.2018.08.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/23/2018] [Accepted: 08/16/2018] [Indexed: 12/19/2022] Open
Abstract
A 205 samples representing eight different infant foods with various based materials were collected and analyzed for their microbiological properties. The contamination rate by aerobic spore formers was achieved 100% in milk based infant food with fruit, vegetables, honey, rice and infant milk powder. While, it was detected in 95, 60 and 65% of the infant food with wheat milk based, ready to use (infant food with fruit) and ready to use (infant food with vegetables), respectively. Biochemical Identification and API 50 CHB used to identify the obtained isolates and revealed that B. subtilis was the most frequently occurring Bacillus spp. Followed by B. licheniformis and B. circulans. While B. cereus was detected in 10.20% of the total isolates. Moreover, B. cereus was confirmed in 21.2% of milk based fruit, vegetables (15.7%), honey (17.2%), rice (14.1%) and wheat (12%) and vanished in the infant milk powder samples. Although, B. cereus noted in lower percentage but this strain is considered as the more harmful one in lower numbers. For that, the following part is focused on B. cereus. Forty five isolates obtained from B. Cereus contaminating samples were screened for prevalence of 3 important virulent enterotoxigenic genes using PCR technique. The CYTK gene had the highest presence which detected in 43 isolates (95.5%), followed by NHEC gene detected in 32 isolates. However, the HBLA gene was detected in just 5 isolates. So, many processes should be applied for controlling of pathogens to preserve infant lives.
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Affiliation(s)
- Zeinab I. Sadek
- Dairy Science Dept., National Research Centre, 33 Elbohoth St., Dokki, Cairo, Egypt
| | - Mohamed A. Abdel-Rahman
- Botany and Microbiology Dept., Faculty of Science (Boys branch), Al-Azhar University, Nasr City, Cairo, Egypt
| | - Mohamed S. Azab
- Botany and Microbiology Dept., Faculty of Science (Boys branch), Al-Azhar University, Nasr City, Cairo, Egypt
| | - Osama M. Darwesh
- Agricultural Microbiology Dept., National Research Centre, 33 Elbohoth St., Dokki, Cairo, Egypt
| | - Mahmoud S. Hassan
- Botany and Microbiology Dept., Faculty of Science (Boys branch), Al-Azhar University, Nasr City, Cairo, Egypt
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47
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Doyle CJ, O'Toole PW, Cotter PD. Genomic Characterization of Sulphite Reducing Bacteria Isolated From the Dairy Production Chain. Front Microbiol 2018; 9:1507. [PMID: 30026740 PMCID: PMC6041559 DOI: 10.3389/fmicb.2018.01507] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/18/2018] [Indexed: 11/25/2022] Open
Abstract
Anaerobic sporeformers, specifically spoilage and pathogenic members of the genus Clostridium, are a concern for producers of dairy products, and of powdered dairy products in particular. As an alternative to testing for individual species, the traditional, and still current, approach to detecting these sporeformers, including non-spoilage/non-pathogenic species, in dairy products has involved testing for a sulphite reducing phenotype [Sulphite reducing Clostridia (SRCs)] under anaerobic conditions. This phenotype is conserved throughout the Order Clostridia. Unfortunately, however, this phenotype is exhibited by other sulphite reducing bacteria (SRBs) also, potentially leading to potential for false positives. Here, this risk was borne out through the identification of several SRBs from industry samples that were identified as Proteus mirabilis and various Bacillus/Paenibacillus sp. Genome wide comparison of a number of representative SRCs and SRBs was employed to determine phylogenetic relationships, especially among SRCs, and to characterize the genes responsible for the sulphite reducing phenotype. This screen identified two associated operons, i.e., asrABC in SRCs, and cysJI in Bacillus/Paenibacillus spp. and P. mirabilis. This screen identified spp. belonging to sensu stricto, Lachnospiraceae and Cluster XIV of the Clostridia all producing the SRC phenotype. This study highlights the inaccuracy of the industry standard SRC test but highlights the potential to generate an equivalent molecular test designed to detect the genes responsible for this phenotype in clostridia.
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Affiliation(s)
- Conor J Doyle
- Teagasc Food Research Centre, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
| | - Paul W O'Toole
- School of Microbiology, University College Cork, Cork, Ireland.,APC Microbiome Ireland, Cork, Ireland
| | - Paul D Cotter
- Teagasc Food Research Centre, Cork, Ireland.,APC Microbiome Ireland, Cork, Ireland
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48
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Pereira APM, Sant’Ana AS. Diversity and fate of spore forming bacteria in cocoa powder, milk powder, starch and sugar during processing: A review. Trends Food Sci Technol 2018. [DOI: 10.1016/j.tifs.2018.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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49
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Guimarães JT, Silva EK, Alvarenga VO, Costa ALR, Cunha RL, Sant'Ana AS, Freitas MQ, Meireles MAA, Cruz AG. Physicochemical changes and microbial inactivation after high-intensity ultrasound processing of prebiotic whey beverage applying different ultrasonic power levels. ULTRASONICS SONOCHEMISTRY 2018; 44:251-260. [PMID: 29680610 DOI: 10.1016/j.ultsonch.2018.02.012] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/13/2018] [Accepted: 02/06/2018] [Indexed: 06/08/2023]
Abstract
In this work, we investigated the effects of the ultrasonic power (0, 200, 400 and 600 W) on non-thermal processing of an inulin-enriched whey beverage. We studied the effects of high-intensity ultrasound (HIUS) on microbial inactivation (aerobic mesophilic heterotrophic bacteria (AMHB), total and thermotolerant coliforms and yeasts and molds), zeta potential, microstructure (optical microscopy, particle size distribution), rheology, kinetic stability and color. The non-thermal processing applying 600 W of ultrasonic power was comparable to high-temperature short-time (HTST) treatment (75 °C for 15 s) concerning the inactivation of AMHB and yeasts and molds (2 vs 2 log and 0.2 vs 0.4 log, respectively), although HIUS has reached a lower output temperature (53 ± 3 °C). The HIUS was better than HTST to improve beverage kinetic stability, avoiding phase separation, which was mainly attributed to the decrease of particles size, denaturation of whey proteins and gelation of polysaccharides (inulin and gellan gum). Thus, non-thermal processing by HIUS seems to be an interesting technology for prebiotic dairy beverages production.
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Affiliation(s)
- Jonas T Guimarães
- Department of Food Technology, Faculty of Veterinary, Fluminense Federal University, Niterói, RJ, Brazil
| | - Eric Keven Silva
- School of Food Engineering, University of Campinas (UNICAMP), Campinas, SP, Brazil.
| | - Verônica O Alvarenga
- School of Food Engineering, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Ana Letícia R Costa
- School of Food Engineering, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Rosiane L Cunha
- School of Food Engineering, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Anderson S Sant'Ana
- School of Food Engineering, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Monica Q Freitas
- Department of Food Technology, Faculty of Veterinary, Fluminense Federal University, Niterói, RJ, Brazil
| | - M Angela A Meireles
- School of Food Engineering, University of Campinas (UNICAMP), 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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50
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Thermal treatment of skim milk concentrates in a novel shear-heating device: Reduction of thermophilic spores and physical properties. Food Res Int 2018; 107:19-26. [DOI: 10.1016/j.foodres.2018.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 02/01/2018] [Accepted: 02/01/2018] [Indexed: 11/23/2022]
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