1
|
Somerton BT, Morgan BL. Comparison of plate counting with flow cytometry, using four different fluorescent dye techniques, for the enumeration of Bacillus cereus in milk. J Microbiol Methods 2024; 223:106978. [PMID: 38936432 DOI: 10.1016/j.mimet.2024.106978] [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: 05/17/2024] [Revised: 06/23/2024] [Accepted: 06/24/2024] [Indexed: 06/29/2024]
Abstract
This study aimed to compare the performance of flow cytometry methods with plate counting for the enumeration of bacteria, using Bacillus cereus as a model organism. It was found that the cFDA-propidium iodide, CellROX™ Green-propidium iodide, and DiOC2 dye techniques had similar accuracy to plate counting, while the SYTO 24-propidium iodide dye technique was not as accurate. The four dye techniques had comparable precision to plate counting, with the CellROX™ Green-propidium iodide dye having the greatest precision. The consistency of the position and shape of the cell clusters on the flow cytometry plots, and the extent of separation of the cell from background clusters, was greatest with the DiOC2 and CellROX™ Green-propidium iodide dyes. Furthermore, the DiOC2 and CellROX™ Green-propidium iodide dyes performed well, even when a sample was measured containing reconstituted whole milk powder at a 10-1 dilution, without the use of sample preparation to specifically remove the milk constituents prior to measurement. Given gating of only one cell cluster was required to be managed with the DiOC2 dye, to determine the viable number of cells, it was found that the DiOC2 dye had the greatest ease-of-use. Overall, results indicated that the DiOC2 dye is an ideal candidate for the enumeration of viable bacteria in dairy samples on a high-throughput, routine basis.
Collapse
Affiliation(s)
- Ben T Somerton
- Fonterra Research & Development Centre, Fonterra, Palmerston North, New Zealand.
| | - Brooke L Morgan
- Fonterra Research & Development Centre, Fonterra, Palmerston North, New Zealand
| |
Collapse
|
2
|
Poscente V, Di Gregorio L, Costanzo M, Bernini R, Bevivino A. Flow cytometry: Unravelling the real antimicrobial and antibiofilm efficacy of natural bioactive compounds. J Microbiol Methods 2024; 222:106956. [PMID: 38759758 DOI: 10.1016/j.mimet.2024.106956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 05/14/2024] [Accepted: 05/14/2024] [Indexed: 05/19/2024]
Abstract
Flow cytometry (FCM) provides unique information on bacterial viability and physiology, allowing a real-time early warning antimicrobial and antibiofilm monitoring system for preventing the spread risk of foodborne disease. The present work used a combined culture-based and FCM approach to assess the in vitro efficacy of essential oils (EOs) from condiment plants commonly used in Mediterranean Europe (i.e., thyme EO, oregano EO, basil EO, and lemon EO) against planktonic and sessile cells of food-pathogenic Listeria monocytogenes 56 LY, and contaminant and alterative species Escherichia coli ATCC 25922 and Pseudomonas fluorescens ATCC 13525. Evaluation of the bacterial response to the increasing concentrations of natural compounds posed FCM as a crucial technique for the quantification of the live/dead, and viable but non-culturable (VBNC) cells when antimicrobial agents exert no real bactericidal action. Furthermore, the FCM results displayed higher numbers of viable bacteria expressed as Active Fluorescent Units (AFUs) with a greater level of repeatability compared with outcomes of the plate-count method. Overall, accurate counting of viable microbial cells is a critically important parameter in food microbiology, and flow cytometry provides an innovative approach with high-throughput potential for applications in the food industry as "flow microbiology".
Collapse
Affiliation(s)
- Valeria Poscente
- Department for Sustainability, Biotechnologies and Agroindustry Division, ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Casaccia Research Center, 00123 Rome, Italy; Department of Agriculture and Forest Sciences, University of Tuscia, 01100 Viterbo, Italy
| | - Luciana Di Gregorio
- Department for Sustainability, Biotechnologies and Agroindustry Division, ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Casaccia Research Center, 00123 Rome, Italy.
| | - Manuela Costanzo
- Department for Sustainability, Biotechnologies and Agroindustry Division, ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Casaccia Research Center, 00123 Rome, Italy
| | - Roberta Bernini
- Department of Agriculture and Forest Sciences, University of Tuscia, 01100 Viterbo, Italy
| | - Annamaria Bevivino
- Department for Sustainability, Biotechnologies and Agroindustry Division, ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Casaccia Research Center, 00123 Rome, Italy
| |
Collapse
|
3
|
Pîndaru AM, Măruțescu L, Popa M, Chifiriuc MC. A Label-Free Optical Flow Cytometry Based-Method for Rapid Assay of Disinfectants' Bactericidal Activity. Int J Mol Sci 2024; 25:7158. [PMID: 39000264 PMCID: PMC11241575 DOI: 10.3390/ijms25137158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 07/16/2024] Open
Abstract
Selecting the appropriate disinfectant to control and prevent healthcare-associated infections (HAIs) is a challenging task for environmental health experts due to the large number of available disinfectant products. This study aimed to develop a label-free flow cytometry (FCM) method for the rapid evaluation of bactericidal activity and to compare its efficacy with that of standard qualitative/quantitative suspension tests. The bactericidal efficiency of eight commercial disinfectants containing quaternary ammonium compounds (QACs) was evaluated against four strains recommended by EN 13727 (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus hirae) and four multidrug-resistant pathogens. The proposed FCM protocol measures changes in scattered light and counts following disinfectant exposure, neutralization, and culture steps. Unlike other available FCM-based methods, this approach does not rely on autofluorescence measurements, impedance cytometry, or fluorescent dyes. The FCM scattered light signals revealed both decreased count rates and morphological changes after treatment with minimum inhibitory concentrations (MICs) and higher concentrations for all tested bacteria. The results from the FCM measurements showed excellent correlation with those from standard assays, providing a rapid tool for monitoring the susceptibility profile of clinical, multidrug-resistant pathogens to chemical disinfectants, which could support infection prevention and control procedures for healthcare environments. This label-free FCM protocol offers a novel and rapid tool for environmental health experts, aiding in the optimization of disinfectant selection for the prevention and control of HAIs.
Collapse
Affiliation(s)
- Andreea Maria Pîndaru
- Department of Botany and Microbiology, Faculty of Biology, University of Bucharest, 91-95 Splaiul Independentei, 050095 Bucharest, Romania; (A.M.P.); (M.C.C.)
| | - Luminița Măruțescu
- Department of Botany and Microbiology, Faculty of Biology, University of Bucharest, 91-95 Splaiul Independentei, 050095 Bucharest, Romania; (A.M.P.); (M.C.C.)
- Research Institute of University of Bucharest, University of Bucharest, 050663 Bucharest, Romania;
| | - Marcela Popa
- Research Institute of University of Bucharest, University of Bucharest, 050663 Bucharest, Romania;
| | - Mariana Carmen Chifiriuc
- Department of Botany and Microbiology, Faculty of Biology, University of Bucharest, 91-95 Splaiul Independentei, 050095 Bucharest, Romania; (A.M.P.); (M.C.C.)
- Research Institute of University of Bucharest, University of Bucharest, 050663 Bucharest, Romania;
| |
Collapse
|
4
|
de Vasconcelos Medeiros GKV, Martins ACS, Vasconcelos MG, Garcia EF, Rodrigues NPA, de Albuquerque TMR, Viera VB, da Conceição ML, de Souza EL, de Oliveira MEG. Cereus jamacaru DC. (mandacaru) fruit as a source of lactic acid bacteria with in vitro probiotic-related characteristics and its protective effects on Pediococcus pentosaceus during lyophilization and refrigeration storage. Int J Food Microbiol 2024; 417:110695. [PMID: 38636163 DOI: 10.1016/j.ijfoodmicro.2024.110695] [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: 01/12/2024] [Revised: 03/23/2024] [Accepted: 04/06/2024] [Indexed: 04/20/2024]
Abstract
This study isolated and identified autochthonous lactic acid bacteria (LAB) from mandacaru fruit and evaluated their potential probiotic and technological aptitudes in vitro, as well as the protective effects of freeze-dried mandacaru fruit on the most promising LAB isolate during lyophilization and refrigeration storage. Initially, 212 colonies were isolated from mandacaru fruit, and 34 were preliminarily identified as LAB. Thirteen isolates identified by 16S-rRNA sequencing as Pediococcus pentosaceus were negative for DNase, gelatinase, hemolytic, and biogenic amine production. The selected isolates showed proteolytic activity, diacetyl and exopolysaccharide production, and good tolerance to different NaCl concentrations while having low cellular hydrophobicity and antagonistic activity against pathogens. The survival of isolates sharply decreased after 3 h of exposure to pH 2 and had a good tolerance to 1 % bile salt. A principal component analysis selected P. pentosaceus 57 as the most promising isolate based on the examined technological and probiotic-related physiological properties. This isolate was lyophilized with mandacaru fruit and stored under refrigeration for 90 days. P. pentosaceus 57 lyophilized with mandacaru fruit had high viable cell counts (9.69 ± 0.03 log CFU/mL) and >50 % of physiologically active cells at 90 days of refrigeration storage. The results indicate that mandacaru fruit is a source of P. pentosaceus with aptitudes to be explored as potential probiotic and technological characteristics of interest for the food industry, besides being a good candidate for use in lyophilization processes and refrigeration storage of LAB due to its cryoprotective effects.
Collapse
Affiliation(s)
| | - Ana Cristina Silveira Martins
- Post-Graduate Program in Food Science and Technology, Department of Food Engineering, Federal University of Paraíba, João Pessoa 58051-900, Brazil
| | - Mateus Gomes Vasconcelos
- Laboratory of Bromatology, Department of Nutrition, Center of Health Sciences, Federal University of Paraíba, João Pessoa 58051-900, Brazil
| | - Estefânia Fernandes Garcia
- Department of Gastronomy, Center for Technology and Regional Development, Federal University of Paraíba, João Pessoa 58058-600, Brazil
| | - Noádia Priscila Araújo Rodrigues
- Department of Gastronomy, Center for Technology and Regional Development, Federal University of Paraíba, João Pessoa 58058-600, Brazil
| | | | - Vanessa Bordin Viera
- Laboratory of Bromatology, Center of Education and Health, Federal University of Campina Grande, Cuité 58175-000, Brazil
| | - Maria Lúcia da Conceição
- Laboratory of Food Microbiology, Department of Nutrition, Federal University of Paraíba, João Pessoa 58051-900, Brazil
| | - Evandro Leite de Souza
- Laboratory of Food Microbiology, Department of Nutrition, Federal University of Paraíba, João Pessoa 58051-900, Brazil
| | - Maria Elieidy Gomes de Oliveira
- Laboratory of Bromatology, Department of Nutrition, Center of Health Sciences, Federal University of Paraíba, João Pessoa 58051-900, Brazil.
| |
Collapse
|
5
|
Zhao Q, Zhao Q, Li J, Yi L. Antibacterial Activity and Action Mechanism of Bacteriocin Paracin wx7 as a Selective Biopreservative against Vancomycin-Resistant Enterococcus faecalis in Fresh-Cut Lettuce. Foods 2024; 13:1448. [PMID: 38790749 PMCID: PMC11119456 DOI: 10.3390/foods13101448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Revised: 05/03/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024] Open
Abstract
Fresh-cut vegetables are widely consumed, but there is no food preservative available to selectively inhibit vancomycin-resistant E. faecalis, which is a serious health menace in fresh-cut vegetables. To develop a promising food biopreservative, a bacteriocin, paracin wx7, was synthesized, showing selective inhibition against E. faecalis with MIC values of 4-8 μM. It showed instant bactericidal mode within 1 h at high concentrations with concomitant cell lysis against vancomycin-resistant E. faecalis. Its lethal effect was visualized in a dose-dependent manner by PI/SYTO9 staining observation. The results of an in vivo control experiment carried out on E. faecalis in fresh-cut lettuce showed that 99.97% of vancomycin-resistant E. faecalis were dead after 64 μM paracin wx7 treatment for 7 days without influencing total bacteria. Further, the action mechanism of paracin wx7 was investigated. Confocal microscopy showed that paracin wx7 was located both on the cell envelope and in cytoplasm. For the cell envelope, the studies of membrane permeability using SYTOX Green dyeing and DNA leakage revealed that paracin wx7 damaged the membrane integrity of E. faecalis. Simultaneously, it exhibited membrane depolarization after analysis using DiSC3(5). Damage to the cell envelope resulted in cell deformation observed by scanning electron microscopy. On entering the cytoplasm, the paracin wx7 induced the production of endogenous reactive oxygen species.
Collapse
Affiliation(s)
- Qian Zhao
- College of Food Science, Southwest University, Chongqing 400715, China
| | - Qingling Zhao
- College of Food Science, Southwest University, Chongqing 400715, China
| | - Jiabo Li
- College of Food Science, Southwest University, Chongqing 400715, China
| | - Lanhua Yi
- College of Food Science, Southwest University, Chongqing 400715, China
- Research Center for Fruits and Vegetables Logistics Preservation and Nutritional Quality Control, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, Southwest University, Chongqing 400715, China
| |
Collapse
|
6
|
Shehata HR, Hassane B, Newmaster SG. Real-time PCR methods for identification and stability monitoring of Bifidobacterium longum subsp. longum UABl-14 during shelf life. Front Microbiol 2024; 15:1360241. [PMID: 38706967 PMCID: PMC11066167 DOI: 10.3389/fmicb.2024.1360241] [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: 12/22/2023] [Accepted: 04/03/2024] [Indexed: 05/07/2024] Open
Abstract
Bifidobacterium longum subsp. longum UABl-14™ is an important probiotic strain that was found to support digestive health. Here we present the development and validation of real-time PCR methods for strain-specific identification and enumeration of this important strain. The identification method was evaluated for specificity using 22 target samples and 30 non-target samples. All target samples successfully amplified, while no amplification was observed from any non-target samples including other B. longum strains. The identification method was evaluated for sensitivity using three DNA dilution series and the limit of detection was 2 pg. of DNA. Coupled with a viability dye, the method was further validated for quantitative use to enumerate viable cells of UABl-14. The viability dye treatment (PMAxx) was optimized, and a final concentration of 50 μM was found as an effective concentration to inactivate DNA in dead cells from reacting in PCR. The reaction efficiency, linear dynamic range, repeatability, and reproducibility were also evaluated. The reaction efficiency was determined to be 97.2, 95.2, and 95.0% with R2 values of 99%, in three replicates. The linear dynamic range was 1.3 × 102 to 1.3 × 105 genomes. The relative standard deviation (RSD%) for repeatability ranged from 0.03 to 2.80, and for reproducibility ranged from 0.04 to 2.18. The ability of the validated enumeration method to monitor cell counts during shelf life was evaluated by determining the viable counts and total counts of strain UABl-14 in 18 multi-strain finished products. The viable counts were lower than label claims in seven products tested post-expiration and were higher than label claims in products tested pre-expiration, with a slight decrease in viable counts below label claim in three samples that were tested 2-3 months pre-expiration. Interestingly, the total counts of strain UABl-14 were consistently higher than label claims in all 18 products. Thus, the method enables strain-specific stability monitoring in finished products during shelf life, which can be difficult or impossible to achieve using the standard plate count method. The validated methods allow for simultaneous and cost-effective identification and enumeration of strain UABl-14 and represent an advancement in the quality control and quality assurance of probiotics.
Collapse
Affiliation(s)
- Hanan R. Shehata
- Purity-IQ Inc., Guelph, ON, Canada
- Department of Integrative Biology, College of Biological Science, University of Guelph, Guelph, ON, Canada
- Department of Microbiology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | | | - Steven G. Newmaster
- Department of Integrative Biology, College of Biological Science, University of Guelph, Guelph, ON, Canada
| |
Collapse
|
7
|
Marole TA, Sibanda T, Buys EM. Assessing probiotic viability in mixed species yogurt using a novel propidium monoazide (PMAxx)-quantitative PCR method. Front Microbiol 2024; 15:1325268. [PMID: 38389538 PMCID: PMC10882272 DOI: 10.3389/fmicb.2024.1325268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/29/2024] [Indexed: 02/24/2024] Open
Abstract
Viability is a prerequisite for any therapeutic benefits associated with the ingestion of probiotic bacteria. Current culture-based techniques are inadequate for the enumeration of probiotics in mixed-species food products. This study utilized a quantitative PCR (qPCR) method coupled with propidium monoazide (PMAxx), and novel species-specific tuf gene primers to selectively enumerate Lacticaseibacillus rhamnosus, Bifidobacterium spp., and yogurt starter cultures in mixed-species probiotic yogurt. The method was optimized for PMAxx concentration and specificity and evaluated for efficiency and applicability. PMAxx-qPCR showed high specificity to the target organisms in mixed-species yogurt, quantifying only viable cells. The linear dynamic ranges were established over five to seven orders of magnitude. The assay was reliable with an efficiency of 91-99%, R2 values > 0.99, and a good correlation to the plate count method (r = 0.882). The results of this study demonstrate the high selectivity, improved lead time, and reliability of PMAxx-qPCR over the culture-dependent method, making it a valuable tool for inline viability verification during processing and improving probiotic quality assurance for processors and consumers.
Collapse
Affiliation(s)
- Tlaleo A Marole
- Department of Consumer and Food Sciences, University of Pretoria, Pretoria, South Africa
| | - Thulani Sibanda
- Department of Consumer and Food Sciences, University of Pretoria, Pretoria, South Africa
| | - Elna M Buys
- Department of Consumer and Food Sciences, University of Pretoria, Pretoria, South Africa
| |
Collapse
|
8
|
Karwowski MSM, Sayuri Kassuia Y, Turchenski DG, Aust ACCDO, Macedo REFD. Novel immobilization method of Lactiplantibacillus plantarum in grains for dry food products. FOOD SCI TECHNOL INT 2024:10820132231224240. [PMID: 38178778 DOI: 10.1177/10820132231224240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
This study aimed to assess the potential use of grains (amaranth, millet, and quinoa) as immobilizing matrices on the metabolic activity of Lactiplantibacillus plantarum and evaluate the viability of the probiotic immobilized in millet during simulated oro-gastrointestinal digestion (OGI) and storage. Firstly, different grains, sterilization and immobilization times were assessed. Secondly, Lp. plantarum was immobilized in millet and its viability and metabolic activity were assessed during non-refrigerated long-term storage and OGI. Metabolic activity was higher with 15 min. of grain sterilization and 72 h of immobilization. Lp. plantarum in millet showed the highest count. Millet grains were able to maintain the high population (>7 log CFU/g) and the metabolic activity of Lp. plantarum during up to 150 d of storage and conferred a protective effect on entrapped probiotic cells during OGI. Millet is a promising immobilizing matrix for the addition of probiotics in dry food products.
Collapse
Affiliation(s)
- Marilia Silva Malvezzi Karwowski
- Laboratory of Agri-food Research and Innovation, Graduate Program in Animal Science, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Yasmine Sayuri Kassuia
- Undergraduate Program in Biotechnology, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Daniela Góes Turchenski
- Laboratory of Agri-food Research and Innovation, Graduate Program in Animal Science, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Ana Carolina Camargo de Oliveira Aust
- Laboratory of Agri-food Research and Innovation, Graduate Program in Animal Science, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| | - Renata Ernlund Freitas de Macedo
- Laboratory of Agri-food Research and Innovation, Graduate Program in Animal Science, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Brazil
| |
Collapse
|
9
|
Zimmermann JA, Sirini N, Olivero CR, Renna MS, Signorini ML, Zbrun MV, Frizzo LS, Soto LP. Macroencapsulation of Limosilactobacillus reuteri DSPV002C as nutritional supplement for piglets: Storage stability and survival in gastrointestinal conditions. Rev Argent Microbiol 2024; 56:90-101. [PMID: 37923699 DOI: 10.1016/j.ram.2023.07.005] [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: 06/27/2022] [Revised: 06/05/2023] [Accepted: 07/05/2023] [Indexed: 11/07/2023] Open
Abstract
The aim of this study was to evaluate the protective effect of the encapsulation of Limosilactobacillus reuteri DSPV002C in macrocapsules made from industrial materials during production, storage and under simulated gastrointestinal conditions in vitro and in vivo. The production of macrocapsules involved the evaluation of different wall materials (matrix), namely, gelatin and pregelatinized starch, different inoculums, matrix ratios, and diverse cryoprotectants (whey permeate and maltodextrin). The different macrocapsules were arranged in molds of similar size to pig pelleted food and lyophilized. Then, the viability of the macrocapsules was assessed over time during storage at different temperatures (freezing, refrigeration and room temperature) and atmospheres (vacuum and non-vaccum). The macrocapsules with 10% w/v gelatin+5% w/v pregelatinized starch, permeated (10%, w/v), with a 9:1 inoculum:matrix ratio (GS7.5P9), stored under freezing conditions and vacuum, exhibited the highest viability of L. reuteri DSPV002C (9.3 log CFU/cap until 210 d). Under simulated gastrointestinal conditions, the encapsulated inoculum showed less viability loss (0.58±0.09 log CFU/ml, 26.53%), compared to the free culture (1.56±0.16 log CFU/ml, 2.85%). Finally, by administering GS7.5P9 to pigs, the tolerance of the bacteria to the gastrointestinal environment was verified, with viable counts equal to or greater than 3.72 log CFU/g of fecal matter throughout the trial. In this study, a high-density carrier probiotic macrocapsule of L. reuteri DSPV002C was obtained, which displayed a long shelf life, a suitable shape to be included in pig feed and an adequate survival of viable cells at the site of action.
Collapse
Affiliation(s)
- Jorge Alberto Zimmermann
- Laboratory of Food Analysis, Institute of Veterinary Science, National University of the Littoral, National Council of Scientific and Technical Research, Kreder 2805, S3080HOF Esperanza, Province of Santa Fe, Argentina
| | - Noelí Sirini
- Laboratory of Food Analysis, Institute of Veterinary Science, National University of the Littoral, National Council of Scientific and Technical Research, Kreder 2805, S3080HOF Esperanza, Province of Santa Fe, Argentina
| | - Carolina Raquel Olivero
- Laboratory of Food Analysis, Institute of Veterinary Science, National University of the Littoral, National Council of Scientific and Technical Research, Kreder 2805, S3080HOF Esperanza, Province of Santa Fe, Argentina
| | - María Sol Renna
- Laboratory of Applied Cellular and Molecular Biology, Institute of Veterinary Science, National University of the Littoral, National Council of Scientific and Technical Research, Kreder 2805, S3080HOF Esperanza, Province of Santa Fe, Argentina
| | - Marcelo Lisandro Signorini
- Department of Public Health, Faculty of Veterinary Science, National University of the Littoral, Kreder 2805, S3080HOF Esperanza, Province of Santa Fe, Argentina; National Council of Scientific and Technical Research, National Institute of Agricultural Technology EEA Rafaela, Ruta 34 Km 227, 2300 Rafaela, Province of Santa Fe, Argentina.
| | - María Virginia Zbrun
- Laboratory of Food Analysis, Institute of Veterinary Science, National University of the Littoral, National Council of Scientific and Technical Research, Kreder 2805, S3080HOF Esperanza, Province of Santa Fe, Argentina; Department of Public Health, Faculty of Veterinary Science, National University of the Littoral, Kreder 2805, S3080HOF Esperanza, Province of Santa Fe, Argentina
| | - Laureano Sebastián Frizzo
- Laboratory of Food Analysis, Institute of Veterinary Science, National University of the Littoral, National Council of Scientific and Technical Research, Kreder 2805, S3080HOF Esperanza, Province of Santa Fe, Argentina; Department of Public Health, Faculty of Veterinary Science, National University of the Littoral, Kreder 2805, S3080HOF Esperanza, Province of Santa Fe, Argentina
| | - Lorena Paola Soto
- Laboratory of Food Analysis, Institute of Veterinary Science, National University of the Littoral, National Council of Scientific and Technical Research, Kreder 2805, S3080HOF Esperanza, Province of Santa Fe, Argentina; Department of Public Health, Faculty of Veterinary Science, National University of the Littoral, Kreder 2805, S3080HOF Esperanza, Province of Santa Fe, Argentina
| |
Collapse
|
10
|
Boyte ME, Benkowski A, Pane M, Shehata HR. Probiotic and postbiotic analytical methods: a perspective of available enumeration techniques. Front Microbiol 2023; 14:1304621. [PMID: 38192285 PMCID: PMC10773886 DOI: 10.3389/fmicb.2023.1304621] [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: 09/29/2023] [Accepted: 11/20/2023] [Indexed: 01/10/2024] Open
Abstract
Probiotics are the largest non-herbal/traditional dietary supplements category worldwide. To be effective, a probiotic strain must be delivered viable at an adequate dose proven to deliver a health benefit. The objective of this article is to provide an overview of the various technologies available for probiotic enumeration, including a general description of each technology, their advantages and limitations, and their potential for the future of the probiotics industry. The current "gold standard" for analytical quantification of probiotics in the probiotic industry is the Plate Count method (PC). PC measures the bacterial cell's ability to proliferate into detectable colonies, thus PC relies on cultivability as a measure of viability. Although viability has widely been measured by cultivability, there has been agreement that the definition of viability is not limited to cultivability. For example, bacterial cells may exist in a state known as viable but not culturable (VBNC) where the cells lose cultivability but can maintain some of the characteristics of viable cells as well as probiotic properties. This led to questioning the association between viability and cultivability and the accuracy of PC in enumerating all the viable cells in probiotic products. PC has always been an estimate of the number of viable cells and not a true cell count. Additionally, newer probiotic categories such as Next Generation Probiotics (NGPs) are difficult to culture in routine laboratories as NGPs are often strict anaerobes with extreme sensitivity to atmospheric oxygen. Thus, accurate quantification using culture-based techniques will be complicated. Another emerging category of biotics is postbiotics, which are inanimate microorganisms, also often referred to as tyndallized or heat-killed bacteria. Obviously, culture dependent methods are not suitable for these products, and alternative methods are needed for their quantification. Different methodologies provide a more complete picture of a heterogeneous bacterial population versus PC focusing exclusively on the eventual multiplication of the cells. Alternative culture-independent techniques including real-time PCR, digital PCR and flow cytometry are discussed. These methods can measure viability beyond cultivability (i.e., by measuring cellular enzymatic activity, membrane integrity or membrane potential), and depending on how they are designed they can achieve strain-specific enumeration.
Collapse
Affiliation(s)
- Marie-Eve Boyte
- NutraPharma Consulting Services Inc., Sainte-Anne-des-Plaines, QC, Canada
| | | | - Marco Pane
- Probiotical Research s.r.l., Novara, Italy
| | | |
Collapse
|
11
|
Jordal PL, Diaz MG, Morazzoni C, Allesina S, Zogno D, Cattivelli D, Galletti S, Guidesi E, Warzée JP, Pane M. Collaborative cytometric inter-laboratory ring test for probiotics quantification. Front Microbiol 2023; 14:1285075. [PMID: 38029213 PMCID: PMC10667725 DOI: 10.3389/fmicb.2023.1285075] [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: 08/29/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. From this definition, accurate enumeration of probiotic products is a necessity. Nonetheless, this definition does not specify the methods for assessing such viability. Colony forming units is the de facto gold standard for enumerating viable in probiotic products. The notion of microbial viability has been anchored in the concept of cultivability, which refers to a cell's capacity to replicate and form colonies on agar media. However, there is a growing consensus that the term "viability" should not be exclusively tied to the ability to cultivate cells. For example, bacterial cells can exist in a Viable But Non-Culturable (VBNC) state, characterized by the maintenance of characteristics such as membrane integrity, enzymatic activity, pH gradients, and elevated levels of rRNA, despite losing the ability to form colonies. Methods Herein we present the results of a collaborative inter-laboratory ring test for cytometric bacterial quantification. Specifically, membrane integrity fluorescence flow cytometry (FFC) method and the newer impedance flow cytometry (IFC) method have been used. Both methods interrogate single cells in solution for the presence of intact membranes. FFC exploits fluorochromes that reflect the presence or absence of an intact membrane. IFC probes membrane integrity in a label-free approach by detecting membrane-induced hindrances to the propagation of electricity. Results A performance ring-test and comparison design on the FFC method showed that the method is robust against the exchange of equipment, procedures, materials, and operators. After initial method optimization with assessments of rehydration medium, wake-up duration, and phase shift gating on the individual strains, the IFC method showed good agreement with the FFC results. Specifically, we tested 6 distinct species of probiotic bacteria (3 Lactobacillus and 3 Bifidobacterium strains) finding good agreement between FFC and IFC results in terms of total and live cells. Discussion Together, these results demonstrate that flow cytometry is a reliable, precise, and user-friendly culture-independent method for bacterial enumeration.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Serena Galletti
- AAT – Advanced Analytical Technologies, Fiorenzuola d’Arda, Italy
| | - Elena Guidesi
- AAT – Advanced Analytical Technologies, Fiorenzuola d’Arda, Italy
| | - Jean-Pol Warzée
- European Scientific League for Probiotics, Brussels, Belgium
| | | |
Collapse
|
12
|
Sielatycka K, Śliwa-Dominiak J, Radaczyńska M, Juzwa W, Kaczmarczyk M, Marlicz W, Skonieczna-Żydecka K, Łoniewski I. Dynamics of Active Fluorescent Units (AFU) and Water Activity (a w) Changes in Probiotic Products-Pilot Study. Foods 2023; 12:4018. [PMID: 37959137 PMCID: PMC10647652 DOI: 10.3390/foods12214018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/26/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023] Open
Abstract
The flow cytometry method (FCM) is a widely renowned practice increasingly used to assess the microbial viability of probiotic products. Additionally, the measurement of water activity (aw) can be used to confirm the presence of viable cells in probiotic products throughout their shelf lives. The aim of this study was to investigate the correlation between changes in aw and variations in active fluorescent units (AFU), a unit commonly used in flow cytometry method, during the aging of probiotic products containing freeze-dried bacteria. We controlled the stability of probiotic products for bacterial counts (using ISO 19344 method) and aw levels in commercially available capsules containing freeze-dried bacteria such as Lactobacillus sp. or combinations of Lactobacillus sp. and Bifidobacterium sp. in standard conditions (25 ± 2 °C and 60% relative humidity) over a period of 24 months. During this time, the bacterial contents decreased by 0.12 Log10 in the single-strain product, by 0.16 Log10 in the two-strain product and by 0.26 Log10 in the multi-strain product. With the increase in aw, the number of bacteria decreased but the aw at the end point of the stability study did not exceed 0.15 in each of the three tested products. FCM combined with aw is a prospective analysis that can be used to assess the stability of probiotic products, both for its ability to detect bacterial viability and for practical (analysis time) and economic reasons.
Collapse
Affiliation(s)
- Katarzyna Sielatycka
- Institute of Biology, Faculty of Exact and Natural Sciences, University of Szczecin, ul. Felczaka 3c, 71-415 Szczecin, Poland
- Sanprobi Sp. z.o.o. Sp.k., ul. Kurza Stopka 5C, 70-535 Szczecin, Poland; (J.Ś.-D.); (M.R.); (M.K.); (W.M.); (I.Ł.)
| | - Joanna Śliwa-Dominiak
- Sanprobi Sp. z.o.o. Sp.k., ul. Kurza Stopka 5C, 70-535 Szczecin, Poland; (J.Ś.-D.); (M.R.); (M.K.); (W.M.); (I.Ł.)
| | - Martyna Radaczyńska
- Sanprobi Sp. z.o.o. Sp.k., ul. Kurza Stopka 5C, 70-535 Szczecin, Poland; (J.Ś.-D.); (M.R.); (M.K.); (W.M.); (I.Ł.)
| | - Wojciech Juzwa
- Depratment of Biotechnology and Food Microbiology, Poznan University of Life Sciences, ul. Wojska Polskiego 28, 60-627 Poznań, Poland;
| | - Mariusz Kaczmarczyk
- Sanprobi Sp. z.o.o. Sp.k., ul. Kurza Stopka 5C, 70-535 Szczecin, Poland; (J.Ś.-D.); (M.R.); (M.K.); (W.M.); (I.Ł.)
| | - Wojciech Marlicz
- Sanprobi Sp. z.o.o. Sp.k., ul. Kurza Stopka 5C, 70-535 Szczecin, Poland; (J.Ś.-D.); (M.R.); (M.K.); (W.M.); (I.Ł.)
- Department of Gastroenterology, Pomeranian Medical University in Szczecin, 70-204 Szczecin, Poland
| | - Karolina Skonieczna-Żydecka
- Department of Biochemical Science, Faculty of Health Sciences, Pomeranian Medical University in Szczecin, 70-204 Szczecin, Poland;
| | - Igor Łoniewski
- Sanprobi Sp. z.o.o. Sp.k., ul. Kurza Stopka 5C, 70-535 Szczecin, Poland; (J.Ś.-D.); (M.R.); (M.K.); (W.M.); (I.Ł.)
- Department of Biochemical Science, Faculty of Health Sciences, Pomeranian Medical University in Szczecin, 70-204 Szczecin, Poland;
| |
Collapse
|
13
|
Zhang J, Ren L, Zhang L, Gong Y, Xu T, Wang X, Guo C, Zhai L, Yu X, Li Y, Zhu P, Chen R, Jing X, Jing G, Zhou S, Xu M, Wang C, Niu C, Ge Y, Ma B, Shang G, Cui Y, Yao S, Xu J. Single-cell rapid identification, in situ viability and vitality profiling, and genome-based source-tracking for probiotics products. IMETA 2023; 2:e117. [PMID: 38867931 PMCID: PMC10989769 DOI: 10.1002/imt2.117] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/22/2023] [Accepted: 05/07/2023] [Indexed: 06/14/2024]
Abstract
Rapid expansion of the probiotics industry demands fast, sensitive, comprehensive, and low-cost strategies for quality assessment. Here, we introduce a culture-free, one-cell-resolution, phenome-genome-combined strategy called Single-Cell Identification, Viability and Vitality tests, and Source-tracking (SCIVVS). For each cell directly extracted from the product, the fingerprint region of D2O-probed single-cell Raman spectrum (SCRS) enables species-level identification with 93% accuracy, based on a reference SCRS database from 21 statutory probiotic species, whereas the C-D band accurately quantifies viability, metabolic vitality plus their intercellular heterogeneity. For source-tracking, single-cell Raman-activated Cell Sorting and Sequencing can proceed, producing indexed, precisely one-cell-based genome assemblies that can reach ~99.40% genome-wide coverage. Finally, we validated an integrated SCIVVS workflow with automated SCRS acquisition where the whole process except sequencing takes just 5 h. As it is >20-fold faster, >10-time cheaper, vitality-revealing, heterogeneity-resolving, and automation-prone, SCIVVS is a new technological and data framework for quality assessment of live-cell products.
Collapse
Affiliation(s)
- Jia Zhang
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
- University of Chinese Academy of SciencesBeijingChina
| | - Lihui Ren
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
- College of Information Science & EngineeringOcean University of ChinaQingdaoShandongChina
| | - Lei Zhang
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
- Qingdao Branch of China United Network Communications Co., Ltd.QingdaoShandongChina
| | - Yanhai Gong
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
- University of Chinese Academy of SciencesBeijingChina
| | - Teng Xu
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
- University of Chinese Academy of SciencesBeijingChina
| | - Xiaohang Wang
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
- University of Chinese Academy of SciencesBeijingChina
| | - Cheng Guo
- Eastsea Pharma Co., Ltd.QingdaoShandongChina
| | - Lei Zhai
- China National Research Institute of Food and Fermentation Industries Co., Ltd., China Center of Industrial Culture CollectionBeijingChina
| | - Xuejian Yu
- China National Research Institute of Food and Fermentation Industries Co., Ltd., China Center of Industrial Culture CollectionBeijingChina
| | - Ying Li
- Qingdao Single‐Cell Biotech. Co., Ltd.QingdaoShandongChina
| | - Pengfei Zhu
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Qingdao Single‐Cell Biotech. Co., Ltd.QingdaoShandongChina
| | - Rongze Chen
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
- University of Chinese Academy of SciencesBeijingChina
| | - Xiaoyan Jing
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
- University of Chinese Academy of SciencesBeijingChina
| | - Gongchao Jing
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
- University of Chinese Academy of SciencesBeijingChina
| | - Shiqi Zhou
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
| | - Mingyue Xu
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
| | - Chen Wang
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
| | | | - Yuanyuan Ge
- China National Research Institute of Food and Fermentation Industries Co., Ltd., China Center of Industrial Culture CollectionBeijingChina
| | - Bo Ma
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
- University of Chinese Academy of SciencesBeijingChina
| | | | - Yunlong Cui
- Eastsea Pharma Co., Ltd.QingdaoShandongChina
| | - Su Yao
- China National Research Institute of Food and Fermentation Industries Co., Ltd., China Center of Industrial Culture CollectionBeijingChina
| | - Jian Xu
- Single‐Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of SciencesQingdaoShandongChina
- Shandong Energy InstituteQingdaoShandongChina
- Qingdao New Energy Shandong LaboratoryQingdaoShandongChina
- University of Chinese Academy of SciencesBeijingChina
| |
Collapse
|
14
|
Zmerli O, Bellali S, Haddad G, Hisada A, Ominami Y, Raoult D, Bou Khalil J. Rapid microbial viability assay using scanning electron microscopy: a proof-of-concept using Phosphotungstic acid staining. Comput Struct Biotechnol J 2023; 21:3627-3638. [PMID: 37501704 PMCID: PMC10371768 DOI: 10.1016/j.csbj.2023.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/27/2023] [Accepted: 07/09/2023] [Indexed: 07/29/2023] Open
Abstract
Multiple stains have been historically utilized in electron microscopy to provide proper contrast and superior image quality enabling the discovery of ultrastructures. However, the use of these stains in microbiological viability assessment has been limited. Phosphotungstic acid (PTA) staining is a common negative stain used in scanning electron microscopy (SEM). Here, we investigate the feasibility of a new SEM-PTA assay, aiming to determine both viable and dead microbes. The optimal sample preparation was established by staining bacteria with different PTA concentrations and incubation times. Once the assay conditions were set, we applied the protocol to various samples, evaluating bacterial viability under different conditions, and comparing SEM-PTA results to culture. The five minutes 10% PTA staining exhibited a strong distinction between viable micro-organisms perceived as hypo-dense, and dead micro-organisms displaying intense internal staining which was confirmed by high Tungsten (W) peak on the EDX spectra. SEM-PTA viability count after freezing, freeze-drying, or oxygen exposure, were concordant with culture. To our knowledge, this study is the first contribution towards PTA staining of live and dead bacteria. The SEM-PTA strategy demonstrated the feasibility of a rapid, cost-effective and efficient viability assay, presenting an open-view of the sample, and providing a potentially valuable tool for applications in microbiome investigations and antimicrobial susceptibility testing.
Collapse
Affiliation(s)
- Omar Zmerli
- Institut Hospitalo-Universitaire Méditerranée Infection 19-21 Boulevard Jean Moulin 13005 Marseille, France
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), UMR Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
| | - Sara Bellali
- Institut Hospitalo-Universitaire Méditerranée Infection 19-21 Boulevard Jean Moulin 13005 Marseille, France
| | - Gabriel Haddad
- Institut Hospitalo-Universitaire Méditerranée Infection 19-21 Boulevard Jean Moulin 13005 Marseille, France
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), UMR Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
| | - Akiko Hisada
- Hitachi, Ltd. Research & Development Group, 2520, Akanuma, Hatoyama, Saitama, 350- 0395, Japan
| | - Yusuke Ominami
- Hitachi High-Tech Corporation, 882 Ichige, Hitachinaka-shi, Ibaraki-ken 312-8504, Japan
| | | | - Jacques Bou Khalil
- Institut Hospitalo-Universitaire Méditerranée Infection 19-21 Boulevard Jean Moulin 13005 Marseille, France
- Aix-Marseille Université, Institut de Recherche pour le Développement (IRD), UMR Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
| |
Collapse
|
15
|
Delmon C, Ferrandon E, Chouzenoux E, Prorot A, Alain S, Lefort C. A computational two-photon fluorescence approach for revealing label-free the 3D image of viruses and bacteria. JOURNAL OF BIOPHOTONICS 2023; 16:e202200266. [PMID: 36642886 DOI: 10.1002/jbio.202200266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 01/05/2023] [Accepted: 01/05/2023] [Indexed: 05/17/2023]
Abstract
Current solutions for bacteria and viruses identification are based on time-consuming technics with complex preparation procedures. In the present work, we revealed label-free the presence of free viral particles and bacteria with a computational two-photon fluorescence (C-TPF) strategy. Six bacteria were tested: Escherichia coli, Staphylococcus epidermidis, Proteus vulgaris, Pseudomonas fluorescens, Bacillus subtilis, and Clostridium perfringens. The two families of viral particles were the herpes virus with the cytomegalovirus (CMV, 300 nm of diameter) and the coronavirus with the SARS-CoV-2 (100 nm of diameter). The instrumental and computational pipeline FAMOUS optimized the produced 3D images. The origin of the fluorescence emission was discussed for bacteria regarding to their two-photon excitation spectra and attributed to the metabolic indicators (FAD and NADH). The optical and computational strategy constitute a new approach for imaging label-free viral particles and bacteria and paves the way to a new understanding of viral or bacterial ways of infection.
Collapse
Affiliation(s)
- Cédric Delmon
- E2LIM, UR24133, University of Limoges, Limoges, France
| | - Erwan Ferrandon
- XLIM Research Institute, UMR CNRS 7252, University of Limoges, Limoges, France
| | - Emilie Chouzenoux
- Center for Visual Computing, CentraleSupélec, Inria Saclay, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Audrey Prorot
- E2LIM, UR24133, University of Limoges, Limoges, France
| | - Sophie Alain
- Bacteriology-Virology-Hygiene Department, RESINFIT, UMR INSERM 1092 University of Limoges, University Hospital Center, Limoges, France
| | - Claire Lefort
- XLIM Research Institute, UMR CNRS 7252, University of Limoges, Limoges, France
| |
Collapse
|
16
|
Huang Z, Qi Z, Liu C. Evaluation of the disinfection effect and mechanism of SO 4•- and HO • UV/persulfate salts. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:52380-52389. [PMID: 36840873 DOI: 10.1007/s11356-023-26120-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Although ultraviolet (UV) and persulfate (PS) have been widely used in water disinfection process, their incompleteness of disinfection, such as inducing the production of viable but non-culturable cells (VBNC), has attracted extensive attention. In this study, the disinfection effect of combined UV and PS was evaluated, and the roles of SO4•- and HO• radicals in UV/PS disinfection were also analyzed. UV/PS more effectively inactivated cells and reduced the number of culturable cells. Also, the test of bacterial dark activation suggested that UV/PS disinfection inhibited the recovery of VBNC bacteria. The mechanisms of UV/PS disinfection were the increase of membrane permeability and oxidative stress, where SO4•- radicals played more role than HO• radicals. Furthermore, UV/PS disinfection more significantly perturbed the metabolism of Pseudomonas aeruginosa (p < 0.05), mainly involving glyoxylate and dicarboxylic acid metabolism, aminoacyl-tRNA biosynthesis, Alanine, aspartate and glutamate metabolism, and citric acid cycle (TCA cycle). In short, UV/PS disinfection can not only significantly reduce the number of culturable bacteria (kill bacteria) but also inhibits the recovery of VBNC bacteria.
Collapse
Affiliation(s)
- Zaihui Huang
- School of Environmental Science and Engineering, Qingdao Key Laboratory of Marine Pollutant Prevention, Shandong Key Laboratory of Environmental Processes and Health, Shandong University, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, People's Republic of China
| | - Zheng Qi
- School of Environmental Science and Engineering, Qingdao Key Laboratory of Marine Pollutant Prevention, Shandong Key Laboratory of Environmental Processes and Health, Shandong University, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, People's Republic of China
| | - Chunguang Liu
- School of Environmental Science and Engineering, Qingdao Key Laboratory of Marine Pollutant Prevention, Shandong Key Laboratory of Environmental Processes and Health, Shandong University, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, People's Republic of China.
- Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangdong Province, People's Republic of China.
| |
Collapse
|
17
|
Cheng W, Chen X, Guo Y, Zhou D, Zeng H, Fu H. The microbial diversity and flavour metabolism of Chinese strong flavour Baijiu: a review. JOURNAL OF THE INSTITUTE OF BREWING 2023. [DOI: 10.58430/jib.v129i1.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
Abstract
Strong flavour Baijiu is widely consumed in China and is produced by the fermentation of grains using microbial starters. However, a comprehensive understanding of the diversity and metabolic characteristics of microbial communities involved in the solid-state fermentation of Baijiu is important for determining the relationship between microbial composition, flavour metabolism and understanding Baijiu fermentation conditions. Although studies have examined the metabolic pathways and impact of major processes on flavour compounds in strong flavour Baijiu, aspects of the fermentation process remain unexplored. In this review, methods are discussed for the optimisation of microbial diversity in strong flavour Baijiu and associated effects on the flavour of Baijiu. Recent studies are reviewed on starters (Daqu), fermented grains (Jiupei), and pit mud together with the effects of microbial composition on the quality of strong flavour Baijiu. The challenges of Baijiu research and production are discussed, including the role of the microbial diversity of Daqu and Jiupei in the flavour composition of strong flavour Baijiu. This review contributes to the current understanding of processing strong flavour Baijiu and serves as a reference for screening flavour related microorganisms, which is valuable for improving the quality of strong flavour Baijiu.
Collapse
|
18
|
Ma X, Wang L, Dai L, Kwok LY, Bao Q. Rapid Detection of the Activity of Lacticaseibacillus Casei Zhang by Flow Cytometry. Foods 2023; 12:foods12061208. [PMID: 36981135 PMCID: PMC10048587 DOI: 10.3390/foods12061208] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/04/2023] [Accepted: 03/08/2023] [Indexed: 03/14/2023] Open
Abstract
Food processing, e.g., freeze-drying, exerts strong pressure on bacteria in the food matrix, decreasing their viability/activity and even forcing them to become viable but unculturable (VBNC), which are often underestimated by traditional plate count. The strict standards of bacterial viability in probiotic products require accurate cell viability/activity enumeration. We developed a staining (5(6)-carboxyfluorescein diacetate succinimide ester, propidium iodide)-based flow cytometry rapid method for detecting the viability/activity of Lacticaseibacillus (Lb.) casei Zhang, a widely used probiotic in the dairy industry in China. We optimized the procedural and instrumental parameters for generating results comparable to that of standard plate counts. This method was also applied to freeze-dried Lb. casei Zhang, yielding 7.7 × 1011 CFU/g, which was non-significantly higher than the results obtained by plate count (6.4 × 1011 CFU/g), possibly due to the detection of VBNC cells in the freeze-dried powder. We anticipated that this method can be used for detecting lactic acid bacteria in other probiotic food/beverages.
Collapse
Affiliation(s)
- Xuebo Ma
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010018, China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Lina Wang
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010018, China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Lixia Dai
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010018, China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Lai-Yu Kwok
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010018, China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Qiuhua Bao
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010018, China
- Key Laboratory of Dairy Products Processing, Ministry of Agriculture and Rural Affairs, Inner Mongolia Agricultural University, Hohhot 010018, China
- Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China
- Correspondence: ; Tel.: +86-47-1430-0591; Fax: +86-47-1430-5357
| |
Collapse
|
19
|
Tracey H, Coates N, Hulme E, John D, Michael DR, Plummer SF. Insights into the enumeration of mixtures of probiotic bacteria by flow cytometry. BMC Microbiol 2023; 23:48. [PMID: 36849905 PMCID: PMC9969615 DOI: 10.1186/s12866-023-02792-2] [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: 10/07/2022] [Accepted: 02/13/2023] [Indexed: 03/01/2023] Open
Abstract
The use of flow cytometry to enumerate microorganisms is gaining traction over the traditional plate count technique on the basis of superior accuracy, precision and time-to-result. Here, we assessed the suitability of live/dead flow cytometry for the enumeration of mixed populations of probiotic bacteria (L. acidophilus, L. paracasei, L. plantarum, L. salivarius, B. lactis and B. bifidum) whilst comparing outcomes with plate counting. Using a novel gating strategy designed specifically for the enumeration of mixed populations, the application of flow cytometry resulted in the detection of higher numbers of viable bacteria with a greater level of repeatability than plate counting (RSD of 6.82 and 13.14% respectively). Across all multi-species blends tested, viable cell input was more accurately recovered by flow cytometry (101.8 ± 6.95%) than plate counts (81.37 ± 16.03%). However, when certain probiotic mixtures contained preparations with high numbers of non-viable cells in their total population, flow cytometry had the potential for overestimation of the viable population. Nevertheless, the comparative plate counts of these mixtures were low and variable, thus supporting the use of flow cytometry for the enumeration of viable bacteria in mixed populations.
Collapse
Affiliation(s)
- Harry Tracey
- Cultech Limited, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, UK
| | - Niall Coates
- Cultech Limited, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, UK.
| | - Eleri Hulme
- Cultech Limited, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, UK
| | - Daniel John
- Cultech Limited, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, UK
| | - Daryn Robert Michael
- Cultech Limited, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, UK
| | | |
Collapse
|
20
|
Shehata HR, Hassane B, Newmaster SG. Real-time polymerase chain reaction methods for strain specific identification and enumeration of strain Lacticaseibacillus paracasei 8700:2. Front Microbiol 2023; 13:1076631. [PMID: 36741903 PMCID: PMC9889646 DOI: 10.3389/fmicb.2022.1076631] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 12/21/2022] [Indexed: 01/19/2023] Open
Abstract
Introduction Reliable and accurate methods for probiotic identification and enumeration, at the strain level plays a major role in confirming product efficacy since probiotic health benefits are strain-specific and dose-dependent. In this study, real-time PCR methods were developed for strain specific identification and enumeration of L. paracasei 8700:2, a probiotic strain that plays a role in fighting the common cold. Methods The assay was designed to target a unique region in L. paracasei 8700:2 genome sequence to achieve strain level specificity. The identification assay was evaluated for specificity and sensitivity. The enumeration viability real-time PCR (v-qPCR) method was first optimized for the viability treatment, then the method was evaluated for efficiency, limit of quantification, precision, and its performance was compared to plate count (PC) and viability droplet digital PCR (v-ddPCR) methods. Results The identification method proved to be strain specific and highly sensitive with a limit of detection of 0.5 pg of DNA. The optimal viability dye (PMAxx) concentration was 50 μM. The method was efficient (> 90% with R 2 values > 0.99), with a linear dynamic range between 6*102 and 6*105 copies. The method was highly precise with a relative standard deviation below 5%. The Pearson correlation coefficient (r) was 0.707 for PC and v-qPCR methods, and 0.922 for v-qPCR and v-ddPCR. Bland-Altman method comparison showed that v-qPCR always gave higher values compared to PC method (relative difference ranging from 119% to 184%) and showed no consistent trend (relative difference ranging from -20% to 22%) when comparing v-qPCR and v-ddPCR methods. Discussion The difference between PC and v-PCR methods can potentially be attributed to the proportion of cells that exist in a viable but non culturable (VBNC) state, which can be count by v-PCR but not with PC. The developed v-qPCR method was confirmed to be strain specific, sensitive, efficient, with low variance, able to count VBNC cells, and has shorter time to results compared to plate count methods. Thus, the identification and enumeration methods developed for L. paracasei 8700:2 will be of great importance to achieve high quality and efficacious probiotic products.
Collapse
Affiliation(s)
- Hanan R. Shehata
- Natural Health Product Research Alliance, Department of Integrative Biology, College of Biological Science, University of Guelph, Guelph, ON, Canada,Department of Microbiology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt,Purity-IQ Inc., Guelph, ON, Canada,*Correspondence: Hanan R. Shehata,
| | | | - Steven G. Newmaster
- Natural Health Product Research Alliance, Department of Integrative Biology, College of Biological Science, University of Guelph, Guelph, ON, Canada
| |
Collapse
|
21
|
Wang M, Bai Z, Liu S, Liu Y, Wang Z, Zhou G, Gong X, Jiang Y, Sui Z. Accurate quantification of total bacteria in raw milk by flow cytometry using membrane potential as a key viability parameter. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.114315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
22
|
Visciglia A, Allesina S, Amoruso A, De Prisco A, Dhir R, Bron PA, Pane M. Assessment of shelf-life and metabolic viability of a multi-strain synbiotic using standard and innovative enumeration technologies. Front Microbiol 2022; 13:989563. [PMID: 36406457 PMCID: PMC9672074 DOI: 10.3389/fmicb.2022.989563] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 09/27/2022] [Indexed: 11/15/2023] Open
Abstract
The number of live bacterial cells is the most used parameter to assess the quality of finished probiotic products. Plate counting (PC) is the standard method in industry to enumerate cells. Application of PC implies critical aspects related to the selection of optimal nutrient media and growth conditions and underestimation of viable but not cultivable (VBNC) cells. Flow-cytometry (FC) is a culture-independent methodology having the potential to selectively enumerate live, damaged, and dead cells representing a powerful tool for in-depth monitoring of probiotic products. We monitored the shelf life of a clinical batch of a synbiotic composition PDS-08 targeting the pediatric population by means of PC and FC according to International Conference on Harmonization (ICH) pharma guidelines testing the Arrhenius model as predictive tool; PC enumeration revealed higher destruction rate than FC suggesting a faster reduction in cultivability than membrane integrity and thus a possible shift of the bacteria into a VBNC status. PDS-08 maintained acidification capability over time, when re-suspended in nutrient medium, even in samples tested sub-optimally for CFU detection (below 1 billion cells/dose). Due to similar kinetics described by the study of metabolic activity and membrane integrity, FC might be suggested as a valid tool for the study of functional stability of a probiotic product.
Collapse
Affiliation(s)
| | | | - Angela Amoruso
- Probiotical Research S.r.l., Enrico Mattei, Novara, Italy
| | | | - Raja Dhir
- Seed Health, Abbot Kinney Blvd, Los Angeles, CA, United States
| | - Peter A. Bron
- Seed Health, Abbot Kinney Blvd, Los Angeles, CA, United States
| | - Marco Pane
- Probiotical Research S.r.l., Enrico Mattei, Novara, Italy
| |
Collapse
|
23
|
Optimized Protocol for Microalgae DNA Staining with SYTO9/SYBR Green I, Based on Flow Cytometry and RSM Methodology: Experimental Design, Impacts and Validation. Methods Protoc 2022; 5:mps5050076. [PMID: 36287048 PMCID: PMC9612149 DOI: 10.3390/mps5050076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/17/2022] [Accepted: 09/20/2022] [Indexed: 11/17/2022] Open
Abstract
Multiple fluorochromes are extensively used to investigate different microalgal aspects, such as viability and physiology. Some of them can be used to stain nucleic acids (DNA). Well-known examples are SYBR Green I and SYTO 9, the latter of which offers several advantages, especially when combined with flow cytometry (FCM)—a powerful method for studying microalgal population heterogeneity and analyzing their cell cycles. However, the effects of these dyes on the microalgae cell physiology have not been fully elucidated yet. A statistical experimental design, using response surface methodology (RSM) with FCM was applied in this study to optimize the DNA staining of a non-conventional microalgae, Chromochloris zofingiensis, with SYBR Green I and SYTO 9, and to optimize the variables affecting staining efficiency, i.e., the dye concentration, incubation time and staining temperature. We found that none of these factors affects the staining efficiency, which was not less than 99.65%. However, for both dyes, the dye concentration was shown to be the most significant factor causing cell damage (p-values: 0.0003; <0.0001) for SYBR Green I and SYTO 9, respectively. The staining temperature was only significant for SYTO 9 (p-value: 0.0082), and no significant effect was observed regarding the incubation time for both dyes. The values of the optimized parameters (0.5 µM, 05 min and 25 °C) for SYTO 9 and (0.5 X, 5 min and 25 °C) for SYBR Green I resulted in the maximum staining efficiency (99.8%; 99.6%), and the minimum damaging effects (12.86%; 13.75%) for SYTO 9 and SYBR Green I, respectively. These results offer new perspectives for improving the use of DNA staining fluorochromes and provides insights into their possible side effects on microalgae.
Collapse
|
24
|
Morandi S, Cremonesi P, Arioli S, Stocco G, Silvetti T, Biscarini F, Castiglioni B, Greco Ç, D'Ascanio V, Mora D, Brasca M. Effect of using mycotoxin-detoxifying agents in dairy cattle feed on natural whey starter biodiversity. J Dairy Sci 2022; 105:6513-6526. [PMID: 35840409 DOI: 10.3168/jds.2022-21793] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 04/15/2022] [Indexed: 11/19/2022]
Abstract
Natural whey cultures (NWC) are undefined multiple-strain bacterial starter communities that can be affected by even small changes along the entire dairy chain. We applied a multidisciplinary approach to investigate how the addition of 2 mycotoxin-detoxifying agents [sodium smectite and lignocellulose-based material (B1); leonardite and betaine (B2)] to cow diets modified the microbiota of the NWC in manufacture of a Grana-like cheese. Microbiological and flow cytometry analyses showed that the content and viability of lactic acid bacteria (LAB) and the total whey microbiota were not affected by the detoxifying agents, and Streptococcus thermophilus, Lactobacillus helveticus, and Limosilactobacillus fermentum were the dominant taxa. Random amplified polymorphic DNA-PCR fingerprinting and metagenomic analysis highlighted differences in the bacterial community of the NWC and in the relative abundance of Bacteroidetes that increased when B1 and B2 were included in the diet. Two of 6 St. thermophilus biotypes were detected only in control samples; conversely, none of the Lb. helveticus biotypes found in control samples were isolated from B1 and B2. In vitro tests showed that the 2 binders did not significantly affect the development of St. thermophilus, but they stimulated the growth of Lb. helveticus strains recovered only from B1 and B2 NWC. The addition of binders in cow feed can affect the LAB biotypes present in NWC.
Collapse
Affiliation(s)
- S Morandi
- Institute of Sciences of Food Production (ISPA), Italian National Research Council (CNR), Via Celoria 2, 20133, Milan, Italy.
| | - P Cremonesi
- Institute of Agricultural Biology and Biotechnology (IBBA), Italian National Research Council (CNR), Via Einstein, 26900, Lodi, Italy
| | - S Arioli
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Via Celoria 2, 20133, Milan, Italy
| | - G Stocco
- Department of Veterinary Science, University of Parma, Via del Taglio 10, I-43126 Parma, Italy
| | - T Silvetti
- Institute of Sciences of Food Production (ISPA), Italian National Research Council (CNR), Via Celoria 2, 20133, Milan, Italy
| | - F Biscarini
- Institute of Agricultural Biology and Biotechnology (IBBA), Italian National Research Council (CNR), Via Einstein, 26900, Lodi, Italy
| | - B Castiglioni
- Institute of Agricultural Biology and Biotechnology (IBBA), Italian National Research Council (CNR), Via Einstein, 26900, Lodi, Italy
| | - Ç Greco
- Institute of Sciences of Food Production (ISPA), Italian National Research Council (CNR), Via Amendola 122/O, 70126, Bari, Italy
| | - V D'Ascanio
- Institute of Sciences of Food Production (ISPA), Italian National Research Council (CNR), Via Amendola 122/O, 70126, Bari, Italy
| | - D Mora
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Via Celoria 2, 20133, Milan, Italy
| | - M Brasca
- Institute of Sciences of Food Production (ISPA), Italian National Research Council (CNR), Via Celoria 2, 20133, Milan, Italy
| |
Collapse
|
25
|
Intensified inactivation of model and environmental bacteria by an atmospheric-pressure air-liquid discharge plasma compared with chlorination. J Environ Sci (China) 2022; 117:80-90. [PMID: 35725092 DOI: 10.1016/j.jes.2022.01.038] [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: 12/02/2021] [Revised: 01/18/2022] [Accepted: 01/23/2022] [Indexed: 11/21/2022]
Abstract
Water-borne pathogenic bacteria are always the top priority to be removed through disinfection process in water treatment due to their threat to human health. It was necessary to develop novel disinfection methods since the conventional chlorine disinfection was inefficient in inactivating chlorine-resistant bacteria, inducing the viable but non-culturable (VBNC) bacteria and forming disinfection by-products (DBPs). In this study, the inactivation of four model strains including Gram-negative (G-), Gram-positive (G+) and environmental samples by atmospheric-pressure air-liquid discharge plasma (ALDP) was assessed systematically. The results showed that ALDP was superior in inactivating all of the samples compared with chlorination. During 10 min ALDP treatment, the G- bacteria were completely inactivated, and the G+ one was inactivated by more than 4.61 logs. The inactivation of bacteria from a campus lake and a wastewater treatment plant effluent exceeded 99.82% and 97.78%, respectively. For G- bacteria, ALDP resulted in a much lower (102∼103 times) levels of VBNC cells than chlorination. ALDP could effectively remove the chlorine-resistant bacteria. More than 96.41% of the intracellular DNA and 99.99% of the extracellular DNA were removed, whereas it was only 56.35% and 12.82% for chlorination. ALDP had a stronger ability to destroy cell structure than chlorination, presumably due to the existence of ROS (·OH, 1O2 and O2-). GC-MS analysis showed that ALDP produced less DBPs than chlorination. These findings provided new insights for the application of discharge plasma in water disinfection, which could be complemental or alternative to the conventional disinfection methods.
Collapse
|
26
|
Chen B, Liang Z, Lin X, Li W, Lin X, He Z. Enhanced survival of fluidized bed-dried microencapsulated Saccharomyces cerevisiae cells in the presence of Hongqu rice distiller's grain peptides. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.113511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
27
|
Synergistic Action of Mild Heat and Essential Oil Treatments on Culturability and Viability of Escherichia coli ATCC 25922 Tested In Vitro and in Fruit Juice. Foods 2022; 11:foods11111615. [PMID: 35681366 PMCID: PMC9180004 DOI: 10.3390/foods11111615] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/24/2022] [Accepted: 05/26/2022] [Indexed: 02/05/2023] Open
Abstract
The strengthening effect of a mild temperature treatment on the antimicrobial efficacy of essential oils has been widely reported, often leading to an underestimation or a misinterpretation of the product’s microbial status. In the present study, both a traditional culture-based method and Flow Cytometry (FCM) were applied to monitor the individual or combined effect of Origanum vulgare essential oil (OEO) and mild heat treatment on the culturability and viability of Escherichia coli in a conventional culture medium and in a fruit juice challenge test. The results obtained in the culture medium showed bacterial inactivation with an increasing treatment temperature (55 °C, 60 °C, 65 °C), highlighting an overestimation of the dead population using the culture-based method; in fact, when the FCM method was applied, the prevalence of injured bacterial cells in a viable but non-culturable (VBNC) state was observed. When commercial fruit juice with a pH of 3.8 and buffered at pH 7.0 was inoculated with E. coli ATCC 25922, a bactericidal action of OEO and a higher efficiency of the mild heat at 65 °C for 5′ combined with OEO were found. Overall, the combination of mild heat and OEO treatment represents a promising antimicrobial alternative to improve the safety of fruit juice.
Collapse
|
28
|
Zawistowska-Rojek A, Zaręba T, Tyski S. Microbiological Testing of Probiotic Preparations. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19095701. [PMID: 35565098 PMCID: PMC9099753 DOI: 10.3390/ijerph19095701] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 04/29/2022] [Accepted: 05/03/2022] [Indexed: 02/04/2023]
Abstract
Probiotic microorganisms that are potentially beneficial to the health of the host are commercially available in a great variety of products. Not all microorganism strains present in products have proven beneficial to the health properties. These products include not only foodstuffs but also dietary supplements, food for special medical purposes, medicinal products, as well as cosmetics and medical devices. These products contain from one to a dozen bacterial strains of the same or different species and sometimes also fungal strains. Since the pro-health effects of probiotics depend on a specific strain, the number of its cells in a dose, and the lack of pathogenic microorganisms, it is extremely important to control the quality of probiotics. Depending on the classification of a given product, its form, and its content of microorganisms, the correct determination of the number of microorganisms and their identification is crucial. This article describes the culture-dependent and culture-independent methods for testing the contents of probiotic microorganisms, in addition to biochemical and genetic methods of identification. The microbiological purity requirements for various product categories are also presented. Due to numerous reports on the low quality of probiotic products available on the market, it is important to standardise research methods for this group of products and to increase the frequency of inspections of these products.
Collapse
Affiliation(s)
- Anna Zawistowska-Rojek
- Department of Antibiotics and Microbiology, National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland; (T.Z.); (S.T.)
- Department of Pharmaceutical Microbiology, Medical University of Warsaw, Banacha 1b, 02-097 Warsaw, Poland
- Correspondence:
| | - Tomasz Zaręba
- Department of Antibiotics and Microbiology, National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland; (T.Z.); (S.T.)
| | - Stefan Tyski
- Department of Antibiotics and Microbiology, National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland; (T.Z.); (S.T.)
- Department of Pharmaceutical Microbiology, Medical University of Warsaw, Banacha 1b, 02-097 Warsaw, Poland
| |
Collapse
|
29
|
Vinderola G, Sanders ME, Salminen S. The Concept of Postbiotics. Foods 2022; 11:foods11081077. [PMID: 35454664 PMCID: PMC9027423 DOI: 10.3390/foods11081077] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 03/31/2022] [Accepted: 04/06/2022] [Indexed: 02/07/2023] Open
Abstract
The scientific community has proposed terms such as non-viable probiotics, paraprobiotics, ghostbiotics, heat-inactivated probiotics or, most commonly, postbiotics, to refer to inanimate microorganisms and/or their components that confer health benefits. This article addresses the various characteristics of different definitions of ‘postbiotics’ that have emerged over past years. In 2021, the International Scientific Association for Probiotics and Prebiotics (ISAPP) defined a postbiotic as “a preparation of inanimate microorganisms and/or their components that confers a health benefit on the host”. This definition of postbiotic requires that the whole or components of inactivated microbes be present, with or without metabolic end products. The definition proposed by ISAPP is comprehensive enough to allow the development of postbiotics from different microorganisms, to be applied in different body sites, encouraging innovation in a promising area for any regulatory category and for companion or production animals, and plant or human health. From a technological perspective, probiotic products may contain inanimate microorganisms, which have the potential to impart a health benefit. However, their contribution to health in most cases has not been established, even if at least one probiotic has been shown to confer the same health benefit by live or inanimate cells.
Collapse
Affiliation(s)
- Gabriel Vinderola
- Instituto de Lactología Industrial (INLAIN, UNL-CONICET), Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santa Fe 3000, Argentina
- Correspondence: ; Tel.: +54-9-3426-31-1943
| | - Mary Ellen Sanders
- International Scientific Association for Probiotics and Prebiotics, Centennial, CO 80122, USA;
| | - Seppo Salminen
- Functional Foods Forum, Faculty of Medicine, University of Turku, 20014 Turku, Finland;
| |
Collapse
|
30
|
Influence of three ultrasound treatments on viability, culturability, cell architecture, enzymatic activity and metabolic potential of Lacticaseibacillus paracasei 90. Int Dairy J 2022. [DOI: 10.1016/j.idairyj.2022.105371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
31
|
Kupczyk W, Maślak E, Railean-Plugaru V, Pomastowski P, Jackowski M, Buszewski B. Capillary Zone Electrophoresis in Tandem with Flow Cytometry in Viability Study of Various ATCC Bacterial Strains under Antibiotic Treatment. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19031833. [PMID: 35162856 PMCID: PMC8835228 DOI: 10.3390/ijerph19031833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 02/04/2023]
Abstract
The aim of this study was to develop an innovative method of examining bacterial survival using capillary zone electrophoresis (CZE) and flow cytometry (FC) as a reference method. For this purpose, standard strains of bacteria from the ATCC collection were used: Enterococcus faecalis ATCC 14506, Staphylococcus aureus ATCC 11632, Klebsiella pneumoniae ATCC 10031, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922, as well as seven antibiotics with different antimicrobial mechanisms of action. The ratio of live and dead cells in the tested sample in CZE measurements were calculated using our algorithm that takes into account the detection time. Results showed a high agreement between CZE and FC in the assessment of the percentage of live cells exposed to the stress factor in both antibiotic susceptibility and time-dependent assays. The applied measuring system to assess the effectiveness of antibiotic therapy in in vitro conditions is a method with great potential, and the data obtained with the use of CZE mostly correspond to the expected drug sensitivity according to EUCAST and CLSI guidelines.
Collapse
Affiliation(s)
- Wojciech Kupczyk
- Department of General, Gastroenterological, and Oncological Surgery Collegium Medicum, Nicolaus Copernicus University, Gagarina 7, 87-100 Toruń, Poland; (W.K.); (M.J.)
| | - Ewelina Maślak
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4 Str., 87-100 Toruń, Poland; (E.M.); (V.R.-P.); (P.P.)
- Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7 Str., 87-100 Toruń, Poland
| | - Viorica Railean-Plugaru
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4 Str., 87-100 Toruń, Poland; (E.M.); (V.R.-P.); (P.P.)
| | - Paweł Pomastowski
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4 Str., 87-100 Toruń, Poland; (E.M.); (V.R.-P.); (P.P.)
| | - Marek Jackowski
- Department of General, Gastroenterological, and Oncological Surgery Collegium Medicum, Nicolaus Copernicus University, Gagarina 7, 87-100 Toruń, Poland; (W.K.); (M.J.)
| | - Bogusław Buszewski
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4 Str., 87-100 Toruń, Poland; (E.M.); (V.R.-P.); (P.P.)
- Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7 Str., 87-100 Toruń, Poland
- Correspondence:
| |
Collapse
|
32
|
Poudel R, Thunell RK, Oberg CJ, Overbeck S, Lefevre M, Oberg TS, McMahon DJ. Comparison of growth and survival of single strains of Lactococcus lactis and Lactococcus cremoris during Cheddar cheese manufacture. J Dairy Sci 2022; 105:2069-2081. [PMID: 35033338 DOI: 10.3168/jds.2021-20958] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/22/2021] [Indexed: 11/19/2022]
Abstract
Traditionally, starter cultures for Cheddar cheese are combinations of Lactococcus lactis and Lactococcus cremoris. Our goal was to compare growth and survival of individual strains during cheesemaking, and after salting and pressing. Cultures used were 2 strains of L. lactis (SSM 7605, SSM 7436) and 2 strains of L. cremoris (SSM 7136, SSM 7661). A standardized Cheddar cheese make procedure was used that included a 38°C cook temperature and salting levels of 2.0, 2.4, 2.8, 3.2, and 3.6% from which were selected cheeses with salt-in-moisture levels of 3.5, 4.5, and 5.5%. Vats of cheese were made using each strain on its own as biological duplicates on different days. Starter culture numbers were enumerated by plate counting during cheesemaking and after 6 d storage at 6°C. Flow cytometry with fluorescent staining by SYBR Green and propidium iodide was used to determine the number of live and dead cells in cheese at the different salt levels. Differences in cheese make times were strain dependent rather than species dependent. Even with correction for average culture chain length, cheeses made using L. lactis strains contained ∼4 times (∼0.6 log) more bacterial cells than those made using L. cremoris strains. Growth of the strains used in this study was not influenced by the amount of salt added to the curd. The higher pH of cheeses with higher salting levels was attributed to those cheeses having a lower moisture content. Based on flow cytometry, ∼5% of the total starter culture cells in the cheese were dead after 6 d of storage. Another 3 to 19% of the cells were designated as being live, but semipermeable, with L. cremoris strains having the higher number of semipermeable cells.
Collapse
Affiliation(s)
- Rhitika Poudel
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan 84322
| | - Randall K Thunell
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan 84322; Vivolac Cultures Corporation, Greenfield, IN 46140
| | - Craig J Oberg
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan 84322; Department of Microbiology, Weber State University, Ogden, UT 84408
| | - Sophie Overbeck
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan 84322
| | - Michael Lefevre
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan 84322
| | - Taylor S Oberg
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan 84322
| | - Donald J McMahon
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan 84322.
| |
Collapse
|
33
|
Probiotics in Functional Foods: Survival Assessment and Approaches for Improved Viability. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12010455] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Nowadays, food is no longer just for nutrition. Consumers are more demanding and expect to get health benefits from their daily meals. Various areas of the food industry are in great demand of functional chemicals to enhance the taste and nutritional value of their products. Probiotic bacteria have already been part of the human’s routine for good gut microbiota maintenance in terms of pharmaceutical products. Their incorporation in food however is a challenging task that offers great opportunities but has limitations as well. Specifically, the purpose of this review is to emphasize the importance of probiotics in food, to assess their survival through gastrointestinal tract, and to highlight the recent advances in approaches for their improved viability.
Collapse
|
34
|
Haji F, Cheon J, Baek J, Wang Q, Tam KC. Application of Pickering emulsions in probiotic encapsulation- A review. Curr Res Food Sci 2022; 5:1603-1615. [PMID: 36161224 PMCID: PMC9493384 DOI: 10.1016/j.crfs.2022.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 09/02/2022] [Accepted: 09/12/2022] [Indexed: 11/25/2022] Open
Abstract
Probiotics are live microorganisms that confer health benefits to host organisms when consumed in adequate amounts and are often incorporated into foods for human consumption. However, this has negative implications on their viability as large numbers of these beneficial bacteria are deactivated when subjected to harsh conditions during processing, storage, and passage through the gastrointestinal tract. To address these issues, numerous studies on encapsulation techniques to protect probiotics have been conducted. This review focuses on emulsion technology for probiotic encapsulation, with a special focus on Pickering emulsions. Pickering emulsions are stabilized by solid particles, which adsorb strongly onto the liquid-liquid interfaces to prevent aggregation. Pickering emulsions have demonstrated enhanced stability, high encapsulation efficiency, and cost-effectiveness compared to other encapsulation techniques. Additionally, Pickering emulsions are regarded as safe and biocompatible and utilize natural materials, such as cellulose and chitosan derived from plants, shellfish, and fungi, which may also be viewed as more acceptable in food systems than common synthetic and natural molecular surfactants. This article reviews the current status of Pickering emulsion use for probiotic delivery and explores the potential of this technique for application in other fields, such as livestock farming, pet food, and aquaculture. Probiotics play an important role in maintaining the health of humans and animals. Encapsulation improves probiotic viability in harsh environments. Probiotics can be encapsulated by many techniques such as emulsification. Pickering emulsions use particles instead of molecules to stabilize emulsions. Natural particles are more acceptable to some consumers than synthetic emulsifiers.
Collapse
Affiliation(s)
- Fatemah Haji
- Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue, Waterloo, ON, N2L 3G1, Canada
| | - James Cheon
- Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue, Waterloo, ON, N2L 3G1, Canada
| | - Jiyoo Baek
- Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue, Waterloo, ON, N2L 3G1, Canada
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, 93 Stone Road W, Guelph, ON, N1G 5C9, Canada
| | - Qi Wang
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, 93 Stone Road W, Guelph, ON, N1G 5C9, Canada
| | - Kam Chiu Tam
- Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue, Waterloo, ON, N2L 3G1, Canada
- Corresponding author.
| |
Collapse
|
35
|
Minj S, Anand S. Development of a spray-dried conjugated whey protein hydrolysate powder with entrapped probiotics. J Dairy Sci 2021; 105:2038-2048. [PMID: 34955247 DOI: 10.3168/jds.2021-20978] [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: 07/07/2021] [Accepted: 10/29/2021] [Indexed: 12/22/2022]
Abstract
Bifidobacterium animalis ssp. lactis ATCC27536 and Lactobacillus acidophilus ATCC4356 were encapsulated in a conjugated whey protein hydrolysate (WPH10) through spray drying. Probiotic cultures were added at the ratio of 1:1 into the conjugated WPH10 solution at a spiking level of about 10 log10 cfu/mL. The mixture was spray dried in a Niro drier with inlet and outlet temperatures of 200°C and 90°C, respectively. The final dried product was determined for cell viability and further stored for 16 wk at 25°, 4°, and -18°C to monitor viability and functionality. Micro images showed the presence of link bridges in non-conjugated WPH10, whereas, in the case of conjugated WPH10, round particles with pores were observed. The mean probiotic counts before and after spray drying were 10.59 log10 cfu/mL and 8.98 log10 cfu/g, respectively, indicating good retention of viability after spray drying. The solubility and wetting time of the WPH10-maltodextrin (MD) encapsulated probiotic powder were 91.03% and 47 min, whereas for WPH10, the solubility and wetting time were 82.03% and 53 min, respectively. At the end of storage period, the counts were 7.18 log10 cfu/g at 4°C and 7.87 log10 cfu/g at -18°C, whereas at 25°C the counts were significantly reduced, to 3.97 log10 cfu/g. The solubility of WPH-MD powder was 82.36%, 83.1%, and 81.19% at -18°C, 4°C, and 25°C, respectively, and wetting times were 61 min, 60 min, and 63 min at -18°C, 4°C, and 25°C, respectively. By contrast, for WPH10 powder, the solubility significantly reduced to 69.41%, 69.97%, and 68.99% at -18°C, 4°C, and 25°C, and wetting times increased to 71 min, 70 min, and 72 min at -18°C, 4°C, and 25°C, respectively. The conjugated WPH10 is thus demonstrated as a promising carrier for probiotics and can be further used as an ingredient for developing functional foods, to harness their enhanced functionality and health benefits derived from both WPH and probiotics.
Collapse
Affiliation(s)
- Shayanti Minj
- Midwest Dairy Foods Research Center, St. Paul, MN 55108-6074; Dairy and Food Science Department, South Dakota State University, Brookings 57007
| | - Sanjeev Anand
- Midwest Dairy Foods Research Center, St. Paul, MN 55108-6074; Dairy and Food Science Department, South Dakota State University, Brookings 57007.
| |
Collapse
|
36
|
Dynamics of physiological responses of potentially probiotic fruit-derived Limosilactobacillus fermentum in apple and orange juices during refrigeration storage and exposure to simulated gastrointestinal conditions. Arch Microbiol 2021; 204:38. [DOI: 10.1007/s00203-021-02672-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/01/2021] [Accepted: 10/18/2021] [Indexed: 11/26/2022]
|
37
|
Fusco V, Fanelli F, de Souza EL. Editorial: Authenticity of Probiotic Foods and Dietary Supplements. Front Microbiol 2021; 12:789049. [PMID: 34912324 PMCID: PMC8667336 DOI: 10.3389/fmicb.2021.789049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 11/08/2021] [Indexed: 11/24/2022] Open
Affiliation(s)
- Vincenzina Fusco
- National Research Council of Italy - Institute of Sciences of Food Production (CNR-ISPA), Bari, Italy
| | - Francesca Fanelli
- National Research Council of Italy - Institute of Sciences of Food Production (CNR-ISPA), Bari, Italy
| | | |
Collapse
|
38
|
Zand E, Froehling A, Schoenher C, Zunabovic-Pichler M, Schlueter O, Jaeger H. Potential of Flow Cytometric Approaches for Rapid Microbial Detection and Characterization in the Food Industry-A Review. Foods 2021; 10:3112. [PMID: 34945663 PMCID: PMC8701031 DOI: 10.3390/foods10123112] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/14/2021] [Accepted: 11/16/2021] [Indexed: 12/11/2022] Open
Abstract
As microbial contamination is persistent within the food and bioindustries and foodborne infections are still a significant cause of death, the detection, monitoring, and characterization of pathogens and spoilage microorganisms are of great importance. However, the current methods do not meet all relevant criteria. They either show (i) inadequate sensitivity, rapidity, and effectiveness; (ii) a high workload and time requirement; or (iii) difficulties in differentiating between viable and non-viable cells. Flow cytometry (FCM) represents an approach to overcome such limitations. Thus, this comprehensive literature review focuses on the potential of FCM and fluorescence in situ hybridization (FISH) for food and bioindustry applications. First, the principles of FCM and FISH and basic staining methods are discussed, and critical areas for microbial contamination, including abiotic and biotic surfaces, water, and air, are characterized. State-of-the-art non-specific FCM and specific FISH approaches are described, and their limitations are highlighted. One such limitation is the use of toxic and mutagenic fluorochromes and probes. Alternative staining and hybridization approaches are presented, along with other strategies to overcome the current challenges. Further research needs are outlined in order to make FCM and FISH even more suitable monitoring and detection tools for food quality and safety and environmental and clinical approaches.
Collapse
Affiliation(s)
- Elena Zand
- Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences Vienna (BOKU), 1190 Vienna, Austria;
| | - Antje Froehling
- Leibniz Institute for Agricultural Engineering and Bioeconomy, Quality and Safety of Food and Feed, 14469 Potsdam, Germany; (A.F.); (O.S.)
| | - Christoph Schoenher
- Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Life Sciences, 1190 Vienna, Austria; (C.S.); (M.Z.-P.)
| | - Marija Zunabovic-Pichler
- Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Life Sciences, 1190 Vienna, Austria; (C.S.); (M.Z.-P.)
| | - Oliver Schlueter
- Leibniz Institute for Agricultural Engineering and Bioeconomy, Quality and Safety of Food and Feed, 14469 Potsdam, Germany; (A.F.); (O.S.)
| | - Henry Jaeger
- Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences Vienna (BOKU), 1190 Vienna, Austria;
| |
Collapse
|
39
|
Sampaio KB, de Albuquerque TMR, Rodrigues NPA, de Oliveira MEG, de Souza EL. Selection of Lactic Acid Bacteria with In Vitro Probiotic-Related Characteristics from the Cactus Pilosocereus gounellei (A. Weber ex. K. Schum.) Bly. ex Rowl. Foods 2021; 10:2960. [PMID: 34945509 PMCID: PMC8700760 DOI: 10.3390/foods10122960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/19/2021] [Accepted: 11/24/2021] [Indexed: 11/16/2022] Open
Abstract
Pilosocereus gounellei (A. Weber ex. K. Schum.) Bly. ex Rowl., popularly known as xique-xique, is a cactus from the Caatinga biome, which is rich in bioactive compounds but has not been previously studied as a source of lactic acid bacteria (LAB) with probiotic aptitudes. This study aimed to identify, characterize, and select LAB isolates with in vitro probiotic-related characteristics from xique-xique cladodes and fruit. Isolates with the most promising probiotic-related characteristics were evaluated regarding their in vitro technological properties and capability of surviving in chestnut milk, whey protein drink, and mate tea with mint during 21 days of refrigeration storage. Seventeen recovered isolates had typical characteristics of LAB. Six out of these seventeen LAB isolates passed the safety tests and were included in experiments to evaluate the in vitro probiotic-related characteristics. Based on the results of a principal component analysis, the isolates 69, 82, 98, and 108 had the best performances in experiments to evaluate the probiotic-related characteristics. In addition to showing good technological properties, the four selected LAB isolates had high viable counts (>7.3 log cfu/mL) and high sizes of physiologically active cell subpopulations in chestnut milk, whey protein drink, and mate tea during refrigeration storage. These four isolates were identified by 16S-rRNA sequencing as being Lacticaseibacillus paracasei or Lacticaseibacillus casei. The results indicate xique-xique as a source of potentially probiotic LAB isolates.
Collapse
Affiliation(s)
- Karoliny Brito Sampaio
- Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa 58051-900, Paraíba, Brazil; (K.B.S.); (T.M.R.d.A.); (N.P.A.R.)
| | - Thatyane Mariano Rodrigues de Albuquerque
- Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa 58051-900, Paraíba, Brazil; (K.B.S.); (T.M.R.d.A.); (N.P.A.R.)
| | - Noádia Priscila Araújo Rodrigues
- Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa 58051-900, Paraíba, Brazil; (K.B.S.); (T.M.R.d.A.); (N.P.A.R.)
| | - Maria Elieidy Gomes de Oliveira
- Laboratory of Bromatology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa 58051-900, Paraíba, Brazil;
| | - Evandro Leite de Souza
- Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa 58051-900, Paraíba, Brazil; (K.B.S.); (T.M.R.d.A.); (N.P.A.R.)
| |
Collapse
|
40
|
da Costa Lima M, Magnani M, Dos Santos Lima M, de Sousa CP, Dubreuil JD, de Souza EL. Phenolic-rich extracts from acerola, cashew apple and mango by-products cause diverse inhibitory effects and cell damages on enterotoxigenic Escherichia coli. Lett Appl Microbiol 2021; 75:565-577. [PMID: 34687563 PMCID: PMC9539876 DOI: 10.1111/lam.13586] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 09/12/2021] [Accepted: 10/19/2021] [Indexed: 11/27/2022]
Abstract
This study aimed to evaluate the inhibitory effects of phenolic-rich extracts from acerola (Malpighia emarginata D.C., PEA), cashew apple (Anacardium occidentale L., PEC) and mango (Mangifera indica L., PEM) by-products on distinct enterotoxigenic Escherichia coli (ETEC) strains. The capability of PEA and PEC of impairing various physiological functions of ETEC strains was investigated with multiparametric flow cytometry. Procyanidin B2 , myricetin and p-coumaric acid were the major phenolic compounds in PEA, PEC and PEM, respectively. PEA and PEC had lower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) (MIC: 31·25 mg ml-1 ; MBC: 62·5 mg ml-1 ) on ETEC strains than PEM (MIC and MIC: >1000 mg ml-1 ). PEA and PEC (15·6, 31·2, 62·5 mg ml-1 ) caused viable count reductions (P < 0·05) on ETEC strains after 24 h of exposure, notably the ≥3 log reductions caused by 62·5 mg ml-1 . The 24 h exposure of ETEC strains to PEA and PEC (31·2, 62·5 mg ml-1 ) led to high sizes of cell subpopulations with concomitant impairments in cell membrane polarization and permeability, as well as in enzymatic, respiratory and efflux activities. PEA and PEC are effective in inhibiting ETEC through a multi-target action mode with disturbance in different physiological functions.
Collapse
Affiliation(s)
- M da Costa Lima
- Laboratory of Food Microbiology, Department of Nutrition, Health Science Center, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| | - M Magnani
- Laboratory of Microbial Processes in Foods, Department of Food Engineering, Technology Center, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| | - M Dos Santos Lima
- Department of Food Technology, Federal Institute of Sertão de Pernambuco, Petrolina, Pernambuco, Brazil
| | - C P de Sousa
- Department of Morphology and Pathology, Center of Biological Sciences and Health, Federal University of São Carlos, São Carlos, São Paulo, Brazil
| | - J D Dubreuil
- Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - E L de Souza
- Laboratory of Food Microbiology, Department of Nutrition, Health Science Center, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| |
Collapse
|
41
|
Shehata HR, Newmaster SG. Enumeration of Probiotic Strain Lacticaseibacillus rhamnosus GG (ATCC 53103) Using Viability Real-time PCR. Probiotics Antimicrob Proteins 2021; 13:1611-1620. [PMID: 34591288 DOI: 10.1007/s12602-021-09849-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2021] [Indexed: 12/18/2022]
Abstract
Probiotic health benefits are strain specific and are dose dependent. Hence, administering the correct strains, at the recommended doses is essential to achieve probiotic health benefits. Reliable methods are needed to facilitate probiotic strain identification and enumeration. Plate count methods are the most commonly used methods for probiotic enumeration. However, these methods are time-consuming, laborious, highly variable, and non-specific. Here, we developed a real-time PCR method for enumeration of a commonly used strain, Lacticaseibacillus rhamnosus GG. The method utilizes PMAxx as a viability dye to enumerate viable cells only. Optimization of viability treatment showed that PMAxx at a final concentration of 50 μM was effective in inactivating DNA from dead cells, and that bead beating for 5 min at 3000 rpm was effective in liberating DNA. The assay demonstrated high efficiency between 93 and 102%, with R2 values > 0.99. The assay showed high precision with relative standard deviation (RSD%) below 2.3%. Assay performance was compared to a plate count method in which there was a strong correlation between both methods (Pearson r = 0.8443). This method offers a 10 × shorter time for results and a higher precision compared to plate count methods. Furthermore, this method enables specific enumeration of L. rhamnosus GG in multi-strain products, which is not possible to achieve using plate count methods. This novel method facilitates faster and more accurate enumeration of L. rhamnosus GG as a raw ingredient as well as in finished products which enables better quality assurance and efficacy of probiotics for consumers.
Collapse
Affiliation(s)
- Hanan R Shehata
- College of Biological Science, NHP Research Alliance, University of Guelph, Guelph, ON, N1G 2W1, Canada.
- Department of Microbiology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt.
| | - Steven G Newmaster
- College of Biological Science, NHP Research Alliance, University of Guelph, Guelph, ON, N1G 2W1, Canada
| |
Collapse
|
42
|
Genovese M, Poulain E, Doppler F, Toussaint R, Boyer M. Bacillus spore enumeration using flow cytometry: A proof of concept for probiotic application. J Microbiol Methods 2021; 190:106336. [PMID: 34560161 DOI: 10.1016/j.mimet.2021.106336] [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: 08/04/2021] [Revised: 09/17/2021] [Accepted: 09/17/2021] [Indexed: 10/20/2022]
Abstract
Use of flow cytometry (FCM) for bacteria quantification is growing in the food industry. We report here a FCM method using a double-staining LDS751/SYTO24 for the quantification of probiotic Bacillus viable cells and its spores, with potential application for the control of commercial product specifications.
Collapse
Affiliation(s)
- Maxime Genovese
- Research and Development Department, Lesaffre International, Lesaffre Group, 59700 Marcq-en-Baroeul, France
| | - Edith Poulain
- Research and Development Department, Lesaffre International, Lesaffre Group, 59700 Marcq-en-Baroeul, France
| | - Florie Doppler
- Research and Development Department, Lesaffre International, Lesaffre Group, 59700 Marcq-en-Baroeul, France
| | - Renaud Toussaint
- Research and Development Department, Lesaffre International, Lesaffre Group, 59700 Marcq-en-Baroeul, France
| | - Mickaël Boyer
- Research and Development Department, Lesaffre International, Lesaffre Group, 59700 Marcq-en-Baroeul, France.
| |
Collapse
|
43
|
Zhang Y, Zhang M, Ye C, Feng M, Wan K, Lin W, Sharma VK, Yu X. Mechanistic insight of simultaneous removal of tetracycline and its related antibiotic resistance bacteria and genes by ferrate(VI). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 786:147492. [PMID: 33984704 DOI: 10.1016/j.scitotenv.2021.147492] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/28/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
The emergence of antibiotics and their corresponding antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have posed great challenges to the public health. The paper demonstrates the removal of co-existing tetracycline (TC), its resistant Escherichia coli (E. coli), and ARGs (tetA and tetR) in a mixed system by applying ferrate(VI) (FeVIO42-, Fe(VI)) at pH 7.0. TC was efficiently degraded by Fe(VI), and the rapid inactivation of the resistant E. coli was found with the complete loss of culturability. The results of flow cytometry suggested that the damage of membrane integrity and respiratory activity were highly correlated with the Fe(VI) dosages. Moreover, high-dose Fe(VI) eliminates 6 log10 viable but non-culturable (VBNC) cells and even breaks the cells into fragments. ARGs in extracellular form (e-ARGs) exhibited a high sensitivity of 4.44 log10 removal to Fe(VI). Comparatively, no removal of intracellular ARGs (i-ARGs) was observed due to the multi-protection of cellular structure and rapid decay of Fe(VI). The oxidized products of TC were assessed to be less toxic than the parent compound. Overall, this study demonstrated the superior efficiency and great promise of Fe(VI) on simultaneous removal of antibiotics and their related ARB and ARGs in water.
Collapse
Affiliation(s)
- Yiting Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Menglu Zhang
- College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, China
| | - Chengsong Ye
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Mingbao Feng
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Kun Wan
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Wenfang Lin
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Virender K Sharma
- Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, TX 77843, USA.
| | - Xin Yu
- College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
| |
Collapse
|
44
|
Rosenberg JN, Cady NC. Surveilling cellular vital signs: toward label-free biosensors and real-time viability assays for bioprocessing. Curr Opin Biotechnol 2021; 71:123-129. [PMID: 34358978 DOI: 10.1016/j.copbio.2021.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 06/20/2021] [Accepted: 07/08/2021] [Indexed: 10/20/2022]
Abstract
Cell viability is an essential facet of mammalian and microbial bioprocessing. While robust methods of monitoring cellular health remain critically important to biomanufacturing and biofabrication, the complexity of advanced cell culture platforms often poses challenges for conventional viability assays. This review surveys novel approaches to discern the metabolic, morphological, and mechanistic hallmarks of living systems - spanning subcellular and multicellular scales. While fluorescent probes coupled with 3D image analysis generate rapid results with spatiotemporal detail, molecular techniques like viability PCR can distinguish live cells with genetic specificity. Notably, label-free biosensors can detect nuanced attributes of cellular vital signs with single-cell resolution via optical, acoustic, and electrical signals. Ultimately, efforts to integrate these modalities with automation, machine learning, and high-throughput workflows will lead to exciting new vistas across the cell viability landscape.
Collapse
Affiliation(s)
- Julian N Rosenberg
- Stack Family Center for Biopharmaceutical Education and Training (CBET), Albany College of Pharmacy and Health Sciences, 257 Fuller Road, Albany, NY 12203, USA.
| | - Nathaniel C Cady
- Nanobioscience Constellation, College of Nanoscale Science and Engineering, SUNY Polytechnic Institute, 257 Fuller Road, Albany, NY 12203, USA
| |
Collapse
|
45
|
Asaithambi N, Singh SK, Singha P. Current status of non-thermal processing of probiotic foods: A review. J FOOD ENG 2021. [DOI: 10.1016/j.jfoodeng.2021.110567] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
46
|
Ansari F, Alian Samakkhah S, Bahadori A, Jafari SM, Ziaee M, Khodayari MT, Pourjafar H. Health-promoting properties of Saccharomyces cerevisiae var. boulardii as a probiotic; characteristics, isolation, and applications in dairy products. Crit Rev Food Sci Nutr 2021; 63:457-485. [PMID: 34254862 DOI: 10.1080/10408398.2021.1949577] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Saccharomyces cerevisiae var. boulardii (S. boulardii) has been isolated from lychee (Litchi chinensis), mangosteen fruit, kombucha, and dairy products like kefir. Dairy products containing S. boulardii have been revealed to possess potential probiotic activities owing to their ability to produce organic acids, essential enzymes, vitamins, and other important metabolites such as vanillic acid, phenyl ethyl alcohol, and erythromycin. S. boulardii has a wide spectrum of anti-carcinogenic, antibacterial antiviral, and antioxidant activity, and is known to reduce serum cholesterol levels. However, this yeast has mainly been prescribed for prophylaxis treatment of gastrointestinal infectious diseases, and stimulating the immune system in a number of commercially available products. The present comprehensive review article reviews the properties of S. boulardii related to their use in fermented dairy foods as a probiotic microorganism or starter culture. Technical aspects regarding the integration of this yeast into the dairy foods matrix its health advantages, therapeutic functions, microencapsulation, and viability in harsh conditions, and safety aspects are highlighted.
Collapse
Affiliation(s)
- Fereshteh Ansari
- Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran.,Research Center for Evidence-Based Medicine, Health Management and Safety Promotion Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran.,Iranian EBM Centre: A Joanna Briggs Institute Affiliated Group
| | - Shohre Alian Samakkhah
- Department of Food Hygiene and Quality Control, Faculty of Veterinary of Medicine, Amol University of Special Modern Technology, Amol, Iran
| | - Ali Bahadori
- Department of Medical Microbiology, Sarab Faculty of Medical Sciences, Sarab, Iran
| | - Seyedeh Maedeh Jafari
- Department of Comparative Bioscience, Faculty of Veterinary Medicine, Tehran University, Tehran, Iran
| | - Mojtaba Ziaee
- Medicinal Plants Research Center, Maragheh University of Medical Sciences, Maragheh, Iran
| | | | - Hadi Pourjafar
- Alborz University of Medical Sciences, Dietary Supplements and Probiotic Research Center, Karaj, Iran.,Department of Food Sciences, Maragheh University of Medical Sciences, Maragheh, Iran
| |
Collapse
|
47
|
Wang L, Ye C, Guo L, Chen C, Kong X, Chen Y, Shu L, Wang P, Yu X, Fang J. Assessment of the UV/Chlorine Process in the Disinfection of Pseudomonas aeruginosa: Efficiency and Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:9221-9230. [PMID: 34138551 DOI: 10.1021/acs.est.1c00645] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
UV irradiation and chlorination have been widely used for water disinfection. However, there are some limitations, such as the risk of generating viable but nonculturable bacteria and bacteria reactivation when using UV irradiation or chlorination alone. This study comprehensively evaluated the feasibility of the UV/chlorine process in drinking water disinfection, and Pseudomonas aeruginosa was selected as the target microorganism. The number of culturable cells was effectively reduced by more than 5 orders of magnitude (5-log10) after UV, chlorine, and UV/chlorine treatments. However, intact and VBNC cells were detected at 103 to 104 cells/mL after UV and chlorine treatments, whereas they were undetectable after UV/chlorine treatment due to the primary contribution of reactive chlorine species (Cl•, Cl2•-, and ClO•). After UV/chlorine treatment, the metabolic activity determined using single cell Raman spectroscopy was much lower than that after UV. The level of toxic opr gene in P. aeruginosa decreased by more than 99% after UV/chlorine treatment. Importantly, bacterial dark reactivation was completely suppressed by UV/chlorine treatment but not UV or chlorination. This study suggests that the UV/chlorine treatment can completely damage bacteria and is promising for pathogen inactivation to overcome the limitations of UV and chlorine treatments alone.
Collapse
Affiliation(s)
- Liping Wang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Chengsong Ye
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, P. R. China
| | - Lizheng Guo
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, P. R. China
| | - Chunyan Chen
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Xiujuan Kong
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Yaoqing Chen
- School of Public Health, Shenzhen, Sun Yat-Sen University, Shenzhen 510000, P. R. China
| | - Longfei Shu
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Peng Wang
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Kowloon 999077, Hong Kong, P.R. China
| | - Xin Yu
- College of the Environment & Ecology, Xiamen University, Xiamen 361102, P. R. China
| | - Jingyun Fang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| |
Collapse
|
48
|
Mabrouk AM, Salama HH, El Sayed HS, El Sayed SM. Preparation of symbiotic whey protein gel as a carrier of free and encapsulated probiotic bacteria. J FOOD PROCESS PRES 2021. [DOI: 10.1111/jfpp.15612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Heba H. Salama
- Dairy Science Department National Research Centre Giza Egypt
| | | | | |
Collapse
|
49
|
Rodrigues NPA, Garcia EF, de Souza EL. Selection of lactic acid bacteria with promising probiotic aptitudes from fruit and ability to survive in different food matrices. Braz J Microbiol 2021; 52:2257-2269. [PMID: 34125419 DOI: 10.1007/s42770-021-00543-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/08/2021] [Indexed: 11/29/2022] Open
Abstract
Lactic acid bacteria (LAB) are among the most prevalent microorganisms forming the autochthonous microbiota of fruit. This study aimed to select LAB isolates with probiotic aptitudes from apple, banana, grape, and orange through evaluation of in vitro safety, technological, and functional-related properties. The ability of most promising selected isolates to survive in commercial apple and orange juice, meat stew, vegetable puree, and UHT milk during 28 days of refrigeration storage was evaluated. Ninety-three isolates identified preliminarily as LAB were recovered from fruit and 66 of these isolates passed safety tests. Most of these isolates were pre-identified as belonging to Lactobacillus or Enterococcus genus based on MALDI-ToF MS profiling. These 66 isolates were categorized into three homogeneous groups based on a preliminary cluster analysis run with data from experiments to measure technological characteristics. Nine LAB isolates were selected as the most promising for probiotic use based on a principal component analysis run with data from experiments to measure probiotic-related properties. Four of these isolates were sensitive to different antibiotics and identified (16S-rRNA gene sequencing) as Lactobacillus brevis (recently reclassified as L. brevis) or Lactobacillus spp. These 4 selected isolates had high viable counts and high percentages of physiologically active cells in apple and orange juice, beef stew, vegetable puree, and UHT milk during refrigeration storage. The results showed that apple, banana, orange, and grape are potential sources of LAB with aptitudes to be exploited for a possible probiotic use and distinguished abilities to survive in different food matrices.
Collapse
Affiliation(s)
- Noádia Priscilla Araújo Rodrigues
- Laboratório de Microbiologia de Alimentos, Departamento de Nutrição, Centro de Ciências da Saúde, Universidade Federal da Paraíba, Campus I, João Pessoa, Paraíba, Brazil.,Departamento de Gastronomia, Centro de Tecnologia E Desenvolvimento Regional, Universidade Federal da Paraíba, Paraíba, João Pessoa, Brazil
| | - Estefânia Fernandes Garcia
- Departamento de Gastronomia, Centro de Tecnologia E Desenvolvimento Regional, Universidade Federal da Paraíba, Paraíba, João Pessoa, Brazil
| | - Evandro Leite de Souza
- Laboratório de Microbiologia de Alimentos, Departamento de Nutrição, Centro de Ciências da Saúde, Universidade Federal da Paraíba, Campus I, João Pessoa, Paraíba, Brazil.
| |
Collapse
|
50
|
Li F, Santillan-Urquiza E, Cronin U, O'Meara E, McCarthy W, Hogan SA, Wilkinson MG, Tobin JT. Assessment of the response of indigenous microflora and inoculated Bacillus licheniformis endospores in reconstituted skim milk to microwave and conventional heating systems by flow cytometry. J Dairy Sci 2021; 104:9627-9644. [PMID: 34127263 DOI: 10.3168/jds.2020-19875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 03/23/2021] [Indexed: 11/19/2022]
Abstract
Heat treatment is one of the most widely used processing technologies in the dairy industry. Its primary purpose is to destroy microorganisms, both pathogenic and spoilage, to ensure the product is safe and has a reasonable shelf life. In this study microwave volumetric heating (MVH) was compared with a conventional tubular heat exchanger (THE), in terms of the effects of each at a range of temperatures (75°C, 85°C, 95°C, 105°C, 115°C, and 125°C) on indigenous microflora viability and the germination of inoculated Bacillus licheniformis endospores in reconstituted skim milk. To assess the heat treatment-related effects on microbial viability, classical agar-based tests were applied to obtain the counts of 4 various microbiological groups including total bacterial, thermophilic bacterial, mesophilic aerobic bacterial endospore, and thermophilic aerobic bacterial endospore counts, and additional novel insights into cell permeability and spore germination profiles post-heat treatment were obtained using real-time flow cytometry (FC) methods. No significant differences in the plate counts of the indigenous microorganisms tested, the plate counts of the inoculated B. licheniformis, or the relative percentage of germinating endospores were observed between MVH- and THE-treated samples, at equal temperatures in the range specified above, indicating that both methods inactivated inoculated endospores to a similar degree (up to 70% as measured by FC and 5 log reduction as measured by plate counting for some treatments of inoculated endospores). Furthermore, increased cell permeability of indigenous microflora was observed by FC after MVH compared with THE treatment of uninoculated skim milk, which was reflected in lower total bacterial count at a treatment temperature of 105°C. This work demonstrates the utility of FC as a rapid method for assessing cell viability and spore inactivation for postthermal processing in dairy products and overall provides evidence that MVH is at least as effective at eliminating native microflora and inoculated B. licheniformis endospores as THE.
Collapse
Affiliation(s)
- F Li
- Food Chemistry and Technology Department, Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, P61 C996, Ireland
| | - E Santillan-Urquiza
- Food Chemistry and Technology Department, Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, P61 C996, Ireland
| | - U Cronin
- Department of Biological Sciences, School of Natural Sciences, Faculty of Science and Engineering, University of Limerick, Limerick, V94 T9PX, Ireland
| | - E O'Meara
- Department of Biological Sciences, School of Natural Sciences, Faculty of Science and Engineering, University of Limerick, Limerick, V94 T9PX, Ireland
| | - W McCarthy
- Food Chemistry and Technology Department, Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, P61 C996, Ireland
| | - S A Hogan
- Food Chemistry and Technology Department, Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, P61 C996, Ireland
| | - M G Wilkinson
- Department of Biological Sciences, School of Natural Sciences, Faculty of Science and Engineering, University of Limerick, Limerick, V94 T9PX, Ireland
| | - J T Tobin
- Food Chemistry and Technology Department, Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, P61 C996, Ireland.
| |
Collapse
|