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Yamashoji S, Al Mamun A, Bari L. Visual and simple determination of glucose-induced acidification by yeast cells: application to rapid cytotoxicity test. Heliyon 2020; 6:e03924. [PMID: 32420490 PMCID: PMC7218269 DOI: 10.1016/j.heliyon.2020.e03924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 02/03/2020] [Accepted: 04/30/2020] [Indexed: 01/03/2023] Open
Abstract
This study demonstrated that glucose-induced proton release from yeast cells was more sensitive to various inhibitors than cell proliferation. In this study the inhibition of glucose-induced proton release was determined on the basis of color change of pH indicator, methyl red, from pH 5 to pH6 at cell density of 2.5 × 107 cells/ml. When yeast cells were incubated with the inhibitors of glucose intake, glycolysis, and plasma membrane H + -ATPase for 1 h, these cytotoxic effects were observed by following the change in absorbance at 527 nm due to methyl red for 5 min. The cytotoxic effects of heavy metal ions, detergents and quinones were observed in the same manner. The above method was superior in sensitivity and measurement time to cell proliferation measurement that required 9 h. This visual cytotoxicity test (methyl red test) is expected to be useful as simple and rapid cytotoxicity test with yeast cells.
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Affiliation(s)
- Shiro Yamashoji
- Microbial Technology Laboratory, 9-50-514 Kaigandori, Tarumi-ku, Kobe City, Hyogo 655-0036, Japan
| | - Arafat Al Mamun
- Center for Advanced Research in Sciences, University of Dhaka, Dhaka-1000, Bangladesh
| | - Latiful Bari
- Center for Advanced Research in Sciences, University of Dhaka, Dhaka-1000, Bangladesh
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2
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Janić Hajnal E, Pezo L, Orčić D, Šarić L, Plavšić D, Kos J, Mastilović J. Preliminary Survey of Alternaria Toxins Reduction during Fermentation of Whole Wheat Dough. Microorganisms 2020; 8:E303. [PMID: 32098250 PMCID: PMC7074859 DOI: 10.3390/microorganisms8020303] [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: 12/31/2019] [Revised: 02/15/2020] [Accepted: 02/18/2020] [Indexed: 11/16/2022] Open
Abstract
The aim of this study was to investigate the fate of the most common Alternaria toxins found in wheat-tenuazonic acid (TeA), alternariol (AOH), and alternariol monomethyl ether (AME) during sourdough processing. For this purpose, spiked whole wheat flour, 3% sourdough starter, 0.5% of baker's yeast, and 105% of water calculated on flour weight as a base were used as raw materials. Spiked whole wheat dough was fermented for 4 h, 8 h, 12 h, 24 h, and 48 h at 25 °C, and at each point the fermented dough samples were taken, frozen, lyophilized, grounded, and stored until further analysis. To study the effect of sourdough processing on TeA, AOH and AME content, the validated method of high-performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for these mycotoxins was used. Mathematical models of Alternaria toxins reduction were developed in the form of Four Parameter Logistic Regression function. The maximum reduction of TeA, AOH, and AME levels was archived at 48 h of dough fermentation at 25 °C compared with dough after kneading (0 h). Under these conditions, a reduction of the toxin levels of 60.3 %, 41.5%, and 24.1% was observed for TeA, AOH, and AME, respectively.
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Affiliation(s)
- Elizabet Janić Hajnal
- Research Center for Technology of Plant Based Food Products, Institute of Food Technology, University of Novi Sad, 21000 Novi Sad, Serbia; (L.Š.); (D.P.); (J.K.); (J.M.)
| | - Lato Pezo
- Institute of General and Physical Chemistry, University of Belgrade, 11000 Belgrade, Serbia;
| | - Dejan Orčić
- Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia;
| | - Ljubiša Šarić
- Research Center for Technology of Plant Based Food Products, Institute of Food Technology, University of Novi Sad, 21000 Novi Sad, Serbia; (L.Š.); (D.P.); (J.K.); (J.M.)
| | - Dragana Plavšić
- Research Center for Technology of Plant Based Food Products, Institute of Food Technology, University of Novi Sad, 21000 Novi Sad, Serbia; (L.Š.); (D.P.); (J.K.); (J.M.)
| | - Jovana Kos
- Research Center for Technology of Plant Based Food Products, Institute of Food Technology, University of Novi Sad, 21000 Novi Sad, Serbia; (L.Š.); (D.P.); (J.K.); (J.M.)
| | - Jasna Mastilović
- Research Center for Technology of Plant Based Food Products, Institute of Food Technology, University of Novi Sad, 21000 Novi Sad, Serbia; (L.Š.); (D.P.); (J.K.); (J.M.)
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Schaarschmidt S, Fauhl-Hassek C. The Fate of Mycotoxins During the Processing of Wheat for Human Consumption. Compr Rev Food Sci Food Saf 2018; 17:556-593. [PMID: 33350125 DOI: 10.1111/1541-4337.12338] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/07/2018] [Accepted: 01/08/2018] [Indexed: 01/10/2023]
Abstract
Mycotoxins are a potential health threat in cereals including wheat. In the European Union (EU), mycotoxin maximum levels are laid down for cereal raw materials and final food products. For wheat and wheat-based products, the EU maximum levels apply to deoxynivalenol (DON), zearalenone, aflatoxins, and ochratoxin A. This review provides a comprehensive overview on the different mycotoxins and their legal limits and on how processing of wheat can affect such contaminants, from raw material to highly processed final products, based on relevant scientific studies published in the literature. The potential compliance with EU maximum levels is discussed. Of the four mycotoxins regulated in wheat-based foods in the EU, most data are available for DON, whereas aflatoxins were rarely studied in the processing of wheat. Furthermore, available data on the effect of processing are outlined for mycotoxins not regulated by EU law-including modified and emerging mycotoxins-and which cover DON derivatives (DON-3-glucoside, mono-acetyl-DONs, norDONs, deepoxy-DON), nivalenol, T-2 and HT-2 toxins, enniatins, beauvericin, moniliformin, and fumonisins. The processing steps addressed in this review cover primary processing (premilling and milling operations) and secondary processing procedures (such as fermentation and thermal treatments). A special focus is on the production of baked goods, and processing factors for DON in wheat bread production were estimated. For wheat milling products derived from the endosperm and for white bread, compliance with legal requirements seems to be mostly achievable when applying good practices. In the case of wholemeal products, bran-enriched products, or high-cereal low-moisture bakery products, this appears to be challenging and improved technology and/or selection of high-quality raw materials would be required.
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Affiliation(s)
- Sara Schaarschmidt
- Dept. Safety in the Food Chain, German Federal Inst. for Risk Assessment (BfR), Max-Dohrn-St. 8-10, D-10589 Berlin, Germany
| | - Carsten Fauhl-Hassek
- Dept. Safety in the Food Chain, German Federal Inst. for Risk Assessment (BfR), Max-Dohrn-St. 8-10, D-10589 Berlin, Germany
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Zhuang S, Smart K, Powell C. Impact of Extracellular Osmolality onSaccharomycesYeast Populations during Brewing Fermentations. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-2017-3505-01] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Shiwen Zhuang
- Division of Food Sciences, School of Biosciences, University of Nottingham, Leicestershire, U.K
| | | | - Chris Powell
- Division of Food Sciences, School of Biosciences, University of Nottingham, Leicestershire, U.K
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5
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Somani A, Bealin-Kelly F, Axcell B, Smart KA. Impact of Storage Temperature on Lager Brewing Yeast Viability, Glycogen, Trehalose, and Fatty Acid Content. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-2012-0427-01] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Abhishek Somani
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | | | - Barry Axcell
- SABMiller Plc., SABMiller House, Woking, Surrey GU21 6HS, UK
| | - Katherine A. Smart
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
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Guo ZP, Olsson L. Physiological responses to acid stress by Saccharomyces cerevisiae when applying high initial cell density. FEMS Yeast Res 2016; 16:fow072. [PMID: 27620460 PMCID: PMC5094285 DOI: 10.1093/femsyr/fow072] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2016] [Indexed: 12/20/2022] Open
Abstract
High initial cell density is used to increase volumetric productivity and shorten production time in lignocellulosic hydrolysate fermentation. Comparison of physiological parameters in high initial cell density cultivation of Saccharomyces cerevisiae in the presence of acetic, formic, levulinic and cinnamic acids demonstrated general and acid-specific responses of cells. All the acids studied impaired growth and inhibited glycolytic flux, and caused oxidative stress and accumulation of trehalose. However, trehalose may play a role other than protecting yeast cells from acid-induced oxidative stress. Unlike the other acids, cinnamic acid did not cause depletion of cellular ATP, but abolished the growth of yeast on ethanol. Compared with low initial cell density, increasing initial cell density reduced the lag phase and improved the bioconversion yield of cinnamic acid during acid adaptation. In addition, yeast cells were able to grow at elevated concentrations of acid, probable due to the increase in phenotypic cell-to-cell heterogeneity in large inoculum size. Furthermore, the specific growth rate and the specific rates of glucose consumption and metabolite production were significantly lower than at low initial cell density, which was a result of the accumulation of a large fraction of cells that persisted in a viable but non-proliferating state.
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Affiliation(s)
- Zhong-Peng Guo
- Department of Biology and Biological Engineering, Division of Industrial Biotechnology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Lisbeth Olsson
- Department of Biology and Biological Engineering, Division of Industrial Biotechnology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
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Boulton C. 125thAnniversary Review: Advances in analytical methodology in brewing. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/jib.47] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Yu Z, Zhao H, Wan C, Sun G, Zhao M. The Dynamic Changes of Proton Efflux Rate in Saccharomyces pastorianus Strains During High Gravity or Very High Gravity Brewing. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/j.2050-0416.2011.tb00457.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Gabriel P, Dienstbier M, Matoulková D, Kosař K, Sigler K. Optimised Acidification Power Test of Yeast Vitality and its Use in Brewing Practice. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/j.2050-0416.2008.tb00338.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Matoulková D, Sigler K. Impact of the Long-Term Maintenance Method of Brewer's Yeast on Fermentation Course, Yeast Vitality and Beer Characteristics. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/j.2050-0416.2011.tb00483.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Wang H, Hou L. Genome shuffling to improve fermentation properties of top-fermenting yeast by the improvement of stress tolerance. Food Sci Biotechnol 2010. [DOI: 10.1007/s10068-010-0020-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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12
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Yeast and stress: from the laboratory to the brewery. KVASNY PRUMYSL 2010. [DOI: 10.18832/kp2010013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Yeast vitality determination based on intracellular NAD(P)H fluorescence measurement during aerobic-anaerobic transition. Folia Microbiol (Praha) 2009; 54:25-9. [PMID: 19330541 DOI: 10.1007/s12223-009-0004-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 09/08/2008] [Indexed: 10/21/2022]
Abstract
This work presents a yeast-cell vitality-assessment method based on on-line intracellular fluorescence measurement. The intracellular NAD(P)H fluorescence of a cell suspension is recorded during transition from aerobic to anaerobic conditions and the output signal is evaluated as a measure of yeast vitality (quality). This fluorescence method showed a highly satisfactory correlation with even low dead cell numbers where the acidification power test could not be applied.
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Sigler K, Matoulková D, Dienstbier M, Gabriel P. Net effect of wort osmotic pressure on fermentation course, yeast vitality, beer flavor, and haze. Appl Microbiol Biotechnol 2009; 82:1027-35. [PMID: 19122996 DOI: 10.1007/s00253-008-1830-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 12/04/2008] [Accepted: 12/14/2008] [Indexed: 11/26/2022]
Abstract
The net effect of increased wort osmolarity on fermentation time, bottom yeast vitality and sedimentation, beer flavor compounds, and haze was determined in fermentations with 12 degrees all-malt wort supplemented with sorbitol to reach osmolarity equal to 16 degrees and 20 degrees. Three pitchings were performed in 12 degrees/12 degrees/12 degrees, 16 degrees/16 degrees/12 degrees, and 20 degrees/20 degrees/12 degrees worts. Fermentations in 16 degrees and 20 degrees worts decreased yeast vitality measured as acidification power (AP) by a maximum of 10%, lowered yeast proliferation, and increased fermentation time. Repitching aggravated these effects. The 3rd "back to normal" pitching into 12 degrees wort restored the yeast AP and reproductive abilities while the extended fermentation time remained. Yeast sedimentation in 16 degrees and 20 degrees worts was delayed but increased about two times at fermentation end relative to that in 12 degrees wort. Third "back-to-normal" pitching abolished the delay in sedimentation and reduced its extent, which became nearly equal in all variants. Beer brewed at increased osmolarity was characterized by increased levels of diacetyl and pentanedione and lower levels of dimethylsulfide and acetaldehyde. Esters and higher alcohols displayed small variations irrespective of wort osmolarity or repitching. Increased wort osmolarity had no appreciable effect on the haze of green beer and accelerated beer clarification during maturation. In all variants, chill haze increased with repitching.
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Affiliation(s)
- K Sigler
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 142 20 Prague 4, Czech Republic.
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Kosín P, Savel J, Broz A, Sigler K. Control and prediction of the course of brewery fermentations by gravimetric analysis. Folia Microbiol (Praha) 2008; 53:451-6. [PMID: 19085082 DOI: 10.1007/s12223-008-0069-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Revised: 06/13/2008] [Indexed: 11/29/2022]
Abstract
A simple, fast and cheap test suitable for predicting the course of brewery fermentations based on mass analysis is described and its efficiency is evaluated. Compared to commonly used yeast vitality tests, this analysis takes into account wort composition and other factors that influence fermentation performance. It can be used to predict the shape of the fermentation curve in brewery fermentations and in research and development projects concerning yeast vitality, fermentation conditions and wort composition. It can also be a useful tool for homebrewers to control their fermentations.
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Affiliation(s)
- P Kosín
- Budweiser Budvar, National Corporation, 370 21, Ceské Budejovice, Czech Republic
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A new method of optical detection of yeast acidification power. Folia Microbiol (Praha) 2008; 53:527-33. [PMID: 19381479 DOI: 10.1007/s12223-008-0083-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Revised: 10/17/2008] [Indexed: 10/20/2022]
Abstract
We describe here a newly developed method for a contact-free optical pH measurement in yeast suspensions supplemented with glucose, and containing the pH sensitive triphenylmethane dye bromocresol green. It is suitable for performing the acidification power test (based on measuring the rate of pH drop of yeast suspension caused by active extrusion of acidity from cells after glucose addition) used for assessing yeast vitality in fermentation industries. Using this methodology we monitored the pH in yeast suspensions in the course of acidification in the pH range of 3.5-5.3. Optical pH measurement allows simultaneous testing of several samples, minimizes the sample volume, simplifies sample handling and reduces the hands-on time in sample processing.
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Current awareness on yeast. Yeast 2007. [DOI: 10.1002/yea.1453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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