{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,24]],"date-time":"2026-06-24T10:51:50Z","timestamp":1782298310181,"version":"3.54.5"},"reference-count":31,"publisher":"American Society for Microbiology","issue":"21","license":[{"start":{"date-parts":[[2016,11,1]],"date-time":"2016-11-01T00:00:00Z","timestamp":1477958400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Appl Environ Microbiol"],"published-print":{"date-parts":[[2016,11]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n          <jats:p>\n            Intracellular pH (pH\n            <jats:sub>i<\/jats:sub>\n            ) critically affects bacterial cell physiology. Hence, a variety of food preservation strategies are aimed at perturbing pH\n            <jats:sub>i<\/jats:sub>\n            homeostasis. Unfortunately, accurate pH\n            <jats:sub>i<\/jats:sub>\n            quantification with existing methods is suboptimal, since measurements are averages across populations of cells, not taking into account interindividual heterogeneity. Yet, physiological heterogeneity in isogenic populations is well known to be responsible for differences in growth and division kinetics of cells in response to external stressors. To assess in this context the behavior of intracellular acidity, we have developed a robust method to quantify pH\n            <jats:sub>i<\/jats:sub>\n            at single-cell levels in\n            <jats:named-content content-type=\"genus-species\">Bacillus subtilis<\/jats:named-content>\n            . Bacilli spoil food, cause disease, and are well known for their ability to form highly stress-resistant spores. Using an improved version of the genetically encoded ratiometric pHluorin (IpHluorin), we have quantified pH\n            <jats:sub>i<\/jats:sub>\n            in individual\n            <jats:named-content content-type=\"genus-species\">B. subtilis<\/jats:named-content>\n            cells, cultured at an external pH of 6.4, in the absence or presence of weak acid stresses. In the presence of 3 mM potassium sorbate, a decrease in pH\n            <jats:sub>i<\/jats:sub>\n            and an increase in the generation time of growing cells were observed. Similar effects were observed when cells were stressed with 25 mM potassium acetate. Time-resolved analysis of individual bacteria in growing colonies shows that after a transient pH decrease, long-term pH evolution is highly cell dependent. The heterogeneity at the single-cell level shows the existence of subpopulations that might be more resistant and contribute to population survival. Our approach contributes to an understanding of pH\n            <jats:sub>i<\/jats:sub>\n            regulation in individual bacteria and may help scrutinizing effects of existing and novel food preservation strategies.\n          <\/jats:p>\n          <jats:p>\n            <jats:bold>IMPORTANCE<\/jats:bold>\n            This study shows how the physiological response to commonly used weak organic acid food preservatives, such as sorbic and acetic acids, can be measured at the single-cell level. These data are key to coupling often-observed single-cell heterogeneous growth behavior upon the addition of weak organic acid food preservatives. Generally, these data are gathered in the form of plate counting of samples incubated with the acids. Here, we visualize the underlying heterogeneity in cellular pH homeostasis, opening up avenues for mechanistic analyses of the heterogeneity in the weak acid stress response. Thus, microbial risk assessment can become more robust, widening the scope of use of these well-known weak organic acid food preservatives.\n          <\/jats:p>","DOI":"10.1128\/aem.02063-16","type":"journal-article","created":{"date-parts":[[2016,8,27]],"date-time":"2016-08-27T02:49:53Z","timestamp":1472266193000},"page":"6463-6471","update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":19,"title":["Intracellular pH Response to Weak Acid Stress in Individual Vegetative Bacillus subtilis Cells"],"prefix":"10.1128","volume":"82","author":[{"given":"Rachna","family":"Pandey","sequence":"first","affiliation":[{"name":"Molecular Biology and Microbial Food Safety, SILS, University of Amsterdam, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Norbert O. E.","family":"Vischer","sequence":"additional","affiliation":[{"name":"Molecular Biology and Microbial Food Safety, SILS, University of Amsterdam, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jan P. P. M.","family":"Smelt","sequence":"additional","affiliation":[{"name":"Molecular Biology and Microbial Food Safety, SILS, University of Amsterdam, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Johan W. A.","family":"van Beilen","sequence":"additional","affiliation":[{"name":"Molecular Biology and Microbial Food Safety, SILS, University of Amsterdam, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexander","family":"Ter Beek","sequence":"additional","affiliation":[{"name":"Molecular Biology and Microbial Food Safety, SILS, University of Amsterdam, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Winnok H.","family":"De Vos","sequence":"additional","affiliation":[{"name":"Department of Veterinary Sciences, Laboratory of Cell Biology and Histology, Antwerp University, Antwerp, Belgium"},{"name":"Department Molecular Biotechnology, Cell Systems and Imaging Group, Ghent University, Ghent, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stanley","family":"Brul","sequence":"additional","affiliation":[{"name":"Molecular Biology and Microbial Food Safety, SILS, University of Amsterdam, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erik M. M.","family":"Manders","sequence":"additional","affiliation":[{"name":"Van Leeuwenhoek Centre for Advance Microscopy, SILS, University of Amsterdam, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_3_2_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.144.3.891-897.1980"},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.1042\/bj2140657"},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1462-2920.2011.02490.x"},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.01391-14"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1128\/aem.62.9.3158-3164.1996"},{"key":"e_1_3_3_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0167-7012(97)00095-X"},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1099\/00221287-143-6-1877"},{"key":"e_1_3_3_9_2","doi-asserted-by":"publisher","DOI":"10.1093\/emboj\/17.15.4257"},{"key":"e_1_3_3_10_2","doi-asserted-by":"publisher","DOI":"10.1016\/0168-1605(85)90035-2"},{"key":"e_1_3_3_11_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.75.5.2244"},{"key":"e_1_3_3_12_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00871725"},{"key":"e_1_3_3_13_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.176.8.2252-2258.1994"},{"key":"e_1_3_3_14_2","doi-asserted-by":"publisher","DOI":"10.1128\/aem.62.1.178-183.1996"},{"key":"e_1_3_3_15_2","doi-asserted-by":"publisher","DOI":"10.1099\/00221287-146-1-49"},{"key":"e_1_3_3_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0065-2911(09)05501-5"},{"key":"e_1_3_3_17_2","doi-asserted-by":"publisher","DOI":"10.1038\/28190"},{"key":"e_1_3_3_18_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbagen.2011.03.011"},{"key":"e_1_3_3_19_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.02126-12"},{"key":"e_1_3_3_20_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.00354-12"},{"key":"e_1_3_3_21_2","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2013.00157"},{"key":"e_1_3_3_22_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.fm.2014.02.013"},{"key":"e_1_3_3_23_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M710470200"},{"key":"e_1_3_3_24_2","doi-asserted-by":"publisher","DOI":"10.1099\/mic.0.022038-0"},{"key":"e_1_3_3_25_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.71.7.3556-3564.2005"},{"key":"e_1_3_3_26_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0058972"},{"key":"e_1_3_3_27_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.freeradbiomed.2011.11.037"},{"key":"e_1_3_3_28_2","volume-title":"A practical guide to curve fitting","author":"Motulsky H","year":"2004","unstructured":"Motulsky H, Christopoulos A. 2004. Fitting models to biological data using linear and nonlinear regression. A practical guide to curve fitting. Oxford University Press, Oxford, United Kingdom."},{"key":"e_1_3_3_29_2","doi-asserted-by":"publisher","DOI":"10.1038\/nbt1278"},{"key":"e_1_3_3_30_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijfoodmicro.2012.03.028"},{"key":"e_1_3_3_31_2","doi-asserted-by":"publisher","DOI":"10.3390\/s110605754"},{"key":"e_1_3_3_32_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0008255"}],"updated-by":[{"DOI":"10.1128\/aem.00861-17","type":"correction","label":"Correction","source":"publisher","updated":{"date-parts":[[2017,5,17]],"date-time":"2017-05-17T00:00:00Z","timestamp":1494979200000}}],"container-title":["Applied and Environmental Microbiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AEM.02063-16","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AEM.02063-16","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,2,23]],"date-time":"2022-02-23T03:02:27Z","timestamp":1645585347000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/AEM.02063-16"}},"subtitle":[],"editor":[{"given":"D. W.","family":"Schaffner","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2016,11]]},"references-count":31,"journal-issue":{"issue":"21","published-print":{"date-parts":[[2016,11]]}},"alternative-id":["10.1128\/AEM.02063-16"],"URL":"https:\/\/doi.org\/10.1128\/aem.02063-16","relation":{},"ISSN":["0099-2240","1098-5336"],"issn-type":[{"value":"0099-2240","type":"print"},{"value":"1098-5336","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,11]]},"assertion":[{"value":"2016-07-13","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2016-08-21","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2016-10-14","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}