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High-throughput pH monitoring method for application in dairy fermentations

Published online by Cambridge University Press:  22 August 2018

Valery Gutsal*
Affiliation:
Arla Innovation Centre, Agro Food Park 19, 8200 Aarhus N, Denmark
Sander Sieuwerts
Affiliation:
Arla Innovation Centre, Agro Food Park 19, 8200 Aarhus N, Denmark
Rodrigo Bibiloni
Affiliation:
Arla Innovation Centre, Agro Food Park 19, 8200 Aarhus N, Denmark
*
*For correspondence; e-mail: [email protected]

Abstract

Optimization of dairy fermentation processes often requires multiplexed pH measurements over several hours. The method developed here measures up to 90 samples simultaneously, where traditional electrode-based methods require a lot more time for handing the same number of samples. Moreover, the new method employs commonly used materials and can be used with a wider range of fluorescence readers than commercial 96-well plates with optical pH sensors. For this application, a milk-like transparent medium is developed that shows acidification properties with dairy starters that are similar to milk. Combination of this milk-like medium and 3 fluorescent indicators allow precise measurements of pH in a range of 4·0–7·0. The new method showed much higher throughput compared to the benchmark electrode systems while being as accurate, as shown by successful application for a comparison of various dairy starter cultures and for optimizing the inoculation rate.

Type
Research Article
Copyright
Copyright © Hannah Dairy Research Foundation 2018 

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References

Arain, S, John, GT, Krause, C, Gerlach, J, Wolfbeis, OS & Klimant, I 2006 Characterization of microtiter plates with integrated optical sensors for oxygen and pH, and their applications to enzyme activity screening, respirometry, and toxicological assays. Sensors and Actuators B: Chemical 113 639648Google Scholar
Carminati, D, Giraffa, G, Quiberoni, A, Binetti, A, Suárez, V & Reinheimer, J 2010 Biotechnology of lactic acid bacteria: Novel applications. Advances and Trends in Starter Cultures for Dairy Fermentations 177 177192Google Scholar
John, GT, Goelling, D, Klimant, I, Schneider, H & Heinzle, E 2003 pH-sensing 96-well microtitre plates for the characterization of acid production by dairy starter cultures. Journal of Dairy Research 70 327333Google Scholar
Kensy, F, Zang, E, Faulhammer, C, Tan, RK & Büchs, J 2009 Validation of a high-throughput fermentation system based on online monitoring of biomass and fluorescence in continuously shaken microtiter plates. Microbial Cell Factories 8 31–00Google Scholar
Kermis, HR, Kostov, Y, Harms, P & Rao, G 2002 Dual excitation ratiometric fluorescent pH sensor for noninvasive bioprocess monitoring: development and application. Biotechnology Progress 18 10471053Google Scholar
Kim, JH, Johannes, L, Goud, B, Antony, C, Lingwood, CA, Daneman, R & Grinstein, S 1998 Noninvasive measurement of the pH of the endoplasmic reticulum at rest and during calcium release. Proceedings of the National Academy of Sciences 95 29973002Google Scholar
McMillan, G 1991 Understand some basic truths of pH measurement. Chemical Engineering Progress 87 3037Google Scholar
Nedergaard, M, Desai, S & Pulsinelli, W 1990 Dicarboxy-dichlorofluorescein: a new fluorescent probe for measuring acidic intracellular pH. Analytical Biochemistry 187 109114Google Scholar
Sipior, J, Bambot, S, Romauld, M, Carter, GM, Lakowicz, JR & Rao, G 1995 A lifetime-based optical CO2 gas sensor with blue or red excitation and stokes or anti-stokes detection. Analytical Biochemistry 227 309318Google Scholar
Tian, Y, Su, F, Weber, W, Nandakumar, V, Shumway, BR, Jin, Y, Zhou, X, Holl, MR, Johnson, HR & Meldrum, DR 2010 A series of naphthalimide derivatives as intra and extracellular pH sensors. Biomaterials 31 74117422Google Scholar
Wolfbeis, OS 2008 Fiber-optic chemical sensors and biosensors. Analytical Chemistry 80 42694283Google Scholar