Effect of aerobic and microaerophilic culture in the growth dynamics of Saccharomyces cerevisiae and in training of quie
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ORIGINAL PAPER
Effect of aerobic and microaerophilic culture in the growth dynamics of Saccharomyces cerevisiae and in training of quiescent and non‑quiescent subpopulations Rosa Carbó1 · Marta Ginovart2 · Akatibu Carta1 · Xavier Portell1 · Luis J. del Valle3
Received: 4 March 2015 / Revised: 28 June 2015 / Accepted: 14 July 2015 / Published online: 24 July 2015 © Springer-Verlag Berlin Heidelberg 2015
Abstract Saccharomyces cerevisiae is industrially the most important yeast, and its growth in different concentrations of oxygen can be used to improve various application processes. The aims of this work were to study in aerobic and microaerophilic growth conditions the cell size and tendency of morphological changes in S. cerevisiae in different stages of growth and to assess the effect of the two growth conditions in the differentiation of quiescent and non-quiescent subpopulations in the stationary phase. Dissolved oxygen levels in the culture medium for aerobic and microaerophilic conditions were 6.6 and 5.2 mg L−1, respectively. In both growth conditions, similar viable cell populations were obtained, although in aerobic conditions the stationary phase was reached and the quiescent and non-quiescent subpopulations were also differentiated. The microaerophilic growth produced a significant reduction in the specific growth rate and consequently also in glucose and oxygen consumption. The most notable changes in cellular size and morphology occurred with the depletion of
Communicated by Olaf Kniemeyer. * Rosa Carbó [email protected] 1
Department of Agri‑Food Engineering and Biotechnology, Universitat Politècnica de Catalunya, Campus Baix Llobregrat, Esteve Terradas 8, 08860 Castelldefels, Barcelona, Spain
2
Department of Applied Mathematics III, Universitat Politècnica de Catalunya, Campus Baix Llobregat, Esteve Terradas 8, 08860 Castelldefels, Barcelona, Spain
3
Department of Chemical Engineering, Molecular Biotechnology Center (CEBIM), ETSEIB, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona, Spain
glucose and oxygen. The concentration of dissolved oxygen in the culture medium significantly modulated the growth kinetics of S. cerevisiae and their development and differentiation to quiescent cells. This could justify the need to readjust small variations in oxygen levels during yeast cultures in biotechnological processes. Keywords Saccharomyces cerevisiae · Aerobic culture · Microaerophilic culture · Quiescent cells
Introduction Saccharomyces cerevisiae is one of the most widely used microorganisms in industrial fermentation. In most applications, the yeast performs the fermentation in conditions that vary throughout the process. The success of the fermentation depends largely on the ability of yeast to adapt to the situations of stress being produced. In fermented food preparation, different types of stress arise, and the most general are concentrations of sugars and ethanol, the limited availability of nutrients and oxygen, adverse temperatures, and pH. The strain
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