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Báo cáo khoa học: Autonomous oscillations in Saccharomyces cerevisiae during batch cultures on trehalose

We report that autonomous oscillations, which usually happen in aerobic glucose-limited continuous cultures of yeast at low dilution rate, were also observed in trehalose discontinuous cultures ofSaccharomyces cerevisiae. This unexpected oscillatory behaviour was therefore examined using fast Fourier transformation of online gas measurements. This robust mathemat-ical analysis underlined the existence of two types of oscillation. | iFEBS Journal Autonomous oscillations in Saccharomyces cerevisiae during batch cultures on trehalose Matthieu Jules Jean Francois and Jean Luc Parrou Centre de Bioingenierie Gilbert Durand UMR-CNRS 5504 UMR-INRA 792 Institut Nationaldes Sciences Appliquees Toulouse France Keywords acid trehalase Ath1p batch culture Fourier transform oscillations trehalose Correspondence J. Francois Centre de Bioingenierie Gilbert Durand UMR-CNRS 5504 UmR-INRA 792 Institut Nationaldes Sciences Appliquees 135 Avenue de Rangeuil 31077 Toulouse cedex 04 France Fax 00 33 5 61 559400 Tel 00 33 5 61 559492 E-mail franjm@insa-toulouse.fr Web site http biopuce.insa-toulouse.fr jmflab Received 15 December 2004 revised 21 January 2005 accepted 31 January 2005 doi 10.1111 j.1742-4658.2005.04588.x We report that autonomous oscillations which usually happen in aerobic glucose-limited continuous cultures of yeast at low dilution rate were also observed in trehalose discontinuous cultures of Saccharomyces cerevisiae. This unexpected oscillatory behaviour was therefore examined using fast Fourier transformation of online gas measurements. This robust mathematical analysis underlined the existence of two types of oscillation. The first was found to be linked to the cell cycle because a the periodicity corresponded to a fraction of the generation time and b the oscillations were accompanied by a transient increase in the budding index mobilization of storage carbohydrates and fermentative activity. Moreover these oscillations occurred in a range of specific growth rates between 0.04 and 0.15 h-1. All these criteria were consistent with the cell-cycle-related metabolic oscillations observed in the same range of growth rates in glucose-limited continuous cultures. The second type were short-period respiratory oscillations independent of the specific growth rate. Both types of oscillation were found to take place consecutively and or simultaneously during batch culture on trehalose. In addition .