Saccharomyces cerevisiae is one of the most employed cell factories for the production of bioproducts. Although monomeric hexose sugars constitute the preferential carbon source, this yeast can grow on a wide variety of nitrogen sources that are catabolized through central nitrogen metabolism (CNM). To evaluate the effects of internal perturbations on nitrogen utilization, we characterized strains deleted or overexpressed in GLT1, encoding for one of the key enzymes of the CNM node, the glutamate synthase. These strains, together with the parental strain as control, have been cultivated in minimal medium formulated with ammonium sulfate, glutamate, or glutamine as nitrogen source. Growth kinetics, together with the determination of protein content, viability, and reactive oxygen species (ROS) accumulation at the single cell level, revealed that GLT1 modulations do not significantly influence the cellular physiology, whereas the nitrogen source does. As important exceptions, GLT1 deletion negatively affected the scavenging activity of glutamate against ROS accumulation, when cells were treated with H2O2, whereas Glt1p overproduction led to lower viability in glutamine medium. Overall, this confirms the robustness of the CNM node against internal perturbations, but, at the same time, highlights its plasticity in respect to the environment. Considering that side-stream protein-rich waste materials are emerging as substrates to be used in an integrated biorefinery, these results underline the importance of preliminarily evaluating the best nitrogen source not only for media formulation, but also for the overall economics of the process.

Brambilla, M., Adamo, G., Frascotti, G., Porro, D., Branduardi, P. (2015). Physiological effects of GLT1 modulation in saccharomyces cerevisiae strains growing on different nitrogen sources. JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY, 26(2), 326-336 [10.4014/jmb.1508.08002].

Physiological effects of GLT1 modulation in saccharomyces cerevisiae strains growing on different nitrogen sources

BRAMBILLA, MARCO;ADAMO, GIUSY MANUELA;FRASCOTTI, GIANNI;PORRO, DANILO
;
BRANDUARDI, PAOLA
2015

Abstract

Saccharomyces cerevisiae is one of the most employed cell factories for the production of bioproducts. Although monomeric hexose sugars constitute the preferential carbon source, this yeast can grow on a wide variety of nitrogen sources that are catabolized through central nitrogen metabolism (CNM). To evaluate the effects of internal perturbations on nitrogen utilization, we characterized strains deleted or overexpressed in GLT1, encoding for one of the key enzymes of the CNM node, the glutamate synthase. These strains, together with the parental strain as control, have been cultivated in minimal medium formulated with ammonium sulfate, glutamate, or glutamine as nitrogen source. Growth kinetics, together with the determination of protein content, viability, and reactive oxygen species (ROS) accumulation at the single cell level, revealed that GLT1 modulations do not significantly influence the cellular physiology, whereas the nitrogen source does. As important exceptions, GLT1 deletion negatively affected the scavenging activity of glutamate against ROS accumulation, when cells were treated with H2O2, whereas Glt1p overproduction led to lower viability in glutamine medium. Overall, this confirms the robustness of the CNM node against internal perturbations, but, at the same time, highlights its plasticity in respect to the environment. Considering that side-stream protein-rich waste materials are emerging as substrates to be used in an integrated biorefinery, these results underline the importance of preliminarily evaluating the best nitrogen source not only for media formulation, but also for the overall economics of the process.
Articolo in rivista - Articolo scientifico
Ammonium sulfate; Central nitrogen metabolism; GLT1; Glutamate; Glutamine; Saccharomyces cerevisiae;
Ammonium sulfate; Central nitrogen metabolism; GLT1; Glutamate; Glutamine; Saccharomyces cerevisiae; Biotechnology; Applied Microbiology and Biotechnology
English
2015
26
2
326
336
reserved
Brambilla, M., Adamo, G., Frascotti, G., Porro, D., Branduardi, P. (2015). Physiological effects of GLT1 modulation in saccharomyces cerevisiae strains growing on different nitrogen sources. JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY, 26(2), 326-336 [10.4014/jmb.1508.08002].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/107588
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