Catabolite inactivation of the sugar transporters in is inhibited by the presence of a nitrogen source

Lucero, Pilar; Moreno, Eulalia; Lagunas, Rosario

doi:10.1016/s1567-1356(01)00045-9

Cited by 9 publications

(9 citation statements)

References 34 publications

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“…The diminished ability to utilize maltose has not been reported for nitrogen-rich media. On the contrary, nitrogen starvation has been implicated in inactivating sugar transporters, which would suggest that higher nitrogen availability would enhance, not hinder, maltose uptake and utilization (Lucero et al 2002). However, others (Batistote et al 2002;Cruz et al 2002) indicated that nitrogen source structural complexity influenced the sugar utilization characteristics of yeasts in a strain-specific manner, pointing to a more complex interaction between carbon and nitrogen metabolism.…”

Section: Discussionmentioning

confidence: 99%

Corn Endosperm Fermentation Using Endogenous Amino Nitrogen Generated by a Fungal Protease

2011

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Cereal Chem. 88(2):117-123Fractionating the corn kernel to separate endosperm from germ and pericarp improves corn ethanol processing by increasing fermentation throughput and generating salable coproducts. One fractionation technology, dry fractionation (DF), suffers from loss of germ-derived nutrients and amino acids, resulting in poor fermentation performance. Such deficiencies may be addressed by increasing nitrogen and other nutritional supplementation. As an alternative to exogenous nitrogen source, we investigated the use of a fungal protease to generate free amino nitrogen (FAN) from corn endosperm. Incubation of endosperm with protease did not affect subsequent liquefaction and saccharification. FAN supplementation through proteolysis resulted in fermentation being 99% complete in 48 hr, compared to 93% maximum with urea supplementation. Viable cell growth rates were similar in FAN and urea-supplemented fermentations.

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Section: Discussionmentioning

confidence: 99%

Corn Endosperm Fermentation Using Endogenous Amino Nitrogen Generated by a Fungal Protease

2011

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“…Interestingly, prolonged N starvation (>3 h) has a negative effect on the expression of all purine transporter genes. This may involve a mechanism analogous to that described in Saccharomyces cerevisiae , in which N starvation is perceived as a stress signal that activates a transporter degradation system involving ubiquitination and endocytosis (Galán et al ., 1994; Omura et al ., 2001; Krampe and Boles, 2002; Lucero et al ., 2002).…”

Section: Discussionmentioning

confidence: 99%

Transcription of purine transporter genes is activated during the isotropic growth phase of Aspergillus nidulans conidia

Amillis

Cecchetto

Sophianopoulou

et al. 2004

Molecular Microbiology

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SummaryAspergillus nidulans possesses three well-characterized purine transporters encoded by the genes uapA , uapC and azgA . Expression of these genes in mycelium is induced by purines and repressed by ammonium or glutamine through the action of the pathwayspecific UaY regulator and the general GATA factor AreA respectively. Here, we describe the regulation of expression of purine transporters during conidiospore germination and the onset of mycelium development. In resting conidiospores, mRNA steady-state levels of purine transporter genes and purine uptake activities are undetectable or very low. Both mRNA steady-state levels and purine transport activities increase substantially during the isotropic growth phase of conidial germination. Both processes occur in the absence of purine induction and independently of the nitrogen source present in the medium. The transcriptional activator UaY is dispensable for the germination-induced expression of the three transporter genes. AreA, on the other hand, is essential for the expression of uapA , but not for that of azgA or uapC , during germination. Transcriptional activation of uapA , uapC and azgA during germination is also independent of the presence of a carbon source in the medium. This work establishes the presence of a novel system triggering purine transporter transcription during germination. Similar results have been found in studies on the expression of other transporters in A. nidulans , suggesting that global expression of transporters might operate as a general system for sensing solute availability.

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“…Nitrogen additions in the third stage of FSCF resulted in a substantial increase in the fermentation rate while biomass production was almost unaffected; this is consistent with previous observations during batch cultures (2,11,20). This recovery of an efficient fermentative activity has been explained by the increase of glucose uptake capacity, related to the de novo synthesis of glucose transporters (2,34,35,59). More generally, previous works reported that one of the main consequences of nitrogen supplementation during wine fermentation was an enhanced de novo synthesis of proteins, which involves an increase in the anabolism of amino acids (36,37).…”

Section: Figmentioning

confidence: 99%

Metabolic Responses of Saccharomyces cerevisiae to Valine and Ammonium Pulses during Four-Stage Continuous Wine Fermentations

Clément

Perez

Mouret

et al. 2013

Appl Environ Microbiol

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Nitrogen supplementation, which is widely used in winemaking to improve fermentation kinetics, also affects the products of fermentation, including volatile compounds. However, the mechanisms underlying the metabolic response of yeast to nitrogen additions remain unclear. We studied the consequences for Saccharomyces cerevisiae metabolism of valine and ammonium pulses during the stationary phase of four-stage continuous fermentation (FSCF). This culture technique provides cells at steady state similar to that of the stationary phase of batch wine fermentation. Thus, the FSCF device is an appropriate and reliable tool for individual analysis of the metabolic rerouting associated with nutrient additions, in isolation from the continuous evolution of the environment in batch processes. Nitrogen additions, irrespective of the nitrogen-containing compound added, substantially modified the formation of fermentation metabolites, including glycerol, succinate, isoamyl alcohol, propanol, and ethyl esters. This flux redistribution, fulfilling the requirements for precursors of amino acids, was consistent with increased protein synthesis resulting from increased nitrogen availability. Valine pulses, less efficient than ammonium addition in increasing the fermentation rate, were followed by a massive conversion of this amino acid in isobutanol and isobutyl acetate through the Ehrlich pathway. However, additional routes were involved in valine assimilation when added in stationary phase. Overall, we found that particular metabolic changes may be triggered according to the nature of the amino acid supplied, in addition to the common response. Both these shared and specific modifications should be considered when designing strategies to modulate the production of volatile compounds, a current challenge for winemakers.

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Catabolite inactivation of the sugar transporters in is inhibited by the presence of a nitrogen source

Cited by 9 publications

References 34 publications

Corn Endosperm Fermentation Using Endogenous Amino Nitrogen Generated by a Fungal Protease

Corn Endosperm Fermentation Using Endogenous Amino Nitrogen Generated by a Fungal Protease

Transcription of purine transporter genes is activated during the isotropic growth phase of Aspergillus nidulans conidia

Metabolic Responses of Saccharomyces cerevisiae to Valine and Ammonium Pulses during Four-Stage Continuous Wine Fermentations

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