Insufficient uracil supply in fully aerobic chemostat cultures of Saccharomyces cerevisiae leads to respiro-fermentative metabolism and double nutrient-limitation

Autor(es)

Basso, Thiago Olitta ^{[1, 2]} ; Dario, Marcelo Goulart ^{[2, 3]} ; Tonso, Aldo ^[1] ; Stambuk, Boris Ugarte ^[3] ; Gombert, Andreas Karoly ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Chem Engn, BR-05424970 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Programa Posgrad Interunidades Biotecnol, BR-05508900 Sao Paulo - Brazil

^[3] Univ Fed Santa Catarina, Dept Bioquim, BR-88040970 Florianopolis, SC - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Biotechnology Letters; v. 32, n. 7, p. 973-977, 2010.
• Área do conhecimento: Engenharias - Engenharia Química
• Citações Web of Science: 11
• Assunto(s): Nutrientes minerais do solo Leveduras Saccharomyces cerevisiae Uracila

Resumo

A combination of chemostat cultivation and a defined medium was used to demonstrate that uracil limitation leads to a drastic alteration in the physiology of auxotrophic cells of Saccharomyces cerevisiae. Under this condition, the carbon source is dissimilated mainly to ethanol and acetate, even in fully aerobic cultures grown at 0.1 h-1, which is far below the critical dilution rate. Differently from nitrogen-, sulphur-, or phosphate-limited cultures, uracil limitation leads to residual sugar (either glucose or sucrose) concentrations below 2 mM, which characterizes a situation of double-limitation: by the carbon source and by uracil. Furthermore, the specific rates of CO2 production and O2 consumption are increased when compared to the corresponding prototrophic strain. We conclude that when auxotrophic strains are to be used for quantitative physiological studies, special attention must be paid to the cultivation conditions, mainly regarding medium formulation, in order to avoid limitation of growth by the auxotrophic nutrient. (AU)

• Processo FAPESP: 07/59776-7 - Engenharia evolutiva de leveduras
• Beneficiário: Andreas Karoly Gombert
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Regular