| Revista: | Brazilian journal of chemical engineering |
| Base de datos: | PERIÓDICA |
| Número de sistema: | 000308892 |
| ISSN: | 0104-6632 |
| Autors: | Rocha-Leao, M.H.M1 Coelho, M.A.Z Araujo, O.Q.F |
| Institucions: | 1Universidade Federal do Rio de Janeiro, Escola de Quimica, Rio de Janeiro. Brasil |
| Any: | 2003 |
| Període: | Sep |
| Volum: | 20 |
| Número: | 3 |
| Paginació: | 241-250 |
| País: | Brasil |
| Idioma: | Inglés |
| Tipo de documento: | Artículo |
| Enfoque: | Experimental, aplicado |
| Resumen en inglés | In S. cerevisiae, catabolite repression controls glycogen accumulation and glucose consumption. Glycogen is responsible for stress resistance, and its accumulation in derepression conditions results in a yeast with good quality. In yeast cells, catabolite repression also named glucose effect takes place at the transcriptional levels, decreasing enzyme respiration and causing the cells to enter a fermentative metabolism, low cell mass yield and yeast with poor quality. Since glucose is always present in molasses the glucose effect occurs in industrial media. A quantitative characterization of cell growth, substrate consumption and glycogen formation was undertaken based on an unstructured macrokinetic model for a reg1/hex2 mutant, capable of the respiration while growing on glucose, and its isogenic repressible strain (REG1/HEX2). The results show that the estimated value to maximum specific glycogen accumulation rate (muG,MAX) is eight times greater in the reg1/hex2 mutant than its isogenic strain, and the glucose affinity constant (K SS) is fifth times greater in reg1/hex2 mutant than in its isogenic strain with less glucose uptake by the former channeling glucose into cell mass growth and glycogen accumulation simultaneously. This approach may be one more tool to improve the glucose removal in yeast production. Thus, disruption of the REG1/HEX2 gene may constitute an important strategy for producing commercial yeast |
| Disciplines | Química, Biología |
| Paraules clau: | Bioquímica, Microbiología, Levaduras, Represión catabólica, Glucógeno, Saccharomyces cerevisiae |
| Keyword: | Chemistry, Biology, Biochemistry, Microbiology, Yeasts, Catabolite repression, Glycogen, Saccharomyces cerevisiae |
| Text complet: | Texto completo (Ver HTML) |
