Study of the production of glutatione from Saccharomyces cerevisiae and evaluation of application of magnetic fields during fermentation / Estudo da produção de glutationa a partir de Saccharomyces cerevisiae e avaliação da aplicação de campos magneticos durante as fermentações

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Glutathione (GSH) is a tripeptide consisting of L-glutamate, L-cysteine and glycine. One of its most important functions is a role as an antioxidant against the toxic effects of oxygen and other oxidative compounds. GSH is important for several metabolic functions of cells, such as protection from oxidation by peroxides, transport of amino acids across cell membranes and elimination of heavy metals. Moreover the discovery of more functions and properties of GSH, this compound is of interest in the food additive, cosmetic and pharmaceutics industries. This tripeptide is currently produced by yeast fermentation. The application of magnetic fields (MF) in the fermentative process can cause stimulants or inhibitory effects. Literature is very poor about the application of MF in S. cerevisiae. The objective of this work was to study the production of GSH and evaluate the application of MF fields in this process. The microorganism used was the yeast S. cerevisiae ATCC 7754 and the fermentations were monitored with the measurements of pH, concentrations of cell, glucose and GSH. In the first step, in the Erlenmeyer flasks (250 mL), have made three experimental design. The levels of temperature, pHinitial, agitation rate, concentrations of glucose and inoculum were studied. The highest concentration of GSH was 168.9 mg/L after 48 h, in run at 24ºC, 300 rpm, pHinitial 5, 60 g/L of glucose and 5% of inoculum. It was obtained a second order model equation and the percent of variation explained by the model was 95%. The results showed that the optimal culture conditions were 300 rpm, 20°C, pHinitial 5,54 g/l of glucose and 5% of inoculum concentration. In the second step, made in fermentor Bioflo III (5 L), the conditions of agitation, aeration, a source of nitrogen and addition of amino acids were studied. The highest concentration of GSH (205.7 mg/L) occurred in 72 h in run at 20°C, 500 rpm, 54 g/L of glucose, 1.1 vvm, with the addition of amino acids and yeast extract as a source of nitrogen. The third step was the application of MF generated by coil, it was used an experimental design and variables time of treatment and induction were studied. The concentration of GSH reached was 340 mg/L, when it was applied 25 mT for 16 h. In the fourth step the fermentation medium was recycled through magnets and was varied the time of exposure to the MF. In run with application of 20 mT by 72 h was seen the highest concentration of GSH of 271.9 mg/L. At all stages in which the run was obtained the highest concentration of GSH (340 mg/L) was conducted with application of 25 mT by 16 h of cultivation in the following conditions: 20°C, pHinicial 5, 200 rpm, 54 g/L of glucose, 50 g/L of yeast extract, 12 g/L of MgSO4.7H2O, 5% of inoculum (v/v), 3.2 vvm and with the addition of amino acids during fermentation

ASSUNTO(S)

delineamento experimental fermentação submersa magnetic fields experimental design glutationa campos magneticos glutatione saccharomyces cerevisiae

ACESSO AO ARTIGO

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