Otimização da produção de xilanase por levedura silvestre / Optimization of xylanase production from wild yeast

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

The interest in the study of systems of xylanases has been stimulated by its usefulness in a variety of biotechnological processes. These enzymes could be applied to bakery, improving texture, volume and mass of the shelf life of products, wineries and breweries, supporting the step of filtration and clarification; also it could be added in poultry and pigs feed to increase digestibility. Due to this importance of application of xylanases and the necessity to develop conditions that optimize the production of these enzymes in order to make its commercial use less restricted, studies have been done to achieve higher productivity with low cost substrates. The objective of this work was to optimize the production of xylanase from a wild yeast strain isolated from Mata Atlântica. Two strains were tested initially in order to select the most appropriated one for this study. Once selected, it was tested the influence of phosphate buffer on the production of xylanase and the results showed that the addition of phosphate buffer to the culture medium has a negative effect on yeast biomass and activity enzyme produced. From these results it was decided to exclude the buffer used in medium and it was applied an experimental design aimed to optimize the conditions for xylanase production. At first, a design Plackett &Burman (PB) was done to determine the main effects of each variable studied in relation to enzymatic activity, where the temperature and the concentration of xylanase were considered statistically significant. Then, a central composite rotational design (DCCR) of 11 trials was carried out, where the independent variables were those considered significant by the PB. The results obtained by DCCR were analyzed by statistical tools that confirmed the reliability of the predict model to the xylanse activity enzyme. According to this model, the maximum enzyme activity (67,45 UI) was found at the central points of planning, where the concentration of xylan was 20 gL-1 and temperature of 30 ° C

ASSUNTO(S)

xilanases leveduras otimização planejamento experimental xylanases optimization experimental design xylan

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