Produção de simbiótico galacto-oligossacarídeo e Saccharomyces boulardii utilizando permeado de soro de leite

Abstract

Functional foods have been prominent in technical-scientific research, in the face of the search for a healthier diet, which in addition to supplying the energy and nutrient needs, also prevent diseases. In this strand, there are symbiotics, which are composed of prebiotics and probiotics. Symbiotics consumption is associated with several health benefits, for instance, cancer prevention and inmune system improvement. The galacto-oligosaccharides (GOS) have proven to have prebiotic characteristics being synthesized from lactose-rich substrates such as whey permeated, through the transgalactosylation reaction, which is performed by the enzyme β-galactosidase, popularly known as lactase, in this work, originated from the fungus Aspergillus oryzae. While probiotics are living microorganisms, S. boulardii stands out for its physiological characteristics of low pH resistance and optimum growth at 37 ºC. In this perspective, the aim of this work was to produce a symbiotic compound composed of galacto-oligosaccharide and S. boulardii. For this, Plackett-Burman experimental design, type, was employed, evaluating the factors: concentration of lactose and enzyme, pH, temperature, nitrogen source, ways of oxygen insertion and S. boulardii addition time. After the experimental assays, it was found that for GOS response variable, the only factor that interfered on the production process was the lactose concentration. However, for the number of viable cells of S. boulardii, the variables that were not significant were pH, nitrogen source and the microorganism addition time. In this way, the new conditions of DCCR design were established, by varying temperature and enzyme concentration. In this second design the condition of assay number 7 (29 °C, 0,055% enzyme, 350 g.L-1 lactose, pH 5.5, soy tryptone, aeration and stirring as oxygen insertion and yeast addition after 6 h of hydrolysis) was the best conditions for symbiotic production, since it presented higher cell growth (2.50.108 viable cells.mL-1) and GOS production equal to 262.13 g.L-1. Thus, the results of this work evidence the whey permeate as a potential carbon source in biotechnological processes, as well as the efficacy of additing S. boulardii probiotic yeast to the GOS production system, aiming not only the production increase but to provide probiotic characteristics to the obtained product.