Cultivo de biomassa de leveduras utilizando permeado de soro de queijo

• Autor(a) principal: Assunção, Grettya Maria
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do UNIOESTE
• Texto Completo: http://tede.unioeste.br:8080/tede/handle/tede/1854
• topic: Permeado de soro de queijo; Biomassa de leveduras; S. cerevisiae; S. boulardii; K. marxianus; Ultrafiltração; Fermentação; Hidrólise; Membranas filtrantes; Levedura; Separação (Tecnologia); Enzimas; Cheese whey permeate; Biomass yeast; CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA

The whey is a dairy industry effluent. Due to its high nutritional content , is used in the production of whey protein concentrate by ultrafiltration. This process generates another residue, cheese whey permeate which also contains high nutritional content, it is rich in lactose, and some minerals (P, K, Mg, Na and Ca). Can be reused in fermentation processes as a source of nutrients. One of these processes is the production of cell biomass from the growth of yeasts for use in food for human and animal consumption. Yeasts are used to obtain the GRAS (generally regarded the safe), in other words, be considered safe for use in foods. Some are: S. cerevisiae, used as a standard micro-organism to have its well-defined characteristics; S. boulardii, used in medicine as probiotic and marketed as a medicine, there are no reports of its production from waste; K. marxianus with potential of metabolizing lactose present in the permeate. This work aims to study the growth of three yeasts, using culture medium as the residue of cheese whey permeate, for the production of biomass. Two experimental design were performed to enzymatic hydrolysis in order to obtain the best condition for this process, and an experimental design was carried out for the fermentations in order to assess which variables are significant in the production of yeast biomass process. The analyzes carried out during the process were: absorbance, reducing sugars, indirect and direct dry weight and pH. Fermentation was carried out with addition of oxygen, aiming an increase in the production of cell biomass, BOD and COD analysis and analysis of the final concentration of ethanol. The best condition for the hydrolysis was obtained using [enzyme] 0.125% , T 35.35 °C and pH 7,7. For the production of biomass without added oxygen, the best values achieved for all yeasts were from 150 g L-1 and permeate temperature of 30 °C, the results were: 14.22 g L-1 of S. cerevisiae at pH 4, 1 g L-1 [(NH4)2SO4], 0.5 g L-1 [MgSO4], and 4 g L-1 [KH2PO4 ]; 22.85 g L-1 of S. boulardii at pH 5,5, 9 g L-1 [(NH4)2SO4], 1.2 g L-1 [MgSO4] and 9 g L-1 [KH2PO4]; and 16.90 g L-1 of K. marxianus at pH 6,5, 2 g L-1 [(NH4)2SO4], 2.5 g L-1 [MgSO4] and 1 g L-1 [KH2PO4]. The results of cell biomass obtained in these process conditions and with the addition of oxygen to the fermentation medium were 16.54 g L-1 of S. cerevisiae, 30.58 g L-1 of S. boulardii and 21.12 g L-1 K. marxianus. The ethanol concentration at the end of the process for each yeast was 28.8 g L-1 of ethanol from S. cerevisiae; 27 g L-1 of ethanol from S. boulardii and 52.1 g L-1 of ethanol from K. marxianus. And the reduction in BOD and COD parameters was 69.31% in COD and 97.19% in BOD using S. cerevisiae; 97.67 % in COD and 99.53 % in BOD using S. boulardii; and 83.53 % in COD and 93.14 % in BOD using K. marxianus. Thus, the study demonstrated that permeate cheese whey is a residue with a potential application in the production of yeast biomass, which allow the end of the fermentation process reduced the initial organic load of the waste being one of the bound parameters to reduce the environmental impact as well as the decreasing cost of the wastewater treatment processes.