Inmovilización de Bacillus licheniformis y Saccharomyces cerevisiae para la producción de etanol a partir de almidón de papa

We evaluated a sequential discontinuous system composed by Bacillus licheniformis and Saccharomyces cerevisiae for ethanol production. For the second phase of the process potato starch hydrolyzed were used, which was obtained from B. licheniformis cells. Both microorganisms were immobilized in a calcium alginate matrix of 3,2% and 2,5% (w/v), where was observed that these concentrations retained the majority of the cells (26x106 and 10x107 UFC/g) and allowed dissemination of its products, gaining 3.3 g/L of reducing sugars and 642 AU/L (units Amylolytic) for B. licheniformis and 0,866% (v/v) ethanol with S. cerevisiae. By means of a 22 factorial design were selected operating conditions at a reactor scale for production of hydrolyzed, finding that by cultivating B. licheniformis with 3 v.v.m. and 150 r.p.m. there were 3.7 g/L of reducing sugars and 669 AU/L after 4 hours of the process. The hydrolyzed was characterized using HPLC chromatography, which determined that it is rich in oligomers and dextrin, and it has low concentration of glucose and maltose. The use of hydrolyzed for ethanol production, generated low percentages (0,47% and 0,74% v/v) in free and immobilized cells respectively.