Abstract:Strains producing glucoamylase were screened from the high temperature Daqu, used to make mould Fuqu, and its production conditions and brewing performance were determined. Two high glucoamylase producing strains JQ-1 and JQ-2 were isolated and identified as Rhizopus oryzae and Mucor circinelloides, respectively. To make the strains more suitable for production, JQ-1 and JQ-2 were used to making mould Fuqu, The test results of Fuqu making performance showed that using whole bran as Fuqu making raw material, controlling the amount (55%) of water (JQ-1 for 96 h and JQ-2 for 72 h) and drying temperature of 40 ℃, these conditions were conducive to the maintenance of glucoamylase activity of Fuqu. The glucoamylase activity of JQ-1 Fuqu and JQ-2 Fuqu reached 1510.33 U/g and 1388.26 U/g, respectively. The results of liquor production performance test showed that the liquor yield of base liquor made by bran Fuqu JQ-1 was 44.42%, and the alcohol degree was 41.22% vol; the liquor yield of base liquor made by bran Fuqu JQ-2 was 37.32%, and the alcohol degree was 35.84% vol. The brewing performance of bran Fuqu JQ-1 was more outstanding. Based on the comprehensive Fuqu preparation and production performance results, strains JQ-1 and JQ-2 were found to play a good role in saccharification in brewing production. And in terms of brewing performance, Fuqu JQ-1>Fuqu JQ-2. This study aims to provide some guidance for the development and production applications of functional microorganisms in Daqu.
