Abstract:The aim of this study was to screen high-yield strains of esterase from Daqu in order to increase the content of esters in Daqu. Medium-temperature Daqu was used as material to screen high-yield esterase producing strains and identify the types of strain. Then we studied on enzyme production conditions of the strains with the target value of esterifying power. The result showed that high-yield esterase producing strain-LD06 was isolated from medium-temperature Daqu, and the morphological and molecular identification results confirmed that the strain was Absidia. Esterifying power was used as reference index to confirm the culture media, which was summed up as follows: 10 g wheat bran as culture substrate, corn flour as the optimum carbon source with the contents of 1.5 g, yeast as the optimum nitrogen source with the contents of 2.0 g, flaxseed oil as inducer with the contents of 1 g/100 g; other composition and addition in the medium with 0.2 g (NH4)2SO4 and 10 mL H2O. With the increase of fermentation time and temperature, esterifying power showed significant increase firstly and then decreased. Culture conditions which concluded temperature and time was confirmed at 36 ℃ and 45 h, respectively. Under these fermentation medium and conditions the highest esterifying power was 9.32 g/L, which was increased by 22.55% than the control.