关键词: 脂肪酶, 蛋白酶, 果胶酶, 皂素, 发酵, 洗涤性能

Abstract: The Bacillus subtilis strain （CICC 23083） and Bacillus licheniformis （CICC 21085） were utilized in this study for expression of lipase, protease and pectinase in vitro using the high concentration of the saponin extracts as fermentation substrates. When the fermentation of CICC 23083 in the substrates with addition of 3% yeast paste was performed, the protease and pectinase exhibited the maximum activity of 792.6 and 4 352.9 U/mL at 32 h, respectively. When 9% sucrose was added to the substrate, the maximum activities of protease and pectinase up to 258.5 and 2 497.5 U/mL occurred at 32 h and 16 h, respectively. When the mixed fermentation with the two strains for enzyme expression was conducted in the substrates with addition of 3% yeast, the enzymatic activities of lipase, protease and pectinase reached the maximum values of 166.7, 245.8 and 4 281.6 U/mL, respectively. When further addition of 7% sucrose in the substrate was implemented, the maximum lipase activity reduced to 133.3 U/mL, while the highest activities of protease and pectinase were increased to 327.4 and 3 318.2 U/mL, respectively. Additionally, the washing performance value of the mixed-fermentation broth was increased by 11.1, 15.2 percentage points compared to that of the fermentation broths of single strain, and 22.6 percentage points compared to that of the initial saponin extract. The foam height of high concentration saponin extract didn’t change significantly before and after fermentation, and remained at （157±5） mm.

Key words: lipase, protease, pectinase, saponin extracts, fermentation, washing performance