阿魏酸酯酶和木聚糖酶协同降解麦糟

Utilization of feruloyl esterase and xylanase for the degradation of brewers' spent grain

橘青霉以麦糟为唯一碳源培养时,阿魏酸酯酶的最佳发酵时间为60 h,其酶活力可达40.8 mU/mL。在pH值为5.0、45℃、料液比1∶30(g∶mL)条件下,取47.5 U/mL的木聚糖酶粗酶液15 mL,加入1.0 g麦糟的乙醇不溶物,反应12 h后,加入40.8 U/mL的阿魏酸酯酶粗酶液15 mL再反应12 h,阿魏酸和低聚木糖释放率分别为54.1%和161 mg/g(麦糟的乙醇不溶物)。实验结果还表明,阿魏酸酯酶与木聚糖酶存在协同作用,能极大提高麦糟中阿魏酸及低聚木糖的释放率,有利于麦糟的降解。

The optimal fermentation time ofPenicillium citrinum feruloyl esterase （ PcFAE ） was 60 h and its activity was 40.8 mU/mL when the Brewers＇ Spent Grain （ BSG ） was used as the sole carbon source for Penicillium citrinum. One gram of alcohol-insoluble residue （ AIR ） of Brewers＇spent grain （ BSG ） was processed by the solution of crude xylanase （ XG180 ） （ 47.5 U/mL, 15 mL ） for 12 hours at the condition of the material-liquid ratio 1 ： 30（ W/V ）, pH 5.0 and 45 ℃, respectively. And then the solution of crude PcFAE （ 40.8 mU/mL ）was added and the sample was processed for another 12 h. The maximum release rate of Ferulic acid （ FA ） was 54.1% and the release amount of xylooligosaccharide （XOS） was 161 mg/g （BSG-AIR）, respectively. The results of our experiments showed that the release rate of FA and XOS from BSG-AIR increased significantly as the PcFAE could coordinate with the xylanase and enzymolysis process was also conducive to the degradation of BSG.