H_2O_2预处理结合微生物发酵提取玉米芯木聚糖的工艺研究

为提高微生物发酵玉米芯提取木聚糖的效率,本研究采用H2O2预处理结合微生物发酵的方法提取玉米芯中的木聚糖,并通过扫描电镜(SEM)从微观结构初步探讨了H2O2预处理提高微生物发酵提取玉米芯木聚糖的原因。其结果表明:利用4%H2O2预处理玉米芯1小时,木聚糖含量可达40. 21±0. 21 mg/g,较未处理组玉米芯中木聚糖含量提高了87. 72%;4%H2O2预处理结合微生物发酵玉米芯,可显著提高木聚糖得率,其含量可达52. 72 mg/g,较未经H2O2预处理组提高了186. 67%;进一步利用响应面法优化微生物发酵经H2O2预处理玉米芯提取木聚糖的工艺,得到了发酵最佳培养基组成为含水量50%、尿素添加量0. 25%、葡萄糖添加量0. 75%,此条件下木聚糖含量达70. 84 mg/g,较未发酵提高了249. 82%;SEM图像显示H2O2预处理使得玉米芯结构变得疏松,微生物发酵结合H2O2预处理后的玉米芯出现较大孔洞,结构变得更为疏松。因此,H2O2预处理可改善玉米芯结构,促进微生物发酵,提高玉米芯木聚糖的提取效率,为玉米芯木聚糖的高效开发利用提供了参考。

Study on extraction condition of corncob xylan by microbial fermentation and H_2O_2 pre-treatment

The aim of this study was to improve the efficiency of microbial fermentation and extraction of corn cob xylan,In this study,the xylan in corncob was extracted by microbial fermentation combined with H2O2 pretreatment,then microstructure of corn cob was observed by scanning electron microscope(SEM)to analysis the reason of increased extraction efficiency of corn cob xylan after H2O2 pre-treatment.The results showed that the content of xylan was up to 40.21±0.21 mg/g when corncob was pretreated with 4%H2O2 for 1 h,which increased by 87.72%compared to untreated group.Microbial fermentation combined with 4%H2O2 pretreatment significantly increased the content of corn cob xylan(52.72 mg/g),which increased by 186.67%compared to untreated group.Optimized the extraction conditions of corncob xylan after microbial fermentation combined with H2O2 pretreatment based on response surface methodology,and obtained the optimal medium substrate contained water content 50%,urea 0.25%and glucose 0.75%.Under these conditions,the xylan content reached up to 70.84 mg/g,which increased by 249.82%compared to unfermented corn cob.SEM images showed that the structure of the corn cob became loose after being pretreated by H2O2,and larger holes appeared on the surface of corn cob after microbial fermentation combined with H2O2 pretreatment.In conclusion,H2O2 pretreatment can improve the structure of corn cob,promote microbial fermentation,and increased extraction efficiency of corn cob xylan,this study will provide a reference for the efficient exploitation and utilization of corn cob xylan.