蒸汽爆破预处理对玉米芯酶水解的影响

EFFECT OF STEAM EXPLOSION PRETREATMENT ON CORNCOB ENZYMETIC HYDROLYSIS

采用不同的蒸汽爆破条件对玉米芯进行预处理,研究蒸汽爆破对玉米芯理化性质和酶水解的影响。结果表明：蒸汽爆破条件为1.4 MPa,300 s时,玉米芯酶水解液中总糖浓度最高为58.17 g/L。蒸汽爆破预处理主要引起半纤维素大量降解,但过高的压力或过长的保压时间会使木糖进一步降解,从而使玉米芯水解糖得率降低。X-衍射结果表明：经1.4 MPa,300 s蒸汽爆破的玉米芯结晶度由对照的24.49%提高到43.09%。由扫描电镜可知,蒸汽爆破可提高玉米芯的孔隙度和表面积,从而提高酶水解效率。

Corncob was pretreated at different steam explosion conditions and the effect of steam explosion on thephysical and chemical properties and enzymatic hydrolysis of pretreated corncob was studied in this research. The resultsshowed that the highest total sugar concentration was 58.17 g/L in enzymatic hydrolysate of corncobs when the steamexplosion was carried out at 1.4 MPa for 300 s. The steam explosion pretreatment mainly causes heavy degradation ofhemicellulose,however,excessive pressure or long holding time will further degrade xylose and reduce the hydrolysissugar yield of corncob. The results of X-ray diffraction showed that the crystallinity of corncob after steam explosion at1.4 MPa for 300 s increased from 24.49% to 43.09%. Scanning electron microscopy showed that steam explosionincreased the porosity and surface area of the corncobs,thereby increasing the efficiency of enzymatic hydrolysis.