Pirmary Research On Hamhoo Processing By Cellulase And Xylanase

A new type of natural fiber, bamboo fiber, is gaining more and more popularity in theworld. The paper reports major research on the properties of cellulases and xylanase, as wellas their application in bamboo. The pretreatment method to enhance the proceesing isinvestigated.Bamboo, used in the experiment contained5.76%of cerolipoid,5.04%hydrotrope,0.64%of pectin,24.03%of hemicellulose,16.34%of lignin and48.19%of cellulose.The properties of acidic cellulase (Cellusoft L, Suhong Cellish L, Cellusoft APL), neutralcellulase (X001,818S, B963,8000L) and xylanase were investigated. The optimum conditionof acidic cellulase was pH4.8at50℃with the enzyme activity of32IU,38IU,39IU,respectively. Similarly, the optimum condition of neutral cellulase was pH7at50℃with theenzyme activity of10IU,11IU,8IU,2855IU, respectively. Enzyme activity of xylanase was139IU at acidic condition,309IU at neutral condition. It was proved that Suhong Cellish Land8000L performed higher reducing sugar yield in enzymatic hydrolysis of bamboocompared to other cellulases. Additionally,15IU is recommended as the suitable cellulaseenzyme dosage acting on the bamboo.40IU of xylanase was needed under combinedprocessing (cellulase and xylanase). Compared to the optimum dosage120IU on the singlexylanase processing, combined processing (cellulase and xylanase) raised66.7%theavailability of the xylanase utilization.In order to study the influence of pretreatments on enzyme hydrolysis, three pretreatmentmethods were employed to enhance the bamboo processing, among which, high temperaturepretreated bamboo showed the most obvious effect in4h~8h. Ultrasound generator pretreatedbamboo achieved a high level of enzymolysis between12h and24h in acidic cellulase system.It was measured that high temperature pretreatment for15min resulted in a predominant effectin acidic cellulase system. The reducing sugar yield of60-minutes high temperature pretreatedbamboo powders was slightly lower than that of90-minutes pretreated bamboo powders onneutral cellulase system, xylanase system.The enzymatic hydrolysate of combined processing was monitored by HPLC. It is foundthat the xylose48.94mg/L in acidic system relative to xylose was16.55mg/L in neutral system,compared to xylose (3.35in acidic system,9.45in neutral system), the former showed morexylose yield.Finally, it was showed that some cerolipoid, part of hemicellulose and lignin wereremoved. Enzymatic hydrolysate by cellulase was identified that it is composed of cellulose,hemicellulose, lignin, a little polyxylose and pectin. Some lignin was removed by enzymaticcoprocessing. XRD revealed that the crystallinity of bamboo increased14.3%after high temperature treatment. Compare to the origin bamboo, crystallinity increased10%,7%,respectively after xylanase hydrolysis and cellulase/xylanase hydrolysis. Thermostability ofbamboo decreased because of the degradation of cellulose and hemicellulose.