超声波辅助竹子酶解体系构建及其机理研究

发布时间：2018-05-08 14:34

本文选题：竹子 + 超声波　；参考：《江南大学》2017年硕士论文

【摘要】：脱胶是由竹子制备竹纤维的一道重要工序,竹子致密的结构和复杂的成分影响生物酶对竹子的脱胶效率。本论文在生物酶脱胶之前预先采用超声波处理竹子,以期破坏竹子复杂紧密的结构,提高脱胶效率,并在此基础上探讨超声波处理木质纤维素材料的作用机理。以纤维素酶作为模型酶,通过单因素试验确定超声波处理竹子的参数范围。在单因素试验的基础上通过正交试验确定不同生物酶水解竹子时最优的超声波处理参数。纤维素酶水解时最优的超声波处理参数为:频率25KHz,功率650W,浴比1:20,时间10min,脉冲周期3/4,在此条件下处理得到的竹粉经纤维素酶水解后生成的还原糖量较原竹粉增加了5.47μg/mL,百分率提高了58.37%;木聚糖酶水解时最优的超声波处理条件为:频率25KHz,功率700W,浴比1:20,时间15min,脉冲周期3/4,在此条件下处理得到的竹粉经木聚糖酶水解后生成的还原糖量较原竹粉增加了0.5μg/mL,百分率提高了8.50%;纤维素酶与木聚糖酶共同水解时最优的超声波处理条件为:频率25KHz,功率650W,浴比1:20,时间10min,脉冲周期3/4,在此条件下处理得到的竹粉经纤维素酶与木聚糖酶共同水解后生成的还原糖量较原竹粉增加了6.84μg/m L,百分率提高了23.34%。实验结果表明,纤维素酶与木聚糖酶在共同水解竹子时具有协同作用,而不同生物酶水解时的最优超声波处理条件有所差异是由生物酶作用底物的的专一性引起的。通过分析手段探讨超声波处理提高酶解效率的相关机理。经分析,超声波处理之后的竹粉表面形貌发生改变,结晶度降低了13.58%,保水值增加了33.38%,但超声波处理并未引起原有基团的消失或者是新的基团生成。经紫外光谱仪分析发现超声波处理的液体介质中出现水溶性木质素类物质,红外光谱图表明液体介质中存在与木质素、半纤维素、纤维素等物质相关的基团,离子色谱分析结果表明液体介质中存在半乳糖和葡萄糖类物质。从被处理底物和处理液体介质两方面解释了超声波预处理提高酶解效率的原因,即超声波处理通过破坏由纤维素、半纤维素及木质素构成的复杂致密结构,竹子中的部分物质从竹子主体脱离,为生物酶提供了更多的附着位点和空间,从而很大程度的提高了生物酶的水解效率。
[Abstract]:Degumming is an important process in the preparation of bamboo fiber from bamboo. The dense structure and complex composition of bamboo affect the degumming efficiency of bamboo by biological enzymes. In order to destroy the complex and compact structure of bamboo and improve the efficiency of degumming, the mechanism of ultrasonic treatment of lignocellulosic materials was discussed in this paper. Using cellulase as model enzyme, the parameter range of ultrasonic treatment of bamboo was determined by single factor experiment. On the basis of single factor experiment, the optimum ultrasonic treatment parameters of bamboo hydrolyzed by different biological enzymes were determined by orthogonal test. The optimum ultrasonic treatment parameters for cellulase hydrolysis are as follows: frequency 25kHz, power 650W, bath ratio 1: 20, time 10 min, pulse cycle 3 / 4. Under these conditions, the amount of reducing sugar produced by cellulose hydrolysis of bamboo powder is higher than that of raw bamboo powder. 5.47 渭 g / mL, percentage increased 58.37.The optimum ultrasonic treatment conditions for xylanase hydrolysis were as follows: frequency 25kHz, power 700W, bath ratio 1: 20, time 15min, pulse period 3 / 4. Under these conditions, the reduced sugar produced by xylanase hydrolysis of bamboo powder was obtained. The optimum ultrasonic treatment conditions for the hydrolysis of cellulase and xylanase were as follows: frequency 25 kHz, power 650 W, bath ratio 1: 20, time 10 min, pulse period 3 / 4. The amount of reducing sugar produced by cellulose and xylanase hydrolysis was increased by 6.84 渭 g / mL, and the percentage was increased by 23.34% compared with the original bamboo powder. The results showed that cellulase and xylanase had synergistic effect in the hydrolysis of bamboo, and the optimum ultrasonic treatment conditions of different bioenzymes were caused by the specificity of the substrate. The mechanism of ultrasonic treatment to improve the efficiency of enzymatic hydrolysis was discussed by means of analysis. After analysis, the surface morphology of bamboo powder changed after ultrasonic treatment, the crystallinity decreased by 13.58, the water retention value increased by 33.38, but ultrasonic treatment did not cause the disappearance of the original group or the formation of new group. By ultraviolet spectrometer analysis, it was found that water-soluble lignin was found in the liquid medium treated by ultrasonic wave. The infrared spectrum showed that there were some groups related to lignin, hemicellulose, cellulose and other substances in the liquid medium. The results of ion chromatography showed that galactose and glucose existed in liquid medium. The reason why ultrasonic pretreatment can improve the enzymatic hydrolysis efficiency is explained from the aspects of treated substrate and treated liquid medium, that is, ultrasonic treatment destroys the complex dense structure made up of cellulose, hemicellulose and lignin. Some substances in bamboo are separated from the main body of bamboo, which provides more attachment sites and spaces for biological enzymes, thus greatly improving the hydrolysis efficiency of biological enzymes.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS102.1

【相似文献】