Abstract:
In an attempt to enhance the value of sugarcane leaf, xylan was extracted and used for xylooligosaccharide (XO) production via enzymatic hydrolysis using xylanase from the black yeast Aureobasidium pullulans. The xylan was extracted from sugarcane leaf using alkali extraction according to the response surface methodology. The highest xylan yield (99.42 ± 4.05 % recovery) was obtained using 14.32 % (w/v) NaOH, 13.25:1 liquid: solid ratio, at 121 °C and 15 lb.in2 for 32 min. Sugar composition and FTIR spectrum analyses confirmed its structure as arabinoxylan. The extracted arabinoxylan had a relatively high molecular weight compared to previous studies. Crude endoxylanase from A. pullulans NRRL 58523 was selected for enzymatic hydrolysis of the xylan. The enzyme hydrolyzed well at 50 °C, pH 4.0 and was relatively stable under this condition (87.38 ± 1.26 % of the activity remained after 60 h). XOs, especially xylobiose and xylotriose, were obtained at the maximum yield of 237.51 ± 17.69 mg/g xylan via endoxylanase hydrolysis under the optimum conditions (50 °C, pH 4.0, 65.31 U/g xylan, 53 h). XOs exhibited species-specific prebiotic activity toward three strains of Lactobacillus spp. but not toward Bifidobacterium spp.
摘要:
为了提高甘蔗叶的价值,提取木聚糖,并使用来自黑色酵母的木聚糖酶通过酶促水解将其用于低聚木糖(XO)生产。根据响应面法,使用碱提取从甘蔗叶中提取木聚糖。使用14.32%(w/v)NaOH获得最高的木聚糖产率(99.42±4.05%的回收率),13.25:1液固比,在121°C和15磅。in2持续32分钟。糖组成和FTIR光谱分析证实其结构为阿拉伯木聚糖。与先前的研究相比,提取的阿拉伯木聚糖具有相对高的分子量。选择来自支链淀粉的粗木聚糖内切酶NRRL58523用于木聚糖的酶促水解。该酶在50°C下水解良好,pH4.0,在此条件下相对稳定(60小时后仍保持87.38±1.26%的活性)。XOs,尤其是木二糖和木三糖,在最佳条件下(50°C,pH4.0,65.31U/g木聚糖,53h).XO对三种乳杆菌属菌株表现出特定物种的益生元活性。但不针对双歧杆菌。