Xylooligosaccharides produced from sugarcane leaf arabinoxylan using xylanase from Aureobasidium pullulans NRRL 58523 and its prebiotic activity toward Lactobacillus spp.

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 degrees 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 degrees 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 degrees 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.

Automated summary

This study aimed to enhance the value of sugarcane leaf by extracting xylan and producing xylooligosaccharide (XO) through enzymatic hydrolysis. The xylan was successfully extracted using alkali extraction, and the resulting arabinoxylan had high molecular weight. Enzymatic hydrolysis with endoxylanase yielded XOs with specific prebiotic activity towards certain strains of Lactobacillus spp.