Enzymatic production of an XOS-containing wheat straw hydrolysate and evaluation of its effect on lactobacilli growth
DOI:
https://doi.org/10.51452/eaj.2026.3(131).2277Abstract
Background and objective. Wheat straw is an abundant and renewable lignocellulosic feedstock that can be used for the production of xylooligosaccharides (XOS), which are of interest as functional carbohydrate components. The aim of this study was to obtain an XOS-containing wheat straw hydrolysate using recombinant Bacillus sonorensis xylanase and to evaluate its effect on the growth of Lactobacillus strains.
Materials and Methods. Wheat straw was pretreated with 18.5% aqueous ammonia solution and hydrolyzed using recombinant B. sonorensis xylanase. Hydrolysis was investigated at enzyme loading of 50, 100, and 200 U/g substrate over 24 h. Reducing sugar content was determined using DNS method, and the qualitative composition of the hydrolysis products was assessed by thin-layer chromatography. The effects of 0.5 and 1 % hydrolysate on L. fermentum ATCC 14931, L. plantarum ATCC 14917, and L. rhamnosus ATCC 53103 were evaluated based on viable cell counts and changes in culture medium pH.
Novelty. The XOS-containing wheat straw hydrolysate produced using recombinant B. sonorensis xylanase showed strain-specific effects on the growth of the tested Lactobacillus strains.
Results. The highest reducing sugar concentration was observed at a xylanase loading of 200 U/g after 24 h of hydrolysis. Thin-layer chromatography revealed xylooligosaccharides in the hydrolysate, predominantly xylobiose(X2) and xylotriose(3). The greatest increase in viable cell count was observed for L. fermentum: with 1.0% hydrolysate, the viable cell count reached (1.38 ± 0.54) × 10 CFU/mL, compared with (1.07 ± 0.95) × 105 CFU/mL in glucose-free medium. An increase in viable cell count was also observed L. plantarum, whereas the effect was less pronounced for L. rhamnosus. Increasing the hydrolysate concentration from 0.5 to 1 % was accompanied by a decrease in culture medium pH. The results demonstrate a strain-specific effect of the wheat straw hydrolysate and support further investigation of its prebiotic properties.
