Prebiotic effect of sorghum biomass xylooligosaccharides employing immobilized endoxylanase from Thermomyces lanuginosus PC7S1T

Abstract

Purified endoxylanase from Thermomyces lanuginosus PC7S1T was immobilized in calcium alginate, resulting in a yield of 78.5% and a reusability for 11 cycles. The stability of the immobilized enzyme was given for a pH range of 4 to 9 for 96 h. Endoxylanase immobilized in calcium alginate at 65 °C exhibited thermal stability equal to the soluble enzyme for 5 h, and at high temperatures of 75 °C and 85 °C showed half-lives of 4 and 3 h, respectively. Both soluble endoxylanase and immobilized forms were able to hydrolyze hemicellulose, obtained from low-lignin sorghum biomass pretreated with 5% H₂O₂ and 2% NaOH, after 1 h of incubation at 65 °C, releasing a mixture of short-chain xylooligosaccharides (X2-X6). The highest amounts of XOS generated were those for X5 (24 to 40%), X4 (33 to 39%), and X3 (11 to 22%). These XOS acted as prebiotics, promoting the growth of the probiotic L. acidophilus, similar to glucose in the MRS broth. These results show the potential of low-lignin sorghum to generate XOS with prebiotic activity, suggesting the application of these compounds in the food industry.

Keywords: Enzymes; Hemicellulose; Immobilization; Probiotic; Xylooligosaccharides.

Fig. 1

Reuse capacity of the immobilized endoxylanase from T. lanuginosus on calcium alginate

Fig. 2

Thermal stability of T. lanuginosus soluble and immobilized endoxylanase at an incubation period of up to 5 h at temperatures of 65, 75, and 85 °C

Fig. 3

pH stability of T. lanuginosus soluble and immobilized xylanase incubated for up to 96 h

Fig. 4

Growth curves of Lactobacillus acidophilus in MRS medium supplemented with XOS ( ), glucose ( ), and without a carbon source ( )

Fig. 5

Performance of Lactobacillus acidophilus in MRS medium supplemented with xylooligosaccharides ( ) and consumption ( )