Production of prebiotic xylooligosaccharides from alkaline extracted wheat straw using the K80R-variant of a thermostable alkali-tolerant xylanase
Författare
Summary, in English
Agricultural by-products are raw materials of importance for increased utilization of renewable biomass. Wheat straw is a raw material of significant production volume and is in this work used for production of xylooligosaccharides (XOS). Extraction of xylan by dilute alkali was followed by hydrolysis using a variant of the alkali-tolerant Bacillus halodurans S7 endoxylanase A mutated at K80R. The xylan yield was on average 56.5 g xylose equivalents per kg dried, ground wheat straw, with 1 arabinose per 12 xylose residues. The K80R variant, which displayed higher specific activity than the wild-type enzyme, was added at a load of 96 U/g extracted xylan. The XOS-yield (xylobiose – xylopentaose) was evaluated at time intervals in the temperature range of 50 to 65 degrees C, at pHs from 7 to 10. The enzyme was optimally active at 60 degrees C up to pH 9. Hydrolysis was completed within 7 h, resulting in 36 % conversion of the xylan to predominantly xylobiose. Xylose content was low (2.4%) despite extended incubation, which is desirable for XOS-production. The XOS-containing hydrolysate was confirmed as a suitable carbon source for the putative probiotic strain Lactobacillus brevis DSM 1269, showing the applicability of the method to obtain prebiotic XOS.
Avdelning/ar
Publiceringsår
2015
Språk
Engelska
Sidor
1-10
Publikation/Tidskrift/Serie
Food and Bioproducts Processing
Volym
93
Issue
Online 22 November 2014
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Industrial Biotechnology
Nyckelord
- XOS
- Bacillus halodurans
- Glycoside hydrolase family 10
- GH10
- Lactobacillus brevis
- arabinoxylan
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1744-3571