Valorization of bamboo shoot shell waste for the coproduction of fermentable sugars and xylooligosaccharides

Qiyao Wang; Yan Su; Yang Gu; Chenhuan Lai; Zhe Ling; Qiang Yong

doi:10.3389/fbioe.2022.1006925

Valorization of bamboo shoot shell waste for the coproduction of fermentable sugars and xylooligosaccharides

Front Bioeng Biotechnol. 2022 Sep 16:10:1006925. doi: 10.3389/fbioe.2022.1006925. eCollection 2022.

Authors

Qiyao Wang¹, Yan Su¹, Yang Gu¹, Chenhuan Lai¹, Zhe Ling¹, Qiang Yong^{1

2}

Affiliations

¹ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China.
² Key Laboratory of Forestry Genetics and Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing, China.

Abstract

In this work, hydrothermal pretreatment (autohydrolysis) was coupled with endo-xylanase enzymatic hydrolysis for bamboo shoot shell (BSS) to produce glucose and valuable xylooligosaccharides (XOS) rich in xylobiose (X2) and xylotriose (X3). Results showed that the enzymatic hydrolysis efficiency of pretreated BSS residue reached 88.4% with addition of PEG during the hydrolysis process. To enrich the portions of X2-X3 in XOS, endo-xylanase was used to hydrolyze the XOS in the prehydrolysate, which was obtained at the optimum condition (170°C, 50 min). After enzymatic hydrolysis, the yield of XOS reached 25.6%, which contained 76.7% of X2-X3. Moreover, the prehydrolysate contained a low concentration of fermentation inhibitors (formic acid 0.7 g/L, acetic acid 2.6 g/L, furfural 0.7 g/L). Based on mass balance, 32.1 g of glucose and 6.6 g of XOS (containing 5.1 g of X2-X3) could be produced from 100.0 g of BSS by the coupled technology. These results indicate that BSS could be an economical feedstock for the production of glucose and XOS.

Keywords: bamboo shoot shell; enzymatic hydrolysis; glucose; hydrothermal pretreatment; xylooligosaccharides.