A sustainable process for procuring biologically active fractions of high-purity xylooligosaccharides and water-soluble lignin from Moso bamboo prehydrolyzate

Abstract

Background Prehydrolyzate, which is from the prehydrolysis process in dissolving pulps industry, contains various sugar-derived and lignin compounds such as xylooligosaccharides (XOS), gluco-oligosaccharides, xylose, glucose, and soluble lignin (S-L). The XOS has several beneficial effects on human physiology. XOS and S-L in prehydrolyzate are difficult to efficiently fractionate due to their similar molecular weights and water solubility. In this work, we proposed a sustainable and green process using polystyrene divinylbenzene (PS-DVB) resin to simultaneously separate and recover XOS and S-L. Enzymatic hydrolysis with endo-1,4-β-xylanase and fermentation with P. stipites were sequentially applied to purify XOS to minimize xylose content as well as amplify contents of xylobiose and xylotriose. In addition, 2D-HSQC NMR was used to analyze the structural characteristics of XOS and S-L. Furthermore, the biological abilities of antioxidants and prebiotics of these fractions were investigated by scavenging radicals and cultivating intestinally beneficial bacterias, respectively. Results Results showed that PS-DVB resin could simultaneously separate XOS and solubilized lignin with excellent yields of 93.2% and 85.3%, respectively. The obtained XOS after being purified by enzymatic hydrolysis and fermentation contained 57.7% of xylobiose and xylotriose. 10.4% amount of inherent xylan was found in the S-L fraction obtained by PS-DVB resin separation. 2D-HSQC NMR revealed that lignin carbohydrate complexes existed in both XOS and S-L as covalent linkages between lignin and 4- O -methylglucuronoarabinoxylan. The biological application results showed that the antioxidant capacity of S-L was stronger than XOS, while XOS was superior in promoting growth of intestinal Bifidobacteria adolescentis and stimulating production of short-chain fatty acids by Lactobacillus acidophilus. Conclusions The proposed strategy of sequentially combining hydrophobic resin separation, enzymatic hydrolysis, and fermentation was successfully demonstrated and resulted in simultaneous production of high-quality XOS and solubilized lignin. These biomass-derived products in prehydrolyzate can be regarded as value-adding prebiotics and antioxidants. Electronic supplementary material The online version of this article (10.1186/s13068-019-1527-3) contains supplementary material, which is available to authorized users.

Protective Effect of Diphlorethohydroxycarmalol Isolated from Ishige okamurae Against Particulate Matter-Induced Skin Damage by Regulation of NF-κB, AP-1, and MAPKs Signaling Pathways In Vitro in Human Dermal Fibroblasts

“…After 3 h, the intracellular ROS levels of ERM-CZ-100-treated HDF cells were evaluated by DCF-DA assay following the protocol described previously [43,44]. After 24 h, the viabilities of ERM-CZ-100-treated HDF cells were measured by MTT assay according to the methods described previously [45,46].…”

Enhanced biochemical process for purifying xylo-oligosaccharides from pre-hydrolysis liquor

“…The spectra were monitored in a transmittance band mode in the range 400 ~ 4000 cm − 1 . Two-dimensional proton-detected heteronuclear single quantum (2D HSQC) spectrum of the samples was recorded to provide structural information of XOS [28]. First, 40 mg of sample were dissolved in 0.5 mL DMSO-d 6 and then added to 5 mL NMR tube to exploit the 2D-HSQC spectra of the samples using a standard Bruker HSQC pulse sequence.…”

The Microstructure and Mechanical Properties of Poplar Catkin Fibers Evaluated by Atomic Force Microscope (AFM) and Nanoindentation

“…The average reduced elastic modulus of the S 2 layer was 5.28 GPa and the hardness was 0.25 GPa, which was lower than that of softwood (6.55-27.5 GPa) and hardwood (16.9-24.6 GPa) [11], but higher than that of cotton fibers (4 GPa) [23] and kapok fibers (2 GPa) [41]. Huang et al [49,50] found that the reduced elastic modulus of bamboo fiber cell walls in the transverse direction was 5.91 GPa, and in the longitudinal direction, was 17.6 GPa, and the hardness was 0.37 GPa. The samples were embedded in epoxy resin, which might result in undesirable chemical modifications caused by epoxy impregnation [50,51].…”