Enzymatic generation of short chain cello-oligosaccharides from Miscanthus using different pretreatments

Preparation of Cello-Oligosaccharides by Precise-Controlled Enzymatic Depolymerization and Its Amphiphilic Functionalization for High-Oil Load Emulsification

Cello-oligosaccharides (COS) are gaining great attention for their prebiotic-like properties, e.g., boosting gut health by promoting beneficial bacteria and improving digestion. This study produced COS, consisting predominantly of 4-10 glucose units (>80% of total COS) through enzymatic selective hydrolysis of cellulose using Ultimase BWL 40 (endoglucanase and xylanase) and Celluclast 1.5 L (cellobiohydrolases and endoglucanase). Celluclast 1.5 L mediated hydrolysis of cellulose for 7 h, yielding 22% COS, and Ultimase BWL 40 for 24 h afforded 32% COS to a large extent governed by the patterns of composed hydrolytes associated with the components and specificity of the enzyme recipe. Moreover, a novel kind of amphiphilic COS product was developed through (2-dodecen-1-yl succinyl) alkylsuccinylation of COS, confirmed by Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (1HNMR) spectroscopy; thereby, COS was endowed with the amphiphilic property. Not surprisingly, alkylsuccinylated COS (SAC12) stabilized cosurfactant-free emulsions of high oil-load, e.g., 70 wt % fish oil-in-water emulsions, achieving remarkably homogeneous nano-/microdroplets (500-540 nm), extremely narrow polydispersity index (PDI < 0.1), and strongly negative zeta potential (-45 to -48 mV), thus demonstrating exceptional stability. Overall, alkylsuccinylated COS (SAC12) offers superior emulsifying capabilities without a cosurfactant while maintaining prebiotic benefits, thus providing a versatile sustainable solution for various nutraceutical/pharmaceutical applications.

Production of cello-oligosaccharides from corncob residue by degradation-synthesis reactions

The cellulose-rich corncob residue (CCR) is an abundant and renewable agricultural biomass that has been under-exploited. In this study, two strategies were compared for their ability to transform CCR into cello-oligosaccharides (COS). The first strategy employed the use of endo-glucanases. Although selected endo-glucanases from GH9, GH12, GH45, and GH131 could release COS with degrees of polymerization from 2 to 4, the degrading efficiency was low. For the second strategy, first, CCR was efficiently depolymerized to glucose and cellobiose using the cellulase from Trichoderma reesei. Then, using these simple sugars and sucrose as the starting materials, phosphorylases from different microorganisms were combined to generate COS to a level up to 100.3 g/L with different patterns and degrees of polymerization. Using tomato as a model plant, the representative COS obtained from BaSP (a sucrose phosphorylase from Bifidobacterium adolescens), CuCbP (a cellobiose phosphorylase from Cellulomonas uda), and CcCdP (a cellodextrin phosphorylase from Clostridium cellulosi) were shown to be able to promote plant growth. The current study pointed to an approach to make use of CCR for production of the value-added COS. KEY POINTS: • Sequential use of cellulase and phosphorylases effectively generated cello-oligosaccharides from corncob residue. • Cello-oligosaccharides patterns varied in accordance to cellobiose/cellodextrin phosphorylases. • Spraying cello-oligosaccharides promoted tomato growth.