Functional Materials from Plant Biomass Obtained by Simultaneous Enzymatic Saccharification and Communition

Abstract

In this review, we show novel methods for utilizing plant biomass, polysaccharides, and lignin. Firstly, the simultaneous enzymatic saccharification and comminution (SESC) of plant materials is described as an extraction method for polysaccharides and lignin that does not require toxic reagents or organic solvents. Secondly, we demonstrate the utilization of saccharides and lignin extracted by SESC, such as for sugar and ethanol synthesis, and as antioxidant, spin trap reagent, heatproof filler, shape memory polymer, and UV protection film. Thirdly, a possibility of SESC in relative to previous utilization technique of plant biomass was presented. A. Introduction A-1. Recent Progress in Utilization of Lignocellulosic Biomass via Physicochemical Extraction To achieve sustainable development goals (SDGs) and realize low-carbon society for sustainable social development, breaking away from petroleum-based material science is essential (1-17). As a natural and renewable alternative to petroleum-based resources such as polylactide (3), plant biomass has attracted attention with respect to generating energy and functional materials (2, 4-7). Lignocellulosic biomass is the main component of non-edible plant biomass, consisting of polysaccharides and lignin. Polysaccharides, including cellulose and hemicellulose, have been used as pulp (5), biofuel (7, 11, 12), and nanofibrous materials (13). Lignin, an aromatic polymer consisting of phenylpropane units, also has potential as a renewable alternative to synthetic aromatic polymers such as polyimide (14). Several studies examined the potential uses of lignin (15), e.g., in high-performance thermoplastics (8), phenolic resin (16), and composite film (17). In plants, cellulose, hemicellulose, and lignin are chemically linked in a complex manner and are thus difficult to separate efficiently (18). The most reliable method for extracting these compounds requires strong chemicals such as acids, bases, and organic solvents under high temperature and pressure (19-21). These conditions for physicochemical extraction are considered necessary to disrupt the macroscopic cell wall structure and break the interactions between lignin and polysaccharides (22). However, the extraction products also cause deterioration and induce side reactions that prevent full utilization of the extracted compounds for biofuel and other secondary products. Such technologies for lignocellulosic processing remain to be successfully implemented on a commercial scale (23, 24). To overcome these challenges, much effort has been devoted to developing new approaches to extract lignocellulosic biomass, such as glycerol thermal processing (25-27), γ-valerolactone-based processes (20), and sulfite pretreatment to overcome the recalcitrance of lignocellulose (SPORL) (28). A-2. Physical Comminution of Plants-A Candidate for Lignocellulosic Biomass Extraction via a Sustainable Process Physical comminution is an important step in preparing lignocellulosic biomass for producing useful chemicals (29-31). However, compar...

Nonflammable UV protective films consisting of clay and lignin with tunable light/gas transparency

“…SESC lignin was prepared from Japanese cedar according to the basic procedures described as follows. [13][14][15][16][17][18][19][20][21][22] For SESC treatment, a mixture of cedar powder (10 w/w% for water; 0.01-2 mm4), an enzyme cocktail prepared by combining equal amounts of commercial enzymes OPTIMASH XL containing cellulase and xylanase (10 300 U g À1 ) and OPTIMASH BG containing xylanase and b-glucosidase (6200 U g À1 ) from DuPont™ Genencor® Science, and 100 mM phosphate buffer (pH 6.0) were ground by bead milling (Labstar® LMZ015; Ashizawa Finetech Ltd, Japan) at a peripheral velocity of 14.0 m s À1 at 50 C. Stainless steel inactivates the enzyme. Therefore, the inner walls of the LMZ015 vessel were covered with a ceramic lining to prevent damage to the enzyme.…”

“…In this process, wet-type ultrane bead milling and enzymatic reactions for plants were used to isolate polysaccharides and lignin, which are the main components of plants, as a sugar solution and lignin water dispersion without the use of toxic reagents and the formation of byproducts. 13,14 The obtained sugar solution and lignin water dispersion can be used in the production of methane gas/drinkable alcohol 15,16 and for heat-proong ller/UV absorber, [17][18][19][20][21] respectively.…”