Production of designer xylose-acetic acid enriched hydrolysate from bioenergy Sorghum, oilcane, and energycane bagasses

Authors: CHENG, MING-HSUN - University Of Idaho; SINGH, SHUCHI - University Of Illinois; CLENNON, AIDAN - University Of Illinois; Dien, Bruce; SINGH, VIJAY - University Of Illinois

Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2023
Publication Date: 4/28/2023
Citation: Cheng, M.H., Singh, S., Carr-Clennon, A.N., Dien, B.S., Singh, V. 2023. Production of designer xylose-acetic acid enriched hydrolysate from bioenergy Sorghum, oilcane, and energycane bagasses. Bioresource Technology. 380. Article 129104. https://doi.org/10.1016/j.biortech.2023.129104.
DOI: https://doi.org/10.1016/j.biortech.2023.129104

Interpretive Summary: Development of an advanced biomass industry is a national priority. Advanced biomass includes woody and agricultural wastes, dedicated biomass crops grown on non-farmland, which could eventually supply over a billion tons of plant material per year. They are of value because sugars can be extracted from them and made available for fermentation to sustainable chemicals and fuels, including sustainable aviation fuel. However, economics is a major barrier to implementing this new industry. This research realized a new process technology that allows for the production of different types of sugar syrups, each of which can be used for the manufacture of various fuels and/or chemicals. The key is that this new process makes use of existing equipment and, therefore, does not materially add to the building costs. Manufacturing a diverse portfolio of bioproducts has kept corn refiners profitable and can likewise benefit this new industry. Reported results will be of interest to farmers seeking uses for marginal farmlands, traditional agricultural processors, and new startups investing in advanced biomass refineries.

Technical Abstract: Xylan accounts for up to 40% w/w of the structural carbohydrates present in lignocellulosic feedstocks. Along with xylose, acetic acid is also present in most sources of hemicellulose, which can be recovered and marketed as a commodity chemical. Through vibrant innovations in bioprocessing engineering, converting lignocellulosic xylose and acetic acid into high-value bioproducts via microbial cultures improves the economic sustainability of lignocellulosic biorefineries. Enzymatic hydrolysis using xylanase supplemented with acetylxylan esterase (AXE) was applied to prepare xylose-acetic acid-enriched designer hydrolysates from sequential hydrothermal-mechanical milling (HMR) pretreated bioenergy sorghum (BSG), oilcane (OC), or energycane (EC). Various biomass solids contents (15% to 25%, w/v) and xylanase loadings (140 to 280 FXU/g biomass) were tested to maximize xylose and acetic acid titers. The xylose and acetic acid yields were significantly improved by supplementing with AXE. The optimal yields of xylose and acetic acid were 92.29% and 62.26% of the maximum possible obtained from hydrolyzing energycane and oilcane at 25% w/w and 15% w/w biomass solids content using 280 FXU xylanase/g biomass and AXE, respectively .