Rice husk pretreatment alters fermentable sugar production, aromatic compound profiles, and n-butyric acid fermentation
Year: 2026
Type: preprint
Abstract: Rice husk hydrolysates produced using different pretreatment methods can exhibit different fermentation responses even after adjusting the fermentable sugar concentration to the same level. In this study, dilute-acid, alkaline, ethanol-organosolv, and ball-milling pretreatments were compared for sugar production and subsequent n -butyric acid fermentation by Clostridium tyrobutyricum BAS7. After enzymatic hydrolysis, each hydrolysate was concentrated to 60 g/L total glucose and xylose without adding commercial sugars. The dilute-acid and alkaline hydrolysates produced 26.45 and 26.52 g/L n -butyric acid, respectively, both of which were significantly higher than that of the commercial-glucose control. The alkaline hydrolysate showed a numerically lower maximum cell growth (OD600 6.81) and significantly lower fermentation gas formation (20.00 mL/mL) than the control (OD600 10.78 and 23.23 mL/mL), although the difference in maximum cell growth was not significant after Dunnett’s adjustment. GC×GC-TOFMS profiling showed pretreatment-dependent differences in aromatic-compound profiles, with the alkaline hydrolysate exhibiting the highest relative signal for carboxyl-containing aromatic compounds. Veratric acid supplementation showed a concentration-dependent numerical decrease in fermentation gas formation; however, the differences from the control were not statistically significant. These findings indicate that pretreatment-dependent hydrolysate composition, in addition to fermentable sugar concentration, was associated with downstream fermentation performance.
Source: Research Square
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7225828250