Abstract
A new bioprocess has been developed that allows for producing β-carotene from the xylose portion of bioenergy sorghum. Bioenergy sorghum was pretreated in a pilot-scale continuous hydrothermal reactor followed by disc refining. Xylose was extracted using low-severity dilute acid hydrolysis. A xylose yield of 64.9% (17.4 g/L) was obtained by hydrolyzing at 120 °C for 5 min with 2% sulfuric acid. The xylose-enriched syrup was separated and concentrated to either 32 g xylose/L (medium-concentrated hydrolysate, MCB) or 66 g xylose/L (high-concentrated hydrolysate, HCB). The non- (NCB), medium-, and high-concentrated xylose syrup were neutralized and fermented to β-carotene using Saccharomyces cerevisiae strain SR8B, which had been engineered for xylose utilization and β-carotene production. In HCB, MCB, and NCB cultures, the yeast produced β-carotene titers of 114.50 mg/L, 93.56 mg/L, and 82.50 mg/L, which corresponds to specific yeast biomass productions of 7.32 mg/g DCW, 8.10 mg/g DCW, and 8.29 mg/g DCW, respectively.
Original language | English (US) |
---|---|
Article number | 123275 |
Journal | Bioresource Technology |
Volume | 308 |
DOIs | |
State | Published - Jul 2020 |
Keywords
- Bioenergy sorghum
- Dilute acid hydrolysis
- Hydrothermally pretreated
- Saccharomyces cerevisiae
- Xylose
- β-Carotene
ASJC Scopus subject areas
- Bioengineering
- Environmental Engineering
- Renewable Energy, Sustainability and the Environment
- Waste Management and Disposal