Mild pretreatment of yellow poplar biomass using sequential dilute acid and enzymatically-generated peracetic acid to enhance cellulase accessibility

• Published in: Biotechnology and bioprocess engineering Vol. 22; no. 4; pp. 405 - 412
• Main Authors: Lee, Hyeong Rae, Kazlauskas, Romas J., Park, Tai Hyun
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Society for Biotechnology and Bioengineering 01.08.2017; Springer Nature B.V; 한국생물공학회
• Subjects: Biomass; Biosynthesis; Biotechnology; Cellulase; Cellulose; Chemistry; Chemistry and Materials Science; Digestibility; Dilution; endo-1,4-beta-glucanase; enzymatic hydrolysis; Glucan; glucose; hydrolysates; Hydrolysis; Industrial and Production Engineering; Lignin; Liriodendron tulipifera; microwave treatment; Oxidation; Peracetic acid; Poplar; Pretreatment; Research Paper; Sulfuric acid; Xylan; Xylose; 생물공학; enzymatic accessibility; biomass; dilute acid; pretreatment; peracetic acid
• ISSN: 1226-8372; 1976-3816
• DOI: 10.1007/s12257-017-0139-7

Biomass contains cellulose, xylan and lignin in a complex interwoven structure that hinders enzymatic hydrolysis of the cellulose. To separate these components in yellow poplar biomass, we sequentially pretreated with dilute sulfuric acid and enzymatically-generated peracetic acid. In the first step, the dilute acid with microwave heating (140°C, 5 min) hydrolyzed 90% of xylan. The xylose yield in hydrolysate after dilute acid pretreatment was 83.1%. In the second step, peracetic acid (60°C, 6 h) removed up to 80% of lignin. This sequential pretreatment fractionated biomass into xylan and lignin, leaving a solid residue enriched in cellulose (~80%). The sequential pretreatment enhanced enzymatic digestibility of the cellulase by removal of the other components in biomass. The glucose yield after enzymatic hydrolysis was 90.5% at a low cellulase loading (5 FPU/g of glucan), which is 1.6 and 18 times higher than for dilute acid-pretreated biomass and raw biomass, respectively. This novel sequential pretreatment with dilute acid and peracetic acid efficiently separates the three major components of yellow poplar biomass, and reduces the amount of cellulase needed.