Paper: Biological abatement of enzyme inhibitors (35th Symposium on Biotechnology for Fuels and Chemicals (April 29-May 2, 2013))

Monday, April 29, 2013

Exhibit Hall

Guangli Cao, Department of Life Science and Technology, Harbin Institute of Technology, Harbin, China, Eduardo Ximenes, Laboratory of Renewable Resources Engineering, Purdue University, West Lafayette, IN, Nancy N. Nichols, Bioenergy Research Unit, United States Department of Agriculture, National Center for Agricultural Utilization Research, Peoria, IL and Michael Ladisch, Laboratory of Renewable Resources, Agricultural and Biological Engineering and Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN

Lignocellulose pretreatments release phenolic compounds that cause enzyme inhibition and deactivation. Bio-abatement, the biological removal of furfurals, acetic acid and phenolics, may utilize fungal fermentation to metabolize these compounds to CO₂, water, cell mass, and heat. Our work with Coniochaeta ligniaria shows a beneficial effect occurs due to removal of inhibitors. Fermentation of liquid obtained from dilute acid pretreatment of corn stover removed all of the acetic acid and between 30 to 95% of formic acid, HMF, furfural, and phenolic compounds in 48 hours. Higher cellulose conversions were observed for bio-abated compared to untreated liquid samples. Hydrolysis was carried out with solka floc (cellulose) at either 3.6 mg cellulase protein/g cellulose or 36 mg protein/g. When a bio-abated liquid from liquid hot water pretreated corn stover was added to solka floc, enzyme hydrolysis gave 67% yield of glucose while conversion in non-bio-abated liquid was 52% at 200 g/L pretreated, not washed solids.

17-36: Biological abatement of enzyme inhibitors