ARS | Publication request: Endo-Xylanase and Beta-Xylosidase from a Newly Isolated Corn Fiber Xylan-Utilizing Fusarium Verticillioides

Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 31, 2000
Publication Date: N/A

Technical Abstract: Commercially available hemicellulase preparations are not effective in hydrolyzing corn fiber xylan. A fungus, Fusarium verticillioides (NRRL 26518), was isolated by screening soil samples using corn fiber xylan as carbon source. The extracellular endo-xylanase and beta-xylosidase from this fungal strain were separately purified to apparent homogeneity. The purified xylanase (specific activity, 470 U/mg protein; MW, 24,000; optimu temperature, 50 deg C; optimum pH, 5.5) released xylobiose and higher xylooligosaccharides from various xylan substrates. The purified beta-xylosidase (specific activity, 57 U/mg protein; MW, 94,000; optimum temperature, 65 deg C; optimum pH, 4.5-5.0) hydrolyzed xylobiose and higher xylooligosaccharides to xylose. The detailed biochemical properties and modes of action of these two enzymes and their synergistic role in xylan hydrolysis will be described. The problems and prospects of enzymatic hemicellulose hydrolysis in lignocellulosic biomass conversion will be presented.