Xylanase from a newly isolated Fusarium verticillioides capable of utilizing corn fiber xylan

A fungus. Fusarium verticillioides (NRRL 26518), was isolated by screening soil samples using corn fiber xylan as carbon source. The extracellular xyl anase from this fungal strain was purified to apparent homogeneity from the culture supernatant by ultrafiltration using a 30,000 cut-off membrane. oc tyl-Sepharose chromatography and Bio gel A-0.5 in gel filtration. The purif ied xylanase (specific activity 492 U/mg protein: MW 24,000. pI 8.6) displa yed an optimum temperature at 50 degreesC and optimum pH at 5.5, a pH stabi lity range from 4.0 to 9.5 and thermal stability up to 50 degreesC. It hydr olyzed a variety of xylan substrates mainly to xylobiose and higher short-c hain xylooligosaccharides. No xylose was formed. The enzyme did not require metal ions for activity and stability.