The first description of an archaeal hemicellulase: the xylanase from Thermococcus zilligii strain AN1

A xylanase has been found in the archaeon Thermococcus zilligii strain AN1 (DSM 2770), which grows optimally at 75 degrees C. The enzyme had a molecul ar mass of 95 kDa and a unique N-terminal sequence. It had activity against all five xylans tested and against xylose oligomers, but not against other carbohydrate polymers. The K-m values found for xylans were typical of tho se found for bacterial xylanases. The pH optimum for activity was pH 6, and the enzyme half-life at 100 degrees C was 8 min. This is the first descrip tion of any archaeal hemicellulase.