A cold-adapted endo-arabinanase from Penicillium chrysogenum

Previously, three arabinan-degrading enzymes were isolated from Penicillium chrysogenum 3 1 B. Here we describe another arabinan-degrading enzyme, termed Abnc, from the culture filtrate of the same organism. Analysis of the reaction products of debranched arabinan by high-performance anion-exchange chromatography (HPAEC) revealed that Abnc cleaved the substrate in an endo manner and that the final major product was arabinotriose. The molecular mass of Abnc was estimated to be 35 kDa by SDS-PAGE. Enzyme activity of Abnc was highest at pH 6.0 to 7.0. The enzyme was stable up to 30 degreesC and showed optimum activity at 30 to 40 degreesC. Compared with a mesophilic counterpart from Aspergillus niger, Abnc exhibited a lower thermal stability and optimum enzyme activity at lower temperatures. Production of Abric in P. chrysogenum was found to be strongly induced by arabinose-containing polymers and required a longer culture time than did other arabinanase isozymes in this strain. (C) 2003 Elsevier B.V. All rights reserved.