Extracellular Enzyme System Utilized by the Fungus Sporotrichum pulverulentum (Chrysosporium lignorum) for the Breakdown of Cellulose

Abstract

A strong synergistic response was observed between the five endo-1,4-β-glucanases and the exo-1,4-β-glucanase obtained from culture solutions of the rot fungus Sporotrichum pulverulentum (formerly called Chrysosporium lignorum), when these enzymes were allowed to degrade de-waxed cotton and Avicel. No synergism was observed if Walseth cellulose, an acid-swollen cellulose, was used. If de-waxed cotton was pretreated with endo-1,4-β-glucanases, the exo-1,4-β-glucanase enzyme released much more degradation products than from an untreated cotton. This strongly supports the theory that the endo-1,4-β-glucanases, acting randomly over the cellulose chain, go in first and open up chain ends where the exo-enzyme can act. In an earlier paper [Eriksson, K.-E. & Pettersson, B. (1975) Eur. J. Biochem. 51, 193–206] physico-chemical differences between the endo-1,4-β-glucanases were demonstrated. Functional differences have now been found. The five endo-enzymes give rise to different degradation products from Avicel, show differences in preferred mode of attack on cellodextrins, and exhibit pronounced differences in synthetic activity. The exo-1,4-β-glucanase released its products in the α-configuration. A method for the separation of cellodextrins on a Biol-Sil A column is also described.