Extracellular Enzyme System Utilized by the Fungus <i>Sporotrichum pulverulentum (Chrysosporium lignorum)</i> 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. &amp; 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.