Cellulolytic Enzymatic Activity of Soft Rot Filamentous Fungi Paecilomyces variotii

Abstract

Cellulases are a group of hydrolytic enzymes capable of hydrolyzing the most abundant organic polymer i.e. cellulose to smaller sugar components including glucose subunits. Cellulases have enormous potential in industries and are used in food, beverages, textile, laundry, paper and pulp industries etc. This study was aimed to investigate the cellulolytic enzymatic activity of soft rot wood degrading filamentous fungi Paecilomyces variotii 103-7 strain from naturally degraded wood. Furthermore, optimal cultural condition for enzyme activity and induction of enzyme synthesis were also determined. The mycelial plugs of these isolate was grown in submerged cultures of modified czapeck dox liquid medium containing the appropriate carbon source (cellulose, CMC, glucose and sucrose) and nitrogen source (peptone, yeast extract, urea and sodium nitrate) at different temperature, pH and incubation period. In fermentation with the addition of Tween 80 (0.1%) as surfactant, the production of cellulase was increased by two fold as compared to fermentation without surfactant. The enzyme activity assay was carried out on the culture filtrate obtained. Cellulase production in agitated shake flask fermentation at 150 rpm was two times higher as compared to fermentation in static flask. This study showed that the wood degrading soft rot fungi Paecilomyces variotii is capable of producing cellulases in submerged cultures.