Physiological and biochemical characteristics of Fusarium oxysporum and Trichoderma viride isolated from old manuscripts of the General Book Organization of Egypt including effects of incubation periods, carbon sources, temperature, pH and relative humidity on linear growth (mm) and dry weight (mg) were established. Cellulolytic activity (Avicelase, CMCase, and Fpase were measured by the size of the clear zone on specific media. The results show that the best incubation period for F. oxysporum was 9 day on PDA solid medium and 12 day for liquid medium, while for T. viride was 6 and 9 day for solid and liquid media respectively. Cellulase production increased gradually over an, incubation period up to a maximum of 18 day for both F. oxysporum and T. viride beyond which a slight decline in the enzyme activity could be observed. The two isolates grow and attain maximum linear and dry weight at temperatures degree between 25 and 30°C. Both organisms can grow on PDA solid medium along a pH ranging from pH 3.5-8.5, with maximum growth at pH 3.5-6.5. F. oxysporum and T. viride grow effectively
on all tested carbon sources (sucrose, maltose, lactose, glucose, arabinose, starch, pectin and raffinose) reaching maximum growth after 7 days of incubation. Cotton pulp was considered the best carbon source for inducing the highest Avicelase enzyme activity for both F. oxysporum and T. viride. Also, maximum growth was attained over a range of relative humidity, as the growth of F. oxysporum was increased by increasing the RH up to 92.3% and up to 100% for T. viride.