Influence of two substrates (casein and glucose) on mycelia growth and dosage of proteolytic activity of Fusarium oxysporum f. sp. albedinis (Foa)

Abstract

The influence of the two substrates tested on 18 isolates of Fusarium oxysporum f. sp. albedinis (Foa) was studied in order to compare the fungus behaviour on Casein and Glucose. It has shown that there is a mycelia growth of 63.63 % using casein, compared to 36.36 % using the Glucose. It has also been observed that the isolate "Foa Mtl 8" has shown a superior growth compared with the other isolates on liquid and solid casein medium, with a weight of 3 g, and it has completely covered the Petri dishes in first (in 6 days). On the same isolate, the detection of proteolytic activity by measuring the clarification diameters was most significant (4.2 cm diameter). On these criteria we had been based in order to select the isolate "Foa Mtl 8" for the determination of proteolytic activity. The colorimetric protein assay was performed by the method of Folin and Ciocalteu at different initial pH (4, 6 and 8). It had also shown that the isolate "Foa Mtl 8" produce a protease in pH range of 7.1 to 7.8.