Amanita sp. from subtropical region of Saudi Arabia as a source of chitinase enzyme and its antifungal activity

Mushroom products have been used as a biotechnological tool for many applications. Particularly, thermostable chitinase plays a vital role in biowaste management and biological control. In the present investigation, Amanita sp. was recorded in the subtropical region of Saudi Arabia, therefore, it was utilized for chitinase production using substrates chitin and dead fungal mycelia (DFM). Compared with the DFM, chitin was more suitable for chitinase activity at different temperatures and pH. Amanita sp. produced chitinase up to 70 °C, but the optimum was 50 °C. The chitinase activity was 4.98, 3.5, and 0.9 U.mg-1 with the use of chitin, while it was 4.6, 3.1, and 0.6 U.mg-1 with the use of DFM at 50, 60, and 70 °C, respectively. Chitinase activity was stable up to 60 °C, then it began to decrease at 70 °C. The chitinase activity was better at pH 4 and 5 than pH 8 and 9. The antifungal effect of the produced chitinase at 50 °C was more effective than at 60 °C. For instance, the Alternaria alternata colony radius was 3.50 cm and 2.26 cm at 50 °C while it was 4.35 cm and 4.13 cm at 60 °C when using DFM and chitin, respectively.