Production Of A-Amylase By Fungi Isolated From Oil-Contaminated Soil In Karbala, Iraq.

Objective: The present study aims to isolate and diagnose of fungi from soil polluted with oils and investigate their ability to produce a-amylase. Methods: Soil samples were collected from different areas of oil-polluted soils in Karbala, Iraq for the period from October to November 2019. 0.5 g of each sample was diluted with distilled water and cultured on potato dextrose agar (PDA). A week later, the purification processes were carried out to obtain pure colonies of isolated fungi. The isolated fungi were diagnosed and their own codes were given. The fungal isolates were then implanted in the nutrient broth to determine the susceptibility of these isolates to produce of a-amylase. After 10 days of incubation, the filtration and centrifuge processes were measured for production media. The amount of the enzyme was measured by using kit of a-amylase in the Reflatron. Results: Four fungal genera were obtained in this study and are belong to five fungal species (45 Isolates), including: Aspergillus niger (20 isolates), Aspergillus flavus (8 isolates), Rhizopus stolonifera (5 isolates), Phoma medicaginis Malbra var. pinodella (9 isolates) and Mucor sp. (3 isolates). Twelve isolates were found in the production of a-amylase produced. The two isolates, Phoma medicaginis Malbra var. pinodella (D7) and Aspergillus niger(A19), were the most productive a-amylase, with the amount of enzyme produced (746 and 321) U/L, respectively. Conclusions: The fungal species found in the soil polluted with oils in the city of Karbala are five fungal species including Aspergillus niger, Rhizopus stolonifer, Phoma medicaginis Malbra var. pinodella, Aspergillus flavus and Mucor sp. The highest production of a-amylase was through the fungal isolation of Phoma medicaginis Malbra var. pinodella D7. [ABSTRACT FROM AUTHOR]