Abstrakt

Isolation and Screening of L-asparaginase Producing Fungi from Soil Samples of Different Rainforest Agroecological Zones of Oyo State, Nigeria

Tairu Hafeez Motala*, Oyelakin AO, Kolawole TA, Adaramola KA, Aribisala LA, Sulaimon NO

L-asparaginase is an enzyme that converts L-asparagine to L-aspartate and ammonia and produced by various microorganisms which it used for the treatment of Acute Lymphoblastic Leukemia (ALL) and other malignant cancers as well as starchy food industry. Isolation and screening of L-asparaginase producing fungi from soil samples from different rainforest agroecological zones in Oyo state was done. The primary screening by qualitative methods using rapid plate assay determined that out of 83 fungal isolates, only 7 fungi showed L-asparaginase activity on plate method assay by pink colour zones. These seven isolates that preliminary screened were grown in liquid media for static and submerged fermentation and then used for secondary screening by nesslerization method. Among seven isolates, it was showed that isolate from EZ (Egbeda Zone) (EZ26A and EZ26B) showed higher values in enzyme activity, amount of ammonia and absorbance value of 58.7 UI/mL, 111.7 µmol/L 1.286 A and 59.3 UI/mL, 112.9 µmol/L 1.432 A and the highest microbial load counts were determined in AZ (akinyele zone) with (76) 7.6 × 10²for dilution factor of 10^-1 and EZ with (24) 2.4 × 10⁴for dilution factor of 10^-3.