تأثیر رژیم‌های غذایی مختلف بر فعالیت آنزیم آلفا- آمیلاز شب‌پره‌ی‌ مدیترانه‌ای آرد (Lepidoptera: Pyralidae) Ephestia kuehniella Zeller, 1879

Ephestia kuehniella Zeller, 1879 (Lepidoptera: Pyralidae), commonly known as the Mediterranean flour moth or mill moth. E. kuehniella primarily infests stored grain products, including flour, maize, rice, and oats. It thrives in warm environments, making flour mills and bakeries prime locations for infestations. In this study, larvae were fed six different diets, including flour, oleaster, dates, pistachios, walnuts, and raisins. 10 fifth instar larvae (for each replicate) were dissected with 2 ml of phosphate buffer (pH 6.8) and gut was extracted. After homogenization, the samples were centrifuged at 1000 rpm for 10 minutes at 4°C. The activity of alpha-amylase was measured by using a 1% starch solution. The procedure involved combining 10 μL of enzyme extract, 20 μL of starch, and 410 μL of phosphate buffer (pH 6.8), and incubating the mixture at 35°C for 30 minutes. After that, 100 μL of 3, 5-dinitrosalicylic acid was added to the mixture, followed by heating the test tubes in boiling water for 15 minutes and then cooling them in ice water for 5 minutes. The absorbance was then measured at 540 nm using an ELISA reader after centrifugation at 10,000 rpm and 4°C for 10 minutes. Based on the results (F=3.66, df= 5, 12, P=0.03). The population reared on the oleaster had the highest alpha-amylase enzyme activity (0.306 ± 0.125 U/mg). In contrast, larvae that had fed on flour had the lowest enzyme activity (0.057 ± 0.001 U/mg). There was no significant difference in enzyme activity among populations raised on pistachio, raisin, and walnut diet. The highest protein concentration in the flour diet was 1.22 ± 0.49 mg/L and the lowest in the raisin diet was 0.02 ± 0.04 mg/L. Our study indicated that various types of carbohydrates significantly affect the activity of the alpha-amylase enzyme. This enzyme is crucial for starch digestion, and its activity levels varied depending on the type of diet consumed by the larvae in our study.