Identification and characterization of alpha-amylase in the Italian locust, Calliptamus italicus (Linnaeus, 1758) (Orthoptera: Acrididae)

Abstract : Calliptamus italicus (linnaeus, 1758) (Orthoptera: Acrididae) is a polyphagous locust which widely distributed throughout of Europe, Middle East and North Africa. Adults and nymphs are pests of great number of plants including cereals, fabaceous, red and sugar-beet, many solanaceous, cruciferous, sunflower, vegetable and young plants of various fruit plants. The present study for the first time showed that á-amylase is present in the C. italicus. Álpha-amylases have been found to be active in different insect species. Italian Locust á-amylase activity pH was determined to be around 8. Generally, optimal pH is corresponding to the pH prevailing in the midgut from which the enzyme has been extracted. The effect of temperature on the enzyme activity was determined showing that the enzyme was active from 20oC to more than 70oC. Optimum temperature was determined to be 40oC. Sharp decrease in enzyme activity was seen at low temperature e.g. temperature lower than 30oC. It seems that the enzyme was more active at high temperatures than low ones. The enzyme was active on the wide range of the temperatures from 30 to 60oC. Even at 60oC more than 50% of the enzyme activity was present. However, at 70oC only about 30% of the enzyme activity was left and more than 70% of the enzyme activity was lost. Native gel electrophoresis analysis showed that a mixture of different iso-enzyme was present in the gut homogenate. The analysis was shown that 9.0 amylase bands were seen in the gel thus the insect use an array of different alpha amylases for digestion of their food in the midgut. In conclusion it should be mentioned that because the Italian locust feed on different plant species, it needs different á-amylases for the digestion of some carbohydrate the insect encounter during feeding
Keyword : Italian locust, á-amylase, gut, temperature, pH
Author(s) : , A. Darvishzadeh, A. R. Bandani
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