Study of carbohydrases in grub of onthophagus catta (COLEOPTERA: SCARABAEIDAE: SCARABAEINAE)

Onthophagus catta is dung beetle species feeding on cattle dung. The characteristics of some Carbohydrases from mid gut (MG) were studied in the third instar grub of Onthophagus catta. Most of the Carbohydrases showed their maximum activities at pH 7.2.While some Carbohydrases were showing pH optima at 5.6 (Cellulase), 6.0 (Trehalase) and 6.8(Raffinase). Temperature optima for all Carbohydrases which were studied in mid gut occurred at 450C. The Km value of Amylase was 0.222% of starch. The Km values of Invertase enzyme was 5.56 X 10-3 M and to that of Trehalase was 7.048X10-3M.The half life of enzyme activities were 22.30 minutes (for Amylase), 25.0 minutes(for Invertase) and 27.15 minutes( for Trehalase)at 600 C. The digestion period of 60 minutes were fitted very well within the linear part of enzymatic action for Invertase and Trehalase enzymes, while Amylase showed digestion period of 30 minutes was fitted very well within the linear part of enzymatic action.