The Digestive Lipase and Protease in the Dung Beetle, Chironitis Arrowi (Janssens)

Characteristics of lipase and protease from mid gut (MG) and hind gut (HG) of adult dung beetle, Chironitis arrowi were studied. The pH maxima, the optimal temperature and Km of these enzymes were determined. Lipase was showing the pH maxima at 8.0, while protease interestingly showed two pH optima at 7.0 and 10.0 in both sexes and guts. Temperature optima for lipase were occurred at 400C in both guts and sexes. However protease was showing higher temperature optima at 550C in both guts of male and female. The Km values of lipase were3.175x10-4M and 2.413x10-4 M in male and female (MG) respectively. For protease the Km values were 0.0312 % in male (MG) and 0.0357 % in female (MG). The 50 % inhibition of lipase occurred at 500C within 9.5 minutes in male (MG) and 9.7 minutes in female (MG). The half life of protease at 650C was occurred within 38.5 minutes and 31.50 minutes, in male and female (MG) respectively. The digestion periods of 10 minutes (for lipase in both sexes, MG) and 20 minutes (for protease in both sexes, MG) were fitted very well within the linear part of enzymatic action.