Study on carbohydrases in beetle ONITIS PHILEMON (FAB.)

Characteristics of ten carbohydrases from midgut (MG) and hindgut (HG) were studied in male and females of dung beetles Onitis philemon (Fab). Most of the carbohydrases showed their optimum activities at pH - 7.2. Enzymes cellulase, trehalase showed optimum pH 5.6 and 6.0. The pH optima of both maltase and invertase was 6.8. Temperature optima for all the carbohydrases which were studied in both guts and sexes occurred at 45oC. The Km values of amylase in MG and HG of male dung beetles were 0.2162℅ and 1.1420℅ respectively. While the Km values of amylase in MG and HG of female dung beetles were 1.140 % and 2.660 % respectively. The Km values of invertase enzyme were 4.87x10-3 M (in male MG), 3.894x10-2 M (in male HG); 4.10x10-3 M (in female MG) and 1.168x10-2 M (in female HG). In male MG the trehalase Km valve was 7.342x10-4M while in female MG the Km value was 6.956x10-4M. The Km value of maltase in male MG was 1.884x10-3M and in female MG was 1.579x10-3M. The half life of amylase activity at 60oC was 70 min. (in male MG); 48 min. (in male HG); 80 min. (in female MG) and 53 min. (in female HG). At the same temperature half life of invertase was at 40 min. (in male MG); 35 min. (in male HG); 30 min. (in female MG) and 28 min. (in female HG). The half life of trehalase and maltase in mid guts at 60sC were 50 min (in male); 53 min. (in female); 35.5 min. (in male) and 43.5 min (in female) respectively. The digestion period of 75 min. (MG and HG amylase in both sexes); 60 min. (MG and HG invertase in both sexes and MG trehalase of male and female) and 30 min. (MG maltase of both sexes) were fitted very well within the liner part of enzymatic action. Bacteriological studies revealed the presence of symbiotic amylolytic, cellulolytic saccharolytic and trehalolytic bacteria in hind gut section of both sexes. MG was major source for carbohydrases, but HG also contributes significantly. This indicates that HG also plays a vital role in the process of digestion of coprophagus adults due to the presence of symbiotic microbiota.