The Characterization and Activity of Digestive Enzymes in Different Sizes of Common Lowland Frog (Rana rugulosa Wiegmann)

Abstract

The activity of serine and acid protease, amylase and li-pase from a 3-day-old whole-body frog, the gastrointestinal tract of a 10-day-old frog, and the stomach, intestine and pancreas of a 45-day-old and a 60-day-old frog (Rana rugulosa Wiegmann) were determined. The results showed that the medium-age frog (45 days) appeared to have higher activity of serine protease and lipase than the old frog (60 days) and tadpoles (3 and 10 days), while the old frog had the highest activity of acid protease. The activity of serine and acid protease from the four ages of frogs had the high activity at pH 8-12 and 3 respectively, while the activity of both amylase and lipase were highest at pH 7. The activity of all kinds of enzymes were shown to have the highest ac-tivity in the pancreas while the activity of acid protease was found to have the highest activity in the stomach. These results will be used as the basis for suitable feed formulation and feedstuffs for different sizes of common lowland frogs so that optimum nutritional value and cost-effectiveness can be achieved.