Purification of a Moderately Thermal Stable Amylase from Earthworm Allolobophora Choloretica for Starch Processing

Amylase catalyzes the hydrolysis of starch, glycogen and gives rise to certain products such as maltopentose, maltotetrose, maltotriose, maltose, and glucose. In the present study, earthworm Allolobophora choloretica, from Lumbricidae family, was used as animal model system. First, the earthworm cell extracts were precipitated by using a gradient of saturated ammonium sulfate and multi-step dialysis, and then α-amylase was purified by Amicon® Ultra filter. The purified enzyme was analyzed on SDS-PAGE and a single 37 KD band observed on the gel. Subsequently, optimum pH and optimum temperature of the purified α-amylase were estimated to be 7 and 53 ℃, respectively. Based on our results, at extreme acidic and alkaline pH conditions, the enzyme showed higher pH stability at pH 9 than 4. Moreover, the values of 〖∆H〗_D^#, 〖∆S〗_D^#and 〖∆G〗_D^# were 63.75 kcal.mol-1, 0.113 cal.mol-1K-1 and 26.66 kcal.mol-1, respectively. In conclusion, the purified moderately thermophilic amylase from earthworm Allolobophora choloretica can be exploited in different industries.