Serratiopeptidase is a proteolytic enzyme extensively used as an anti-inflammatory and analgesic drug. Present work reports a thermoactive serratiopeptidase from Serratia marcescens AD-W2, a soil isolate from the North-Western Himalayan region of India. The extracellular metalloprotease has been purified by a simple two-step procedure resulting in a specific activity of 20,492 Units/mg protein with 5.28-fold purification. The molecular mass of the metalloprotease, as determined by SDS-PAGE was ~ 51 kDa. The purified serratiopeptidase presented optimum activity at pH 9.0, temperature 50 °C and stability in wide pH and temperature range. Critical temperature of 50 °C confirmed the thermoactivity of the purified serratiopeptidase. The kinetic studies of the purified serratiopeptidase revealed Vmax and Km of 57,256 Units/mL and 1.57 mg/mL, respectively, for casein. The purified serratiopeptidase from S. marcescens AD-W2 was found to be 100% identical to serralysin from Serratia marcescens ATCC 21074/E-15. The catalytic domain comprising of Zn coordinated with three histidine residues (His192, His196, His202), along with glutamate (Glu193) and tyrosine (Tyr232) residues, further confirmed that the purified protein is identical to serralysin.

In this study, an Econometric analysis has been conducted to identify the important factors that affect the food grain productions inBangladesh. Here, we have considered time series data for the years from 1989- 1990 to 2019-2020. Vector Autoregressive (VAR)Model and Autoregressive Integrated Moving Average (ARIMA) model have been considered in this study. Both these modelshave been considered to forecast the productions of food grains in Bangladesh. The forecasting performances of these two modelshave been compared by using RMSE, MAE, and MAPE. It has been found that the VAR model is better than the ARIMA model toforecast the food grain production. On the other hand, it has been come out from the analysis that there is no significant impact ofchemical fertilizer on the food grain production, but irrigation area has significant impact on the food grain production. Among thethree variables: food grain production, irrigation area and chemical fertilizer, there exists short run relationship. Dhaka Univ. J. Sci. 70(1): 8-13, 2022 (January)

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