Effect of Soil Temperature, Moisture and pH on Soil L-glutaminase Activity

Abstract

The experiment was carried out in the department of soil science and agricultural chemistry, College of Agriculture, Rajendranagar, PJTSAU. The enzyme L-Glutaminase (L-glutamine amido hydrolase E.C. 3.5.1.2) cause the hydrolysis of L-glutamine to ammonia, L-glutamic acid, thus it makes the amide form of nitrogen available to the plants. We have detected this enzyme in soils. A simple, precise, rapid and sensitive method was used to assay its activity which involves determination of the NH+ 4 released by l-glutaminase activity when soil is exposed to l-glutamine, Tris (hydroxymethyl) aminomethane (THAM) buffer and toluene at 37°C for 2 h. The NH+ 4-N released is determined by treatment of the soil sample with 2.5 m KCl containing a l-glutaminase inhibitor (Ag2SO4) and steam distillation of an aliquot of the resulting soil suspension (Frankenberger and Tabatabai, 1991). The aim of this research work was to determine the effect of moisture, pH, and temperature on L-glutaminase activity. The results showed that the optimum temperature, moisture, pH, for L-glutaminase activity was at 50oC, 50%, pH of 8 respectively. The optimum conditions were suitable for enzyme activity, any deviation from these optimum conditions were led to lower in enzyme activity. Introduction