Role of trehalase and protease during the development of the brine shrimp, Artemia parthenogenetica

The functional significance of trehalase and protease in different developmental stages of Artemia parthenogenetica was assessed by studying the enzyme activity in relation to substrate concentration and pH, respectively. Trehalase activity was maximum in the encysted embryos (31.26 ± 1.13 units/mg protein/min) and hydrated cysts (30.44 ± 1.16 units/mg protein/min) compared with other developmental stages. The decline in trehalase activity can be attributed to a reduced utilization of the substrate trehalose. On the other hand, protease activity was high in the encysted embryos at pH 5.0 and in other developmental stages at alkaline pH. It is therefore evident that intracellular pH (one of the factors influencing the kinetic property) has an impact on the general behaviour of the enzymes throughout the developmental stages. Since Artemia lives in hypersaline environments these enzymes show physiological adaptatior during cryptobiosis.