Isolation of thermostable aspartase producing microorganisms from hot water springs

Water and soil samples collected from various hot water springs were used to isolate the thermostable aspartase producing microorganisms. Water samples were also analyzed for various physico-chemical characteristics. Presence of inorganic nutrients in an appropriate quantity in hot water springs rendered them more suitable for the growth of variety of microorganisms. About 22 isolates of thermophilic bacteria were isolated, but only five of them had the ability to produce aspartase. The thermostability of aspartase from Bacillus sp. TP-8 was investigated at different temperatures (40–60°C). The relative enzyme activity of aspartase at 40°C after 60 min was 63.5%. The half-life of enzyme at 50–55°C was 30 min. At 60°C after 2.5 min the relative enzyme activity was 80.5% and decreased drastically thereafter.