Stability study of the extracted mycelium bound lipase activity of Aspergillus flavus

Specific activity of lipase extracted from the wet mycelium using 0.05 M Tris HCI pH 8.2 increased nearly 40 times higher than that of the dry mycelium. The activity and specific activity of extracted lipase kept at 4 C decreased steadily during storage. The decrease in lipase activity could most probably be due to the co-existence of proteases that have the ability to deactivate the lipases. More than half of the proteases present in the extracted solution were successfully separated by acetone precipitation at 1.0:1.0 ratio (extraction solution:acetone). Addition of 1mM of ethylenediaminetetraacetic-acid-disodium salt (EDTA) and 1,10 phenanthroline (lmM to 8mM) successfully inhibited the metalloprotease activity and maintained the lipase activity for 32 days at 4°C.