HALOSTABLE ALKALINE AMYLASE AND PROTEASE FROM AN EXTREMELY HALOALKALIPHILIC ARCHAEON, NATRINEMA SP. SSBJUP-1 ISOLATED FROM LONAR LAKE.

Abstract

An extremely haloalkaliphilic archaeon Natrinema sp. SSBJUP-1 showing potent
amylolytic and proteolytic activities was isolated from the saline alkaline Lonar Lake,
India. Amylase and protease were active over the neutral to alkaline pH range from 6 to
9. Amylase was more stable over a narrower temperature range of 40-60oC than the
protease but had the higher optimum (55oC) for activity. By contrast, protease was
active over a broader range 10-75oC with an optimum of 40oC. The amylase was stable
over a broader salinity range, but with an optimum salt concentration of 10-12%,
whereas the protease was with a higher optimum concentration of 18% salt in the
reaction mixture. Calcium and Magnesium behaved as activators for both enzymes
while Copper was an activator for protease while being an inactivator for amylase.
Amylase was highly tolerant to five commercial detergents tested while the protease
was tolerant only to one.