An extracellular protease from a newly isolated seawater haloalkaliphilic bacterium, haloalkaliphilic bacteria Ve(2)-20-9(1) [HM047794], was purified and characterized. The enzyme is a monomer with a 37.2 kDa estimated molecular weight. It catalyzed reactions in the pH range 8-11 and performed optimally at pH 10. While maximal activity occurred at 50 degrees C, the temperature profile shifted from 50 to 80 degrees C in 1-3M NaCI. The enzyme's thermal stability was probed using circular dichroism (CD) spectroscopy with NaCI at 50 and 70 degrees C. The changes in the enzyme's secondary structure were also analyzed using Fourier transform infrared spectroscopy (FTIR). The N-terminal amino acid sequence GKDGIVGLCGEFGCI exhibited low homology with other bacterial proteases, which highlights the enzyme's novelty. The enzyme was labile in anionic surfactant (1% wiv SDS) but showed stability in non-ionic surfactants (Tween 20, Tween 80 and Triton X-100 all 1% v/v), commercial detergents, and oxidizing and reducing agents. The enzyme's excellent stability in commercial detergents highlights its potential as a detergent additive. (C) 2014 Elsevier Ltd. All rights reserved.