Purification and Properties of a Novel Surface-active Agent-and Alkaline-resistant Protease from Bacillus sp. Y.

Abstract

In the course of a search for an alkaline stable protease for industrial use, an alkaline protease (protease BYA) was isolated from an alkalophilic Bacillus sp. Y, and its properties were characterized. Its optimum pH was pH 10.0-12.5, when casein was used as a substrate. In addition to the stability of protease BYA at pH 6.5-13.0, it was also very stable towards various surface-active agents, such as sodium dodecyl sulfate and sodium linear alkylbenzene sulfonate. Protease BYA was most active at 70 degrees C. The isoelectric point (pI) of protease BYA was about 10.1. Protease BYA was characterized as a serine protease because of its sensitivity to phenylmethanesulfonyl fluoride and diisopropyl fluorophosphate. The protease seems to be related to proteases of the subtilisin family, such as subtilisin BPN', subtilisin Carlsberg, and No. 221 protease.

Protease activity in the egg yolk during the development of Meleagris gallopavo (Galliformes: Phasianidae) embryos

“…The general protease activity was measured according to the protocol in Shimogaki et al (1991) and Cupp-Enyard (2008) with modifications. Briefly, 0.5 mL of the yolk samples were added to 2.5 mL of substrate solution containing 0.65% casein in 20 mM buffers at different pH.…”

Bacteriolytic Activity of Detergent Protease and Its Enhancement by Detergent's Materials

“…Protease activity was determined essentially by Anson-Hagiwara's method (13). To 3 ml of reaction mixture containing 0.6% milk casein and 10 mM boraxNaOH buffer (pH 10.5), 0.5 mL of enzyme solution was added at 35 .…”

Bacteriolytic Activity of Alkaline Protease BYA from Bacillus sp. Y

“…Alkaline protease BYA was prepared by Shimogaki's method (10). Deozyme (12) was obtained from Novozymes.…”

“…2 3 1 Assay of protease activity Protease activity was determined using the AnsonHagiwara method (10). Briefly, 0.5 mL of enzyme solution was added to 3 mL of reaction mixture containing 0.6 milk casein and 10 mM borax-NaOH buffer (pH 10.5).…”