Streptomyces flavogriseus HS1 : Isolation and Characterization of Extracellular Proteases and Their Compatibility with Laundry Detergents

Abstract EN

The present study describes the isolation of a new protease producing Streptomyces strain HS1 and the biochemical characterization of the secreted proteases.

By sequencing of its noted 16S rDNA, HS1 strain was found to have a 100% identity with Streptomyces flavogriseus.

The highest protease production was found using FermII media.

In these conditions maximum protease production (99 U/mL) was obtained after 96 h incubation at 30°C and 150 rpm.

HS1 strain produced at least five proteases as revealed by zymogram technique.

The enzyme preparation exhibited activity over a broad range of pH (5–11) and temperature (25–70°C).

Optimum activity was observed at a pH of 7.0 and a temperature of 50°C.

Proteolytic activity was significantly unaffected by Ca2+ and Mg2+.

EDTA and PMSF highly decreased the original activity.

The crude extracellular proteases showed high stability when used as a detergent additive.

These properties offer an interesting potential for enzymatic hydrolysis at the industrial level.