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BioMed Research International
Volume 2014 (2014), Article ID 345980, 8 pages
Research Article

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

Laboratoire de Génie Enzymatique et de Microbiologie, Ecole Nationale d’Ingénieurs de Sfax, BP 1173, 3038 Sfax, Tunisia

Received 13 January 2014; Revised 22 February 2014; Accepted 5 March 2014; Published 6 April 2014

Academic Editor: Neelu Nawani

Copyright © 2014 Sofiane Ghorbel et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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.