Antibacterial Effect of Bacillus Strains and Partial Characterization of Their Extracts

Abstract

Aims: The focus of this study was to isolate and to identify strains with antibacterial activity followed by a partial characterization of their extracts. Study Design: Screening and identification of bacteria having an anti-mycobacterial effect from soil and water of different biotopes of Fez Morocco were performed and active substances responsible for the biological activity were partially characterized. Place and Duration of Study: The study was carried out at laboratory of Microbial Biotechnology, Department of Biology, Faculty of Sciences and Technical, University Sidi Mohamed Ben Abdellah, BP 2202, Road of Immouzer, Fez, Morocco, during the period from January 2011 to October 2011. Methodology: Samples of soil and water of different biotopes of Fez Morocco were explored to isolate compounds-producing microorganisms. The inhibitory spectrum of the isolated bacteria was evaluated against M. smegmatis, M. aurum, S. aureus, S. haemolyticus, B. subtilis, E. coli DH5 α, P. aeruginosa and Erwinia chrysanthemi by using agar well diffusion test and/or a modified spot-onlawn assay. Identification of strains was executed on the basis of Gram stain, biochemical characteristics and PCR followed by DNA sequencing of 16S ribosomal RNA gene. Crude extracts obtained after precipitation by ammonium sulfate were exposed to proteolytic enzymes (Pepsin and