Effet de Sources de Carbone et d’Azote Sur la Croissance et le Spectre Antimicrobien de Bacillus spp

Abstract

It has been shown that bacteria of the genus Bacillus spp are widely used in industry thanks to their interest in producing antibiotics and their resistance to extreme conditions. In order to select species of the genus Bacillus spp, 10 soil samples from different regions of the wilaya of Ain Témouchent and Tlemcen are taken under sterile conditions. After a series of dilution and inoculation, 44 different strains are isolated and purified on the basis of a macroscopic identification and then a microscopic observation step, 34 strains were retained according to the criteria of what genus belongs or bacilli to Gram positive and capable of forming spores. In addition, the antibacterial activity of these strains was tested by the well method which must perform against the following pathogenic bacteria: Staphylococcus aureus, Candida albicans, Escherichia coli, Bacillus cereus, but thanks to the confinement only Escherichia coli was tested and showed that the two strains encoded K1 and N1 exhibit activity on gram-negative bacteria, through their zones of inhibition. The search for a nutrient source favorable to the production of antibiotics must be carried out by studying the effect of carbon and nitrogen sources on the production of these secondary metabolites in liquid medium, but the planning of this work is not yet finished because of the pandemic.