Bacillus spp with an Antibacterial Activity

Bacterial resistance to antibiotics poses a serious challenge to chemotherapy. Indeed, in recent
decades, the risk of contracting infectious diseases has increased significantly due to the emergence
and spread of multi-drug-resistant bacteria. The whole world is thus confronted with this situation
which motivated scientists to find out new active molecules with an antibacterial effect. Therefore, the
present investigation aims to isolate and identify microorganisms secreting substances with an
antibacterial activity and to partially characterize their extracts. Thus, six bacteria were isolated from
soil and water of different biotopes of Fez Morocco having an antibacterial effect against M.
smegmatis, M. aurum, Gram-positive and Gram-negative bacteria. Based on biochemical
characterization and 16S rDNA sequence analysis, it was revealed that the isolates belong to the
genus Bacillus. The antibacterial activity of three of them was fully affected by proteases (pepsin and
proteinase K) and heat treatment at 80ºC and 100ºC but it was stable at 4ºC for a month and 37ºC
during 3h. The lost of the activity suggests a proteinaceous nature of the bio-active compounds, which
might be useful in the development of antibacterial agents after their total purification in further work
against bacterial infections.