Author(s): Eman A. Al-Imara1 and Ghaidaa J. Al-Gazzawy
Article publication date: 2016-03-01
Vol. 34 No. 1/2 (yearly), pp. 35-42.
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Keywords
Bacillus spp., Secondary metabolites, Antibacterial activity, MIC, VITEK
Abstract
Twenty Bacillus spp. isolates were identified from sediment and water samples from different locations in Basrah Governorate, Iraq. The bacterial isolates were cultivated, identified by morphological, biochemical and by using VITEK BCL card. The antibacterial effects of Bacillus extracts against target bacteria included: Methicillin Resistant Staphylococcus aureus (MRSA), Kocuria kristinae, Pseudomonas aeruginosa,
and Escherichia coli were examined by agar diffusion test as well as by measuring the
Minimum Inhibitory Concentration (MIC) in microtiter dilution assay. The produced
extracts showed a variable activity against target bacteria with a MICs ranged between
(1.6-6.24) μg/ml against Pseudomonas aeruginosa, (1.6-3.12) μg/ml against Escherichia
coli, (0.4-1.6) μg/ml against MRSA, and (0.2-0.8) μg/ml against Kocuria kristinae
respectively. Our findings highlighted the importance of sediments and water bacterial
isolates for production of compounds with interesting bioactivities that may contribute to
drug research field.