Journal of
eISSN: 2469 - 2786
Submit manuscript...
Research Article Volume 9 Issue 2
Isolation and molecular identification of Bacillus safensis (MK-12.1) exhibiting broad-spectrum antibacterial activity against multi-drug resistant isolates
Sajid Iqbal, Muhammad Qasim, Farida Begum, Hazir Rahman
Department of Microbiology, Kohat University of Science and Technology, Pakistan
Department of Biochemistry, Abdul Wali Khan University Mardan, Pakistan
Department of Microbiology, Abdul Wali Khan University Mardan, Pakistan
Received: May 14, 2021 | Published: June 7, 2021
Citation: Iqbal S, Qasim M, Begum F, et al. Isolation and molecular identification of Bacillus safensis (MK-12.1) exhibiting broad-spectrum antibacterial activity against multi-drug resistant isolates. J Bacteriol Mycol Open Access. 2021;9(2):87-92. DOI: 10.15406/jbmoa.2021.09.00302
Abstract
Introduction: The emergence of drug resistance in pathogenic bacteria is a global challenge over the past century. Therefore, the search for new antibacterial agents is essential to tickle the challenge of increasing spread of multidrug-resistant (MDR) bacteria. The Bacillus spp. has the potential to produce a wide arsenal of biologically active metabolites. Objective: The current study was aimed to isolate an antibacterial exhibiting Bacillus safensis from a diverse region and characterize their antibacterial metabolites. Material and methods: Bacillus safensis was isolated and screened for antibacterial activities against a set of indicator isolates by standard agar well diffusion assay. The strain MK-12.1 was identified based on 16S rRNA gene sequence supported by biochemical characterization. The molecular nature, size, and toxicity of the antibacterial metabolites produced by strain MK-12.1 were evaluated. Various culturing parameters such as temperature, pH, incubation time, and growth medium were optimized for growth and antibacterial metabolites synthesis. Results: Among a total of 69 isolated Bacillus spp. the strain MK-12.1exhibited promising antibacterial activities against all indicator strains including MDR pathogenic bacteria. The antibacterial metabolites were extracted using ethyl acetate and showed maximum antibacterial activity against Salmonella typhimurium while comparatively lower activity was recorded against Klebsiella pneumoniae. The minimum inhibitory concentration of extracted antibacterial metabolites was determined and range from 2.34-4.68 mg/ml against ATCC strains and 3.12-6.25 mg/ml against clinical MDR. The antibacterial metabolites were confirmed to be protein in nature, showed no hemolysis on human blood agar, and molecular weight was estimated to be >20kDa. The optimum antibacterial activity and biomass were achieved at pH 8, 30° C after 48 hours in the shaking incubator when cultured in a modified Opt medium. Conclusion: The present study revealed that the unexplored diverse regions are rich sources of antibacterial metabolites producing Bacillus spp. and may produce a novel antibacterial agent that could be used to combat MDR pathogenic bacteria in future.
Keywords: Bacillus spp. antibacterial metabolites, partial extraction, molecular identification, optimization
©2021 Iqbal, et al. This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and build upon your work non-commercially.