Identification and characterization of a novel antimicrobial peptide compound produced by Bacillus megaterium strain isolated from oral microflora

Abstract

In recent years, the decreased efficacy of existing antibiotics toward management of emergent drug-resistant strains has necessitated the search for novel antibiotics from natural products. In this regard, Bacillus sp is well known for producing variety of secondary metabolites of potential use. Therefore, we performed an investigation to isolate and identify Bacillus sp from oral cavity for production of novel antimicrobial compounds. We extracted, purified, and identified a novel bioactive compound by B. megaterium (KC246043.1). The optimal production of compound was observed on de Man Rogosa and Sharpe broth by incubating at 37 °C, and pH 7.0 for 4 days. The bioactive compound was extracted by using n-butanol (2:1 v/v), purified on TLC plates with detection at Rf 7.8 cm; further characterized and identified as a cyclic ploypeptide sharing structural similarity with bacitracin. Minimum inhibitory concentration of bioactive compound was found to be 0.25, 0.5, 1.0, 3.125 and 6.25 μg/ml against Micrococcus luteus ATCC10240, Salmonella typhi ATCC19430, Escherichia coli ATCC35218. Pseudomonas aeruginosa ATCC27853 and Staphylococcus aureus ATCC25923 respectively, with no activity against Candida albicans ATCC10231. Our findings have revealed a novel cyclic peptide compound from B. megaterium with broad spectrum antimicrobial activity against both Gram positive and Gram negative bacteria.

Antibacterial Activity of Bacterial Cellulose Loaded with Bacitracin and Amoxicillin: In Vitro Studies

“…The peak at 1205 cm −1 is attributed to the CH deformation vibration. The asymmetrical stretch vibrations of the C-C are identified at 1160 cm −1 [ 23 , 24 ]. The band from 1156 cm −1 is assigned to the asymmetric C-O-C stretching vibrations.…”

Isolation and Identification of Antibacterial Bioactive Compounds From Bacillus megaterium L2

“…Natural resources such as microorganisms, plants, and animals are used to extract novel compounds, of which microbes are a major source for finding new antimicrobial agents. Among the microbes, Bacillus megaterium is a rich source of metabolites, which is well-known to produce metabolites with antibacterial and antifungal activities ( Al-Thubiani et al, 2018 ; Mannaa and Kim, 2018 ). Before the widespread prevalence of Bacillus subtilis , B. megaterium had been widely used in biochemical research due to its extensive metabolic capacity and physical properties conducive to biotechnology applications ( Hitchins et al, 1968 ; Elmerich and Aubert, 1971 ).…”

The “beauty in the beast”—the multiple uses of Priestia megaterium in biotechnology

“…P. megaterium can be found in diverse habits including honey (López and Alippi 2009 ), wine (von Cosmos et al 2017 ), raw meat (Yucel et al 2009 ), fish (Al Bulushi et al 2010 ), sea water (Xu et al 2014 ), the oral cavity of humans (Al-Thubiani et al 2018 ), and most typically plants and soil (Dobrzanski et al 2018 ). Consequently, its metabolism is adapted to a variety of different carbon sources including xylose (a byproduct of hemicellulose), glycerol (de Jesus et al 2016 ; Korneli et al 2013 ; Moreno et al 2015 ), disaccharides such as cellobiose, maltose or sucrose (Youngster et al 2017 ), and a range of cheap mixed saccharide sources such as sugarcane molasses (Kanjanachumpol et al 2013 ).…”