Characterization of a broad range antibacterial substance from a new Bacillus species isolated from Amazon basin

Abstract

A Bacillus sp. strain producing a bacteriocin-like substance was characterized by biochemical profiling and 16S rDNA sequencing. The phylogenetic analysis indicated that this strain has low sequence similarity with most Bacillus spp., suggesting a new species was isolated. The antimicrobial activity was detected starting at the exponential growth phase, and maximum activity was observed at stationary phase. The substance was inhibitory to a broad range of indicator strains, including pathogenic and food spoilage bacteria such as Listeria monocytogenes, B. cereus, Aeromonas hydrophila, Erwinia carotovora, Pasteurella haemolytica, Salmonella Gallinarum, among other. The antibacterial substance was stable over a wide pH range, but it was sensitive to pronase E and lipase. The antibacterial substance was bactericidal and bacteriolytic to L. monocytogenes and B. cereus at 160 AU ml(-1). The identification of a broad range bacteriocin-like inhibitory substance active against L. monocytogenes addresses an important aspect of food protection against pathogens and spoilage microorganisms.

Evaluation antibacterial and antibiofilm activity of the antimicrobial peptide P34 against Staphylococcus aureus and Enterococcus faecalis

“…However, all strains of E. faecalis were sensitive to the action of this antimicrobial in planktonic condition. Contrary to these results, Motta et al (2007a) , using the transmission electron microscopy against planktonic cells of L. monocytogenes, the authors report that cells treated with BLS P34 showed vesiculation of the protoplasm, pore formation and disintegration of the cells. It is possible that the antimicrobial activity against the isolates of this study has occurred in a similar way, because both are Gram-positive.…”

“…The production and partial purification was determined in accordance with Motta et al (2007a). For the production of BLS P34, Bacillus sp.…”

“…The AU ml -1 was determined against Listeria monocytogenes ATCC 7644 as indicator strain due susceptibility to BLS P34. The fractions showing antimicrobial activity were pooled, sterilized through a 0.22 µm filter (Millipore, Bedford, USA) and frozen stored (Motta et al 2007a). …”

“…An alternative for the prevention and eradication of biofilm formation, would consider that antimicrobial peptides could be used. The antimicrobial peptide P34 was isolated and characterized as a bacteriocin-like substance (BLS) by Motta et al (2007a) and the inhibitory activity was detected against Listeria monocytogenes, Bacillus cereus, and Salmonella Enteritidis (Motta et al 2007b. Furthermore, some studies showed low cytotoxicity in eukaryotic cells and antiviral activity against pathogenic virus of domestic animals (Vaucher et al 2010, Silva et al 2014.…”

Influence of Peptide P34 on Gene Expression of Listeria Monocytogenes and Listeria Seelegeri

“…These studies have suggested that the interaction of class II bacteriocins is highly dependent on EII Man and that the mechanism of resistance to class II bacteriocins can be observed in strains of L. monocytogenes, in which resistance seems to be associated to reduced expression of a mannose-specific phosphotransferase system (EIIAB Man A novel antimicrobial peptide was produced by a Bacillus sp. isolated from aquatic environments of Brazilian Amazon basin [28], with the potential to be used as food preservative. This peptide, named as P34, was purified and characterised as described elsewhere [29].…”