RESUMEN
The genome of the thermophilic bacterium, Aeribacillus pallidus 8, encodes the bacteriocin pallidocin. It belongs to the small class of glycocins and is posttranslationally modified, containing an S-linked glucose on a specific Cys residue. In this study, the pallidocin biosynthetic machinery is cloned and expressed in Escherichia coli to achieve its full biosynthesis and modification. It targets other thermophilic bacteria with potent activity, demonstrated by a low minimum inhibitory concentration (MIC) value. Moreover, the characterized biosynthetic machinery is employed to produce two other glycopeptides Hyp1 and Hyp2. Pallidocin and Hyp1 exhibit antibacterial activity against closely related thermophilic bacteria and some Bacillus sp. strains. Thus, heterologous expression of a glycocin biosynthetic gene cluster including an S-glycosyltransferase provides a good tool for production of hypothetical glycocins encoded by various bacterial genomes and allows rapid in vivo screening.
Asunto(s)
Bacillaceae/metabolismo , Bacteriocinas/biosíntesis , Secuencia de Aminoácidos , Antibacterianos/biosíntesis , Antibacterianos/química , Antibacterianos/farmacología , Bacillaceae/genética , Bacteriocinas/genética , Bacteriocinas/farmacología , Clonación Molecular , Disulfuros/química , Escherichia coli/genética , Escherichia coli/metabolismo , Genes Bacterianos , Glicopéptidos/biosíntesis , Glicopéptidos/genética , Glicopéptidos/farmacología , Pruebas de Sensibilidad Microbiana , Familia de Multigenes , Estructura Terciaria de Proteína , Homología de Secuencia de AminoácidoRESUMEN
There is a growing interest in supporting human health by using prebiotics, such as oligosaccharides, and beneficial bacteria, also called probiotics. Combining these two components we can develop synbiotics. In order to create successful combination of synbiotic it is very important to evaluate the influence of prebiotic oligosaccharides to probiotic bacteria and their behavior, such as growth and secretion of health related biomolecules, including bacteriocins. In this study seven type strains of probiotic bacteria (five Lactobacillus sp. and two Lactococcus sp.) and two Lactobacillus sp. strains, isolated from probiotic yoghurt, were cultivated with various commercially available and extracted oligosaccharides (OS). The aim of this study was to evaluate the influence of these OS on type and isolated bacterial strains growth and antibacterial activity. Obtained results suggest that combination of certain OS with probiotic strains may considerably improve their growth and/or antibacterial activity. We also determined the antibacterial activity spectrum of investigated strains with combination of OS against common food borne pathogens. Results of this work show that prebiotic OS can be useful for modulating probiotic bacteria growth, antibacterial activity and even specificity of this activity.