Abstract
Laboratory experiments have revealed many active mechanisms by which bacteria can inhibit the growth of other organisms. Bacteriocins are a diverse group of natural ribosomally synthesized antimicrobial peptides produced by a wide range of bacteria and which seem to play an important role in mediating competition within bacterial communities. In this study, we have identified and established the structural classification of putative bacteriocins encoded by 317 microbial genomes in the human intestine. On the basis of homologies to available bacteriocin sequences, mainly from lactic acid bacteria, we report the widespread occurrence of bacteriocins across the gut microbiota: 175 bacteriocins were found to be encoded in Firmicutes, 79 in Proteobacteria, 34 in Bacteroidetes, and 25 in Actinobacteria. Bacteriocins from gut bacteria displayed wide differences among phyla with regard to class distribution, net positive charge, hydrophobicity and secondary structure, but the α-helix was the most abundant structure. The peptide structures and physiochemical properties of bacteriocins produced by the most abundant bacteria in the gut, the Firmicutes and the Bacteroidetes, seem to ensure low antibiotic activity and participate in permanent intestinal host defense against the proliferation of harmful bacteria. Meanwhile, the potentially harmful bacteria, including the Proteobacteria, displayed highly effective bacteriocins, probably supporting the virulent character of diseases. These findings highlight the eventual role played by bacteriocins in gut microbial competition and their potential place in antibiotic therapy.
Highlights
Bacteriocins are natural antimicrobial peptides that are ribosomally synthesized by many bacteria and some Archaea (Cotter et al, 2005; Zacharof and Lovitt, 2012; Yang et al, 2014)
The bacteriocin sequences differ greatly in size and composition, with sequences ranging from 10 amino acids to 2,064 amino acids, with average length and weight of 160 amino acids and 18 kDa, respectively
These bacteriocin sequences can be classified into the three classes as follows: 243 in the Class I, 492 in the Class II and 624 in the Class III
Summary
Bacteriocins are natural antimicrobial peptides that are ribosomally synthesized by many bacteria and some Archaea (Cotter et al, 2005; Zacharof and Lovitt, 2012; Yang et al, 2014). Probiotics are used to enhance the ratio of beneficial to undesirable bacteria in human gastrointestinal microbiota (Fooks and Gibson, 2002) probably via the production of bacteriocins. Bacteriocins may play a crucial role in determining the composition of gut microbiota (Corr et al, 2007; Angelakis et al, 2013; Million et al, 2013). They are presumed to actively participate in gastrointestinal host defense mechanisms by inhibiting one ecosystem, encouraging another, and offering a competitive advantage to bacteria in the intestinal tract
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
