Screening and Characterization of Novel Bacteriocins from Lactic Acid Bacteria

Abstract

Bacteriocins produced by lactic acid bacteria (LAB) are expected to be safe antimicrobial agents. While the best studied LAB bacteriocin, nisin A, is widely utilized as a food preservative, various novel ones are required to control undesirable bacteria more effectively. To discover novel bacteriocins at the early step of the screening process, we developed a rapid screening system that evaluates bacteriocins produced by newly isolated LAB based on their antibacterial spectra and molecular masses. By means of this system, various novel bacteriocins were identified, including a nisin variant, nisin Q, a two-peptide bacteriocin, lactococcin Q, a leaderless bacteriocin, lacticin Q, and a circular bacteriocin, lactocyclicin Q. Moreover, some LAB isolates were found to produce multiple bacteriocins. They were characterized as to their structures, mechanisms of action, and biosynthetic mechanisms. Novel LAB bacteriocins and their biosynthetic mechanisms are expected for applications such as food preservation and peptide engineering.

Defining the Structure and Receptor Binding Domain of the Leaderless Bacteriocin LsbB

“…Many, if not all, leaderless bacteriocins have formylmethionine at their N termini, a feature that distinguishes these molecules from other processed bacteriocins (15). Most of the leaderless bacteriocins have been identified in recent years, and insight into their biosynthetic pathways, structures, and mode of action is still limited (16). To our knowledge, the only leaderless bacteriocin that has been determined structurally is the two-peptide bacteriocin enterocin 7, which consists of the peptides Ent7A and Ent7B (7).…”

Antimicrobial antagonists against food pathogens: a bacteriocin perspective

“…Zendo and co-workers [49,50] developed a rapid screening method using electrospray ionisation liquid chromatography/mass spectrometry (ESI/LC/MS) coupled with statistical analysis of antimicrobial spectra to accelerate the discovery of novel bacteriocins isolated from various sources. An example of a novel lantibiotic that has recently been discovered using a genome mining and PCR approach is the broad spectrum cerecidin A1 and cerecidin A7 from B. cereus strain As 1.1846 isolated from spoiled soya milk.…”

Identification and Characterization of a Bacteriocin-Like Substance, Produced by <i>Leuconostoc mesenteroides</i>, as a Bio-Preservative Against <i>Listeria monocytogenes</i>

“…Their inhibition spectrum is towards closely related species with nano-molar concentration, while several bacteriocins produced by LAB have broad inhibition activity, including food spoilage and pathogenic microorganisms. Besides that, bacteriocins Leuconostoc mesenteroides, as a Bio-Preservative Against Listeria monocytogenes produced by LAB with desirable properties, like safe compounds, pH and heat tolerant provide prospective benefits for food preservation, importantly, bacteriocins have not exhibited lethal to humans, and thus discovery of new bacteriocins produced by LAB have been taken more attentions [12][13].…”

“…Screening for the bacteriocin producers, as the first step for discovery of novel bacteriocin, has been utilized from several products, and the methods have been utilized recently [13][14][15]. Bacteriocin-producers, isolated and analyzed from dairy product, and their characteristics have been partly or fully understood as well [16][17].…”