In recent years, the increase in the number of multi-drug resistant pathogens and food safety have become serious global problems, and it is increasingly important to find or develop a new generation of antibacterial drugs or preservatives. Scientists have discovered that bacteria-produced bacteriocins can control clinically relevant susceptible and resistant bacteria, and purified bacteriocins can be added to foods as natural preservatives. Bacteriocins can be added to animal feeds as anti-pathogen additives to protect livestock from pathogen damage. In medicine, bacteriocin has the potential to replace antibiotics as antibacterial drugs and is a new type of anticancer drug.

1. How Much Do You Know about Bacteriocin?
In recent years, the increase in the number of multi-drug resistant pathogens and food safety
have become serious global problems, and it is increasingly important to find or develop a
new generation of antibacterial drugs or preservatives. Scientists have discovered that
bacteria-produced bacteriocins can control clinically relevant susceptible and resistant
bacteria, and purified bacteriocins can be added to foods as natural preservatives.
Bacteriocins can be added to animal feeds as anti-pathogen additives to protect livestock
from pathogen damage. In medicine, bacteriocin has the potential to replace antibiotics as
antibacterial drugs and is a new type of anticancer drug.
What’s Bacteriocin?
Bacteriocins are small, thermostable, ribosomally synthesized antimicrobial peptides
produced by bacteria that are active against other bacteria and to which the producer is
immune. They exhibit considerable diversity in size, structure, mechanism of action, inhibitory
profile, immune mechanism, and target cell receptors.
They exhibit antimicrobial activity against the same bacterial strain from which they are
produced or against strains of closely related species. The synthesis of bacteriocin takes place
under the control of genes located in plasmid or chromosomal DNA that simultaneously
contain the genetic determinants of the resistance of the producer to the produced
bacteriocin.
Genes encoding active proteins, genes encoding protein resistance, genes responsible for
export of bacteriocin from cells, and occasionally genes encoding enzymes involved in post-
translational modification of bacteriocin were expressed simultaneously.
Bacteriocins are composed of Gram-positive bacteria (Lactobacillus, Lactococcus,
Streptococcus, Enterococcus, Leuconostoc, Pediococcus, and Propionibacterium) and Gram-
negative bacteria (Escherichia coli, Shigella, Serratia bacteria, Klebsiella, and Pseudomonas).
"Bacteriocin" refers to a toxic protein or peptide produced by any type of bacteria that is
active against the related bacteria but does not harm the producing cells. This is the first
described bacteriocin produced by E. coli. In this case, the suffix cin is added to the production
species, e.g., pyocins are from Pseudomonas pyocyanea. Genus names are also used to name
bacteria, such as klebicins (from Klebsiella), lactococcins (from Lactococcus). Although
bacteriocins are toxic to bacteria, they should not be confused with "toxins" (exotoxins).
Enterobactin, the first bacteriocin to be identified, was named by discoverer André Gratia in
1925 when he noticed that a strain of E. coli produced a toxic diffusible substance that killed
neighboring E. coli.
Since then, hundreds of peptides and protein bacteriocins have been described that are part
of a diverse library of natural antimicrobial compounds made by Gram-negative and Gram-

2. positive bacteria to ward off competitors. In keeping with the origins of bacteriocin research,
colistin remains the most studied, especially in terms of how bacteriocins disrupt the bacteria's
powerful defense mechanisms.
Colicins kill cells through a variety of mechanisms, which fall into two cytotoxic categories;
enzymatic colicins cleaves nucleic acid or peptidoglycan precursors, while pore-forming
colistins depolarize the cytoplasmic membrane.
Characteristics of Bacteriocins
In complex and overcrowded environments, microbes tenaciously compete with each other
for territory and nutrients, thus developing a plethora of defense mechanisms. Among them,
bacteriocin is considered to be the most widely distributed mechanism at present. By
definition, bacteriocins are secreted, ribosomally synthesized peptides of prokaryotic origin
with antimicrobial properties.
From a human health perspective, bacteriocins represent a library of potential lead
compounds honed by 3 billion years of evolution. Their narrow target range, high activity,
surprising stability, and low toxicity make them viable alternatives or complements to existing
small-molecule antibiotics. They use these powerful weapons to thrive in microbial warfare.
To complete this arsenal, bacteriocin-producing strains are given effective strategies to evade
being killed by their own toxins. Most bacteriocins are active in the picomolar or nanomolar
range and target bacterial species that are phylogenetically close to the production strain,
although some bacteriocins exhibit a broader spectrum of activity.
In fact, many bacteriocins, for example, have a narrow spectrum of activity, exhibiting
antimicrobial activity against strains closely related to the producer, while others exhibit
antimicrobial activity against a variety of different genera. Regulation of bacteriocin
production can be complex and, in some cases, influenced by environmental conditions such
as pH, temperature, and growth media.
Bacteriocins are strong candidates for use as future therapeutics. Recent studies have shown
that bacteriocins have exemplary antibacterial activity in vitro. Nonetheless, the next step in
developing new bacteriocin-based therapeutics involves the use of in vivo models. The
antibacterial and/or toxic effects of bacteriocins have been studied in mouse models and the
latest alternative animal models, such as drosophila, zebrafish embryos, roundworms, wax
moths or brine shrimp. These results suggest that bacteriocins can exert multiple positive
responses in the host, such as altered immunogenic responses, altered inflammatory
responses, and reduced infection-related biochemical and histopathological parameters. On
the other hand, 20% of studies conducted in surrogate models assessed antibacterial activity
but did not report toxicity. These data demonstrate that bacteriocin lacks an in vivo model for
toxicity and biosafety studies, which are critical for advancing clinical trials.
Collected by Creative BioMart Microbe that provides customers with a one-stop service for

3. bacteriocin production, from the optimization of production parameters to the purification of
bacteriocins and the determination of antibacterial activity.