5/20/2018 Bacteriocins Are Proteinaceous Toxins Produced by Bacteria to Inhibit the Gr...

http:///reader/full/bacteriocins-are-proteinaceous-toxins-produced-by-bacteria-to-in

Bacteriocins are proteinaceous toxins produced by bacteria to inhibit the growth of similar or closely

related bacterial strain(s). They are typically considered to be narrow spectrum antibiotics, though this

has been debated.[1] They are phenomenologically analogous to yeast and paramecium killing factors,

and are structurally, functionally, and ecologically diverse.

Medical significance[edit]

Bacteriocins are of interest in medicine because they are made by non-pathogenic bacteria that

normally colonize the human body. Loss of these harmless bacteria following antibiotic use may allow

opportunistic pathogenic bacteria to invade the human body .[citation needed]

Bacteriocins have also been suggested as a cancer treatment.[17][18] They have shown distinct promise

as a diagnostic agent for some cancers,[19][20][21][22][23] but their status as a form of therapy remains

experimental and outside the main thread of cancer research. Partly this is due to questions about their

mechanism of action and the presumption that anti-bacterial agents have no obvious connection tokilling mammalian tumor cells. Some of these questions have been addressed, at least in part.[24][25]

Bacteriocins[which?] were tested as AIDS drugs around 1990, but did not progress beyond in-vitro tests

on cell lines.[26] Bacteriocins can target individual bacterial species, or provide broad-spectrum killing of

many microbes. As with today's antibiotics, bacteria can evolve to resist bacteriocins. However, they can

be bioengineered to regain their effectiveness. Further, they could be produced in the body by

intentionally introduced beneficial bacteria, as some probiotics do.[27]

Farkas-Himsley H, Zhang YS, Yuan M, Musclow CE (1992). "Partially purified bacteriocin kills malignant

cells by apoptosis: programmed cell death". Cell. Mol. Biol. (Noisy-le-grand) 38 (56): 64351. PMID

1483114.

Jump up ^ Farkas-Himsley H, Musclow CE (1986). "Bacteriocin receptors on malignant mammalian cells:

are they transferrin receptors?". Cell. Mol. Biol. 32 (5): 60717. PMID 3779762

Lactic acid bacteria (LAB) have been used for centuries in the fermentation of a variety of dairy products.

The preservative ability of LAB in foods is attributed to the production of anti-microbial metabolites

including organic acids and bacteriocins. Bacteriocins generally exert their anti-microbial action by

interfering with the cell wall or the membrane of target organisms, either by inhibiting cell wall

biosynthesis or causing pore formation, subsequently resulting in death. The incorporation of

bacteriocins as a biopreservative ingredient into model food systems has been studied extensively and

5/20/2018 Bacteriocins Are Proteinaceous Toxins Produced by Bacteria to Inhibit the Gr...

http:///reader/full/bacteriocins-are-proteinaceous-toxins-produced-by-bacteria-to-in

has been shown to be effective in the control of pathogenic and spoilage microorganisms. However, a

more practical and economic option of incorporating bacteriocins into foods can be the direct addition

of bacteriocin-producing cultures into food. This paper presents an overview of the potential for using

bacteriocin-producing LAB in foods for the improvement of the safety and quality of the final product. It

describes the different genera of LAB with potential as biopreservatives, and presents an up-to-date

classification system for the bacteriocins they produce. While the problems associated with the use of

some bacteriocin-producing cultures in certain foods are elucidated, so also are the situations in which

incorporation of the bacteriocin-producer into model food systems have been shown to be very

effective.

5/20/2018 Bacteriocins Are Proteinaceous Toxins Produced by Bacteria to Inhibit the Gr...

http:///reader/full/bacteriocins-are-proteinaceous-toxins-produced-by-bacteria-to-in