Streptococcus lactis, nisin

Nisin is an antimicrobial elaborated by Streptococcus lactis N. Due to the fact that nisin is not used for human or animal therapy or as a feed additive and growth promotor, its use in food is per-... 

From other bacteria nisin subtilin Streptococcus lactis P... 

Nisin (Fig. 17), isolated from Streptococcus lactis culture broths in 1952, was structurally clarified only in 1970 by Gross et al. 219). A partial sequence (ring A) of nisin was synthesized in 1983 by Shiba et al. 220). 

Gasson MJ (1984) Transfer of sucrose fermenting ability, nisin resistance and nisin production in Streptococcus lactis 712. FEMS Microbiol Lett 21 7-10... 

Froseth BR, Herman RE, McKay LL (1988) Cloning of nisin resistance determinant and replication origin on 7.6-kilobase EcoRI fragment of pNP40 from Streptococcus lactis subsp. diacetylactis DRC3. Appl Environ Microbiol 54 2136-2139... 

Nisin belong to a group of polypeptide antibiotics (called bacteriocins) produced by Streptococcus lactis which have inhibitory properties directed toward other LAB (Radler, 1990a, 1990b). Yeasts, by comparison, are unaffected. The concentration needed for inhibition varied with species. Leu-conostoc oenos and Pediococcus sp. were controlled at relatively low treatment levels, whereas lactobacilli required much higher doses for inhibition (Radler, 1990a). 

Nisin (C143H230N42O37S7) is an antibiotic produced by Streptococcus lactis and is effective against the Gram-positive bacteria, especially the lactic acid bacteria. It is used in processed cheese and some canned foods where permitted (see section 6.7). 

Nisin is a substance consisting of a mixture of at least two homeomeric peptides. Mattick and Hirsch (406) in 1947 obtained nisin from cultures of a strain of Streptococcus lactis, which exhibits remarkable antibiotic activity with respect to S. agalactiae. It is obtained in the following manner (64). 

Antibacterial Spectrum. Hawley reported that various species and strains of the genera Staphylococcus, Streptococcus, Neisseria, Bacillus, Clostridium, and Corynebacterium are inhibited by nisin (Hawley 1957A, B). Mattick and Hirsch (1947) added actinomycetes, pneumococci, mycobacteria, and Erysipelothrix to this list. The nisin concentration required for complete inhibition is organism specific and ranges from 0.25 to 500 units per milliliter. Inhibition of L. casei by antibiotics from S. lactis and S. cremoris was observed by Baribo and Foster (1951). Inhibition of Propionibacterium by nisin but not of coliform bacteria was reported by Galesloot (1957). 

Fig. 7. Alignment of leader peptides of class lA, and class lAn lantibiotics and class 11 non-lantibiotic bacterlocins. Lantibiotics with class lAj leaders include nisin A and nisin Z from different strains of Lactococcus lactis [83], subtilin from Bacillus subtilis [84], epidermin, gal-lidermin and Peps from various Staphylococcus epidermidis strains [29,90,188], Lantibiotics with class lAn leaders include lacticin 481 (lactococcin DR) from L. lactis [211], streptococcin A-FF22 from Streptococcus sp. [199], salivaricin A from Streptococcus salivarius and cytolysin LI and L2 from Enterococcus faecalis [122]. Bacteriocins of the non-lantibiotic class 11 type include leucocin A from Leuconostocgelidum [69], lactococcin A, B and M from L. lactis [46,125,126,135,136],pediocin PA-1 from Pediococcus acidilactici [130], and sakacin A and lactacin F from Lactobacillus sp. [43,203]...

Nisin belongs to a group of bactericidal peptides called type A lantibiotics (Willey and van der Donk, 2007). Four natural nisin variants (A, Z, Q, and U) have been discovered. Nisins A, Z, and Q are produced by L. lactis while nisin U is produced by Streptococcus uberis. Two main variants of nisin A and Z have been described (De Vuyst and Vandamme, 1994). Nisin Z is widely distributed and contains asparagine instead of histidine at position 27 of the amino acid sequence of nisin A (Fig. 11.2). The two variants have nearly equal bactericidal activity, membrane insertion, and pore-forming ability. 

Food preservatives are yet another product of industrial fermentation. Organic acids, particularly lactic and citric acids, are extensively used as food preservatives. Some of these preservatives (such as citric acid) are used as flavoring agents. A mixture of two bacterial species (Lactobacillus and Streptococcus) is usually used for industrial production of lactic acid. The mold Asper Uus niger is used for citric acid manufacturing. Another common preservative is the protein nisin. Nisin is produced via fermentation by the bacterium Lactococcus lactis. It is employed in the dairy industry especially for production of processed cheese. 

Nisin is a bacteriocin that is produced by some strains of Lactococcus lactis subsp. lactis. Its name is derived from group N (Streptococcus) Inhibitory Substance. It was originally thought (wrongly) that nisin was the cause of slow acid development in cheese manufacture. Interest in nisin was re-stimulated when its effectiveness as an antimicrobial preservative was recognised in the 1940s. 

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