Unmodified Peptide-Bacteriocins (Class II) Produced by Lactic Acid Bacteria

Author(s):  
Helge Holo ◽  
Ingolf Nes ◽  
Havard Hildeng Hauge ◽  
Gunnar Fimland ◽  
Jon Nissen Meyer
2002 ◽  
Vol 68 (12) ◽  
pp. 6451-6456 ◽  
Author(s):  
Franck Biet ◽  
Yves Cenatiempo ◽  
Christophe Fremaux

ABSTRACT A 2,665-bp cryptic plasmid, pTXL1, isolated from Leuconostoc mesenteroides subsp. mesenteroides Y110 was identified. This plasmid harbors a replicon localized on a 1,300-bp fragment. Two observations suggested that pTXL1 does not belong to rolling-circle replication (RCR)-type plasmids and most likely replicates via a theta mechanism. These hypotheses are supported by the observation that no detectable single-stranded intermediate was found for the replicon and that, unlike in RCR-type plasmids, the pTXL1 replicon sequence lacks an open reading frame encoding a replicase. The small-sized pTXL1 plasmid is stable and, according to its origin, can be considered in the “generally recognized as safe” category. Its ability to replicate in several lactic acid bacteria was exploited to develop a vector producing mesentericin Y105, a class II anti-Listeria bacteriocin. With this new vector, a recombinant industrial Leuconostoc cremoris strain able to produce mesentericin Y105 was constructed.


2001 ◽  
Vol 7 (4) ◽  
pp. 281-305 ◽  
Author(s):  
L. M. Cintas ◽  
M. P. Casaus ◽  
C. Herranz ◽  
I. F. Nes ◽  
P. E. Hernández

During the last few years, a large number of new bacteriocins produced by lactic acid bacteria (LAB) have been identified and characterized. LAB-bacteriocins comprise a heterogeneous group of physicochemically diverse ribosomally-synthesized peptides or proteins showing a narrow or broad antimicrobial activity spectrum against Gram-positive bacteria. Bacteriocins are classified into separate groups such as the lantibiotics (Class I); the small (<10 kDa) heat-stable postranslationally unmodified non-lantibiotics (Class II), further subdivided in the pediocin-like and anti Listeria bacteriocins (subclass IIa), the two-peptide bacteriocins (subclass IIb), and the sec-dependent bacteriocins (subclass IIc); and the large (>30 kDa) heat-labile non-lantibiotics (Class III). Most bacteriocins characterized to date belong to Class II and are synthesized as precursor peptides (preprobacteriocins) containing an N-terminal double-glycine leader peptide, which is cleaved off concomitantly with externalization of biologically active bacteriocins by a dedicated ABC-transporter and its accessory protein. However, the recently identified sec-dependent bacteriocins contain an N-terminal signal peptide that directs bacteriocin secretion through the general secretory pathway (GSP). Most LAB-bacteriocins act on sensitive cells by destabilization and permeabilization of the cytoplasmic membrane through the formation of transitory poration complexes or ionic channels that cause the reduction or dissipation of the proton motive force (PMF). Bacteriocin producing LAB strains protect themselves against the toxicity of their own bacteriocins by the expression of a specific immunity protein which is generally encoded in the bacteriocin operon. Bacteriocin production in LAB is frequently regulated by a three-component signal transduction system consisting of an induction factor (IF), and histidine protein kinase (HPK) and a response regulator (RR). This paper presents an updated review on the general knowledge about physicochemical properties, molecular mode of action, biosynthesis, regulation and genetics of LAB-bacteriocins.


2002 ◽  
Vol 28 (1) ◽  
pp. 1-6 ◽  
Author(s):  
E Simova ◽  
D Beshkova ◽  
A Angelov ◽  
Ts Hristozova ◽  
G Frengova ◽  
...  

2020 ◽  
Vol 29 (12) ◽  
pp. 59-63
Author(s):  
O.I. Parakhina ◽  
◽  
M.N. Lokachuk ◽  
L.I. Kuznetsova ◽  
E.N. Pavlovskaya ◽  
...  

The research was carried out within the framework of the theme of state assignment № 0593–2019–0008 «To develop theoretical foundations for creating composite mixtures for bakery products using physical methods of exposure that ensure homogeneity, stability of mixtures and bioavailability of nutrients, to optimize diets population of Russia». The data on the species belonging of new strains of lactic acid bacteria and yeast isolated from samples of good quality gluten-free starter cultures are presented. A comparative assessment of the antagonistic and acid-forming activity of strains of lactic acid bacteria and the fermentative activity of yeast was carried out. The composition of microbial compositions from selected strains of LAB and yeast was developed. The influence of the starter culture on the new microbial composition on the physicochemical, organoleptic indicators of the bread quality and resistance to mold and ropy-disease was investigated.


Author(s):  
O.A. Savkina ◽  
◽  
G.V. Ternovskoi ◽  
M.N. Lokachuk ◽  
E.N. Pavlovskaya ◽  
...  

2005 ◽  
Vol 34 (1) ◽  
pp. 91-99 ◽  
Author(s):  
K. Szekér ◽  
J. Beczner ◽  
A. Halász ◽  
Á. Mayer ◽  
J.M. Rezessy-Szabó ◽  
...  

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