Review: Bacteriocins of Lactic Acid Bacteria

2001 ◽  
Vol 7 (4) ◽  
pp. 281-305 ◽  
Author(s):  
L. M. Cintas ◽  
M. P. Casaus ◽  
C. Herranz ◽  
I. F. Nes ◽  
P. E. Hernández
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Secretory Pathway ◽  
Response Regulator ◽  
Ionic Channels ◽  
Class Ii ◽  
Biologically Active ◽  
Leader Peptide ◽  
Class Iii ◽  
Activity Spectrum

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.

scholarly journals Co-Microencapsulation of Anthocyanins from Black Currant Extract and Lactic Acid Bacteria in Biopolymeric Matrices

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1700 ◽  
Author(s):  
Iuliana Maria Enache ◽  
Aida Mihaela Vasile ◽  
Elena Enachi ◽  
Vasilica Barbu ◽  
Nicoleta Stănciuc ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Biological Activities ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Confocal Laser ◽  
In Vitro Digestibility ◽  
Black Currant ◽  
Active Compounds ◽  
Food Ingredients

Anthocyanins from black currant extract and lactic acid bacteria were co-microencapsulated using a gastro-intestinal-resistant biocomposite of whey protein isolate, inulin, and chitosan, with an encapsulation efficiency of 95.46% ± 1.30% and 87.38% ± 0.48%, respectively. The applied freeze-drying allowed a dark purple stable powder to be obtained, with a satisfactory content of phytochemicals and 11 log colony forming units (CFU)/g dry weight of powder (DW). Confocal laser microscopy displayed a complex system, with several large formations and smaller aggregates inside, consisting of biologically active compounds, lactic acid bacteria cells, and biopolymers. The powder showed good storage stability, with no significant changes in phytochemicals and viable cells over 3 months. An antioxidant activity of 63.64 ± 0.75 mMol Trolox/g DW and an inhibitory effect on α-amylase and α-glucosidase of 87.10% ± 2.08% and 36.96% ± 3.98%, respectively, highlighted the potential biological activities of the co-microencapsulated powder. Significantly, the in vitro digestibility profile showed remarkable protection in the gastric environment, with controlled release in the intestinal simulated environment. The powder was tested by addition into a complex food matrix (yogurt), and the results showed satisfactory stability of biologically active compounds when stored for 21 d at 4 °C. The obtained results confirm the important role of microencapsulation in ensuring a high degree of protection, thus allowing new approaches in developing food ingredients and nutraceuticals, with enhanced functionalities.

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

2001 ◽  
Author(s):  
Helge Holo ◽  
Ingolf Nes ◽  
Havard Hildeng Hauge ◽  
Gunnar Fimland ◽  
Jon Nissen Meyer
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Class Ii ◽  
Unmodified Peptide

scholarly journals Adjuvant Effects for Oral Immunization Provided by Recombinant Lactobacillus casei Secreting Biologically Active Murine Interleukin-1β

2009 ◽  
Vol 17 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Akinobu Kajikawa ◽  
Kazuya Masuda ◽  
Mitsunori Katoh ◽  
Shizunobu Igimi
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Casei ◽  
Oral Immunization ◽  
Biologically Active ◽  
Interleukin 1Β ◽  
Intestinal Loop ◽  
Adjuvant Effects

ABSTRACT Vaccine delivery systems using lactic acid bacteria are under development, but their efficiency is insufficient. Autologous cytokines, such as interleukin-1β (IL-1β), are potential adjuvants for mucosal vaccines and can be provided by recombinant lactic acid bacteria. The aim of this study was the construction and evaluation of recombinant Lactobacillus casei producing IL-1β as an adjuvant delivery agent. The recombinant strain was constructed using an expression/secretion vector plasmid, including a mature IL-1β gene from mouse. The biological activity of the cytokine was confirmed by IL-8 production from Caco-2 cells. In response to the recombinant L. casei secreting IL-1β, expression of IL-6 was detected in vivo using a ligated-intestinal-loop assay. The release of IL-6 from Peyer's patch cells was also detected in vitro. Intragastric immunization with heat-killed Salmonella enterica serovar Enteritidis (SE) in combination with IL-1β-secreting lactobacilli resulted in relatively high SE-specific antibody production. In this study, it was demonstrated that recombinant L. casei secreting bioactive murine IL-1β provided adjuvant effects for intragastric immunization.

scholarly journals Identification of a Replicon from pTXL1, a Small Cryptic Plasmid from Leuconostoc mesenteroides subsp. mesenteroides Y110, and Development of a Food-Grade Vector

2002 ◽  
Vol 68 (12) ◽  
pp. 6451-6456 ◽  
Author(s):  
Franck Biet ◽  
Yves Cenatiempo ◽  
Christophe Fremaux
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Leuconostoc Mesenteroides ◽  
Class Ii ◽  
Open Reading Frame ◽  
Cryptic Plasmid ◽  
Rolling Circle Replication ◽  
Rolling Circle ◽  
Reading Frame ◽  
Food Grade

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.

scholarly journals Temporal Regulation of Genes Encoding the Flagellar Proximal Rod in Caulobacter crescentus

2001 ◽  
Vol 183 (2) ◽  
pp. 725-735 ◽  
Author(s):  
Charles H. Boyd ◽  
James W. Gober
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Developmental Stages ◽  
Caulobacter Crescentus ◽  
Response Regulator ◽  
Class Ii ◽  
Class Iii ◽  
Swarmer Cell ◽  
Sequencing Project

ABSTRACT The gram-negative bacterium Caulobacter crescentus has a life cycle that includes two distinct and separable developmental stages, a motile swarmer phase and a sessile stalked phase. The cell cycle-controlled biogenesis of the single polar flagellum of the swarmer cell is the best-studied aspect of this developmental program. The flagellar regulon is arranged into a rigid trans-acting hierarchy of gene expression in which successful expression of early genes is required for the expression of genes that are later in the hierarchy and in which the order of gene expression mirrors the order of assembly of gene products into the completed flagellum. TheflgBC-fliE genes were identified as a result of the C. crescentus genome sequencing project and encode the homologues of two flagellar proximal rod proteins, FlgB and FlgC, and one conserved protein, FliE, that is of unknown function. Footprint assays on a DNA fragment containing the operon promoter as well as in vivo mutant suppressor analysis of promoter mutations indicate that this operon is controlled by the cell cycle response regulator CtrA, which with ς70 is responsible for regulating transcription of other early flagellar genes in C. crescentus. Promoter analysis, timing of expression, and epistasis experiments place these genes outside of the flagellar regulatory hierarchy; they are expressed in class II mutants, andflgB deletions do not prevent class III gene expression. This operon is also unusual in that it is expressed from a promoter that is divergent from the class II operon containing fliP, which encodes a member of the flagellum-specific protein export apparatus.

scholarly journals A New Class of Caulobacter crescentusFlagellar Genes

1998 ◽  
Vol 180 (19) ◽  
pp. 5010-5019 ◽  
Author(s):  
Guy Leclerc ◽  
Shui Ping Wang ◽  
Bert Ely
Keyword(s):  
Posttranslational Modification ◽  
Caulobacter Crescentus ◽  
Response Regulator ◽  
Class Ii ◽  
Class Iii ◽  
New Class ◽  
Regulator Protein ◽  
Flagellar Filament ◽  
Response Regulator Protein ◽  
Flagellar Genes

ABSTRACT Eight Caulobacter crescentus flagellar genes,flmA, flmB, flmC, flmD,flmE, flmF, flmG, andflmH, have been cloned and characterized. These eight genes are clustered in pairs (flmAB, flmCD,flmEF, and flmGH) that appear to be structurally organized as operons. Homology comparisons suggest that the proteins encoded by the flm genes may be involved in posttranslational modification of flagellins or proteins that interact with flagellin monomers prior to their assembly into a flagellar filament. Expression of the flmAB, flmEF, andflmGH operons was shown to occur primarily in predivisional cells. In contrast, the flmCD operon was expressed throughout the cell cycle, with only a twofold increase in predivisional cells. The expression of the three temporally regulated operons was subject to positive regulation by the CtrA response regulator protein. Mutations in class II and III flagellar genes had no significant effect on the expression of the flm genes. Furthermore, the flm genes did not affect the expression of class II or class III flagellar genes. However, mutations in theflm genes did result in reduced synthesis of the class IV flagellin proteins. Taken together, these data indicate that theflm operons belong to a new class of flagellar genes.

scholarly journals Isolation, Characterization, and Applicability of Helveticin 34.9, A Class Iii Bacteriocin Produced By Lactobacillus Helveticus 34.9

2021 ◽  
Author(s):  
Iulia-Roxana Angelescu ◽  
Silvia-Simona Grosu-Tudor ◽  
Lucia-Roxana Cojoc ◽  
Gabriel-Mihai Maria ◽  
Medana Zamfir
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Large Scale ◽  
Morphological Changes ◽  
Bacterial Species ◽  
Fermented Milk ◽  
Lactobacillus Helveticus ◽  
Proteinase K ◽  
Fermented Foods ◽  
Class Iii

Abstract Traditionally fermented foods and beverages are still produced and consumed at a large scale in Romania. They are rich sources for novel lactic acid bacteria with functional properties and with potential application in food industry or health. Lactobacillus helveticus 34.9, isolated from a home-made fermented milk is able to inhibit the growth of other bacteria, such as other lactic acid bacteria, but also strains of Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, and Halobacillus hunanensis, a halobacterium isolated from the degraded wall of a Romanian monastery. L. helveticus 34.9 produces a large bacteriocin (35 KDa), active in a wide pH range, but inactivated by heat and proteinase K treatment. Bacteriocin production was enhanced under stress conditions, especially when combined stresses were applied. Its mode of action and degree of inhibition depended on the indicator strain and on the concentration of bacteriocin that was used. L. delbrueckii subsp. bulgaricus LMG 6901T cells from a suspension were killed within 8 h, but the viability of H. hunanensis 5Hum cells was only reduced to 60%. However, the bacteriocin was able to prevent the bacterial growth of both indicator strains when added to the medium prior inoculation. Scanning electron microscopy images revealed morphological changes induced by the bacteriocin treatment in both sensitive strains, but more severe in the case of L. delbrueckii subsp. bulgaricus. This class III bacteriocin, with inhibitory activity against various bacterial species, may find application in food and non-food related fields, including in the restoration of historical buildings.

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