scholarly journals Isolation of a bacteriocin-producing Lactococcus lactis subsp. lactis and application to control Listeria monocytogenes in Moroccan jben

2000 ◽  
Vol 89 (6) ◽  
pp. 960-968 ◽  
Author(s):  
N. Benkerroum ◽  
H. Oubel ◽  
M. Zahar ◽  
S. Dlia ◽  
A. Filali-Maltouf
Keyword(s):  
Listeria Monocytogenes ◽  
Lactococcus Lactis ◽  
Lactococcus Lactis Subsp

Behavior of Listeria monocytogenes in the Presence of Lactic Acid Bacteria in an Agitated Medium with Internal pH Control

1991 ◽  
Vol 54 (3) ◽  
pp. 183-188 ◽  
Author(s):  
JANE M. WENZEL ◽  
ELMER H. MARTH
Keyword(s):  
Lactic Acid ◽  
Statistical Analysis ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Ph Control ◽  
Lactococcus Lactis Subsp ◽  
Streptococcus Lactis ◽  
Streptococcus Cremoris ◽  
Internal Ph

An agitated medium with internal pH control (IPCM-2) was inoculated to contain Listeria monocytogenes (strain V7, Scott A or California) at ca. 103 CFU/ml and Streptococcus cremoris (Lactococcus lactis subsp. cremoris) or Streptococcus lactis (Lactococcus lactis subsp. lactis) at 0.25 or 1.0% The inoculated medium was incubated with shaking in a waterbath at 30°C for 30 h. L. monocytogenes and lactic acid bacteria were enumerated and pH was determined at appropriate intervals. The area on a figure between curves for the control and treatment and designated as the area of inhibition (AI) was calculated and used to quantify inhibition of each strain of L. monocytogenes for a particular set of conditions in IPCM-2. Statistical analysis of AI values calculated from data obtained at 6, 24, and 30 h of incubation revealed no significant (p < 0.05) difference in inhibition among the three strains of L. monocytogenes for each type of lactic streptococcus present. Streptococcus cremoris was significantly (0.01 < p < 0.05) more inhibitory to all three strains of L. monocytogenes than was S. lactis at 24 and 30 h of incubation. IPCM-2 is considered ready for use at a pH of 5.4 or less, which was reached between 12 and 15 h of incubation in samples containing 0.25 or 1.0% S. cremoris. Populations of L. monocytogenes in such samples were ca. 104 to 106 CFU/ml regardless of strain of Listeria or percentage of S. cremoris added as inoculum. In samples initially containing 0.25 or 1.0% S. lactis, pH 5.4 was not reached until after 18–24 h of incubation. At this point all three strains of L. monocytogenes had grown to ca. 105 CFU/ml regardless of percentage of S. lactis added as inoculum. Despite the inhibition seen, substantial numbers of the pathogen were present when the medium was ready for use.

INHIBITION OF LISTERIA MONOCYTOGENES BY LACTOCOCCUS LACTIS SUBSP. LACTIS ISOLATED FROM ITALIAN RAW HAM

1992 ◽  
Vol 12 (4) ◽  
pp. 295-302 ◽  
Author(s):  
MARA LUCIA STECCHINI ◽  
VALERIA AQUILI ◽  
ILEANA SARAIS ◽  
ANNA PITOTTI
Keyword(s):  
Listeria Monocytogenes ◽  
Lactococcus Lactis ◽  
Lactococcus Lactis Subsp

scholarly journals Autochthonous Enterococcus durans PFMI565 and Lactococcus lactis subsp. lactis BGBU1–4 in Bio-Control of Listeria monocytogenes in Ultrafiltered Cheese

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1448
Author(s):  
Marina Ivanovic ◽  
Nemanja Mirkovic ◽  
Milica Mirkovic ◽  
Jelena Miocinovic ◽  
Ana Radulovic ◽  
...  
Keyword(s):  
Lactic Acid ◽  
High Temperature ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Lactococcus Lactis ◽  
Chemical Additives ◽  
Enterococcus Durans ◽  
Lactococcus Lactis Subsp ◽  
Bacteriocin Producer ◽  
Cheese Production

Nowadays, consumers are interested in cheese produced without chemical additives or high-temperature treatments, among which, protective lactic acid bacteria (LAB) cultures could play a major role. In this study, the aims were to isolate, identify and characterize antilisterial LAB from traditionally produced cheese, and utilize suitable LAB in cheese production. Among 200 isolated LAB colonies, isolate PFMI565, with the strongest antilisterial activity, was identified as Enterococcus durans. E. durans PFMI565 was sensitive to clinically important antibiotics (erytromicin, tetracycline, kanamycin, penicillin, vancomycin) and had low acidifying activity in milk. E. durans PFMI565 and the previously isolated bacteriocin producer, Lactococcus lactis subsp. lactis BGBU1–4, were tested for their capability to control Listeria monocytogenes in experimentally contaminated ultrafiltered (UF) cheeses during 35 days of storage at 4 °C. The greatest reductions of L. monocytogenes numbers were achieved in UF cheese made with L. lactis subsp. lactis BGBU1–4 or with the combination of L. lactis subsp. lactis BGBU1–4 and E. durans PFMI565. This study underlines the potential application of E. durans PFMI565 and L. lactis subsp. lactis BGBU1–4 in bio-control of L. monocytogenes in UF cheese.

Behavior of Listeria monocytogenes during the Manufacture, Ripening, and Cold Storage of Afuega'l Pitu Cheese

1997 ◽  
Vol 60 (6) ◽  
pp. 689-693 ◽  
Author(s):  
ABELARDO MARGOLLES ◽  
ANA RODRÍGUEZ ◽  
CLARA G. de los REYES-GAVILÁN
Keyword(s):  
Listeria Monocytogenes ◽  
Lactococcus Lactis ◽  
Cell Damage ◽  
Salt Content ◽  
Northern Spain ◽  
Growth And Survival ◽  
Lactococcus Lactis Subsp ◽  
Whole Milk ◽  
Serotype 1 ◽  
Serotype 4B

Afuega'l Pitu is an artisanal acid-coagulated cheese manufactured in Asturias (northern Spain) and mainly consumed between the 3rd and the 30th day of ripening. Six cheese-making trials were performed in a pilot plant by using pasteurized whole milk inoculated with Listeria monocytogenes (strain L2 [serotype 1/2a], L39, or L41 [serotype 4b]) to ca. 2.7 log CFU/ml. A starter containing three strains, Lactococcus lactis subsp. lactis IPLA 947, Lactococcus lactis subsp. lactis biovar diacetylactis IPLA 838, and Leuconostoc citreum IPLA 616, grown separately in milk and combined in the volumetric proportion 3:1:1.3 was used. During the acidification L. monocytogenes counts increased 2.78- to 7.03-fold, depending on the strain, and remained within the curd; from this time counts decreased abruptly and were not detected in cheeses beyond the 7th day. The average pH in the curd was 4.43, and it decreased to around 4.0 in 5- to 7-day-old cheeses. These pH values were near the tolerance limit for L. monocytogenes and probably caused cell damage. Although moisture, aw, and NaCl levels were not limiting for the growth and survival of L. monocytogenes, salt content must be considered as a contributing factor in L. monocytogenes inactivation. Finally, the L2 strain grew better in curd and was slightly more resistant to low pH and refrigeration than strain L39 or L41. The manufacture of Afuega'l Pitu cheese from pasteurized milk and the design of a specific starter from the autochthonous lactic microbiota can lead to a safer product that can be consumed after very short ripening periods.

scholarly journals Antimicrobial activity of the Nisin Z producer Lactococcus lactis subsp. lactis Lc08 against Listeria monocytogenes in skim milk

2013 ◽  
Vol 65 (5) ◽  
pp. 1554-1560 ◽  
Author(s):  
L.M. Perin ◽  
R.O. Miranda ◽  
A.C. Camargo ◽  
M. Colombo ◽  
A.F. Carvalho ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Lactococcus Lactis ◽  
Food Systems ◽  
Skim Milk ◽  
In Vitro Tests ◽  
Lactococcus Lactis Subsp ◽  
Ph Values ◽  
Nisin Z

The presented study aimed to verify the effect of different pH values, enzyme solutions and heat treatments on the antimicrobial activity of the bacteriocinogenic strain Lactococcus lactis subsp. lactis Lc08 and to test their antimicrobial activity against Listeria monocytogenes in reconstituted skim milk at refrigeration temperatures. This strain was previously described as a nisin Z producer and capable of inhibiting L. monocytogenes growth in in vitro tests. The antimicrobial activity of the bacteriocin cell-free supernatant of Lc08 was sensitive to enzyme treatments (except papain). The pH values and heating (65ºC for 30min, 75ºC for 15s) had no apparent effect on the antimicrobial activity of the bacteriocin produced by Lc08. Only treatment at autoclave conditions result in loss of their antimicrobial activity. Lc08 presented antimicrobial activity against L. monocytogenes in the milk system after 12h at 25ºC. No effect was found at 7ºC. The results show the application viability of the Lc08 in food systems as a biopreservative against L. monocytogenes.

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