scholarly journals Influence of Enterococci and Lactobacilli on Listeria

2010 ◽  
Vol 27 (Special Issue 2) ◽  
pp. 12-17
Author(s):  
K. Kučerová ◽  
I. Korbová ◽  
Š. Horáčková ◽  
E. Šviráková ◽  
M. Plocková
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Raw Milk ◽  
Proteinase K ◽  
Cow Milk ◽  
Live Cells ◽  
Enterococcus Spp ◽  
Almost All

A collection of lactic acid bacteria (38 Enterococcus and 41 Lactobacillus strains) was tested for the antilisterial activity against 15 Listeria spp. strains (two L. monocytogenes, one L. ivanovii and 12 L. innocua strains) using agar spot method. Out of all 79 bacteria only six Enterococcus strains (1/3A, 3/3A, 6/4D, 6/1A, 1282 and EN3) exhibited antilisterial activity against almost all used indicator strains, when their live cells were tested. When their cell free neutralised supernatants (CFNS) were tested against four selected indicator strains (L. innocua Ln-03, Ln-06, Ln-10 and L. monocytogenes CCM5576) only two Enterococcus spp. strains were active – E. faecalis 6/1A strain from raw cow milk of minor interest due to the activity of its CFNS only against L. innocua Ln-06 and thermolability of the compound and E. mundtii 1282 strain from goat raw milk with CFNS active against 13 Listeria spp. strains including L. monocytogenes. E. mundtii 1282 strain produced probably a bacteriocin, because it completely lost the activity after treatment CFNS with proteinase K.

scholarly journals Antilisterial activity of lactic acid bacteria against Listeria monocytogenes strains originating from different sources

2014 ◽  
Vol 32 (No. 2) ◽  
pp. 145-151 ◽  
Author(s):  
I. Složilová ◽  
S. Purkrtová ◽  
M. Kosová ◽  
M. Mihulová ◽  
E. Šviráková ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Starter Culture ◽  
Raw Milk ◽  
Starter Cultures ◽  
Cow Milk ◽  
Live Cells ◽  
Dairy Equipment ◽  
Different Sources

Eight individual bacteriocin-producing lactic acid bacteria (LAB) strains and three bacteriocin-non-producing cheese starter cultures were evaluated for their ability to inhibit the growth of six Listeria monocytogenes strains, originating from the guinea-pig lymph nodes, raw cow milk, and manufacturing dairy equipment. Results showed that either live cells or cell-free neutralised supernatant (CFNS) and/or heated CFNS of six individual LAB strains (Lcc. lactis subsp. lactis CCDM 416 and NIZO R5, Lbc. plantarum HV 11 and DC 1246, P. acidilactici HV 12, and Ent. mundtii CCM 1282) and one starter culture (DELVO-ADD<sup>&reg;</sup> 100-X DSF) were effective in the suppression of at least one listeria strain. Neither any individual LAB strain nor starter culture was antagonistic toward all studied L. monocytogenes strains, indicating diverse sensitivity/resistance among L. monocytogenes strains to antimicrobial compounds of LAB. The significant susceptibility of listerias isolated from raw milk and dairy equipment together with the strong antilisterial activity of DELVO-ADD<sup>&reg; </sup>100-X DSF could be applied in dairy technology, where commonly used starter cultures could play both the biopreservative and fermentation role. &nbsp;

scholarly journals Flow Cytometric Assessment of Viability of Lactic Acid Bacteria

2001 ◽  
Vol 67 (5) ◽  
pp. 2326-2335 ◽  
Author(s):  
Christine J. Bunthof ◽  
Karen Bloemen ◽  
Pieter Breeuwer ◽  
Frank M. Rombouts ◽  
Tjakko Abee
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Cell Sorting ◽  
Direct Evidence ◽  
Agar Medium ◽  
Live Cells ◽  
Plate Count ◽  
Viability Assessment ◽  
Flow Cytometric ◽  
Almost All

ABSTRACT The viability of lactic acid bacteria is crucial for their applications as dairy starters and as probiotics. We investigated the usefulness of flow cytometry (FCM) for viability assessment of lactic acid bacteria. The esterase substrate carboxyfluorescein diacetate (cFDA) and the dye exclusion DNA binding probes propidium iodide (PI) and TOTO-1 were tested for live/dead discrimination using aLactococcus, a Streptococcus, threeLactobacillus, two Leuconostoc, anEnterococcus, and a Pediococcus species. Plate count experiments were performed to validate the results of the FCM assays. The results showed that cFDA was an accurate stain for live cells; in exponential-phase cultures almost all cells were labeled, while 70°C heat-killed cultures were left unstained. PI did not give clear live/dead discrimination for some of the species. TOTO-1, on the other hand, gave clear discrimination between live and dead cells. The combination of cFDA and TOTO-1 gave the best results. Well-separated subpopulations of live and dead cells could be detected with FCM. Cell sorting of the subpopulations and subsequent plating on agar medium provided direct evidence that cFDA labels the culturable subpopulation and that TOTO-1 labels the nonculturable subpopulation. Applied to cultures exposed to deconjugated bile salts or to acid, cFDA and TOTO-1 proved to be accurate indicators of culturability. Our experiments with lactic acid bacteria demonstrated that the combination of cFDA and TOTO-1 makes an excellent live/dead assay with versatile applications.

scholarly journals In vitro evaluation of bacteriocin-like inhibitory substances produced by lactic acid bacteria isolated during traditional Sicilian cheese making

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Giusi Macaluso ◽  
Gerlando Fiorenza ◽  
Raimondo Gaglio ◽  
Isabella Mancuso ◽  
Maria Luisa Scatassa
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Salmonella Enteritidis ◽  
Raw Milk ◽  
Starter Cultures ◽  
Proteinase K ◽  
Alternative Methods ◽  
Diffusion Assay

Bacteriocins are antimicrobial proteins produced by bacteria that inhibit with a bactericidal or bacteriostatic mode of action, the growth of other bacteria. Many lactic acid bacteria (LAB) produce a high diversity of different bacteriocins. Bacteriocinogenic LAB are generally recognized as safe (GRAS) and useful to control the frequent development of pathogens and spoilage microorganisms; for this reason they are commonly used as starter cultures in food fermentations. In this study, the authors describe the results of a screening on 699 LAB isolated from wooden vat surfaces, raw milk and traditional Sicilian cheeses, for the production of bacteriocin-like inhibitory substances (BLIS), by comparing two alternative methods. The antagonistic activity of LAB and its proteinaceous nature were evaluated using the <em>spot on the lawn</em> and the <em>well-diffusion assay</em> and the sensitivity to proteolytic (proteinase K, protease B and trypsin), amylolytic (α-amylase) and lipolytic (lipase) enzymes. The indicator strains used were: <em>Listeria monocytogenes</em>, <em>Staphylococcus aureus</em>, <em>E. coli</em>, <em>Salmonella enteritidis</em>. A total of 223 strains (belonged to the species <em>Enterococcus</em> spp., <em>Lactobacillus</em> spp., <em>Pediococcus</em> spp., <em>Streptococcus</em> spp., <em>Leuconostoc</em> spp. and <em>Lactococcus lactis</em>) were found to inhibit the growth of <em>Listeria monocytogenes</em> by using the <em>spot on the lawn</em> method; only 37 of these were confirmed by using the well-diffusion assay. The direct addition of bacteriocin-producing cultures into dairy products can be a more practical and economic option for the improvement of the safety and quality of the final product.

Microbiological Study of León Raw Cow-Milk Cheese, a Spanish Craft Variety

1995 ◽  
Vol 58 (9) ◽  
pp. 998-1006 ◽  
Author(s):  
MARIA L. RODRIGUEZ MEDINA ◽  
MARIA E. TORNADIJO ◽  
JAVIER CARBALLO ◽  
ROBERTO MARTIN SARMIENTO
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Starter Culture ◽  
Raw Milk ◽  
Point Of View ◽  
Starter Cultures ◽  
Cow Milk ◽  
Sampling Point ◽  
Organoleptic Characteristics ◽  
Microbial Groups

The levels of several microbial groups (aerobic mesophilic flora, aerobic psychrotrophic flora, lactic acid bacteria, Micrococcaceae, enterococci, Enterobacteriaceae, and molds and yeasts), and some biochemical parameters were investigated during the manufacture and ripening of four batches of León cow cheese produced from raw milk without the addition of starter cultures. The study of the microbial characteristics of this cheese constitutes the first step towards the establishment of a starter culture which would allow the making of a product both more uniform and safer from the point of view of health. The total microbial counts were high throughout the elaboration and ripening. Almost all the microbial groups reached their maximum counts in curd and afterwards dropped throughout the ripening process. The greatest drop was shown by Enterobacteriaceae, which had disappeared after 3 months of ripening. Lactic acid bacteria were the major microbial group, reaching counts similar to the total aerobic mesophilic flora at all sampling points. Lactococcus lactis subsp. lactis dominated in milk (62.5% of the isolates obtained in de Man-Rogosa-Sharpe (MRS) agar at this sampling point), curd (82.5% of the isolates obtained at this sampling point) and one-week-old cheese (85% of isolates obtained at this sampling point), while Lactobacillus casei subsp. casei was the most predominant species in eight-week-old cheese (55% of isolates obtained at this sampling point) and twelve-week-old cheese (47.5% of isolates obtained at this sampling point). According to our data, a starter suitable for the production of León cow cheese would be made up of these two species. Some species of Leuconostoc or enterococci could also be added to this starter with the aim of improving the organoleptic characteristics of the final product or to emphasize the characteristics of this variety.

scholarly journals RAW COW MILK AS A POTENTIAL SOURCE OF BENEFICIAL LACTIC ACID BACTERIA (LAB)

2021 ◽  
Vol 4 (1) ◽  
pp. 37-39
Author(s):  
Kokila Muniyandi ◽  
Ganesh Punamalai ◽  
Nandhini Chandrasekaran ◽  
Yoganathan Kamaraj
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Raw Milk ◽  
Cow Milk ◽  
Isolation And Identification ◽  
Good Source ◽  
Milk Samples ◽  
Naturally Occurring ◽  
Potential Source ◽  
The Many

Milk itself is also considered to be one of the nature habitats of the LAB, It contains the many other nutrients and including protein and lactose. The aim of the research was a isolation and identification of naturally occurring lactic acid bacteria from cow raw milk. A total of ninety isolates of lactic acid bacteria were collected of which seven genera belonging to Lactobacillus (29.32%), Lactococcus (23.68%), Leuconostoc (21.09%), Streptococcus (12.09%), Aerococcus (9.09%), Pediococcus (17.09%) and Enterococcus (12.09%) were identified. Leuconostoc, Enterococcus, Pediococcus, Lactococcus, and Aerococcus were cocci and rod shape of Lactobacillus. In the current study, Lactobacillus (29.32%) was the main genera of lactic acid bacteria identified from cow raw milk samples. We can conclude from this research that raw cow milk is a good source of healthy lactic acid bacteria.

scholarly journals Effect of Different Farming Practices on Lactic Acid Bacteria Content in Cow Milk

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 522
Author(s):  
Luciana Bava ◽  
Maddalena Zucali ◽  
Alberto Tamburini ◽  
Stefano Morandi ◽  
Milena Brasca
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Management Practices ◽  
Negative Impact ◽  
Raw Milk ◽  
Cow Milk ◽  
Plate Count ◽  
Farming Practices ◽  
Grana Padano ◽  
Bacterial Groups

The natural load of lactic acid bacteria (LAB) in milk is the basis of the production of raw milk cheeses, such as Grana Padano PDO. In the last decades, improvements in livestock hygiene management resulted in bulk cow milk with less than 20,000 colony forming units (CFU) of bacterial count, unable to ensure a sufficient supply of LAB, with a negative impact on cheese quality. This study investigated the relations between farm management practices and prevalence of different groups of bacteria in cow milk. Sixty-two intensive dairy farms located in Lombardy (Italy) where involved, most of them destined as milk for the production of Grana Padano. Season had no significant effect on the content of most of the bacterial groups, except for coliforms. A strong relation among standard plate count (SPC) and other bacterial groups was evidenced. Cluster analysis showed that the most productive farms applied a complete milking routine and produced milk with the lowest value of SPC, the lowest count of the other bacteria, including LAB, but the highest LAB/SPC. The study suggests that complexity of farming practices can affect the microbial population of milk.

Evaluating the technological properties of lactic acid bacteria in Wagyu cattle milk

2021 ◽  
pp. 1-7
Author(s):  
Harutoshi Tsuda ◽  
Kana Kodama
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Raw Milk ◽  
Starter Cultures ◽  
Technological Properties ◽  
Mature Milk ◽  
16S Rdna Sequence Analysis ◽  
Physiological And Biochemical Characteristics ◽  
Fermented Dairy Products ◽  
Fermented Dairy

Abstract This paper reveals the technological properties of lactic acid bacteria isolated from raw milk (colostrum and mature milk) of Wagyu cattle raised in Okayama Prefecture, Japan. Isolates were identified based on their physiological and biochemical characteristics as well as 16S rDNA sequence analysis. Streptococcus lutetiensis and Lactobacillus plantarum showed high acid and diacetyl-acetoin production in milk after 24 h of incubation at 40 and 30°C, respectively. These strains are thought to have potential for use as starter cultures and adjunct cultures for fermented dairy products.

scholarly journals Production of Nigerian Yoghurt Using Lactic Acid Bacteria as Starter Cultures

2020 ◽  
pp. 32-42
Author(s):  
S. Aforijiku ◽  
S. M. Wakil ◽  
A. A. Onilude
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Proximate Composition ◽  
Room Temperature ◽  
Starter Cultures ◽  
Cow Milk ◽  
Spontaneous Fermentation ◽  
Overall Acceptability ◽  
Fermentation Control ◽  
Better Than

Aim: This work was carried out to investigate the influence of Lactic Acid Bacteria (LAB) on organoleptic quality and proximate composition of yoghurt, and viability of starter cultures in yoghurt. Methods: The LAB starter cultures were selected based on their ability to produce diacetyl and lactic acid. Results: Lactobacillus caseiN1 produced the highest quantity (2.72 g/L) of diacetyl at 48 hrs of incubation while Pediococcus acidilacticiG1 had the lowest amount (0.50 g/L). The pH of produced yoghurt ranged between 4.40 and 5.58 while the corresponding lactic acid contents ranged between 0.70 and 0.96 g/L. Yoghurt produced with cow milk inoculated with L. PlantarumN24 and L. BrevisN10 had the lowest pH (4.40) at significant level of P≤0.05. Yoghurt with mixed culture of L. PlantarumN24 and L. PlantarumN17 had the highest protein content (5.13%) while spontaneous fermentation (control) produced the least (0.48%). Yoghurt produced from cow milk inoculated with L. PlantarumN24 and L. PlantarumN17 was rated best with overall acceptability (9.0) during first day of storage while the commercial yoghurt (5.8) and spontaneous fermentation (6.8) had least overall acceptability at P≤0.05. Conclusion: Yoghurt samples stored in refrigerator had more viable LAB counts for a period of 21 days while the samples stored at room temperature had a day count except for yoghurt produced with cow milk inoculated with L. plantarumN24 which retained its viability at the second day. The yoghurt produced with selected LAB starters are better than commercial yoghurt in terms of sensory properties, proximate composition, pH and viability.

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