scholarly journals Occurrence of Enterocin Genes in Enterococci from Slovak Milk Product Žinčica

2019 ◽  
Vol 50 (3) ◽  
pp. 197-202 ◽  
Author(s):  
A. Lauková ◽  
V. Strompfová ◽  
M. Tomáška ◽  
M. Kološta

Abstract Žinčica is a popular Slovak dairy product made from ewes’ milk. It is a by-product resulting during ewes’ lump cheese processing. Microbiota in Žinčica have rarely been studied, especially enterococci; however, they can produce beneficial substances – bacteriocins. In this study, the presence of Enterocins (Ents) genes were analysed in enterococci from Žinčica and partially also the inhibition activity. Samples of Žinčica were collected from different agrofarms producing ewes’ lump cheese (34) in Central Slovakia. In the enterococci tested, Ent P gene was the most frequently detected (in 6 out of 7 enterococci), followed by Ent A and Ent L50B genes. Ent B gene was detected only in E. faecium 30E1. On the other hand, E. faecalis 31E2 did not contain Ent genes, although it showed inhibition activity against the indicator strains Enterococcus avium EA5, Staphylococcus aureus SA5, Listeria monocytogenes CCM4699 (inhibition zone sizing up to 20 mm). E. faecium 30E1 contained genes of four Ents; however, it showed no inhibition activity. Growth of the four indicators was inhibited due to the antimicrobial activity of E. faecium 32E1 with Ent P gene detection. This is the first study reporting on the occurrence of Ent genes in enterococci from Žinčica.

2013 ◽  
Vol 1 (01) ◽  
pp. 38-43
Author(s):  
G. Ramakrishnaiah ◽  
T. Hariprasad

In the present study we investigated antimicrobial activity of diethyl ether and methanol extractions of bark and leaves of Ficus religiosa plant against three bacteria (E.coli, Staphylococcus aureus and Pseudomonas aurignosa) and one fungi (Aspergillus niger). The results showed that the methanol extracts of both leaves and bark showed antimicrobial activity on three tested bacteria and no effect on A.niger. In methanol extracts S.aureus showed maximum sensitivity (inhibition zone 28mm) followed by E.coli (inhibition zone 16mm) and Pseudomonas aeruginosa (inhibition zone 12mm). Diethyl ether extracts of leaves were also showed maximum inhibition on S.aureus followed by E.coli and P.aeruginosa. Both methanol and diethyl ether extracts of bark showed antimicrobial activity on three types of tested bacteria and very less inhibition activity on A.niger. But comparatively bark extracts of both the solvents were showed less antimicrobial activity than leaves extracts on the tested microbes.


2015 ◽  
Vol 1 (2) ◽  
pp. 126
Author(s):  
Urnemi ◽  
Sumaryati Syukur ◽  
Endang Purwati ◽  
Sanusi Ibrahim ◽  
Jamsari

ABSTRACT Lactic acid bacteria (LAB) were isolated from of cocoa beans fermentation Forestero variety from West Sumatera, that were eleven isolates. The isolates were tested to antimicrobial activity against pathogenic bacteria E.coli NBRC 14237, Staphylococcus aureus NBRC 13276, Bacillus subtilis BTCCB 612, listeria m. dan S. Typhii. Results the research showed that, isolates had inhibition zone to pathogenic bacteria, that were 7 mm till 12 mm at 48 hours observation. R2.4 isolate was most potential to inhibition zones growth pathogenic bacteria, that was 11mm till 12 mm to five pathogens. R2.4 isolates was the highest to against pathogenic bacteria (Bacillus subtilis BTCCB, Listeria monocytogenesis and Staphylococcus aureus NBRC) had inhibition zones, that was 12.00 mm till 48 hours. Listeria monocytogenesis had been known as pest bacterium of food born, so that R2.4 isolate can be used as food biopreservative. Crude of R2.4 isolate molecular weight was 10 kDa by SDS-PAGE.  Key words: Lactic acid bacteria, Antimicrobial activity, SDS-PAGE, Cocoa fermentation and food biopreservative                                                      


BioScience ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 79
Author(s):  
Nada Nafion ◽  
Dwi Hilda Putri ◽  
Irdawati Irdawati

Cases of bacterial resistance to antibiotics are discussed with serious problems in the world of health. New antimicrobial compounds are needed which are more effective in treating infectious diseases. Isolate B.J.T.A-6 is an endophytic bacteria from Andalas plants (Morus macroura Miq.) which is known to be able to produce antimicrobial active compounds. Antimicrobial compounds can be produced by growing them on fermented media. The purpose of this study was to optimize the medium fermentation of Andalas endophytic bacteria of B.J.T.A-6  isolates in producing antimicrobial compounds. While medium fermentation is Nutrient Broth (NB), Muller Hinton (MH), and Luria Bertani Broth (LB). Antimicrobial activity tests were carried out by means of diffusion. The parameters used were the diameter of the inhibition zone against Staphylococcus aureus around the disc paper. The profile of medium fermentation optimization was analyzed statistically. The results showed that B.J.T.A-6  isolates could inhibit the highest growth of S. aureus by using LB fermentation medium. 


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9656-9671
Author(s):  
Akram Sabzikar ◽  
Seyyed Khalil Hosseinihashemi ◽  
Younes Shirmohammadli ◽  
Abbas Jalaligoldeh

Different concentrations of ethanolic extracts of thyme (Zataria multiflora) and rosemary (Rosmarinus officinalis) were evaluated to determine their antimicrobial activity using the agar-well diffusion method. The values of inhibition zone diameter (IZD) for Candida albicans fungus and Staphylococcus aureus Gram-positive bacteria were determined. The bioactivities of two various extracts were studied, and the chemical composition of the extracts were identified using gas chromatography-mass spectrometry (GC-MS) technique. The results of the test showed that at concentrations of 10% and 40% thyme extract, the values of IZD were 12.5 mm and 23.3 mm, respectively, against the growth of S. aureus, which were higher than C. albicans (7.0 mm and 22.5 mm, respectively). The rosemary extract at concentrations of 20% and 60% showed lower antibacterial activity against S. aureus (4.7 mm and 8.7 mm IZD, respectively) and lower antifungal activity against C. albicans (12.2 mm and 1.7 mm IZD, respectively). At a concentration of 40% thyme extract, the highest antibacterial (23.3 mm IZD) and antifungal (22.5 mm IZD) activities were observed. The GC/MS analysis showed that carvacrol (52.3%), linalool L (16%), and thymol (9.6%) were the main components of thyme extract, while in the rosemary extract β-amyrone (18.0%), verbenone (8.0%), and 1,8-cineole (7.26%) were the major constituents.


2012 ◽  
Vol 30 (No. 4) ◽  
pp. 330-335 ◽  
Author(s):  
K. Trivedi ◽  
R. Sedmíková ◽  
R. Karpíšková

In total 228 enterococci strains isolated from food were studied. Enterococcus faecalis, E. faecium, and E. casseliflavus were found to be the dominant strains while E. durans and E. mundtii were present in a smaller extent. Antimicrobial activity determined by double layer technique revealed that 150 (65.7%) strains showed antimicrobial activity against the individual tested pathogenic strains of Listeria monocytogenes, Staphylococcus aureus, and methicilin resistant S. aureus (MRSA). Cell-free neutralised supernatants (CFNS) were prepared from 150 potential bacteriocin producers. Of these 150, CFNS 107 (71.3%) strains were active in the bacteriocin production against one or more pathogenic strains tested. S. aureus and MRSA were found to be more sensitive to the antimicrobial substances than L. monocytogenes. Multiplex PCR for the detection of seven virulence genes in bacteriocin producing strains showed that 47.6% of strains were able to amplify one or more virulence genes. E. faecalis was the most virulent species. The presence of tyrdc gene was seen in all bacteriocin producing strains. None of the strains carried genes encoding the resistance to vancomycin.  


2019 ◽  
Vol 8 (4) ◽  
Author(s):  
Francesca Pedonese ◽  
Giada Verani ◽  
Beatrice Torracca ◽  
Barbara Turchi ◽  
Antonio Felicioli ◽  
...  

Propolis antimicrobial activity has been limitedly studied in food, particularly in dairy products. We studied the antimicrobial activity of an alcoholic extract of an Italian propolis in sterile skim milk, pasteurized cow’s milk, and cow’s and goat’s whey cheese (ricotta). Following the determination of the minimal inhibitory concentration on Gram+ and Gram- bacteria, the extract was employed at 2 and 5% (P2, P5), using controls with the same ethanol concentrations (E2, E5) and without any addition. In milk trials, Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, and Pseudomonas fluorescens were tested. P2 and P5 samples registered significant decreases of Gram+ bacteria in skim milk. The same was true for P5 in cows’ milk, but only with S. aureus for P2. Ricotta was inoculated with L. monocytogenes, S. aureus and B. cereus and stored at 8.5°C. In cow’s milk ricotta, L. monocytogenes counts in P5 were always lower than control during the storage time, significantly so from the 14th day. In goat’s ricotta, L. monocytogenes counts in P5 were at least one logarithm lower than E5, whereas the extract didn’t show a significant effect on S. aureus and B. cereus. The antimicrobial activity of propolis, particularly on L. monocytogenes, could be employed in ready-to-eat refrigerated dairy products.


2019 ◽  
Author(s):  
N. Halla ◽  
K. Boucherit ◽  
B. Zeragui ◽  
D. Hellal ◽  
A. Bentoumi ◽  
...  

The aim of this work was to investigate the essential oil of Artemisia judaica L. (ssp. Sahariensis) originated from south of Algeria by evaluating its antimicrobial activity as well as its mechanisms of action against bacterial and fungal microorganisms. The antimicrobial activity was evaluated against 17 microbial strains. The mechanisms of action of Artemisia judaica essential oil (AJEO) have been studied by the evaluation of the release of cellular material (260 nm), the cell viability, the activity of lipase, and the salt tolerance. The AJEO yield was 1.27 ± 0.24% (w/w). The chemical composition of AJEO was characterized by a high content of piperitone (71.1%). The most sensitive bacterium was Staphylococcus aureus with an MIC of 2.73 mg/mL. AJEO was found to be enough to kill strains tested at least 40% after thirty seconds of incubation and to induce release of cellular material. On the other hand, AJEO showed complete inhibition of lipase activity of Candida albicans cells as well as the ability of cells to form colonies on saline medium. AJEO has a powerful antimicrobial activity against different microbial organisms with different mechanisms of action. AJEO seem to be useful in pharmaceutical, food, and cosmetic application.


2007 ◽  
Vol 70 (5) ◽  
pp. 1267-1271 ◽  
Author(s):  
HUDAA NEETOO ◽  
MU YE ◽  
HAIQIANG CHEN

Plastic films were coated with a cellulose-based carrier solution containing nisin, a natural antimicrobial peptide with the potential to inhibit growth of food spoilage and pathogenic microorganisms such as Listeria monocytogenes. Five commercial plastic films with different chemical compositions and surface properties were compared in this study: low-density polyethylene, ethylene–vinyl acetate copolymer, and three types of ethylene–methacrylic acid copolymers: Surlyn 1601, Nucrel 0403, and Nucrel 0903. The films were coated with nisin at a concentration of 1,000 IU/cm2. Nisin-coated films were stored at room temperature (21°C) and at 4°C and analyzed weekly for 12 weeks. Antimicrobial activity of the different nisin-coated films against a nisin indicator strain, Lactococcus lactis subsp. cremoris ATCC 14365, and against L. monocytogenes ATCC 19115 was assessed using an inhibition zone assay. Nisin incorporated into the films was recovered by a boiling and extraction procedure, and its activity was quantified using an agar well diffusion assay. Film type did not have any significant effect on the antimicrobial activity of the nisin-coated films (P < 0.05); all five film types had comparable inhibition zones on both assays. The films maintained stable activity for the duration of the study, both at room temperature and refrigeration. The results of this study demonstrate that commercially available packaging films can be coated with nisin and the resulting antimicrobial films can be conveniently stored at room temperature with no adverse effect on nisin activity.


2003 ◽  
Vol 58 (11-12) ◽  
pp. 850-854 ◽  
Author(s):  
Ayşen Özdemir Türk ◽  
Meral Yılmaz ◽  
Merih Kıvanç ◽  
Hayrettin Türk

Abstract In this study, the antimicrobial activity of the acetone, diethyl ether and ethanol extracts of the lichen Cetraria aculeata has been investigated. The extracts were tested against twelve bacteria and eight fungi and found active against Escherichia coli, Staphylococcus aureus, Aeromonas hydrophila, Proteus vulgaris, Streptococcus faecalis, Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa, Listeria monocytogenes. No antimicrobial activity against the fungi was detected. It was determined that only one substance in the extracts has antimicrobial activity and it was characterized as protolichesterinic acid. The MICs of the extracts and protolichesterinic acid were also determined.


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