In this paper, the effect of different temperatures, pH, and NaCl concentration on the growth of autochthonous lactic acid bacteria isolated from traditionally made Serbian cheese (Sokobanja area) ...was investigated by using the spectrophotometric method. Growth of tested Lactobacillus (Lb. fermentum, Lb. plantarum, and Lb. brevis) and Lactococcus lactis subsp. lactis biovar. diacetylactis five isolates were better in acidic pH, while the growth of Enterococcus isolates (E. durans, E. faecium, and E. faecalis) was better in basic pH, at 37 °C. At 4 °C after 24 h, none of the tested bacteria showed growth. Since the autochthonous isolates were tolerant to a tested range of dairy processing conditions, further studies need to include the characterization of enzymatic activity of selected isolates, as well as the ability to use these isolates like starter cultures or food supplements in dairy or non-dairy products.
The purpose of this study was the investigation of the growth ability of lactic acid bacteria (LAB), isolated from traditionally made cheese from Southeastern Serbia, in the presence of different ...percent of sugars and sugar substitutes (fructose, lactose, inulin, and mannitol). Dextrose was included for comparative purposes. The results indicated that fructose and lactose stimulated the growth of Lactobacillus strains, with exceptions of Lactobacillus plantarum KGPMF62 and Lb. plantarum LP 299v. Lactose showed similar effects like dextrose on the growth of Lactococcus strains, while higher growth rates of Enterococcus hirae KGPMF9, E. durans KGPMF10, E. faecium KGPMF14, and E. faecalis KGPMF47 were observed for lactose and mannitol. The results indicated the potential use of tested sugars and sugar substitutes as prebiotic compounds for the development of symbiotics with tested LAB, in medical or food industry.
Nine species (sixteen isolates) of lactic acid bacteria (LAB) isolated from traditionally made Serbian cheese were evaluated for their enzymatic activities in order to select indigenous strains of ...technical interest for the manufacture of cheese. These strains were selected based on their previously determined biochemical and physiological characteristics, as well as their antimicrobial activity, and were identified as Lactococcus lactis subsp. lactis (one isolate), Lc. lactis subsp. lactis biovar. diacetylactis (five isolates), Lactobacillus fermentum (two isolates), Lb. plantarum (one isolate), Lb. brevis (one isolate), Enterococcus faecalis (three isolates), E. faecium (one isolate), E. durans (one isolate) and E. hirae (one isolate). The enzymatic activities (acid and alkaline invertases, alkaline phosphatase, alkaline protease, a-amylase) were measured by using the spectrophotometric method. The results indicated that all Lactobacillus isolates showed protease, amylase, and alkaline phosphatase activities, while the activities of acid and alkaline invertases were not observed. The Lactococcus isolates showed protease, acid invertase and alkaline phosphatase activities, except the KGPMF50 isolate, which showed no alkaline phosphatase activity. The tested Enterococcus isolates showed weakly and strain-specific enzymatic activity. The results indicated that the enzymes produced by the investigated strains have a role in the formation of the specific flavor of cheese and that these isolates, especially Lactobacillus isolates, showed the potential for use in the dairy industry or applied biotechnology.
In this paper, we investigated, for the first time, the enzyme activity of enterobacteria from cheese from Southeastern Serbia (Sokobanja), which was produced in a traditional way. The tested ...bacteria were selected from the spring, summer, and autumn collections and grown in two different broths. The enzyme activity was investigated in the two broths and measured using spectrophotometry method. It was concluded that there were differences in the amount of extracellular enzymes depending on the broths. A statistically significant rise in the amount of enzymes was demonstrated in Tripton soy broth. Bacteria in cheese do not possess the ability to produce extracellular enzymes in large amounts. Therefore, they do not change the organoleptic characteristics of the cheese. There is a possibility that if they are found outside their natural environment (cheese), without interactions with antagonists, they may exhibit stronger enzyme activity.
This study observed the preliminary investigation of Oleum Hyperici, an original product made from Hypericum perforatum flowers, collected from Goč Mountain (Serbia). Some of the chemical properties ...(pH, the content of metals and metalloids - As, Cr, Pb, Cd, Ni, Hg) and the microbiological safety of the product including the total count of aerobic mesophilic bacteria, coagulase positive staphylococci, Escherichia coli, Pseudomonas aeruginosa, Proteus sp., as well as fungi: molds and yeasts) were evaluated. Antimicrobial activity of H. perforatum oil against 18 species of bacteria was determined using the disc diffusion and microdilution methods, by determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The antibiofilm activity of Oleum Hyperici was evaluated using the biofilm formation assay. The results indicated that oil did not contain potentially pathogenic microorganisms. Oleum Hyperici product showed the antimicrobial activity on the most of tested bacteria (inhibition zone was in a range from 14 - 24 mm), except on Klebsiella pneumoniae ATCC 70063, K. pneumoniae, E. coli ATCC 25922, P. mirabilis, Bacillus subtilis ATCC 6633 and B. subtilis IP 5832. According to the obtained results, tested bacteria (planktonic and biofilm form) showed sensitivity up to 10-2 dilution of Oleum Hyperici. Based on the obtained preliminary results, it could be concluded that Oleum Hyperici can be used in traditional medicine for development control of some potential human pathogens.
Objective
The objective of this study was to evaluate the probiotic potential as well as the ability of adhesion and aggregation of natural and autochthonous lactic acid bacteria, isolated from ...traditionally made cheese.
Results
Lactic acid bacteria from natural food sources can be promising probiotic candidates and they can be used in natural food preservation or like starter cultures. Tested autochthonous isolates showed tolerance to the simulated gastrointestinal condition as well as the sensitivity to clinically relevant antibiotics, especially to ampicillin (MIC at 0.195 μg mL
−1
for lactobacilli and from 0.195 to 3.125 μg mL
−1
for lactococci). Among isolates, the highest percentage of adhesion was detected with chloroform, while the adhesion ability of selected isolates to pig intestinal epithelium was in the correlation with the results of adhesion ability with solvents. The auto-aggregation ability of isolates was demonstrated, while co-aggregation with
Escherichia coli
was strain specific.
Conclusion
The results indicated the potential probiotic properties of the isolates and give evidence for further investigation and potential application in the dairy industry.
The series of pyrazolyl-phthalazine-dione derivatives (PPDs) was subjected to evaluation of their in vitro lipoxygenase (LOX) inhibition and antimicrobial activities. Results obtained for LOX ...inhibition activities of PPDs showed that all compounds exhibit good to excellent activity, whereby compounds with eudesmic, syringic, vanillic or toluic moiety are the most active. Molecular modelling study was performed to investigate the possible mechanism of action and binding mode of compounds within the LOX active site. Docking results revealed that activity of the examined compounds depends on the functional group ability to create hydrogen bond accepting (HBA) and hydrophobic features (Hy) in the LOX-Ib active site. In addition, all substances were tested for their antibacterial and antifungal activities. The investigated compounds showed better antifungal than antibacterial activity. The highest antifungal activity was on Aspergillus fumigatus ATTC 204305 and Trichoderma viridae ATCC 13233.
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•New coumarine derivatives and palladium(II) complexes were synthesized.•Characterized by microanalysis, infrared, 1H and 13C NMR spectroscopy and DFT methods.•In vitro antitumor ...activity for ligands and complexes is investigated.•In vitro antimicrobial activity for ligands and complexes is investigated.•Molecular docking studies with epidermal growth factor receptor (EGFR).
In the present manuscript, palladium(II) complexes (C1, C2) with newly synthesized coumarine ligands 3-(1-((3-chlorophenyl)amino)ethylidene)-chroman-2,4-dione (L1) and 3-(1-((4-chlorophenyl)amino)ethylidene)-chroman-2,4-dione (L2) were prepared and structurally characterized by spectroscopic techniques (FT-IR, 1H NMR, 13C NMR) in combination with elemental analysis and theoretical methods (DFT). The structures of all compounds were fully optimized using the B3LYP-D3BJ theoretical method. Cytotoxic activity of investigated compounds was tested against two cells lines (human colorectal carcinoma, HCT-116, and human fibroblast lung MRC-5), while their antimicrobial activity was screened against nine strains of pathogenic bacteria, five mould species and two yeast species. Unfortunately, their cytotoxic and antibacterial activities were weak. Docking studies for all compounds with epidermal growth factor receptor (EGFR) were performed. It was found that hydrophobic interactions that include chlorine atom have somewhat lower values of the pairwise interaction energies compared to the purely hydrophobic interactions. In addition, it was found the chlorine atom in the para position contributes to the slightly higher binding free energy and lower values of constant of inhibition.
Objective
The objectives of this research project were isolation, identification, and evaluation of the safety aspect and probiotics properties of 21
Enterococcus faecium
strains isolated from ...sausages originated from southeastern Serbia.
Results
Analyzed
E. faecium
isolates showed tolerance to simulated gastrointestinal conditions. All the examined isolates grew well on media with 0.1% and 0.2% of phenol. None of the tested isolates were histamine-producers, while the synthesis of tyramine was observed for
E. faecium
sk8-1 and sk8-17. Full resistance to antibiotics was not observed for any examined isolate of
E. faecium
(penicillin, amoxicillin, and ofloxacin showed the effect on all tested isolates). An inhibition zone against examined pathogens was exhibited by all strains, with the largest inhibition zone against
Pseudomonas
spp.,
Proteus
spp. and
E. coli
(12–30 mm/MIC values ranged from 0.5 to 12 mg mL
−1
).
Conclusion
The results indicated that
E. faecium
isolates from spontaneously fermented sausage showed a potential for further investigation and possible application as probiotics.
The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and ...Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA)/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru)/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+) bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide) viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells.
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