In this study, a total of 21 coccoid forms of lactic acid bacteria (lactococci) were isolated from Turkish kefir samples. As a result of the identification tests, 21 lactococci isolates were ...identified as
Lactococcus cremoris (11 strains),
Lactococcus lactis (4 strains),
Streptococcus thermophilus (3 strains) and
Streptococcus durans (3 strains). The amount of produced lactic acid, hydrogen peroxide, proteolytic activity, diacetyl and acetaldehyde productions of the lactococci were determined. Different amounts of lactic acid were produced by strains studies; however, lactic acid levels were 2.3–9.9
mg/ml. While
Lac. lactis Z13S,
Str. durans Z7S, Z8S, Z15S,
Lac. cremoris Z9S, Z16S, Z17S, Z19S, Z20S and Z21S strains were not shown hydrogen peroxide,
Lac. lactis Z1S and Z2S strains had a maximum hydrogen peroxide (0.17
μg/ml).
Lac. lactis Z2S, Z3S,
Str. thermophilus Z5S, Z12S,
Str. durans Z7S, Z8S,
Lac. cremoris Z14S and Z16S strains were not show proteolytic activity,
Lac. cremoris Z20S strain produced the maximum amount (0.09
mg/ml) of proteolytic activity. Acetaldehyde concentration produced in
Lactobacillus strains ranged between 0.18 and 3.96
μg/ml. Antimicrobial effects of the lactococci on
Escherichia coli NRLL B-704,
Staphylococcus aureus 4-63,
Pseudomonas aeruginosa ATCC 29212 were also determined by an agar diffusion method. All of the strains were able to inhibit
S. aureus, while
Lac. lactis Z1S, Z2S and
Lac. cremoris Z6S strains were able to inhibit
E. coli and
P. aeruginosa. Also,
Str. thermophilus Z5S strain were able to inhibit
P. aeruginosa.
Inhibitory effect of cell-free filtrates of Lactobacillus bulgaricus (6 strains), L. casei (4 strains), L. plantarum (2 strains), L. acidophilus (2 strains), L. brevis (2 strains), L. fermentum (1 ...strain), L. lactis (1 strain), and L. helveticus (1 strain) isolated from Turkish dairy products were determined against test bacteria (Staphylococcus aureus, Escherichia coli, Yersinia enterocolitica). All strains showed antimicrobial activity against test bacteria. Bacteriocin-like substances producing strains were determined under conditions eliminating the effects of organic acids and hydrogen peroxide. As a result, it was observed that inhibitory activities of three strains were due to bacteriocin-like substances. They were resistant to heat (100°C for 10 and 20min). The inhibitory activity of bacteriocin-like substances was not lost after 10 and 20min at 100°C. The inhibition observed in these studies could not have been due to the probable hydrogen peroxide production, since it was unaffected by catalase. The purified bacteriocin-like substances were identified as 29kDa peptide by sodium dodecyl sulfate-polyacrylamide gel (SDS-PAGE). Molecular weights of bacteriocin-like substances were found the same in all three strains. This bacteriocin-like substances might be useful as a natural preservative.
This study was designated to evaluate the antimicrobial activity of the essential oils obtained from the aerial parts of Origanum minutiflorum and Sideritis erytrantha, both endemic species in ...Turkey, against 19 plant pathogenic bacteria. Two essential oils were analyzed by GC-FID and GC/MS. The major components of O. minutiflorum oil were carvacrol (73.93%) and p-cymene (7.20%). The essential oil of O. minutiflorum exhibited an extremely strong activity against tested plant pathogenic bacteria such as Agrobacterium spp., Erwinia spp., Rathayibacter spp., Xanthomonas spp., Clavibacter sp. and Curtobacterium sp., but did not show any antimicrobial activity against Pseudomonas spp. The minimum inhibitory concentration (MIC) values for bacterial strains which were sensitive to the essential oil of O. minutiflorum and S. erytrantha subsp. erytrantha were in the rage of 125-400 µg/mL and 300-500 µg/mL, respectively.
Mesophilic aeromonads are among the most common bacteria in water habitats throughout the world, and these bacteria frequently cause disease in fishes. They are also causative agents of acute ...diarrheal disease in man following ingestion water. In this study, a total of 132 market fish (64 freshwater and 68 seawater) samples representing were collected in Ankara (Turkey) and investigated for the presence of Aeromonas spp. They were isolated from 106 (80.3%) out of the 132 fish samples tested. The distribution of Aeromonas spp. varied depending on the samples (gill, intestine, liver, kidney) examined. In freshwater samples, the predominant species was A. caviae (66.0%), followed by A. hydrophila (22.6%) and A. veroni bv. sobria (11.6%). In seawater samples, the predominant species was found A. veroni bv. sobria (41.5%), followed by A. hydrophila (30.1%) and A. caviae (28.3%). The 132 isolated Aeromonas spp. strains were further examined for hemolytic, lipolytic and proteolytic activity. Of the present isolates, more than 80% (A. veroni bv. sobria, A. hydrophila) were positive for hemolysin activities. Lipolytic and proteolytic activity of identified strains were found in more lower incidence. All aeromonads (A. hydrophila, A. veroni bv. sobria, A. caviae) strains showed resistance to ampicillin, cephalothin and trimethoprim. The least resistance was found for chloramphenicol (9.0%). In contrast, all the strains were susceptible to ciprofloxacin and ceftriaxone. In Turkey, there have been few studies on Aeromonas and its virulence factors. This study therefore highlights an important incidence of Aeromonas spp., with virulence and antibiotic resistance, isolated from fish intended for human consumption in Turkey.
Russula delica Fr. is a well known macrofungi which is used as a food in Turkey. The ethanolic extract of
R. delica exhibited antimicrobial activity against some of the tested foodborne and spoilage ...bacteria. The phenolic composition of
R. delica ethanolic extract was analyzed by high performance liquid chromatography (HPLC). The major component in
R. delica ethanolic extract was catechin (5.33
mg/L). Antioxidant activities of the ethanolic extract of
R. delica was evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging and chelating ability on ferrous ions assays. Scavenging effect on DPPH radicals was 26% at 10
mg/ml and chelating effects on ferrous ions was 58% at 5
mg/ml. In addition, the amounts of total phenol content (6.23
mg/g), ascorbic acid (2.93
mg/g), β-carotene (0.11
mg/g) and lycopene (0.03
mg/g) in the macrofungi ethanolic extract were determined.
In this study, isolation and characterization of exopolysaccharides produced by
Pseudomonas aeruginosa B1,
P. fluorescens B5,
P. stutzeri B11 and
P. putida B15 which had been seen to produce ...exopolymers of potential interest in biotechnological applications were examined. To initiate the observation of the organic pollutants–polymer interactions, the yield and properties of their extracellular polysaccharide were researched. The exopolysaccharide production by these strains during growth in nutrient broth medium (control) was 41–75
mg
L
−1. Also,
P. aeruginosa B1,
P. fluorescens B5,
P. stutzeri B11 and
P. putida B15 had exhibited high production of EPSs in presence of various organic pollutants (2,4-D, benzene, BTX and gasoline, respectively) in mineral salt medium (MSM) as a sole carbon source. EPS production by the 4 strains ranged from 40
mg
L
−1 to 8
mg
L
−1. Monosaccharide composition of EPS produced by these cultures were analyzed by HPLC. Results indicated that EPSs of strains contained neutral sugars and acetylated amino sugars. The neutral sugars in the EPS were mainly composed of glucose, arabinose, glycerol, ribose. The presence of galactronic acid,
N-acetyl-
d-galactosamin and
N-acetyl-
d-glucosamine indicated the acidic nature of the polysaccharide. Glycerol was the basic structural unit of EPS produced by the strains except
P. stutzeri B11 (MSM with 1% BTX). Strain B1 (in NB medium) was found to be composed of neutral sugars (100%) while strain B1 in MSM medium with 0.2% (v/v) 2.4-D contained neutral sugars (70.0%), acetylated amino sugars (30.0%). Also, EPS content of strain B5 (in the NB medium) was neutral sugars (99.8%), acetylated amino sugars (0.2%) while the strain B5 in MSM medium containing the 1% (v/v) benzene was found to contain neutral sugars (99.9%), acetylated amino sugars (0.1%). However, EPS monomer composition by strain B11 was detected as neutral sugars (99.77%), acetylated amino sugars (0.23%) in NB medium while the strain B11 in MSM medium with 1% (v/v) BTX contained neutral sugars (98.2%) and acetylated amino sugars (1.8%). Lastly, in NB medium by strain B15 was found to contain neutral sugars (99.9%) and acetylated amino sugars (0.1%) while in MSM medium in the presence of 1% (v/v) gasoline it was found to contain neutral sugars (83.6%), acetylated amino sugars (16.4%). Monomer composition of control EPSs changed to different structures in the presence of various organic pollutants. Diversities of organic compounds as carbon source affected the monomer composition of EPS produced by some
Pseudomonas spp. cultures.
In this study, exopolysaccharides (EPSs) production was investigated by growing strains of
Pseudomonas aeruginosa G1 and
Pseudomonas putida G12 in medium containing various carbon sources such as ...glucose, mannose, fructose, and xylose. EPS production (192 and 182
mg/L, respectively) of these strains grown in PAP medium with 2% glycerol (v/v) was used as control. The highest EPS production of the two strains was found in the xylose containing medium. The effect of different concentrations 2–6% (w/v) of xylose on EPS production of both strains was also studied. The maximum EPS yield (368
mg/l
−1) of the strain G1 was recorded in 3% (w/v) xylose, while the highest yield EPS yield (262
mg/L
−1) of the strain G12 was recorded in 2% (w/v) xylose. The monosaccharide compositions of EPS produced by the two strains were analyzed by HPLC. Strain G1 2% (w/v) glycerol was found to compose of neutral sugars (92.0%), acetylated amino sugars (8.0%), while strain G1 3% (w/v) xylose contained neutral sugars (99.2%), acetylated amino sugars (0.8%). However, the composition of strain G12 2% (w/v) glycerol was neutral sugars (96.8%), acetylated amino sugars (3.2%) and the strain G12 2% (w/v) xylose was found to contain neutral sugars (96.1%), acetylated amino sugars (3.9%).
This work describes the use of template synthesis to fabricate multifunctional composite silica nano test tubes for targeted drug delivery. The tubular nanostructures were formed within nanoporous ...anodized alumina templates and their inner voids were filled with a drug-bearing gel matrix while the test tubes were embedded within the template. Upon template removal, the composite nanocarriers were biofunctionalized with a targeting moiety towards breast cancer cells. The results show that targeting is critical in inducing cell death and the targeted nanocarriers are extensively more cytotoxic towards cancer cells compared with healthy controls.
This study evaluated the antimicrobial activities of an essential oil of
Origanum minutiflorum (O. Schwarz and P.H. Davis) against ciprofloxacin-resistant
Campylobacter spp., by broth microdilution ...and agar well-diffusion methods. Moreover,
O. minutiflorum oil was analyzed by gas chromatography/mass spectrometry (GC/MS). Twenty-nine components were identified, representing 98.7 of the oil. The oil yield from the plants was 4.0–4.4%
v/w. The major components of
O. minutiflorum oil were carvacrol (73.9%) and
p-cymene (7.20%). The oil has lower contents of carvacrol methyl ether (0.05%), heptadecanol (0.06%) and carvacryl acetate (0.06%). Twenty-one
Campylobacter spp. (12
C. jejuni, 5
C. lari and 4
C. coli) strains using in this study were selected among 300 isolates according to their resistance to ciprofloxacin. The minimum inhibitory concentration (MIC) values for bacterial strains, which were sensitive to the essential oil of
O. minutiflorum, were in the range of 7.8–800
μg/ml. The essential oil obtained showed strong antimicrobial activity against all of the tested ciprofloxacin-resistance
Campylobacter spp. These results suggest that the essential of
O. minutiflorum may be used as a natural preservative in food against food-born disease, such as Campylobacteriosis.
Glaucium species (Papaveraceae) are the medicinal plant that has been used traditionally to have been used for centuries to treat memory impairment. The aim of this study is to investigate the G. ...acutidentatum methanol and water extracts' phytochemicals and neuroprotective, anti-inflammatory, anti-mutagenic and anti-genotoxic potentials.
Chemical composition was screened by using capillary gas chromatography–mass spectrometry (GC–MS). Neuroprotective effect was analyzed on nerve growth factor (NGF) differentiated-PC12 (dPC12) cells from neuroinflammation and neurodegeneration. Also, these extracts were screened for the mutagenic and anti-mutagenic activity by the Salmonella/microsome test system. In addition, genotoxic profiles and anti-genotoxic effects of these extracts were also analyzed by Comet technique.
Extracts of G. acutidentatum had strong neuroprotective effects against hydrogen peroxide (H2O2)-induced damage. Also, neurite length was dose-dependently increased in extracts exposed groups compared with the H2O2-treated group. The anti-inflammatory effect of these extracts was parallel to neuroprotective effect. However, these extracts showed strong anti-mutagenicity (72.9–75.0%) and anti-genotoxic properties. Any genotoxic effect was observed of these extracts in lymphocyte cells, analyzed by the Comet assay.
These results suggest that methanol and water extracts of G. acutidentatum had neuroprotective and anti-mutagenic effects and contained protective substances that decreasing damage to genetic material.
•G. acutidentatum methanol and water extracts show neuroprotective activity.•G. acutidentatum methanol and water extracts show anti-inflammatory effect.•G. acutidentatum methanol and water extracts show anti-mutagenic effect.•G. acutidentatum methanol and water extracts show anti-genotoxic effect.
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