Antimicrobial screening of Mentha piperita essential oils

Essential oils of peppermint Mentha piperita L. (Lamiaceae), which are used in flavors, fragrances, and pharmaceuticals, were investigated for their antimicrobial properties against 21 human and plant pathogenic microorganisms. The bioactivity of the oils menthol and menthone was compared using the combination of in vitro techniques such as microdilution, agar diffusion, and bioautography. It was shown that all of the peppermint oils screened strongly inhibited plant pathogenic microorganisms, whereas human pathogens were only moderately inhibited. Chemical compositions of the oils were analyzed by GC and GC/MS. Using the bioautography assay, menthol was found to be responsible for the antimicrobial activity of these oils.     

Proteome profiling of the compatible interaction between wheat and stripe rust

Over the last decade, comparative molecular profiling studies between compatible and incompatible plant-pathogen interactions have shown that susceptible response of the host to a pathogen requires factors that promote disease development. In this study, we examined proteome profiles during a compatible interaction between wheat and stripe rust. A 2D-LC system (ProteomeLab PF2D) was used for protein separation and to compare the proteome from infected and control samples. More than 700 protein peaks at each time point were compared between pathogen- and mock-inoculated samples. Selected proteins, with significant differences in abundance were identified by nanoLC-ESI- MS/MS and generated spectra were searched against the wheat protein databases from UniProt, and NCBI and the Puccinia database from The Broad Institute. In total, the identified proteins comprised of 62 % wheat and 38 % Pst proteins. All identified proteins were searched by bioinformatics-based algorithms to detect their subcellular localization and signal peptide motifs which have the potential to catch the candidate effector proteins. The wheat proteins were classified based on their function. Although a compatible interaction, many wheat proteins, such as antioxidants, PRs and cold-responsive proteins, are implicated in defense and stress tolerance. On the pathogen side, 64 proteins were identified, and included some important pathogenicity proteins that can play role in pathogen virulence and suppress the host defense. In addition, we discovered that nine proteins have a signal sequence and three of the hypothetical fungal proteins, PGTG_11681T0, PGTG_07231T0 and CBH50687.1, have been tentatively identified as candidate effectors.     

Long‐term changes of aggregate‐associated and labile soil organic carbon and nitrogen after conversion from forest to grassland and cropland in northern Turkey

Soil management systems can have great effect on soil chemical, physical and biological properties. Conversion of forest to grassland and cropland can alter C and N dynamics. The objective of this study was to evaluate the changes in aggregate‐associated and labile soil organic C and N fractions after conversion of a natural forest to grassland and cropland in northern Turkey. This experiment was conducted on plots subject to three different adjacent land uses (forest, grassland and cropland). Soil samples were taken from 0–5, 5–15 and 15–30 cm depths from each land use. Some soil physical (soil texture, bulk density), chemical (soil pH, soil organic matter, lime content, total organic C and N, inorganic N, free and protected organic C) and biological (microbial biomass C and N, mineralizable C and N) properties were measured. The highest and lowest bulk densities were observed in grassland (1.41 g cm⁻³) and cropland (1.14 g cm⁻³), respectively. Microbial biomass C and total organic C in forest were almost twice greater than grassland and four‐times greater than cropland. Cultivation of forest reduced total organic N, mineralizable N and microbial biomass N by half. The great portion of organic C was stored in macroaggregates (>250 µm) in all the three land uses. Free organic C comprised smaller portion of soil organic C in all the three land uses. Thus, this study indicated that long‐term conversion of forest to grassland and cropland significantly decreased microbial biomass C, mineralizable C and physically protected organic C and the decreases were the greatest in cropland. Copyright © 2011 John Wiley & Sons, Ltd.     

Effect of Pregnancy and Foetal Number on Diameter of Corpus Luteum,Maternal Progesterone Concentration and Oxidant/Antioxidant Balance in Ewes

The aim of this study was to determine the changes in diameter of corpus luteum (CL), maternal progesterone (P) concentration, lipid peroxidation and non‐enzymatic antioxidant levels along with enzymatic antioxidant activities in pregnant ewes bearing single and twin foetuses. The ewes were selected from healthy animals that were brought to the abattoir for slaughtering. The ewes were divided into three groups: Group 1 (non‐pregnant, non‐oestrous, n = 30), Group 2 (pregnant bearing a single foetus, n = 30) and Group 3 (pregnant bearing twin foetuses, n = 12) after they were slaughtered. Pregnant ewes were in the first half of the pregnancy. The diameter of CL and P concentration of pregnant ewes bearing a single foetus or twin foetuses were found higher than that found in non‐pregnant ewes. Similarly, the P concentration of pregnant ewes bearing twin foetuses was higher than that found in pregnant ewes bearing a single foetus. Malondialdehyde (MDA) level in pregnant ewes bearing twin foetuses was higher than that found in both non‐pregnant and pregnant ewes bearing a single foetus. The serum glutathione (GSH) level and glutathione‐peroxidase (GSH‐Px) activity of pregnant ewes bearing twin foetuses were found lower than that found in non‐pregnant ewes. Additionally, the GSH‐Px activity of pregnant ewes bearing twin foetuses was found lower than that found in pregnant ewes bearing a single foetus. No significant difference was found between pregnant ewes bearing female and male foetus with respect to diameter of CL, P concentration and oxidative stress parameters. There were significant positive correlations between foetal number (0, 1, 2) and diameter of CL, P concentration, MDA level, and between P concentration and diameter of CL, MDA level. However, significant negative correlations were found between foetal number (0, 1, 2) and GSH level, GSH‐Px activity, and between P concentration and GSH‐Px activity. In conclusion, the diameter of CL enlarges, P production increases and oxidant/antioxidant balance impairs because of the gestation stress in ewes during pregnancy.     

Antimicrobial activity of the essential oil of Centaurea aladagensis

Composition of the water-distilled oil of the aerial parts of Centaurea aladagensis, endemic in Turkey, was analysed by GC-MS. Hexadecanoic acid (39.3%), caryophyllene oxide (6.6%) and hexahydrofarnesyl acetone (4.3%) were found as main constituents in the oil. The oil was tested against 7 human pathogenic microorganisms.     

Distribution of hepatitis B virus (HBV) genotypes among HBV carriers in Isparta

BACKGROUND: The aim of this study was to investigate the prevalence of hepatitis B virus (HBV) genotypes in Isparta, Southwest of Turkey, as well as the clinical features and transmission route for patients with HBV infections. METHODS: Patients (n = 135) with HBV infection were included in the study. Epidemiological and clinical data were obtained. HBV genotypes were determined with a preS2 epitope ELISA kit. RESULTS: Although the HBV transmission route remained unidentified in 51.1% of the patients, blood contact was determined as the most common probable transmission route (38.5%). One hundred twenty-four (91.8%) of 135 samples, could be genotyped. One hundred fifteen (85.1%) were genotyped as type D/E, six (4.4%) were genotyped as type A, two (1.4%) were genotyped as type C, and one (0.7%) were genotyped as type F. CONCLUSION: Genotype D/E is determined as the predominant HBV genotype circulating in Isparta, Southwest of Turkey. No relationship between genotypes and disease severity and transmission route has been detected.     

Passalora blight of anise (Pimpinella anisum) and its control in Turkey

Passalora blight of anise, caused byPassalora malkoffii (Bubák) U. Braun, is an important disease of anise in Turkey. The disease affects all the aboveground parts of plants including flower clusters. Infected seeds have dark, linear stromata. Detection of the pathogen on seeds was studied by the blotter method, agar method, washing test and sowing infected seeds in disease-free soils. The pathogen was recovered only by the washing test and to a limited extent by water agar + seed decoction agar. Sixteen of 24 seed samples from diseased regions were found to be infected. The pathogen was not detected by any other methods. However, several indigenous fungi,e.g. Alternaria alternata, were isolated, which may have prevented the growth of the pathogen. Seed washings of infected seed samples had typical spores of the pathogen up to 10⁶ conidia per gram of seed. Transmission of the pathogen was shown by sowing infected seeds in disease-free field soils in two locations where anise had not been grown previously. Azoxystrobin, chlorothalonil + carbendazim and flutriafol seed treatments at 0.04 g a.i. kg⁻¹ seed, 1.0 g + 4.5 g a.i. kg⁻¹ seed and 0.015 g a.i. kg⁻¹ seed reduced the disease by 92.5%, 89.6% and 36.2% in 2002 and by 78.9%, 75.8% and 41.2% in 2003, respectively. Three foliar applications of axosystrobin, chlorothalonil + carbendazim and flutriafol at the rates of 187.5 g a.i. ha⁻¹, 1500 g + 6750 g a.i. ha⁻¹ and 31.3 g a.i ha⁻¹ reduced disease incidence by 92.5%, 86.0% and 96.8% in 2002 and by 97.5%, 90.8% and 97.0% in 2003, respectively. http://www.phytoparasitica.org posting May 17, 2005.