Characterization and purification of polyphenol oxidase from artichoke (Cynara scolymus L.)

In this study, the polyphenol oxidase (PPO) of artichoke (Cynara scolymus L.) was first purified by a combination of (NH(4))(2)SO(4) precipitation, dialysis, and a Sepharose 4B-L-tyrosine-p-aminobenzoic acid affinity column. At the end of purification, 43-fold purification was achieved. The purified enzyme migrated as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Polyacrylamide gel electrophoresis indicated that PPO had a 57 kDa molecular mass. Second, the contents of total phenolic and protein of artichoke head extracts were determined. The total phenolic content of artichoke head was determined spectrophotometrically according to the Folin-Ciocalteu procedure and was found to be 425 mg 100 g(-1) on a fresh weight basis. Protein content was determined according to Bradford method. Third, the effects of substrate specificity, pH, temperature, and heat inactivation were investigated on the activity of PPO purified from artichoke. The enzyme showed activity to 4-methylcatechol, pyrogallol, catechol, and L-dopa. No activity was detected toward L-tyrosine, resorsinol, and p-cresol. According to V(max)/K(m) values, 4-methylcatechol (1393 EU min(-1) mM(-1)) was the best substrate, followed by pyrogallol (1220 EU min(-1) mM(-1)), catechol (697 EU min(-1) mM(-1)), and L-dopa (102 EU min(-1) mM(-1)). The optimum pH values for PPO were 5.0, 8.0, and 7.0 using 4-methylcatechol, pyrogallol, and catechol as substrate, respectively. It was found that optimum temperatures were dependent on the substrates studied. The enzyme activity decreased due to heat denaturation of the enzyme with increasing temperature and inactivation time for 4-methylcatechol and pyrogallol substrates. However, all inactivation experiments for catechol showed that the activity of artichoke PPO increased with mild heating, reached a maximum, and then decreased with time. Finally, inhibition of artichoke PPO was investigated with inhibitors such as L-cysteine, EDTA, ascorbic acid, gallic acid, d,L-dithiothreitol, tropolone, glutathione, sodium azide, benzoic acid, salicylic acid, and 4-aminobenzoic acid using 4-methylcatechol, pyrogallol, and catechol as substrate. The presence of EDTA, 4-aminobenzoic acid, salicylic acid, gallic acid, and benzoic acid did not cause the inhibition of artichoke PPO. A competitive-type inhibition was obtained with sodium azide, L-cysteine, and d,L-dithiothreitol inhibitors using 4-methylcatechol as substrate; with L-cysteine, tropolone, d,L-dithiothreitol, ascorbic acid, and sodium azide inhibitors using pyrogallol as substrate; and with L-cysteine, tropolone, d,L-dithiotreitol, and ascorbic acid inhibitors using catechol as a substrate. A mixed-type inhibition was obtained with glutathione inhibitor using 4-methylcatechol as a substrate. A noncompetitive inhibition was obtained with tropolone and ascorbic acid inhibitors using 4-methylcatechol as substrate, with glutathione inhibitor using pyrogallol as substrate, and with glutathione and sodium azide inhibitors using catechol as substrate. From these results, it can be said that the most effective inhibitor for artichoke PPO is tropolone. Furthermore, it was found that the type of inhibition depended on the origin of the PPO studied and also on the substrate used.     

Epidemiology of <Emphasis Type="Italic">Oestrus ovis</Emphasis> infestations in sheep in Kars province of north-eastern Turkey

This study was carried out to determine the prevalence of cavical myiasis caused by Oestrus ovis larvae in sheep of Kars province of north-eastern part of Turkey. From 30 to 35 sheep heads (total of 387) were examined every month regularly for O. ovis larvae during 12 months. Of 387 heads, 156 (%40.3) were infested with O. ovis larvae.. The prevalence of nasal myiasis was 54.3% in spring, 41% in summer, 28% in fall, and 38.9% in winter. The differences among seasons were significant statistically (P < 0.05). Infestation rate up to 1-years-old was 30.0%, 1 to 3 years-old 40.0% and older than 3 years old was 52.4%. The number of larvae made peak in spring months and went down in the months of fall. The mean number of larvae regarding examined animals was 1.8, and the mean according to infested animals was 4.5. Density of O.ovis larvae in infested sheep were changed from 1 to 31. Infestation rate in the morkaraman breed was higher (43.4%) comparing to the rate in the akkaraman breed (31.3%). The differences between sheep breed were also significant (p < 0.05). Sheep with dark colored head had higher infestation rate than that of sheep with light colored head (p < 0.05).     

Heavy Metal Content of Plant Species along Nilüfer Stream in Industrialized Bursa City, Turkey

The Paraíba do Sul river is located in one of the most developed part of Brazil and receives many organic and industrial effluents directly affecting the ichthyofauna. Concentration of four heavy metals (Cu, Cr, Zn and Pb) were determined in two tissues (muscle and gonads) of three abundant fish species from different trophic levels (Oligosarcus hepsetus—carnivore, Geophagus brasiliensis—omnivore and Hypostomus luetkeni—detritivore) between November 2002 and April 2003. The aim was to test the hypothesis that the trophic level and the proximity from impacted areas influence levels of contamination and to assess if these species are indicators of large-scale habitat quality. Levels of heavy metals were detected by Total Reflection X-ray Fluorescence with Synchrotron Radiation (SR-TXRF) at the Brazilian National Synchrotron Radiation Laboratory (LNLS). Generally, gonads showed higher metal concentration than muscles, except for Cr. All examined metals, but Cu, exceeded the maximum permitted concentration (mpc) by the Brazilian legislation for human consumption in at least one tissue. O. hepsetus (carnivore) showed the highest contamination levels, followed by G. brasiliensis (omnivore) and H. luetkeni (detritivore). The middle-upper segment, which encompasses large urban areas, showed the highest levels of metal contamination in most cases. O. hepsetus showed the highest levels of contamination in muscles for Pb in the middle-upper river segment (7.98?±?3.73; mpc?=?2.0 μg g^?1) and for Cr in the upper (5.53?±?0.05; mpc?=?0.10 μg g^?1) and middle-upper (4.20?±?0.85; mpc?=?0.10 μg g^?1) segments, which indicates that human population should avoid to consume these fishes species from these segments of the Paraíba do Sul river.     

Effects of grape Vitis vinifera seed oil supplementation on growth,survival, fatty acid profiles,antioxidant contents and blood parameters in rainbow trout Oncorhynchus mykiss

In this study, effects of grape Vitis vinifera seed oil supplementation (0, 250 mg, 500 mg, 1,000 mg/kg feed) for 60 days on rainbow trout Oncorhynchus mykiss juveniles were investigated. The average final fish weights were not different between the control group and 500 mg/kg feed group (p > .05), but 250 mg/kg feed group were lower than those of the control group, and 1,000 mg/kg feed group were higher than those of the control group. Although the SFA, MUFA and n3 ratios of the control group were higher than that of the other groups, no statistical difference was found. The highest fatty acids in the fish were palmitic acid C 16: 0 in the SFA group and C 18: 1n‐9 and docosahexaenoic acid C 22: 6n‐3 in the PUFA group. The EPA ratio was significantly increased in all groups compared with the control group. The DHA ratio was significantly higher in the control group than in the experimental groups, and there was no difference between the experimental groups. Urea were significantly lower in the 250 mg/kg feed group. Total protein and aspartate aminotransferase were significantly increased in the 1,000 mg/kg feed group. Only the 1,000 mg/kg feed group showed an increase in antioxidant activities, and this concentration also yielded positive results in terms of growth performance, survival rates, fatty acid composition and antioxidant enzyme activities in rainbow trout juvenile and can be used as a natural feed additive.     

Seroprevalence of coxiellosis in cattle, sheep and people in the east of Turkey

Serum samples collected randomly from 416 cattle in 48 herds, and 411 sheep in 47 flocks, in eight different locations in the east of Turkey between June and December 1998, were examined by indirect fluorescent antibody test (IFAT) to determine the prevalence of Q fever. The age, sex, breed, tick control and abortion history of the animals were also recorded. In addition, 102 serum samples were collected from apparently healthy people who were at risk of contracting the disease, such as farmers, veterinarians, abattoir and laboratory workers, and veterinary students. Seropositivity was observed in 5-8 per cent (24/416) of the cattle in 17 (35-4 per cent) of the herds and in 10-5 per cent (43/411) of the sheep in 21 (44-7 per cent) of the flocks. Eight of the 102 people were seropositive, with the highest prevalence (12-0 per cent) in farmers and abattoir workers. All the seropositive farmers had seropositive animals. None of the laboratory workers or veterinary students was seropositive.     

Seroprevalence of enzootic bovine leukosis in Trakya district (Marmara region) in Turkey

In this study, 481 cattle belonging to 77 farms from nine localities in Trakya district in the Marmara region of Turkey were blood sampled and serologically tested for enzootic bovine leukosis (EBL). Antibodies to bovine leukosis virus (BLV) were detected in 51 cattle sera (11%) belonging to nine farms in five localities. Cattle tested were mostly female Holstein or Brown Swiss of ages ranging between 18 months and 10 years. Analysis of the relationships between age, breed or sex and seropositivity to EBL in seropositive herds indicated no significant associations (p>0.05). The relationship between seropositivity and haematological changes was also studied, and seropositive cattle had higher lymphocyte percentage and lower neutrophil percentage than seronegative cattle (p<0.001).     

The Effect of Different Formulations on Turnip Juice Production in Controlled Conditions

Black carrots （Daucus earota L. spp. sativus. ） were fermented for 4 weeks by using six different starter dough formulations. Some of the samples were pasteurized to detemaine the effects of heat treatment on fermentation. Fermentation was followed by physicochemical and microbiological analysis. Some characteristics such as dry matter, crude fiber, water soluble extract, alcohol soluble extract, ether soluble extract, crude energy, total sugar, pH, salt and colour values and mineral contents of black carrot were determined. In the beginning of the fermentation, dry matter is highest in the brines with coriandrium and dry matter of the other brines are close to each other and lower than that of the brines with coriander. The number of Lactic acid bacteria, total bacteria, moulds-yeasts and coliform bacteria decreased through the end of fermentation. Heat treatment had a considerable effect on microbial growth. The microbial growth was higher in the nnpastenrized samples. Total bacteria number reached the highest level for the pasteurized samples （ 104 cfu/mL - 105 cfu/mL ） and for the unpasteurized samples （106 cfu/mL - 107 cfu/mL） in the second day. After the fermentation, sensory analyses were carried out to determine the storage stability of the last products. While ＂a＂ value increased, ＂b＂ and ＂L＂ values decreased during storage time. Yoghurt inoculated brine were preferred from the colour, odour and acceptability points of view.     

Determination of histological and genotoxic effects of formalin on Nile tilapia (Oreochromis niloticus L.)

Formalin (37–40% formaldehyde) is one of the most effective, widely used chemical in pisciculture for its antiparasitic, antifungal and prophylactic activities. It is used in paints, cleaning products and textile industry, as well. Genotoxic and histological effects of sublethal formalin exposure on Nile tilapia (Oreochromis niloticus) are investigated in this study. The semi‐static acute test was employed. One‐tenth, one‐fifth and half of the 96‐h LC₅₀ value, 148 mg L^?1, were used as sublethal exposure concentrations: 15, 30 and 75 mg L^?1 for 24, 48, 96 and 168 h respectively. The micronucleus test was applied to investigate the genotoxic effects on fish erythrocytes at the end of predetermined exposure periods and all tissues of the fish were sampled for histological examination. The micronucleus frequencies increased significantly in all exposure groups when compared with their control groups in a dose and time dependent manner (P < 0.05). Results of histological examination showed no histopathological findings in the gonads, heart, skeletal muscle, spleen and intestine tissues after sublethal formalin exposure. Passive hyperaemia of liver tissue in varying proportions, hydropic degeneration, fatty degeneration in high concentrations, branchitis on gill tissues in varying proportions, epithelial lifting, telangiectasia, bleeding in kidney and hyperaemia were found in Nile tilapia exposed to formalin at different concentrations and durations. As a result, it is thought that formalin leads to tissue damage and shows genotoxic effects even at 15 mg L^?1 concentration in O. niloticus.     

Status of invasive alien plants included in EPPO Lists in Turkey

Turkey is one of the richest areas in the middle latitudes in terms of plant diversity. It has approximately 12 000 plant species and a great number of new species are being added each year. However, invasive alien species have not yet been fully considered in Turkey and only two plant species are in Turkey's quarantine list (Arceuthobium spp. and Eichhornia crassipes). EPPO is an intergovernmental organization responsible for cooperation in plant protection in the European and Mediterranean region and maintains the A1 and A2 Lists of pests recommended for regulation (A1 species are absent from the EPPO region, A2 species are present but of limited distribution), the List of Invasive Alien Plants, the Observation List of invasive alien plants and the Alert List. Eichhornia crassipes, Heracleum persicum, Heracleum sosnowskyi, Ludwigia peploides, Polygonum perfoliatum and Solanum elaeagnifolium are among the species which were recorded in Turkey and are included in the EPPO A2 List. Species recorded in the EPPO List of invasive alien plants which are present in Turkey are: Acroptilon repens, Ailanthus altissima, Ambrosia artemisiifolia (= A. elatior), Carpobrotus edulis, Cortaderia selloana, Cyperus esculentus, Paspalum distichum (= P. paspalodes), Oxalis pes‐caprae and Sicyos angulatus. Azolla filiculoides and Rhododendron ponticum are listed in the EPPO Observation List of Invasive alien plants and Miscanthus sinensis, listed in the EPPO Alert List, are also recorded in the Turkish flora.     

Soil sodicity is more detrimental than salinity for quinoa (Chenopodium quinoa Willd.): A multivariate comparison of physiological,biochemical and nutritional quality attributes

Soil salinization is a serious environmental problem worldwide. To explore the comparative effects of soil salinity and sodicity on physiological, biochemical and nutritional quality attributes of four quinoa genotypes (A1, A7, Puno, Vikinga), pot and field experiments were performed on non‐saline soil and two types of salt‐affected soils designated as SS1 (saline) and SS2 (saline‐sodic). The results of both the experiments showed similar reduction pattern in biomass (11%–44%), chlorophyll content (10%–36%), stomatal conductance (18%–32%) and grain yield (30%–47%) of four genotypes on SS2 compared with SS1. Higher sodicity level of SS2 resulted in more Na accumulation (23%–40%) and oxidative damage (12%–35% decrease in membrane stability) leading to an increase in the activities of antioxidant enzymes (SOD, POD, CAT) in all the genotypes. Grain mineral contents (except Na and Mg) were decreased more in SS2 than SS1. Multivariate analysis revealed that grain Na content has negative correlation with all the nutritional quality attributes except Mg and fibre contents. Genotypes A1 and A7 were more salt tolerant with better grain nutritional quality than Puno and Vikinga. It is concluded that soil sodicity is more detrimental than salinity, and quinoa genotypes A1 and A7 are better than Puno and Vikinga for cultivation on saline and saline‐sodic soils.