Temperature and pH effect on the microbial reductive transformation of pentachloronitrobenzene

The effect of pH and temperature on the microbial reductive transformation of pentachloronitrobenzene (PCNB), an organochlorine fungicide, was investigated with a mixed fermentative/methanogenic culture developed from a contaminated estuarine sediment. Culture series were incubated at a temperature range from 4 to 45 degrees C at pH 6.9+/-0.1 and at a pH range from 2.7+/-0.1 to 7.6+/-0.1 at 22 degrees C. Significant differences were observed in terms of biotransformation rate, extent, and products as a function of temperature. Incubation at different pH values resulted in differences in biotransformation rate and extent, but not in terms of products formed. PCNB (3 microM) was transformed to pentachloroaniline (PCA) in all culture series. However, sequential dechlorination of PCA was observed only at a temperature range from 4 to 35 degrees C and at a pH range from 6.2+/-0.1 to 7.6+/-0.1. The highest PCA dechlorination rate was observed at 22 degrees C and at pH 7.6+/-0.1. The effect of temperature on the PCA dechlorination rate was modeled using an Arrhenius relationship, which accounts for both enzyme activation and deactivation. The dechlorination of PCA and chlorinated aniline intermediates was simulated using a branched-chain Michaelis-Menten model, and kinetic constants were determined.     

Effects of microbial phytase and 1,25-dihydroxycholecalciferol on the absorption of minerals from broiler chicken diets containing different levels of calcium

The aim of this study was to investigate the effect of various calcium:total phosphorus (Ca:tP) ratios due to addition of microbial phytase and 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] on the absorption levels of minerals. In a 42-day experiment repeated three times, 144 day-old male broiler chicks (ISA 220) were divided into six groups of eight chicks each. Diets containing two different (1:1 and 2:1) Ca levels were prepared. Groups 1, 2 and 3 received a diet of 1:1 Ca:tP ratio while Groups 4, 5 and 6 a diet of 1:2 Ca:tP ratio. These diets contained 1,25-(OH)2D3 and phytase in levels of 5 micrograms/kg and 600 FYT/kg, respectively. The faeces was collected to analyse the absorption of minerals. At the end of the study, the absorption levels of Ca, P, Zn, Mn and Cu were increased by the addition of phytase enzyme (p < 0.05). This effect was obvious in the 3rd week. On the other hand, in the 6th week only Ca and P absorption levels were influenced positively by the addition of phytase enzyme. The results proved the positive effect of phytase, an enzyme which is used for increasing the utilisation rate of phytate P, Ca and other minerals in broilers.     

The Effects of Lithology on Water Pollution: Natural Radioactivity and Trace Elements in Water Resources of Eskisehir Region (Turkey)

The high radioactivity and trace elements in drinking water are common concerns for human health. The aim of this study was to investigate the eligibility of groundwater for drinking purpose in terms of both radioactivity and trace element contents in Eskisehir Region (Turkey). The study area is located in a highly populated residential area where water supply is mostly met from groundwater. The area is about 20,000 km², where igneous, metamorphic, and sedimentary rocks are exposed. The 209 water samples collected from 84 water resources (including thermal waters) were analyzed with respect to major ions, trace elements, and radioactivity (gross alpha and gross beta) during both in wet and dry seasons. Based on the analysis results, trace elements in 49 samples of 84 water resources were over the limits of Code TS 266 1997 (Turkish Drinking Water Standards) and WHO 1993 standards. Particularly, Fe, Mn, Al, As, Ba, Zn, Cr, Cu, and B ion concentrations exceeded the limits. The gross alpha values in 18 locations and gross beta values in three locations also exceeded the limits of aforementioned standards in terms of radioactivity (gross alpha?=?0.1 Bq L^?1; gross beta?=?1 Bq L^?1). Furthermore, water radioactivity levels were close to the allowable limits in 33 water resources. The obtained results explicitly indicate that there is a strong relationship between the higher radioactivity–trace element contents and geochemical composition of rocks, which controls the radioactivity and trace element concentrations present in the aquifer.     

Reducing bacterial density in the semen of rainbow trout (Oncorhynchus mykiss) by applying gradient centrifugation and swim‐up washing methods

The objective of this study was to demonstrate the effectiveness of disinfection procedures to reduce bacterial load of rainbow trout, Oncorhynchus mykiss (Walbaum 1792), semen. Fresh semen was obtained from 3–4‐year‐old male species by abdominal sampling of sperm into pre‐cooled test tubes. After sperm cryopreservation and thawing, experiments were accomplished at 4–9°C. ‘Swim‐up’ and gradient centrifugation were used as a sperm washing method with commercial kits. Phosphate buffered saline was also used as washing solution. Bacterial growth tests were employed before and after washing the semen samples. Samples were inoculated on tryptic soy agar (TSA), modified Anacker and Ordal agar (MAOA) as well as brain heart infusion (BHI) agar. After using ‘swim‐up’ method for washing the semen, many bacterial colonies were observed. However, after semen washing with gradient centrifugation, lower bacterial growth was observed on TSA, MAOA and BHI. Some motile (40%) spermatozoa were obtained doing gradient washing procedure. Although sperm motility was not satisfactory, apparently the gradient centrifugation method reduced bacterial contamination as known from the mammalians.     

The Chemical and Sensory Quality of Smoked Sturgeon (Huso huso): A Case Study

In this study, the tail flesh of sturgeon acquired from the fish market in Be?ikta?-Istanbul, Turkey was put through hot smoking. The chemical composition of raw and smoked sturgeon was determined. The protein, lipid, ash, and moisture of the muscle tissue in raw and smoked sturgeon were found to be 17.63 to 17.49, 6.07 to 9.59, 0.79 to 2.71, and 75.42 to 68.40%, respectively. Both the raw fish and the smoked fish meat were categorized to possess high quality characteristics with pH, total volatile base nitrogen (TVB-N), and trimethylamine nitrogen (TMA-N) values. After smoking, the skin color lightness (L*) of raw fish was determined to decrease, while the flesh color lightness of raw fish was determined to increase. The redness (a*) and the yellowness (b*) of both the skin and the flesh were determined to increase. Sensory parameters of color, smoke aroma, flavor, texture, chewiness, and overall acceptance for smoked sturgeon was described as excellent and its flesh tasty.     

Present and historical landscape structure shapes current species richness in Central European grasslands

Landscape Ecology - Current diversity and species composition of ecological communities can often not exclusively be explained by present land use and landscape structure. Historical land use may...     

Investigation of Immunmodulatory effects of levamisole and vitamin E on Immunity and some blood parameters in newborn Jersey calves

The immunmodulatory effects of dl-α tocopherol (vitamin E) and levamisole on the immune system and some blood parameters of newborn Jersey calves were investigated with the present study. Treatment groups 1, 2 and 3 were injected 13,3 ml isotonic saline solution (0,9% NaCl), 3 mg/kg levamisole HCl and 2000 IU vitamin E weekly, starting at birth until the age of two weeks. Average serum IgM levels of the control, levamisole and vitamin E calves were 111,7 ± 9,3 mg/100 ml, 251,9 ± 27,6 mg/100 ml, 202,2 ± 43,3 mg/100 ml respectively on day 22. Average serum IgG levels of the levamisole and vitamin E groups elevated, compared to the control group on days 1, 8, 15 and 22. However, there were stastistically differences in treatment and control groups for serum total cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL), triglyceride and cortisol values and whole blood counts. All differences were in the reference ranges. Levamisole and vitamin E could be used as an alternative way for their beneficial effects such as improving the humoral immune responses of calves and their safety and practical use against the neonatal period infections in the field.