Cryopreservation of scaly carp (Cyprinus carpio) sperm: effect of different cryoprotectant concentrations on post-thaw motility, fertilization and hatching success of embryos

The aim of the present study was to determine the effect of various cryoprotectants on post-thaw sperm quality and fertilizing capacity of cryopreserved scaly carp (Cyprinus carpio) semen. The present study focused on freezing of scaly carp sperm utilizing a practical and inexpensive protocol for aquaculture. Semen was diluted with Kurokura’s extender composing 3.6 g/l NaCl, 10 g/l KCl, 0.22 g/l CaCl₂, 0.08 g/l MgCl₂ and 0.2 g/l NaHCO₃. The extender contained three different cryoprotectants (DMSO, DMA and egg yolk) at ratios of 5, 10 and 15 %. Semen was placed into 0.25-ml straws and exposed to liquid nitrogen vapor (?120 °C) using an insulated box with an adjustable tray for 10 min and then plunged into liquid nitrogen (?196 °C) tank. The thawing process was performed in a water bath at 40 °C for 10 s. The results indicated that type of cryoprotectants and their concentrations are rather effective in scaly carp sperm cryopreservation on post-thaw sperm quality, while they are very important in order to obtain high fertilization rates. The highest fertilization rate was determined as 96.4 ± 0.15 % with 15 % egg yolk, while the highest hatching rate was determined as 99.3 ± 0.80 with 15 % DMA. In conclusion, the applied cryopreservation method for scaly carp sperm is suitable to fertilize high amounts of eggs.     

The Effect of Frying – the Chemical,Microbiological, and Acrylamide Composition of Mussels as a Street Food

The effects of frying methods and covering processes on the proximate composition, fatty acid profile, amino acid profile, cholesterol, acrylamide, and microbiological content of fried mussel (Mytilus galloprovincialis 1819) were investigated in the present study. The group of mussels that were purchased for study was divided into six groups (control – unprocessed mussel meat; Group A – covered mussels fried in deep fat; Group B – mussel fried in low fat; Group C – uncoated mussel meat fried in deep fat; Group D – uncoated mussel fried in low fat; and Group E – mussel served in restaurants). It was determined that the mussel frying methods can affect the nutritional composition and cause changes in the amino acid, fatty acid, and cholesterol content.     

Purification of glucose-6-phosphate dehydrogenase and glutathione reductase enzymes from the gill tissue of Lake Van fish and analyzing the effects of some chalcone derivatives on enzyme activities

Glucose-6-phosphate dehydrogenase (G6PD) and glutathione reductase (GR) are metabolically quite important enzymes. Within this study, these two enzymes were purified for the first time from the gills of Lake Van fish. In the purifying process, ammonium sulfate precipitation and 2′,5′-ADP Sepharose 4B affinity column chromatography techniques for glucose-6-phosphate dehydrogenase, temperature degradation and 2′,5′-ADP Sepharose 4B affinity column chromatography for glutathione reductase enzyme were used. The control of the enzyme purity and determination of molecular weight were done with sodium dodecyl sulfate polyacrylamide gel electrophoresis. K _M and V _max values were determined with Lineweaver–Burk plot. Besides, the effects of some chalcone derivatives on the purified enzymes were analyzed. For the ones showing inhibition effect, % activity–[I] figures were drawn and IC₅₀ values were determined. K _i value was calculated by using Cheng–Prusoff equation.     

CO2-defatted oats: Solubility,emulsification and foaming properties

Functional properties of conventional oat materials are relatively poor with respect to foam and emulsion formation and stabilization. This is largely due to the poor solubility of oat proteins and the presence of lipids in aqueous extracts of oats. In the experimental part of this study, extracts were prepared from different type oat flours (oat endosperm flour, oat fine flour, CO₂-defatted whole oat flour and CO₂-defatted oat flour) with a buffered aqueous extraction procedure at acidic (pH 4.5 and 6.5) and basic (pH 8.5 and 10.5) regions. The solubility of proteins was the highest at pH 10.5 and NaCl concentration of 2%. Among the extracts, CO₂-oat flour showed improved foaming and emulsifying properties at basic pH values. The presence of 0.1% NaCl resulted in the lowest foam volumes, but the emulsion activity and stability values being the highest. Sucrose addition resulted in increased foam and emulsion stability of suspensions. Heat treatment at 80 °C impaired foam properties, whereas the stability of emulsions increased with the increase in temperature from 20 °C to 80 °C. CO₂-extracted oats can be useful raw materials in beverages and other aqueous applications where protein functionality plays an important role.     

Antioxidant activity, reducing power and total phenolic content of some lichen species

The total antioxidant activity, total phenolic content and reducing power of methanol and water extracts of four lichen species, Bryoria fuscescens, Dermatocarpon intestiniformis, Peltigera rufescens and Pseudevernia furfuracea, were determined in vitro. Water and methanol extracts of P. rufescens showed the highest antioxidant activity. However, there was no correlation between antioxidant activity and total phenolic content of the extracts. Although the methanol extract of P. furfuracea had the highest total phenolic contents, it exhibited low antioxidant activity. In contrast, there was a strong correlation between reducing power and total antioxidant activity of the extracts. The highest reducing power was determined for the methanol extract of P. rufescens.     

Clavibacter michiganensis subsp. michiganesis: Tracking strains using their genetic differentiations by ISSR markers in Southern Turkey

There is no available data published related to the dissemination of bacterial canker caused by Clavibacter michiganensis subsp. michiganensis (Cmm) and its genetic diversity in Turkey. It is important to control new introduced inoculum sources by commercial seeds and seedlings. Pathogens were identified by morphological features and the identity was confirmed by PCR amplification using a specific primer PSA-4, PSA-R in addition to microbiological tests. ISSR markers showing high polymorphism ratios were selected and used to characterize Cmm strains. The collected strains were classified into different groups on the basis of ISSR-PCR fingerprints, which showed remarkable genetic specificity and diversity not previously identified in Cmm, suggesting that genetic differences are related to dissemination of the pathogen in the region. This is the first ever study carried out on the characterization of Cmm using ISSR. The selected ISSR primers to characterize Cmm can be used to determine genetic differences in further studies.     

The chemical and sensorial changes in rainbow trout caviar salted in different ratios during storage

In this study, the intention was to investigate the chemical and sensorial changes occurring during cold storage (4 ± 1°C) of caviar obtained from rainbow trout Oncorhynchus mykiss W. 1792 that was dry salted in different ratios. Caviar has a higher fat and protein content than other seafood products, and in processing it with dry salting technology, it was determined that the shelf life could be up to 28 days for the experimental group in which salt was applied at a rate of 4% and up to 35 days for the experimental group in which salt was applied at a rate of 8%. Thus the storage period of the samples is longer for the products to which a high (8%) amount of salt was applied than the products to which a low (4%) amount of salt was applied in the salting process.