Funda Turan

Effects of red clover extract on growth performance and body composition of African catfish Clarias gariepinus

The present study was conducted to investigate the effects of the red clover extract on growth, body composition and survival of African catfish Clarias gariepinus. Three concentrations (25, 50 and 75 mg/kg) of red clover at dietary were used for 120 days. The final weights of red clover-treated groups were significantly different from each other and the control group. The best growth was observed in the group receiving the 75 mg/red clover kg diet. Fish fed with all levels of red clover had higher weight gains than the control. The highest values of the specific growth rate and the food conversion rate were 1.14±0.01 and 2.26±0.04, respectively, for the 75 mg/red clover kg diet group. During the red clover administration period, the survival ranged from 97.78% for the 50 p.p.m. group to 95.56% for the 25 and 75 p.p.m. groups. Protein contents of the dosage groups were significantly different from control (P<0.05). The highest value of protein content (19.97%) was observed for the 75 mg/ red clover kg diet. Lipid and ash contents were significantly affected by the red clover levels in the diets. The highest lipid contents were in the 75 mg/red clover kg diet (4.67%), and the highest ash content was 1.39% for the 25 mg/red clover kg diet.

Competitive biosorption of different forms of lead (Pb(NO 3 ) 2 and Pb(CH 3 COO) 2 ) on growth, biomass and proline in Spirulina platensis (Cyanophyta)

Spirulina platensis growth parameters [chlorophyll a (chl a) and dry-wet weight] effects on proline content, lead accumulation and the combined effect of the different forms of lead [Pb (NO 3 ) 2 , Pb (CH 3 COO) 2 ] and pH (6 to 8) were investigated for 192 h. The accumulation and form of lead were determined to be effective on growth parameters. While the highest chl a value (562.37 μgl -1 ) and lead accumulation (58.74 μgg -1 ) were found in medium with 30 mgl -1 Pb (CH 3 COO) 2 and pH 6, the highest proline content was found in 30 mgl -1 Pb (NO 3 ) 2 and pH 6. This study depict an inverse relationship between lead accumulation in the test algae and low pH which suggests that proline might be produced at the expense of the material(s) required for the development of S. platensis. Key words: Spirulina, heavy metal, growth parameters, uptake.

Bioavailability of iron speciations and EDTA-iron complexes for Thallassiosira weissflogii (Bacillariophyta)

This study aimed to determine the effects of daily and/or initial additions of various amounts of Fe (II) and Fe (III), in combination with or without EDTA, on the growth of Thalassiosira weissflogii cultures. The results reveal that growth parameters were higher in the cultures containing 5000 nM Fe(III) ± EDTA than those of 5 nM Fe(III) and Fe(II). T. weissflogii cells seemed not to have used EDTA-bound iron, but their own released ligand to bind iron when Fe(III) concentration was high, and to have preferred inorganic Fe(II). Cell abundance and chl-a level were higher in daily supplemented cultures, with regard to those supported with iron only initially, evidencing the importance of continuous supply of iron in chl-a synthesis. Key Words : Thallassiosira weissflogii , iron speciation, EDTA, growth.