Edible macroalga Ulva prolifera as microelemental feed supplement for livestock: the fundamental assumptions of the production method

In the present paper, the possibility of the application of marine macroalga Ulva (Enteromorpha) prolifera, as microelemental feed supplement for livestock, was evaluated. The concept was based on two facts: the natural macroalga contains high concentrations of microelements and there is a possibility to greatly increase this content via biosorption. In order to characterize the biosorption process of metal ions by U. prolifera, preliminary experiments were conducted with Cr(III) ions. The effect of temperature, pH and the biomass concentration on the equilibrium of biosorption was investigated. For further experiments (biosorption of Mn(II), Zn(II), Cu(II), Co(II)), the following experimental conditions were chosen: pH 5, 25A degrees C, the biomass concentration 1.0 g l(-1). Equilibrium of the biosorption process could be described by the Langmuir equation. The theoretical maximum biosorption capacity was also determined by potentiometric titration of the biomass. The investigation of the external structure of the macroalga and atomic concentration of elements on the surface of the biomass was analyzed using scanning electron microscopy. The content of microelements in the biomass after biosorption increased 110,555; 44,228; 21,177; 2,281 and 1,458 times for Co(II), Cr(III),Cu(II), Zn(II), Mn(II), respectively. Therefore, biomass of U. prolifera enriched with individual microelements, mixed in the proper proportion could be used as feed supplement in animal feeding to cover the nutrient requirements for microelements.