Document Type : IAAQC Conference
Authors
Department of Ecology Sciences, University of Al-Qadisiya, Diwaniyah, Iraq.
Abstract
along with biochemical tests to determine its biological characteristics. A yeast culture was prepared on a medium, and four different concentrations (1, 0.5, 0.25, and 0.12 mg/ml) were prepared for testing. An antioxidant activity of yeast was evaluated. The four concentrations mentioned above were also used in this test with the reagent (DPPH). The results indicated the ability of yeast to remove DPPH free radicals, and the removal activity was as follows: 0.1522, 0.1684, 0.3035, 0.3559 absorbency. Then, a hemolysis test was performed using a sample of healthy human blood, and the yeast demonstrated the ability to induce beta-hemolysis (β-hemolysis), with the following values: 0.4652, 0.3966, 0.3772, and 0. 3558µL.In the Biological efficacy test (BET), five types of bacteria were used, namely (Staphylococcus, Escherichia coli, Acinetobacter baumannii, Klebsiella, Pseudomonas). The yeast showed a clear antibacterial and anti-biofilm effect that depended on concentration, with strong inhibition of all tested bacteria at high concentrations (1mg/ml) and minimal activity at low concentrations, which confirms its effectiveness mainly at high doses. The results showed that yeast has a variable capacity to remove heavy metals, with the removal process depending on several factors. These factors include the components of the cell wall, which plays a crucial role in determining biosorption efficiency, as the cell structure dictates the interaction between the microorganism and the heavy metal. Other factors include nutrition, biomass growth, age, pH, the microorganism's growth medium, temperature, and the microorganism's metabolic activity, such as metabolite release and respiration, which in turn alters the microenvironment.
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