The Effects of Heavy Metals and Molasses on Enzyme Activity of Candida Yeast

Lipases are mainly applied in the food, abluent and medicine industries. Through the high production costs of lipase enzymes for industrial applications, cheap and eco-friendly enzyme production has gained great importance in recent years. Yeasts can produce lipase enzyme and grow in acidic media. In the present study, the act of Cu2+, Ni2+ and molasses concentrations on the enzyme activity of Candida yeasts were investigated in a batch system. The maximum enzyme activities of microorganisms were determined at pH:4. Lipase enzyme activity was investigated changing metal ion and molasses sucrose concentrations by 25-250 mg/L and 1-20 g/L respectively. When molasses sucrose concentration was increased, the enzyme activity of all yeasts increased to 10 g/L, and the lipase enzyme activity decreased at the higher molasses concentrations. Enzyme activity of yeasts decreased with increasing both metal ion concentrations at constant molasses sucrose concentrations. Ni2+ cations were more inhibited to enzyme activity of all yeasts than Cu2+. Among the yeasts, Candida membranefeciens (936.96 U/L) showed the highest enzyme activity in media containing a constant molasses concentration of 10 g/L.