Combined effects of sugarcane bagasse extract and Zinc(II) ions on the growth and bioaccumulation properties of yeast isolates.

摘要

Bioaccumulation of zinc(II) ions by yeast isolates viz. Candida rugosa and Cryptococcus laurentii was investigated in different growth media. Both the isolates showed maximum bioaccumulation of zinc(II) in the medium prepared from sugarcane bagasse extract. The growth and zinc(II) bioaccumulation properties of yeasts in sugar cane bagasse extract were tested as a function of pH, temperature and initial metal concentrations. The combined effects of sugar extracted from bagasse and initial zinc(II) ion concentrations on specific growth rate and bioaccumulation efficiencies of yeasts were investigated. At a constant zinc(II) concentration, the growth and zinc(II) bioaccumulation increased with increasing concentrations of sugar up to 24 g/L. The inhibition effect of zinc(II) ions on the specific growth rate of yeasts was studied by non competitive and uncompetitive inhibition models at various concentrations of zinc(II) ranging from 0-50 mg/L at constant sugar concentrations (8- 24 g/L). Bioaccumulation of zinc(II) by the yeast isolates followed first-order-reaction kinetics.