Biological Adsorption and Accumulation Analysis of Hizikia fusiforme Response to Copper Stress Conditions

Abstract

Coastal water pollution is an important environmental problem now days. Hizikia fusiforme is cultivated in coastal water, being considered as a healthy food. However, little information exists concerning on this species responses to copper stress conditions. Experiments were conducted to distinguish biological adsorption and biological accumulation of H. fusiforme in regard to copper stress; it was determined the long-term stress with lower concentrations of copper (0.25 mg/L and 0.50 mg/L) and short-term stress with higher concentrations of copper (1.5 mg/L and 3.0 mg/L) on H. fusiforme. Results suggested that H. fusiforme has different response to various copper stresses; lower concentration stress could significantly enhance the growth of H. fusiforme, while H. fusiforme growth was inhibited and mitigated injured by 0.25-0.50 mg/L copper stress. Under the highest stress, H. fusiforme was extremely harmed, the biomass loss was significant and dry weight/fresh weight was also significantly decreased. Results suggested that lower and higher concentrations of copper stress have different impacts on H. fusiforme; the biological adsorption amount is lower than that of biological accumulation amount under low copper stress conditions, but the biological adsorption amount is much higher under high concentration copper stress. A better understanding of H. fusiforme responses to heavy metal stress should bring more data about its physiological adaptation mechanism under such conditions.