Aspergillus niger absorbs copper and zinc from swine wastewater

Wastewater from swine confined-housing operations contains elevated levels of copper and zinc due to their abundance in feed. These metals may accumul ate to phytotoxic levels in some agricultural soils of North Carolina due t o land application of treated swine effluent. We evaluated fungi for their ability to remove these metals from wastewater and found Aspergillus niger best suited for this purpose. A. niger was able to grow on plates amended w ith copper at a level five times that inhibitory to the growth of Saccharom yces ccs cerevisiae. We also found evidence for internal absorption as the mechanism used by A. niger to detoxify its environment of copper, a propert y of the fungus that has not been previously exploited for metal bioremedia tion. In this report, we show that A. niger. is capable of removing 91% of the copper and 70% of the zinc from treated swine effluent. (C) 2001 Elsevi er Science Ltd. All rights reserved.