Abstract: The seaweed Enteromorphasp. distributes widely in the coastal areas of China. There are, however, few studies on Enteromorphain the South China Sea. In this study, we identified one Enteromorphasp. isolated from Daya Bay using molecular method based on 18S rDNA sequence, and analyzed its nutrient (PO₄-P, NO₂-N, NO₃-N, and NH₄-N) removal capacity in aquaculture wastewater. The 18S rRNA gene sequence of Enteromorphasp. was acquired with the length of 1154bp. Blast search and phylogenetic analysis showed that Enteromorphasp. from Daya Bay was closely related to Ulva intestinalisand had large genetic distance with the species that caused the green tide in Qingdao in 2008. The results of nutrient absorption experiment indicated that the optimal treatment dose of Enteromorphasp. for the wastewater was 1.1 g·L^-1. Sixty-five percent of PO₄-P, 47% of NO₂-N, 91% of NO₃-N, and 50% of NH₄-N could be removed by the seaweed in four hours, and 72% of PO₄-P, 81% of NO₂-N, 100% of NO₃-N, and 74% of NH₄-N could be removed in eight hours. Therefore, it has advantage of high efficiency to use Enteromorphato treat aquaculture wastewater. Enteromorphacan be a candidate for treating eutrophic water or aquaculture wastewater. This study could provide a scientific reference for the treatment and utilization of farming wastewater.

Key words: Enteromorpha sp., 18S rDNA, nutrient, wastewater, bioremediation