The role of Ulva fasciata in the evolution of the microbial community and antibiotic resistance genes in maricultural sediments

Abstract

This study explored changes in the microbial community and antibiotic resistance genes (ARGs) in maricultural clam sediment after 3-month co-culture with different densities (0, 5 and 12 g L−1) of seaweed Ulva fasciata (U. fasciata). The maximum removal rates of NO3−-N, PO43−-P, and inhibition of Vibrio culturability occurred at presence of 12 g L−1U. fasciata. A significant decrease by 14.0% of the total ARGs was found in control sediment without U. fasciata after separation from the original niches, while the total ARGs further increased by 5.58%and 4.65% at presence of 5 and 12 g L−1 of U. fasciata in compared with control sediment, respectively, strongly related with Chloroflexi, Spirochaetes, Proteobacteria and Bacteroidetes hosts. In addition, U. fasciata favored the decline of absolute gene numbers of some tetracycline resistance genes (tetPB, tetW, otrA, tetT, tetO) and class 1 integron-integrase gene.