18s rdna sequences from microeukaryotes reveal oil indicators in mangrove sediment18 s rdna序列microeukaryotes揭示油指标红树林沉积物.pdfVIP

18S rDNA Sequences from Microeukaryotes Reveal Oil Indicators in Mangrove Sediment Henrique F. Santos, Juliano C. Cury, Flavia L. Carmo, Alexandre S. Rosado, Raquel S. Peixoto* ´ Laboratory of Molecular Microbial Ecology, Department of General Microbiology, Institute of Microbiology Professor Paulo de Goes, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil Abstract Background: Microeukaryotes are an effective indicator of the presence of environmental contaminants. However, the characterisation of these organisms by conventional tools is often inefficient, and recent molecular studies have revealed a great diversity of microeukaryotes. The full extent of this diversity is unknown, and therefore, the distribution, ecological role and responses to anthropogenic effects of microeukaryotes are rather obscure. The majority of oil from oceanic oil spills (e.g., the May 2010 accident in the Gulf of Mexico) converges on coastal ecosystems such as mangroves, which are threatened with worldwide disappearance, highlighting the need for efficient tools to indicate the presence of oil in these environments. However, no studies have used molecular methods to assess the effects of oil contamination in mangrove sediment on microeukaryotes as a group. Methodology/Principal Findings: We evaluated the population dynamics and the prevailing 18S rDNA phylotypes of microeukaryotes in mangrove sediment microcosms with and without oil contamination, using PCR/DGGE and clone libraries. We found that microeukaryotes are useful for monitoring oil contamination in mangroves. Our clone library analysis revealed a decrease in both diversity and species richness after contamination.