Microeukaryotic Community Structure And Response To Bioremediation In Intertidal Mudflats Of Fujian Coast

In this study,macrobenthos(Perinereis aibuhitensis,Tegillarca granosa)were introduced to mudflat sediments for bioremediation in Sansha bay and in-door simulated experiment in Xiamen,and the microeukaryortic community stucture and response to macrobenthos were investigated using 18 S rDNA clone library construction,Restriction Fragment Length Polymorphism(RFLP),Denaturing Gradient Gel Electrophoresis(DGGE)and sequence analysis.The results could extend the understanding of the function of microeukaryotic community in bioremediation process,optimizing bioremediation measures,improving environment evaluation index and,finally for developing real-time and dynamic monitoring system of microbes.The results were as follows:1.Clone library construction,RFLP and DGGE were used to study the microeukaryotic community structure and response to macrobenthos bioturbation in the intertidal mudflat sediments of Sansha Bay.The results indicated that:(1)The microeukaryotic community structure in intertidal sediments of Sansha bay: The microeukaryotes were divided into 10 phyla,in which Annelida and Arthropoda were the most dominant groups,and Gastrotricha and Nematoda were the second dominant groups.A small amount of Cercozoa,Bacillariophyta,Chlorophyta,Alveolata,Amoebazoa,Chytridiomycota and some unclassified microeukaryotes were also present.(2)Seasonal variation: The microeukaryotic community structure in Sansha Bay sediments presented a clear variation with time(season).The eukaryotic community structure in December was significantly different from those in other months and the diversity in December was the highest.Annelida and Arthropoda was dominant in the sample collected in June,while the phyla Bacillariophyta and Alveolata was dominant in the sample collected in December.(3)Response to introduced macrobenthos: Macrobenthos bioturbation changed the microeukartotic community structure and increased the microeukartotic diversity.The phyla Annelida(mainly Tharyx sp.)and Arthropoda(mainly Spinileberis quadriaculeata and Acartia pacifica)increased after sowing macrobenthos,while Gastrotricha,Cercozoa and Alveolata(80% of which were Spirotrichea)decreased.Some phyla,such as Chlorophyta,Amoebozoa and Chytridiomycota,were only detected in December,and Chytridiomycota and Amoebozoa decreased while Chlorophyta increased after introducing macrobenthos.Species of Nematoda was higher in the treatment groups.2.PCR-DGGE was used to investigate the microeukaryotic community structure and response to a indoor simulated bioremediation by nereids of mudflat sediments in Jimei,Xiamen.The results indicated that the microeukaryotes in mudflat sediments of Jimei were mainly divided into four groups: Metazoa(including 6 phyla: Gnathostomulida,Annelida,Nematoda,Arthropoda,Mollusca and Gastrotricha),Cercozoa,Bacillariophyta and Alveolata(including Pyrrophyta and Ciliophora).The dominant group was Ciliophora,and the subdominant group was Nematoda.Peridinium quinquecorne(belonging to Pyrrophyta)was the dominant species.Cluster analysis of DGGE profiles indicated that nereids bioturbation had influenced the microeukaryotic community,.More Nematoda were detected in treatment samples,which probably indicated that the nereid bioturbation stimulated the growth of Nematoda.