Construction and Analysis of Metagenome Library from Bacterial Community Associated with Toxic Dinoflagellate Alexandrium tamiyavanichii

Abstract

Previous studies have suggested that a specific community of bacteria coexists within the phycosphere of marine dinoflagellates. In order to better understand the dinoflagellate-bacteria relationships, a fosmid clone library was constructed from the metagenome DNA and analyzed. Some of the fosmid clones were end-sequenced. A total of 1501 fosmid clones with insert sizes of 30–40 Kbp were produced. End sequenc-ing of 238 clones showed that 55% of the genes had known functions, 11% were of putative function and 34% were genes of unknown function or had no match in Genbank. There were approximately 14% sequences with no classification and could potentially represent novel genes. Analysis of these partial sequences also revealed some promising enzymes that possess various potential industrial applications such as chitinases, kinases, agarases and oxygenases. The results also showed that the bacterial flora of the Alexandrium tamiyavanichii culture was dominated by the Alpha-proteobacteria, followed by Bacteroidetes and Gamma-proteobacteria. The findings in this study suggested that the bacterial community may play various role in the association with dinoflagellate. This study had also shown that dinoflagellate-associated bacterial community is a valuable source for discovery of novel genes and gene products.