Caracterización molecular de las comunidades bacterianas asociadas a sedimentos de un sistema costero del norte de la corriente de Humboldt, bahía de Mejillones del Sur, Chile

Abstract

To assess the structure of bacterial communities associated to coastal marine sediments of the Humboldt Current System of Mejillones bay (23°S), Chile, we examined 16S rDNA fragments of Bacteria Domain by denaturing gradient gel electrophoresis (DGGE), along with multidimensional scaling analysis (MDS). Sediments were taken from four sampling stations located at the bay and samples from four different depth points were analyzed for three periods during one year. The genetic analysis of prokaryont communities revealed a high bacterial diversity product indicated by the high number of bands detected by DGGE. The MDS analysis showed changes among the bacterial communities in all sampling stations, particularly on the community structures of prokaryotic cells associated to sediments at 10 m, although we also found subtle differences in the structure of prokaryotic communities in all the depth analyzed. The findings of changes in the structure communities of prokaryotic cells could be triggered by changes in circulation water patterns inside the bay, which could be related to upwelling waters found at the northeast margin of the bay. In conclusion, the use of DGGE technique allowed us to establish bacterial community changes by qualitative analysis of samples obtained from different sampling stations at different periods.