INVESTIGADORES
LLAMES Maria Eugenia Del Rosario
congresos y reuniones científicas
Título:
STUDY OF THE BACTERIOPLANKTON DIVERSITY OF A FEGUIAN PEAT BOG USING METAGENOMIC ANALYSIS TOOLS
Autor/es:
QUIROGA, M.V.; VALVERDE, A.; COWAN, D.A.; LLAMES, M.E.; GONZALEZ GARRAZA, G.; MATALONI, G.
Lugar:
La Plata
Reunión:
Congreso; CAL VI; 2014
Resumen:
Rancho Hambre peat bog is located in a protected area in Tierra del Fuego province (54°S 67ºW)and forms part of the southern-most peatland complex in the world. Since 2008, this area hasbeen used as a limnological case-study, in which the abundance, composition and diversity ofthe plankton communities have been evaluated in relation to abiotic conditions. The presentstudy aims to use modern metagenomic methods to analyze the composition and diversity of thebacterioplankton community in this peat bog. During the spring of 2012, triplicate surface watersamples were collected from five pools (RH1 ? RH5) with different morphometric and trophicconditions, filtered in situ through 0.22 μm membranes and stored in RNAlater (Sigma) fortransport. Metagenomic DNA was extracted directly from the filters using the MoBio Power SoilDNA kit, and amplified using 16S rRNA gene universal primers 27F and 519R. The purified finalproducts were analysed with the GS FLX (Roche 454) Titanium chemistry. Pyrosequencing datawere analyzed using MOTHUR following a previously established pipeline (Schloss et al., 2011).In order to compare the different pools, the same number of reads (2015) per individual samplewas subsampled. A total of 962 OTUs (97% cut-off sequence similarity level) were identified,of which 92% were distributed among the phyla Proteobacteria (51%), Actinobacteria (19%),Bacteroidetes (15%) and Verrucomicrobia (7%), while unclassified bacteria accounted for 7%.Noteworthy, no picocyanobacteria were detected, corroborating epifluorescence observations.16S rRNA gene pyrosequencing analysis revealed highly diverse and specific bacterial communitieswithin each pool. Thus, a total of 775 OTUs were unique to the respective pool: 154 (RH1), 136(RH2), 165 (RH3), 149 (RH4) and 171 (RH5), whereas only 5 OTUs were shared between the fivepools. Moreover, cluster analysis revealed that samples from minerotrophic pools (RH1 and RH4)and those from ombrotrophic ones (RH2, RH3 and RH5) formed two separated groups. Theseresults concur with previous studies of the diversity of planktonic eukaryotes in these habitats andindicate that bacterial species turnover is higher between pools than within pools, which agreeswith a dominant role of deterministic processes on bacterial community composition. Therefore, itseems that peat bog associated bacteria show strong habitat associations that have likely emergedthrough their adaptation to these particular habitats.