Prokaryotic Community Analysis of a Hyperalkaline Spring in the Philippines Using 16S rRNA Gene Clone Library Construction

Abstract

The prokaryotic diversity associated with serpentinization-driven Manleluag Hyperalkaline (pH 11) Spring in Pangasinan, Philippines was investigated. DNA extracted directly from the sediment samples was used to construct clone libraries based on bacterial and archaeal 16S rRNA gene sequences. Phylogenetic analysis of 16S rRNA gene sequences from the clone library revealed that the clones were grouped into Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Cyanobacteria, Bacteroidetes, and Firmicutes. Analysis of the archaeal 16S rRNA clones revealed the presence of sequences associated with members of Euryarchaeota and Thaumarchaeota. Most of the sequences from Euryarchaeota were related to Methanobacteria and Methanomicrobia. Some clones show little affiliation with known taxa and may represent novel sequences of organisms adapted to the hyperalkaline conditions. The populations found suggest the type of metabolisms that drive this specific environment, which include ammonia oxidation, and hydrogen-based and methanogenic metabolisms. This study represents the first analysis of prokaryotic diversity from community DNA of a hyperalkaline environment in the Philippines.