VOLUME 12 (Supplement)

Archaeal community profiling of a mixed culture from mud and water slurry from a solfataric mudspring as revealed by a community proteome approach

Analysis of microbial community composition is usually done by DNA-based approaches. Here we used a community proteome approach to study the Archaeal community in carboxy-methyl cellulose-enriched mud and water slurry from Mudspring, a solfataric spring of Mount Makiling in the Philippines. The peptides obtained from proteolytic digestion of total protein extracts were analyzed by using liquid chromatography-electrospray ionization coupled with tandem mass spectrometry (nanoLC-ESI-MS/MS). Majority of the proteins sampled and identified appear to be largely from Sulfolobus species, a number of which are known to be cellulase-producing that could be actively engaged in cellulose degradation in the setup. Furthermore, proteins with high similarity to those from Caldivirga maquilingensis, Metallosphaera sedula, Desulforococcus, Pyrococcus furiosus, and Pyrodictium occultum were identified. Many of these Archaea were not detected in earlier reports of Mudspring microbial community analysis. A feasibly exhaustive knowledge of the Mudspring microbial community using different approaches will foster an understanding of the microbial diversity in such ecological niches and may enable isolation of thermally stable proteins of commercial value in the future. Metaproteomic technique allows functional and taxonomic survey of community structure.