Microbial Observatories: The Galapagos Microbial Observatory: Analysis of Novel Archaeal and Bacterial Diversity Associated with Iguanas Across Environmental Gradients

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

A grant funded by the Microbial Observatories program and the NSF Office of International Science and Engineering has been awarded to Drs R. Mackie, and I. Cann of the University of Illinois, and M. Wikelski of Princeton University to identify and characterize novel archaeal and bacterial diversity and dynamics in the intestinal tract of unique herbivorous iguanas using a combination of classical cultivation and modern molecular methods. The Galapagos archipelago harbors two endemic genera of large herbivorous lizards, the marine (Amblyrhynchus) and land (Conolophus) iguanas. These islands are situated over a volcanic hotspot 1000 km west of Ecuador and have never been in contact with any continental landmass. The Galapagos Islands were declared a UNESCO Biosphere Reserve in 1984. They will utilize an array of classical cultivation based techniques for enrichment, isolation and characterization of uncultured and undescribed anaerobic bacteria and archaea. To assess molecular diversity and phylogeny, they will utilize a culture independent approach based on retrieval of genomic DNA directly from the iguana intestinal samples. DNA fingerprinting technique (PCR-DGGE) as well as clone libraries encoding16S rDNA and large genomic fragments from mixed microbial community DNA such that each cloned fragment contains a phylogenetically-informative end (SuperPhylo-BAC) libraries will be used for this purpose. Samples will be collected in the cool-dry season (September) and the hot-wet season (February) for this two-year "proof of diversity " award. The long-term objective is to link phylogenetic and functional microbial diversity in iguanas with the environmental and ecological gradients that exist within this natural laboratory of evolutionary biology. The results are expected to reveal novel biochemical and genetic capacity of the bacteria and archaea accessed by the culture-dependent and independent approaches. This award will provide a molecular and culture database for future screening of novel genes and potentially useful products. The project will foster collaboration with the Universidad San Francisco de Quito, Ecuador and Charles Darwin Research Station through training of US and Ecuadorian undergraduate and graduate students, and contribute significantly to the long-term conservation of the Galapagos world heritage site.