This program seeks to investigate the application of newly available, massively parallel DNA sequencing technology for the pursuit of environmental microbiology objectives, with particular attention to high-priority deep biosphere studies under IODP. Using 5 samples from Site 1229 of ODP Leg 201 (Peruvian deep biosphere drilling), the researchers will conduct a proof-of-concept study to sequence DNA focusing on material that is considered DNA-poor by conventional measures. They will first produce an estimated 300,000 sequences of 100 base pairs (~30 Mb) for each of the five samples and then map these metagenomes. During a second phase of the study, they will conduct a focused study either on an important horizon at Site 1229 or on samples from another hole and produce ~90 Mb of additional genomic DNA data in 3 or 4 rounds of sequencing. The primary broader impact of this research is its potential to revolutionize microbial ecology, particularly for difficult-to-study samples of the deep marine biosphere. In addition, the research will support a graduate student and strengthen the interdisciplinary collaboration between a geomicrobiologist and a microbial ecologist.