Novel Microbial Diversity Retrieved by Autonomous Robotic Exploration of the World's Deepest Vertical Phreatic Sinkhole
- ASTROBIOLOGY, 10(2), p.201-213, 2010 .
The deep phreatic thermal explorer (DEPTHX)is an autonomous underwater vehicle designed to navigate an unexplored environment, generate high-resolution three-dimensional (3-D)maps, collect biological samples based on an autonomous sampling decision, and return to its origin. In the spring of 2007, DEPTHX was deployed in ZacatoŽn, a deep (*318m), limestone, phreatic sinkhole (cenote)in northeastern Mexico. As DEPTHX descended, it generated a 3-D map based on the processing of range data from54 onboard sonars. The vehicle collected water column samples and wall biomat samples throughout the depth profile of the cenote. Post-expedition sample analysis via comparative analysis of 16S rRNA gene sequences revealed a wealth of microbial diversity. Tradi-tional Sanger gene sequencing combined with a barcoded-amplicon pyrosequencing approach revealed novel, phylum-level lineages from the domains Bacteria and Archaea; in addition, several novel subphylum lineages were also identified. Overall, DEPTHX successfully navigated and mapped ZacatoŽn, and collected biological samples based on an autonomous decision, which revealed novel microbial diversity in a previously unexplored environment.