A novel hydrothermal vent biosampler (HVB) sampler was developed by the JPL Robotic Vehicles Group with input from the Biotechnology and Planetary Protection Group and experts from the Monterey Bay Aquatic Research Institute (MBARI), Scripps Institute of Oceanography (SIO) and Woods Hole Oceanographic Institute (WHOI). The HVB has been designed to collect large-volume samples of hydrothermal vent fluid untainted by the surrounding waters.   The HVB both filters and concentrates large volumes of vent fluid.  In-situ sensing devices have been positioned throughout the system to monitor real-time temperature and flow rates during sampling, ensuring that samples are collected within the target environmental conditions.  If a temperature deviation occurs from the desired level, the collected water is released through the bypass system until the desired temperature is reached (i.e. they are ‘pristine’).

For this study, the HVB was deployed on the bank of Lynx Pond in Rio Tinto.  The intake line was inserted into the selected site of the pond through visual guidance.  Additionally, temperature and chemical sensors were available to further pin-point a precise sampling area.  The water was pumped through the bypass pipe and flushed through the flow outlet line.  In between sample collections, the field site water was pumped through the bypass to prevent cross-contamination between sampling events.  After bypass, the pump was then rotated to one of three sample collection valves and pumped through the filtration system for 10 min.  The first two samples were collected from the Lynx pond and the third sample was collected from Jana’s stream.  The 90, 60 and 7 µm filters were aseptically removed from the HVB and placed individually in sterile conical tubes.  Each individual filter was immersed in a suitable buffer and sonicated for 2 min at a frequency of 25 kHz.  The biomatter samples recovered from the filters were concentrated to a final volume of <500 µL using a 50 kDa filter.  DNA was isolated from each concentrated sample, and PCR or qPCR was performed using universal primers targeting bacterial 16S rRNA, eukaryotic 18S SSU rRNA and archaeal 16S rRNA. 

Excellent PCR amplification of Eukaryotic DNA was obtained from the filters.  Bacterial DNA qPCR concentrations ranged from 10² – 10⁴ copy numbers.  Cloning/sequencing, PhyloChip and MycoChip analyses will be used to determine the microbial diversity of the samples. 

The high acidity and iron content of the Rio Tinto waters did not impact performance of the HVB and it proved to be robust and versatile in collecting samples from extreme environments of astrobiological relevance