Description: Sulfate-reducing bacteria (SRB) participate in microbially induced corrosion (MIC) of equipment and H 2 S-driven reservoir souring in oil field sites. Successful management of industrial processes requires methods that allow robust monitoring of microbial communities. This study investigated the applicability of denaturing high-performance liquid chromatography (DHPLC) targeting the dissimilatory sulfite reductase ß-subunit ( dsrB ) gene for monitoring SRB communities in oil field samples from the North Sea, the United States, and Brazil. Fifteen of the 28 screened samples gave a positive result in real-time PCR assays, containing 9 x 10 1 to 6 x 10 5 dsrB gene copies ml –1 . DHPLC and denaturing gradient gel electrophoresis (DGGE) community profiles of the PCR-positive samples shared an overall similarity; both methods revealed the same samples to have the lowest and highest diversity. The SRB communities were diverse, and different dsrB compositions were detected at different geographical locations. The identified dsrB gene sequences belonged to several phylogenetic groups, such as Desulfovibrio , Desulfococcus , Desulfomicrobium , Desulfobulbus , Desulfotignum , Desulfonatronovibrio , and Desulfonauticus . DHPLC showed an advantage over DGGE in that the community profiles were very reproducible from run to run, and the resolved gene fragments could be collected using an automated fraction collector and sequenced without a further purification step. DGGE, on the other hand, included casting of gradient gels, and several rounds of rerunning, excising, and reamplification of bands were needed for successful sequencing. In summary, DHPLC proved to be a suitable tool for routine monitoring of the diversity of SRB communities in oil field samples.

Description: By whichever means we explore Earth from its surface, the information gained about our planet’s interior is always indirect, a model put together using multiple types of evidence. Drilling is the only way to verify such models against reality. However, drilling and retrieving samples and data is costly, complex, and sometimes dangerous - this is exactly where the International Continental Scientic Drilling Program (ICDP) comes in. The goal of the ICDP is to encourage Earth scientists to use the investigative tool of scientic drilling to test models from information gathered at the Earth’s surface. Given the typically high cost of drilling and of research in boreholes, it is clear that any proposals for drilling with ICDP’s help must address substantial scientific questions with a strong focus on societal needs. This Science Plan lays out some of the most important issues that ICDP aims to investigate over the next decade. The key questions address fundamental science, but many also link to wider societal challenges encompassed in the United Nations Sustainable Development Goals (SDGs). In particular, ICDP projects can provide important information to underpin the SDGs related to clean water and sanitation, affordable and clean energy, sustainable cities and communities, and climate action.