Microbial Genome Sequencing: Genomic Biodiversity in Hypersaline Environments

University Of Maryland Biotechnology Institute, Baltimore MD

Investigators

Abstract

Extremely halophilic archaea inhabit brine pools containing 3-5 M NaCl, which are extraordinarily diverse and dynamic with respect to salinity, pH, temperature, pressure, nutrients, etc. In addition to their obligately halophilic character,some are also acidophilic, alkaliphilic, psychrophilic, barophilic, or slightly thermophilic. Extreme halophiles are easily cultured in the laboratory and are excellent experimental systems with well-developed genetic tools. However, thus far, only a single genome from an extremely halophilic archaeon, Halobacterium species NRC-1, has been sequenced. In order to study the genomic diversity of extreme halophiles, we plan to sequence the genome of Haloarcula marismortui, a metabolically versatile halophile with a high-resolution ribosome structure. If time and resources permit, additional genomic analysis will be conducted on diverse strains, including Natrialba asiatica, a non-pigmented alkaliphile. Halorubrum lacusprofundi, a psychrophile capable of growing at temperatures down to 4oC, Halosimplex carlsbadense, a likely ancient halophile recently isolated from a Permian brine inclusion, which appears to be a genetic chimera, and Halobacterium species GRB, a closely related strain to NRC-1. Sequencing will be conducted at the Institute for Systems Biology and annotation will be done at the University of Maryland Biotechnology Institute, Center of Marine Biotechnology. This project will provide better understanding of biodiversity among extreme halophiles, including genome structure and evolution, adaptation to extreme environments, and lateral gene transfer. In the long term, the proposed work should provide novel applications in biotechnology, e.g. engineering salt tolerance in crop plants and development of new antibiotics. This is a Microbial Genome Sequencing Award funded through a collaborative program between the National Science Foundation and the Department of Agriculture Initiative for Future Agriculture and Food Systems.