Proteome Enabled Discovery of Growth and Survival Strategies of the High Level Nuclear Waste Actinomycete, Kineococcus radiotolerans
EMSL Project ID
17095
Abstract
Heavily polluted industrial and DOE environments typically contain complex mixtures of contaminants in varying concentrations. Because of the prohibitive cost and inefficiencies of existing chemical and physical remedial strategies to address large volumes of contaminant mixtures, newly advanced technologies are greatly needed for reduction and treatment of nuclear legacy waste. Bioremediation is a potentially powerful and innovative technology for converting toxic pollutants to benign end products with a significant cost savings over conventional approaches. Successful application of bioremediation for radiological mixed waste, though, demands a bacterial agent that is capable of maintaining acceptable rates of metabolism and growth on target pollutants in the presence of co-contaminant toxins, salts, and radioactivity. Kineococcus radiotolerans was isolated within a shielded cell work area containing highly radioactive nuclear waste at the Savannah River Site, SRS (Aiken, SC). Kineococcus is an orange pigmented, aerobic, nonsporulating actinomycete belonging to the Kineosporiaceae family. Kineococcus is exceptionally robust, capable of withstanding high concentrations of metals and alkali cations, prolonged desiccation, as well as acute and chronic doses of ionizing radiation. Energetic metabolism in Kineococcus incorporates key organic constituents of SRS and Hanford high-level radioactive waste, as well as many common DOE environmental organopollutants. K. radiotolerans is the only known representative of this species, but kineococci are naturally occurring and have been detected on masonry and lime wall paintings (Schabereiter-Gurtner et al., 2001), leaf litter (Radajewski and Duxbury, 2001), McMurdo Dry Valleys of Antarctica (Torre et al., 2003) and arid desert environments (Garrity et al., 1996; Rainey et al., 2005). Related taxa have been detected in high-level nuclear waste contaminated soils at the Hanford site, WA (Fredrickson et al., 2004). Through a combination of experimentation and insights gleaned from the genome sequence of Kineococcus, we aim to construct a more complete picture of the metabolic capabilities of this unique bacterium as well as a better understanding of the genetic and physiological adaptations affording survival in extreme and mixed waste environments.
In 2003 Kineococcus radiotolerans was nominated for complete genome sequencing at the DOE Joint Genome Institute (JGI). The Kineococcus genome has been in the polishing stages of closure at JGI-LANL for more than 1 year. High %GC, secondary structures and GC rich hard stop gaps have delayed sequencing progress and JGI has expressed specific concerns about the accuracy of the assembly for this particular genome (personal communication; draft release Sept. 2004). Genome assembly and annotation will almost certainly improve with greater genome coverage (estimated at 95% as of July 2005), but proteomics technologies could play an important role in validation of ORF assignments for GC rich bacterial genomes that present assembly problems, and may also provide preliminary functional role assignments for unknown and hypothetical genes through direct experimentation. Additionally, through proteomics we will be able to maintain our current research agenda of a systems level investigation of this unique bacterium prior to public release of the completed genome.
The overarching objective of this EMSL User Proposal is to utilize cutting-edge proteomics technologies to begin exploring growth and oxidative stress physiology in the high-level waste actinomycete Kineococcus radiotolerans.
Project Details
Project type
Exploratory Research
Start Date
2006-02-06
End Date
2007-03-20
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Bagwell CE, KK Hixson, CE Milliken, D Lopez-Ferrer, and KK Weitz. 2010. "Proteomic and Physiological Responses of Kineococcus radiotolerans to Copper." PLoS One 5(8):Article No. e12427. doi:10.1371/journal.pone.0012427