The stalks synthesized by some members of the α-Proteobacteria take up diffuse compounds from water sources, a feature that could be exploited for bioremediation, specifically the uptake of toxic compounds from contaminated water sources. Furthermore, extracellular polysaccharides from some of the stalked bacteria sequester metals, a feature that could be used to remediate environments affected by metal toxicity. Therefore, three non-budding prosthecate bacteria (Asticcacaulis biprosthecum, Asticcacaulis excentricus, and Brevundimonas subvibrioides) and three budding prosthecate bacteria (Ancalomicrobium adetum, Hyphomicrobium denitrificans and Rhodomicrobium vannielii) have been selected for genome sequencing.
The genomes will be analyzed with respect to mechanisms for the biosynthesis and function of stalks, the biosynthesis and regulation of extracellular polysaccharide, the extent of conservation of regulatory pathways for stalk and adhesin biosynthesis, and the interesting and potentially useful physiological properties of these organisms. Comparative analysis of the genome sequences of the stalked bacteria will further our understanding of prokaryotic stalk synthesis and stalk protein targeting and provide the information necessary to engineer stalked bacteria to efficiently remove toxic compounds from contaminated water sites. The particular advantage of this system is that these strains can be engineered to efficiently take up toxins present at low concentrations in water sources. Using stalks for the efficient uptake of pollutants has an obvious advantage in the case of Ancalomicrobium adetum, which synthesizes up to eight stalks. In addition, the stalked bacteria to be sequenced are physiologically diverse, including both anoxygenic and aerobic bacteria. Therefore, it should be possible to engineer specific genera of stalked bacteria to combat contamination in specific environments.
Principal Investigators: Yves V. Brun (Indiana Univ.)