DOE-JGi will sequence the genomes of two members of the Micromonosporaceae: Micromonospora strain L5, which was originally isolated from roots of Casuarina equisetifolia, an actinorhizal plant that is nodulated by Frankia, and recently shown to fix atmospheric nitrogen into ammonia; and the ATCC strain M. aurantiaca 27029, which, based on 16S RNA DNA phylogeny, is closely related to strain L5. Species of Micromonospora are important for biocontrol and bioremediation. They have incredible metabolic versatility, among which nitrogen fixation has been added to the traits exhibited by these microbes.
Micromonospora strain L5. Micrograph courtesy Ann M. Hirsch.
Micromonospora species exhibit both saphrophytic (living off dead tissues) and potentially symbiotic lifestyles, and they are ubiquitous in the environment. They are found in soils, sediments, aquatic environments–fresh water, salty pools, and marine settings–as well as in the rumen of cattle and the guts of termites. In termite guts, they degrade plant cell walls and fibers, in this way providing carbon to their host. Several investigators have noted that Micromonospora species have lignocellulase activity. Our preliminary results show that strain L5 and M. aurantiaca 27029 degrade cellulose in liquid-based culture and in plate assays. Micromonosporas also have a unique way of making spores, so comparisons with Frankia and Streptomyces genomes will give us a better understanding of key developmental processes. The spores are highly resistant to desiccation stress and may retain viability for hundreds of years. Knowing the genomes of these two micromonosporas will not only offer tools for studying the different lifestyles exhibited by these organisms, but will also open up opportunities to discover new pathways for biocontrol; for degradation of xenobiotics, plant fibers, and cell walls; and for interesting secondary metabolites.
Principal Investigator: Ann M. Hirsch (Univ. of California, Los Angeles)