Frankia sp. CcI3

Names Frankia sp. CcI3
Accession numbers NC_007777
Background Frankia sp. are filamentous bacteria that grow by hyphal branching and tip extension. They produce three cell types during growth: vegetative hyphae, sporangiospores and lipid-enveloped cellular structures known as "vesicles". Frankia sp. have the ability to form symbiotic nitrogen-fixing root nodules on certain woody angiosperms, termed "actinorhizal plants". The vesicle cell type develops during N-starvation and contains the O2-labile nitrogenase. During symbiosis, they supply sufficient combined nitrogen so that the plant can grow without added nitrogen. Frankia thus can supply most or all of the host plant nitrogen needs. Consequently, actinorhizal plants colonize and often thrive in soils that are low in combined nitrogen. This type of symbiosis adds a large proportion of new nitrogen to several ecosystems. It constitutes the major N2-fixing symbioses in temperate forests, dry chaparral and matorral, coastal dunes, alpine communities and in colder regions such as in Scandinavia, Canada, Alaska or New Zealand where legumes are insignificant or absent. Frankiae have all housekeeping genes necessary for saprophytic existence plus genes for sporulation, vesicle development, symbiosis, N2 fixation and secondary metabolite production. Frankia sp. strain CcI3 was isolated in 1983 at Harvard Forest in John Torrey's lab. It is a member of the narrow host range "Casuarinaceae" strain (Cluster 1 subclade). It grows slowly on organic acids such as propionate or pyruvate and will grow on some complex media. It is resistant to kanamycin and, like many actinomycetes, to nalidixic acid. Its ultrastructure has been studied both with respect to its free-living existence and its presence in nodules of Casuarina sp. The Casuarinaceae is a tropical family of trees and shrubs whose natural range includes Australia and the Melanesian region of the Pacific. They have been planted on islands and in coastal regions of the Indian Ocean, New Zealand, Africa and North and South America, especially in the Caribbean islands, Florida and California where they have been used for soil stabilization, as windbreaks and for lumber and firewood. (HAMAP: FRASC)
Strain CcI3
Complete Yes
Sequencing centre (07-FEB-2006) National Center for Biotechnology Information, NIH, Bethesda, MD 20894, USA
(19-JAN-2006) US DOE Joint Genome Institute, 2800 Mitchell Drive B100, Walnut Creek, CA 94598-1698, USA
Sequencing quality Level 6: Finished
Sequencing depth NA
Sequencing method Sanger
Isolation site Root nodules of Casuarina cunninghamiana in 1983 at Harvard Forest
Isolation country USA
Number of replicons 1
Gram staining properties Positive
Shape Filamentous
Mobility No
Flagellar presence NA
Number of membranes 1
Oxygen requirements Aerobic
Optimal temperature NA
Temperature range Mesophilic
Habitat Multiple
Biotic relationship Symbiotic
Host name NA
Cell arrangement Filaments
Sporulation Sporulating
Metabolism Nitrogen fixation
Energy source Chemoorganotroph
Diseases NA
Pathogenicity No