Burkholderia phymatum is a highly effective nitrogen-fixing symbiont of Mimosa spp. and fixes nitrogen ex planta.
* The ability of Burkholderia phymatum STM815 to effectively nodulate Mimosa spp., and to fix nitrogen ex planta, was compared with that of the known Mimosa symbiont Cupriavidus taiwanensis LMG19424. * Both strains were equally effective symbionts of M. pudica, but nodules formed by STM815 had greater nitrogenase activity. STM815 was shown to have a broader host range across the genus Mimosa than LMG19424, nodulating 30 out of 31 species, 21 of these effectively. LMG19424 effectively nodulated only nine species. GFP-marked variants were used to visualise symbiont presence within nodules. * STM815 gave significant acetylene reduction assay (ARA) activity in semisolid JMV medium ex planta, but no ARA activity was detected with LMG19424. 16S rDNA sequences of two isolates originally from Mimosa nodules in Papua New Guinea (NGR114 and NGR195A) identified them as Burkholderia phymatum also, with nodA, nodC and nifH genes of NGR195A identical to those of STM815. * B. phymatum is therefore an effective Mimosa symbiont with a broad host range, and is the first reported beta-rhizobial strain to fix nitrogen in free-living culture.
Elliott
Geoffrey N
GN
School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
Chen
Wen-Ming
WM
Chou
Jui-Hsing
JH
Wang
Hui-Chun
HC
Sheu
Shih-Yi
SY
Perin
Liamara
L
Reis
Veronica M
VM
Moulin
Lionel
L
Simon
Marcelo F
MF
Bontemps
Cyril
C
Sutherland
Joan M
JM
Bessi
Rosana
R
de Faria
Sergio M
SM
Trinick
Michael J
MJ
Prescott
Alan R
AR
Sprent
Janet I
JI
James
Euan K
EK
D001426:Bacterial Proteins / Q000145:classification / Q000235:genetics; D001431:Bacteriological Techniques; D019117:Burkholderia / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D049921:Cupriavidus / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004275:DNA, Ribosomal / Q000737:chemistry / Q000145:classification; D007887:Fabaceae / Q000382:microbiology; D049452:Green Fluorescent Proteins / Q000032:analysis; D031298:Mimosa / Q000382:microbiology*; D009591:Nitrogenase / Q000378:metabolism; D010802:Phylogeny; D053204:Root Nodules, Plant / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D013045:Species Specificity; D013559:Symbiosis
D001426:Bacterial Proteins; D004275:DNA, Ribosomal; D049452:Green Fluorescent Proteins; D009591:Nitrogenase