Burkholderia graminis sp. nov., a rhizospheric Burkholderia species, and reassessment of [Pseudomonas] phenazinium, [Pseudomonas] pyrrocinia and [Pseudomonas] glathei as Burkholderia

Abstract

In a survey of soil and wheat or maize rhizoplane bacteria isolated using a medium containing azelaic acid and tryptamine as sole carbon and nitrogen sources, respectively, a large proportion of Burkholderia-l i ke bacteria were found. Among them, a homogeneous group of strains was identifiable based on phenotypic properties, fatty acid composition, DNA-DNA hybridizations and 16s rDNA sequences. According to molecular data, this group belongs to the genus Burkholderia but its weak similarity to previously described species suggests that it belongs to a novel species. Closest 16s rDNA phylogenetic neighbours of this species are Burkholderia caryophylli and two previously named Pseudomonas species which clearly appear to be part of the Burkholderia genus and were thus named Burkholderia glathei comb. nov. ), where wheat is grown either continuously or in rotation with a lupin-based pasture; the soil is an alphisol. Walpeup is an experimental wheat-growing station, situated in Victoria (Australia), on a very poor sandy soil, in a fixed sand dune system. Soil samples of the two Australian stations have been collected and used for growing wheat (cv. Spear) in pots under glasshouse conditions (three plants per pot containing 1.5 kg soil). After 3-4 weeks, wheat plants were harvested and used to isolate bacteria from their rhizoplane, as above. A few strains were isolated directly on PCAT medium from salt-affected and hydrophobic soils near Adelaide. Also included in Table 1 are 18 reference strains of Burkholderia, Pseudomonas, Ralstonia and Alcaligenes. Among the eleven type strains of Burkholderia species, only type strains of B. mallei and B. pseudomallei were not grown in this laboratory.Biochemical characterization. All tests were performed at 28 "C. The Biolog GN system was used as recommended by the manufacturer to test the oxidation of 95 carbon substrates. Results were read automatically with a spectrophotometer after 24 or 48 h incubation at 28 "C. To test the reproducibility of the method, eight isolates were run in duplicate. Numerical analysis of the results was made using the G N Microlog 2N software which calculates Microlog distances derived from the number of differences between strains. This software also permits clustering analysis using the UPGMA (unweighted mean pair group method) algorithm of Sneath & Sokal(44).Carbon substrate assimilation tests were performed using auxanographic API 50CH strips (bioMCrieux) as recommended by the manufacturer. Nine isolates were tested in duplicate. Numerical analysis was performed on data obtained after 7 d incubation. Interstrain distances were calculated using the coefficient of Dice and a phenogram was built using UPGMA.The API 20NE microtube system (bioMCrieux) was used as a standardized method to test oxidase activity, nitrate reduction, gelatin and aesculin hydrolysis, glucose fermentation, arginine dihydrolase activity and production of indole, P-galactosidase and urease.MIDI-FAME. The MIDI-FAME technique is based on the conversion of fatty acids to met...

Burkholderia kururiensis sp. nov., a trichloroethylene (TCE)-degrading bacterium isolated from an aquifer polluted with TCE.

“…FAME analysis of strain KP23 T showed the presence of 3-OH C16 : 0, which was a characteristic feature of the genus Burkholderia (Viallard et al, 1998). The main cellular fatty acids in the strain were similar to those of representative species in the genus Burkholderia (Yabuchi et al, 1992(Yabuchi et al, , 1995.…”

Novel Burkholderia bacteria isolated from Lebeckia ambigua – A perennial suffrutescent legume of the fynbos

“…Strains WSM4181 and WSM4182 (which could not be authenticated on L. ambigua) form group two, and show very high similarity (100%) in 16S rRNA, recA and gyrB to B. graminis LMG 18924 T (Peter Vandamme Ghent University, personal communication). B. graminis strains were isolated from the rhizospheres of wheat, corn and pasture grasses from South Australia and Côte Saint André in France (Viallard et al, 1998). Although B. graminis strains are not able to nodulate legumes, they are known for their nematode reduction capacity in sugarcane (Omarjee et al, 2008).…”

Endofungal bacterium controls its host by an hrp type III secretion system

“…According to the cladogram, the nearest relative of SctC was found in Burkholderia graminis C4D1M (accession ZP 02881763.1), a ubiquitous rhizosphere colonizer (Viallard et al, 1998). To our knowledge the function of this gene cluster is unknown.…”