title: A new species of Burkholderia isolated from sugarcane roots promotes plant growth.
abstract: Sugarcane is a globally important food, biofuel and biomaterials crop. High nitrogen (N) fertilizer rates aimed at increasing yield often result in environmental damage because of excess and inefficient application. Inoculation with diazotrophic bacteria is an attractive option for reducing N fertilizer needs. However, the efficacy of bacterial inoculants is variable, and their effective formulation remains a knowledge frontier. Here, we take a new approach to investigating diazotrophic bacteria associated with roots using culture-independent microbial community profiling of a commercial sugarcane variety (Q208(A) ) in a field setting. We first identified bacteria that were markedly enriched in the rhizosphere to guide isolation and then tested putative diazotrophs for the ability to colonize axenic sugarcane plantlets (Q208(A) ) and promote growth in suboptimal N supply. One isolate readily colonized roots, fixed N2 and stimulated growth of plantlets, and was classified as a new species, Burkholderia australis sp. nov. Draft genome sequencing of the isolate confirmed the presence of nitrogen fixation. We propose that culture-independent identification and isolation of bacteria that are enriched in rhizosphere and roots, followed by systematic testing and confirming their growth-promoting capacity, is a necessary step towards designing effective microbial inoculants.
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St. Lucia, Qld, 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Qld, 4072, Australia; ARC Centre of Excellence in Bioinformatics, The University of Queensland, St. Lucia, Qld, 4072, Australia.
authors.forename: Chanyarat
authors.initials: C
authors.lastname: Paungfoo-Lonhienne
authors.forename: Thierry G A
authors.initials: TG
authors.lastname: Lonhienne
authors.forename: Yun Kit
authors.initials: YK
authors.lastname: Yeoh
authors.forename: Richard I
authors.initials: RI
authors.lastname: Webb
authors.forename: Prakash
authors.initials: P
authors.lastname: Lakshmanan
authors.forename: Cheong Xin
authors.initials: CX
authors.lastname: Chan
authors.forename: Phaik-Eem
authors.initials: PE
authors.lastname: Lim
authors.forename: Mark A
authors.initials: MA
authors.lastname: Ragan
authors.forename: Susanne
authors.initials: S
authors.lastname: Schmidt
authors.forename: Philip
authors.initials: P
authors.lastname: Hugenholtz
mesh_terms: D058448:Biota; D019117:Burkholderia / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation; D010802:Phylogeny; D063245:Plant Development; D018517:Plant Roots / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D031786:Saccharum / Q000382:microbiology* / Q000502:physiology*; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S