Burkholderia perseverans sp. nov., a bacterium isolated from the Restinga ecosystem, is a producer of volatile and diffusible compounds that inhibit plant pathogens

Abstract

Gram-negative, aerobic, rod-shaped, non-spore-forming, motile bacteria, designated CBAS 719 T , CBAS 732 and CBAS 720 were isolated from leaf litter samples, collected in Espírito Santo State, Brazil, in 2008. Sequences of the 16S rRNA, gyrB, lepA and recA genes showed that these strains grouped with Burkholderia plantarii LMG 9035 T , Burkholderia gladioli LMG 2216 T and Burkholderia glumae LMG 2196 T in a clade of phytopathogenic Burkholderia species. Digital DNA-DNA hybridization experiments and ANI analyses demonstrated that strain CBAS 719 T represents a novel species in this lineage that is very closely related with B. plantarii. The genome sequence of the type strain is 7.57 Mbp and its G + C content is 69.01 mol%. The absence of growth on TSA medium supplemented with 3% (w/v) NaCl, citrate assimilation, β-galactosidase (PNPG) activity, and of lipase C14 activity differentiated strain CBAS 719 T from B. plantarii LMG 9035 T , its nearest phylogenetic neighbor. Its predominant fatty acid components were C 16:0 , C 18:1 ω7c, cyclo-C 17:0 and summed feature 3 (C 16:1 ω7c and/or C 15:0 iso 2-OH). Based on these genotypic and phenotypic characteristics, the strains CBAS 719 T , CBAS 732 and CBAS 720 are classified in a novel Burkholderia species, for which the name Burkholderia perseverans sp. nov. is proposed. The type strain is CBAS 719 T (= LMG 31557 T = INN12 T ).

Genome-based taxonomy of Burkholderia sensu lato: Distinguishing closely related species

“…“ Burkholderia perseverans ” was isolated from leaf litter of Brazilian’s Restinga ecosystem and exhibits antifungal properties. It was differentiated from B. plantarii type strain through ANI, dDDH, and biochemical tests, including lack of growth in TSA medium containing 3% NaCl, citrate assimilation, and β-galactosidase activity ( Andrade et al, 2021 ). These authors also characterized another two “ B. perseverans ” isolates that formed a separated cluster in the phylogenetic tree.…”

“…However, we agree with the proposal of the new species ( Table 1 ) due to the following data: i) both genomes are complete and result in ANIb values below 95%. ANIb is more robust and the current preferential ANI methodology; ii) dDDH formula 2 is below 70% and is the developer’s recommended formula; iii) other “ B. perseverans ” isolates formed a separated clade in the phylogenetic tree; and iv) they exhibit diagnostic phenotypic traits ( Andrade et al, 2021 ). This case highlights the eminent necessity for establishing more precise and detailed criteria for species delineation using genome metrics by the ICSP.…”

Extracellular DNAses Facilitate Antagonism and Coexistence in Bacterial Competitor-Sensing Interference Competition

“…S8-1), and the negative-control Staphylococcus colonies were transferred and spotted on the plate using a sterile flat toothpick. Plates were incubated overnight at 25°C, and the zone of inhibition (ZOI) was determined, as well as the exDNase activity by flooding the plate with 1 N HCl ( 23 ).…”

“…Many of these compounds have DNase activity ( 22 ), indicating a role for DNases in competition. This is further illustrated in several studies showing that extracellular DNases (exDNases) and effectors of these have roles in hydrolyzing extracellular DNA (exDNA) in situations like biofilm development, toxin production in the presence of exDNA, in enriched plant root-associated bacteria ( 23 – 27 ), and are even differentially selected for by crop plants ( 28 ). Therefore, we further hypothesize that exDNase production has an important role in the structure of bacterial interaction networks.…”

Antifungal strains M1-8 and M6-4 as biocontrol agents against Aspergillus flavus on peanut kernels

“…Burkholderia cepacia strain (QBC03) was examined and exhibited in vitro biocontrol activity against various fungi of Aspergillus, Penicillium and Fusarium (Zeidan et al, 2019). Andrade et al (2021) reported that Burkholderia cepacia may also be beneficial as a biocontrol agent. Different species of Burkholderia spp.…”