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Seventeen Gram-negative, facultatively anaerobic bacterial strains were isolated from bleeding cankers of various broadleaf hosts and oak rhizosphere soil in Great Britain. The strains were tentatively identified as belonging to the genus Raoultella based on 16S rRNA gene sequencing. Multilocus sequence analysis (MLSA), based on four protein-encoding genes (fusA, leuS, pyrG, and rpoB), separated the strains into three clusters within the Raoultella genus clade. The majority of strains clustered with the type strain of Raoultella terrigena, with the remaining strains divided into two clusters with no known type strain. Whole genome sequencing comparisons confirmed these two clusters of strains as belonging to two novel Raoultella species which can be differentiated phenotypically from their current closest phylogenetic relatives. Therefore, two novel species are proposed: Raoultella scottia sp. nov. (type strain = BAC 10a-01-01T = LMG 33072T = CCUG 77096T) and Raoultella lignicola sp. nov. (type strain = TW_WC1a.1T = LMG 33073T = CCUG 77094T). [ABSTRACT FROM AUTHOR]

Following a screening campaign of bleeding cankers of broadleaf hosts in Great Britain, numerous bacterial strains were isolated, identified by 16S rRNA and protein-coding gene sequencing and ultimately classified. During the course of the study, several Gram-negative, facultatively anaerobic strains were isolated from bleeding Platanus x acerifolia (London plane) and Tilia x europaea (common lime) cankers that could not be assigned to an existing species. Partial 16S rRNA gene sequencing placed these strains in the genus Erwinia, as a close phylogenetic relative of Erwinia toletana. In an effort to determine the taxonomic position of the strains, a polyphasic approach was followed including genotypic, genomic, phenotypic, and chemotaxonomic assays. Multilocus sequence analysis based on four protein-coding genes (gyrB, rpoB, infB, and atpD) confirmed the phylogenetic position of the strains as a novel taxon of subgroup 3 of the genus Erwinia, along with E. toletana and E. iniecta, and furthermore, provided support for their reclassification in a novel genus. Whole genome comparisons allowed the delimitation of the novel species and also supported the proposed transfer of subgroup 3 species to a novel genus in the Erwiniaeae. Phenotypically the novel species could be differentiated from E. toletana and E. iniecta, and the novel genus could be differentiated from the closely related genera Erwinia and Mixta. Therefore, we propose (1) the reclassification of E. toletana and E. iniecta in a novel genus, Winslowiella gen. nov., as Winslowiella toletana comb. nov. and Winslowiella iniecta comb. nov., with W. toletana comb. nov. as the type species (type strain A37T = CFBP 6631T = ATCC 700880T = CECT 5263T), and (2) classification of the novel strains as Winslowiella arboricola sp. nov. (type strain BAC 15a-03bT = LMG 32576T = NCPPB 4696T). [ABSTRACT FROM AUTHOR]

Several strains of a previously undescribed bacterial species were isolated from mature Tilia hybrid trees suffering from bleeding cankers at various geographic locations in the UK. The strains were Gram-negative, facultatively anaerobic, and partial sequencing of the gyrB gene revealed that the strains belong to the genus Brenneria with the closest phylogenetic neighbours being Brenneria corticis and Brenneria nigrifluens . Further investigation using a polyphasic approach was undertaken to determine the taxonomic position of the novel species. Phylogenies based on the 16S rRNA gene and multilocus sequence analysis of partial housekeeping gene sequences of gyrB , rpoB , infB and atpD revealed that the strains formed an independent cluster within the genus Brenneria . The phenotypic and chemotaxonomic assays demonstrated that the strains could be differentiated from the closest relatives. Genome analysis of representative strains revealed in silico DNA-DNA hybridization values below the threshold for species delimitation, although the average nucleotide identity values obtained when compared to B. corticis (95.9-96%) were slightly higher than the suggested cut-off value of 95%. However, as all other data suggests that the strains belong to a novel taxon that can be differentiated from the closest relatives, we propose that the strains represent a novel species in the genus Brenneria , Brenneria tiliae sp. nov. (type strain WC1b.1 T =LMG 32575 T =NCPPB 4697 T ).

Ancient woodlands in Europe are currently subjected to fragmentation, which leads to ecological deterioration and genetic isolation. This is likely to intensify with further climate change and increased land use. Tilia are keystone, ancient woodland indicators, represented in the UK by two species (Tilia cordata and Tilia platyphyllos) and their hybrid (Tilia x europaea). For management of the species, we need to investigate genetic differentiation and population genetic structure. Morphology can usually separate the two species but the distinguishing features are not always observable, particularly in less optimum, shady, conditions. Here, we test for the first time 13 microsatellite markers to discriminate the species and hybrid, and to assess the population genetic diversity of the two species. The markers successfully distinguished the species and hybrid. The two species show significant genetic differentiation, indicating two distinct biological units. Sub-structure within both species is loosely related to geographic location. Because Tilia populations in the UK are highly fragmented, future conservation should consider provenance issues. [ABSTRACT FROM AUTHOR]