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Order Lysobacterales (earlier known Xanthomonadales ) is a taxonomically complex group of a large number of gamma-proteobacteria classified in two different families, namely Lysobacteraceae and Rhodanobacteraceae . Current taxonomy is largely based on classical approaches and is devoid of whole-genome information-based analysis. In the present study, we have taken all classified and poorly described species belonging to the order Lysobacterales to perform a phylogenetic analysis based on the 16 S rRNA sequence. Moreover, to obtain robust phylogeny, we have generated whole-genome sequencing data of six type species namely Metallibacterium scheffleri , Panacagrimonas perspica , Thermomonas haemolytica , Fulvimonas soli , Pseudofulvimonas gallinarii and Rhodanobacter lindaniclasticus of the families Lysobacteraceae and Rhodanobacteraceae . Interestingly, whole-genome-based phylogenetic analysis revealed unusual positioning of the type species Pseudofulvimonas , Panacagrimonas , Metallibacterium and Aquimonas at family level. Whole-genome-based phylogeny involving 92 type strains resolved the taxonomic positioning by reshuffling the genus across families Lysobacteraceae and Rhodanobacteraceae . The present study reveals the need and scope for genome-based phylogenetic and comparative studies in order to address relationships of genera and species of order Lysobacterales ., Competing Interests: The authors declare that there are no conflicts of interest., (© 2019 The Authors.)

A Gram-stain-positive, motile, endospore-producing, facultative anaerobic bacterial strain, designated ATCC 27380 T , was isolated from heat-stressed soil of Cape Canaveral, Florida, USA. Growth was observed at 20-42 °C (optimum, 37 °C), at pH 6.0-10.0 (optimum pH 7.0) and in the presence of 0.5-3 % NaCl (optimum 0.5 %). The cell wall contained meso-diaminopimelic acid as the diagnostic amino acid and the isoprenoid quinone was MK-7. The polar lipids present were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol and one unknown phospholipid. The main fatty acids were iso-C15 : 0 and anteiso-C15 : 0. Phylogenetic analysis based on 16S rRNA gene sequencing affiliated strain ATCC 27380 T to the genus Paenibacillus, and showed the highest sequence similarity to Paenibacillus rigui JCM 16352 T (97.0 %). The other closely related type strains exhibited 16S rRNA gene sequence similarity values below 95.9 %. The draft genome of ATCC 27380 T had a size of 4,361,187 bases, with a G+C content of 51.0 %. The average nucleotide identity and in silico DNA-DNA hybridization values between strain ATCC 27380 T and P. rigui JCM 16352 T were 72.5% and 18.5 %, respectively, which were below the threshold suggested for species differentiation (96% and 70 %, respectively). The average amino acid identity between strain ATCC 27380 T and P. rigui JCM 16352 T was 68.72 %, which was above the suggested genus level demarcation of 65 %. Based on phenotypic, genotypic and chemotaxonomic data, strain ATCC 27380 T represents a novel species in the genus Paenibacillus, for which the name Paenibacillusxerothermodurans sp. nov. (=DSM 520 T =NRRL NRS-1629 T =ATCC 27380 T ) is proposed.

Stenotrophomonas maltophilia has evolved as one of the leading multidrug-resistant pathogens responsible for a variety of nosocomial infections especially in highly debilitated patients. As information on the genomic and intraspecies diversity of this clinically important pathogen is limited, we sequenced the whole genome of 27 clinical isolates from hospitalized patients. Phylogenomic analysis along with the genomes of type strains suggested that the clinical isolates are distributed over the Stenotrophomonas maltophilia complex (Smc) within the genus Stenotrophomonas. Further genome-based taxonomy coupled with the genomes of type strains of the genus Stenotrophomonas allowed us to identify five cryptic genomospecies, which are associated with the clinical isolates of S. maltophilia and are potentially novel species. These isolates share a very small core genome that implies a high level of genetic diversity within the isolates. Recombination analysis of core genomes revealed that the impact of recombination is more than mutation in the diversification of clinical S. maltophilia isolates. Distribution analysis of well-characterized antibiotic-resistance and efflux pump genes of S. maltophilia across multiple novel genomospecies provided insights into its antibiotic-resistant ability. This study supports the existence of multiple cryptic species within the Smc besides S. maltophilia, which are associated with human infections, and highlights the importance of genome-based approaches to delineate bacterial species. This data will aid in improving clinical diagnosis and for understanding species-specific clinical manifestations of infection due to Stenotrophomonas species.