De Canck, Evelien

A Gram-stain-negative coccobacillus, LMG 32992T, was isolated from water that had collected in a tyre in Pingtung, Donggang Township, Taiwan. Upon preliminary 16S rRNA gene sequence analysis, it was most closely related to members of the genus Ralstonia (16S rRNA gene sequence similarities of 96.7–97.5%). The present study aimed to elucidate its taxonomic position and to propose a formal classification. To this end, the complete genome sequence was determined, and taxonomic, phylogenomic, metabolic and physiological analyses were performed. Comparative genomic analyses demonstrated that strain LMG 32992T and another unclassified strain, Burkholderiaceae bacterium PBA, which was isolated earlier from textile wastewater in Malaysia, represented a single novel species within a novel genus of the family Burkholderiaceae. The G+C content of the LMG 32992T genomic DNA was 63.77 mol%. Genomic analyses and growth tests demonstrated that LMG 32992T had an asaccharolytic metabolism but that it was well-equipped to synthetize, if necessary autotrophically, and transform all required carbohydrates and that it used the Krebs and related cycles to generate reductive power for a heterotrophic energy metabolism. We propose the name Imbroritus primus gen. nov., sp. nov. with strain LMG 32992T (=CIP 112179T=BCRC 81361T=A30B1T) as the type strain, for this novel taxon.

Strain LMG 33000T was isolated from a Bombus lapidarius gut sample. It shared the highest percentage 16S rRNA sequence identity, average amino acid identity, and amino acid identity of conserved genes with Convivina intestini LMG 28291T (95.86 %, 69.9 and 76.2 %, respectively), and the highest percentage OrthoANIu value with Fructobacillus fructosus DSM 20349T (71.4 %). Phylogenomic analyses by means of 107 or 120 conserved genes consistently revealed Convivina as nearest neighbour genus. The draft genome of strain LMG 33000T was 1.44 Mbp in size and had a DNA G+C content of 46.1 mol%. Genomic and physiological analyses revealed that strain LMG 33000T was a typical obligately fructophilic lactic acid bacterium that lacked the adhE and aldh genes and that did not produce ethanol during glucose or fructose metabolism. In contrast, Convivina species have the adhE and aldh genes in their genomes and produced ethanol from glucose and fructose metabolism, which is typical for heterofermentative lactic acid bacteria. Moreover, strain LMG 33000T exhibited catalase activity, an unusual characteristic among lactic acid bacteria, that is not shared with Convivina species. Given its position in the phylogenomic trees, and the difference in genomic percentage G+C content and in physiological and metabolic characteristics between strain LMG 33000T and Convivina species, we considered it most appropriate to classify strain LMG 33000T into a novel genus and species within the Lactobacillaceae family for which we propose the name Eupransor demetentiae gen. nov., sp. nov., with LMG 33000T (=CECT 30958T) as the type strain.