Proposal of Furfurilactobacillus cerevisiae sp. nov. isolated from spoiled beer and Furfurilactobacillus cerealis sp. nov. isolated from sourdough

A core genome phylogenomic analysis of two lactic acid bacteria isolates from spoiled beer, <i>Furfurilactobacillus</i> sp. LTH 5742 and LTH 5750, one isolate from sourdough, <i>Furfurilactobacillus</i> sp. C5, and the type strains of five <i>Furfurilactobacillus</i> species were performed. Average nucleotide identity and digital DNA-DNA hybridization analyses revealed two distinct phylogenetic lineages, both clearly separated from the five previously described <i>Furfurilactobacillus</i> species. Based on these data, two novel species were proposed: <i>Furfurilactobacillus cerevisiae</i> sp. nov., represented by strains LTH 5742^T (=DSM 120514^T=LMG 34151^T) and LTH 5750, and <i>Furfurilactobacillus cerealis</i> sp. nov., represented by strain C5^T (=DSM 120515^T=LMG 34152^T). Comparative genomic analyses highlighted distinct metabolic signatures concerning the 1,2-propanediol and hydroxycinnamic acid metabolism. The gene <i>aldA</i> encoding lactaldehyde dehydrogenase, contributing to 1,2-propanediol production from lactate, is present in <i>Ff</i>. spp. LTH 5742^T and LTH 5750, <i>Ff</i>. spp. C5^T and <i>Furfurilactobacillus rossiae</i> but not in <i>Furfurilactobacillus milii</i>. Genes for 1,2-propanediol conversion to propionate and propanol are present in <i>Ff. rossiae</i> but not in one of the other species. The glutathione reductase gene, <i>gshR</i>, was uniquely detected in <i>Ff. cerealis</i>, <i>Ff. rossiae</i> and '<i>Furfurilactobacillus entadae'</i>. These findings expand the diversity of the genus <i>Furfurilactobacillus</i> and provide insight into their ecological adaptation in cereal-based fermentations.