Luteitalea pratensis gen. nov., sp. nov. a new member of subdivision 6 Acidobacteria isolated from temperate grassland soil

Albeit being widespread and abundant in soils worldwide, bacteria of the phylum Acidobacteria have remained grossly understudied due to difficulties in their cultivation and isolation. To date, only 48 species have been validly described, including a single member of the phylogenetically diverse Acidobacteria subdivision 6. Here, we report the polyphasic characterization of strain HEG_-6_39(T), a novel representative of Acidobacteria subdivision 6 isolated from a grassland soil in Thuringia, Germany. Cells of HEG_-6_39(T) are Gram-stain-negative, non-motile, non-spore-forming, non-capsulated short rods that form small dark yellow colonies. This slow growing bacterium is psychrotolerant and grows between 0 and 36 degrees C. It displays a narrower pH tolerance (5.3-8.3) than most acidobacteria. The strain is an aerobe that grows chemo-organotrophically utilizing mostly sugars and proteinaceous substrates such as peptone, yeast extract, casein hydrolysate and casamino acids as substrates. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol and two unknown phospholipids are identified as polar lipids. Major fatty acids are iso-C-15 : 0, summed feature 3 (C-16 : 1 omega 6c/C-16 : 1 omega 7c), C-18 : 1 omega 9c and iso-C-17 : 1 omega 9c. The major respiratory quinone is MK-8. The G+C content of the genomic DNA is 64.7 mol%. 16S rRNA gene sequence analysis indicated that this bacterium was related to Vicinamibacter silvestris Ac_5_C6(T) with 93.6% sequence similarity. Based on the present taxonomic characterization, strain HEG_-6_39(T) represents a new species of a novel genus for which the name Luteitalea pratensis gen. nov., sp. nov., is proposed. The type strain of the type species is HEG_6_39(T) (=DSM 100886(T)=KCTC 52215(T)).