Ktedonosporobacter rubrisoli gen. nov., sp. nov., a novel representative of the class Ktedonobacteria, isolated from red soil, and proposal of Ktedonosporobacteraceae fam. nov.

Abstract

A novel filamentous, spore-forming, Gram-stain-positive bacterium, designated SCAWS-G2T, was isolated from red soil in Jiangxi Province, PR China. The strain grew at 25–45 °C and at pH 4.0–7.0, and was able to tolerate up to 50 mM Zn2+. The complete genome of strain SCAWS-G2T was a circular chromosome of ~11.34 Mb, which contained four 16S rRNA genes with three sequence types (0.4–0.8 % differences). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SCAWS-G2T formed a distinct lineage within the order Ktedonobacterales , showing <89.2 % sequence similarities to the recognized taxa of this order. The whole-genome based phylogenomic tree separated strain SCAWS-G2T from the recognized families within Ktedonobacterales . The genome-wide average nucleotide identity values between strain SCAWS-G2T and the related type strains were <68.2 %. The strain can also be differentiated from the recognized families by a number of phenotypic characteristics. The polar lipids of SCAWS-G2T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, seven unidentified glycolipids and one unidentified lipid. The peptidoglycan amino acids contained ornithine, glycine, glutamic acid and alanine, and the cell-wall sugars were mainly galactose and rhamnose. The major fatty acids were C16 : 1 2-OH, C16 : 0 and iso-C17 : 0. Based on all these data, we propose that strain SCAWS-G2T represents a novel genus and species, Ktedonosporobacter rubrisoli gen. nov., sp. nov., within the new family Ktedonosporobacteraceae fam. nov. of the order Ktedonobacterales . The type strain of Ktedonosporobacter rubrisoli is SCAWS-G2T (=CGMCC 1.16132T=DSM 105258T).

Transition from unclassified Ktedonobacterales to Actinobacteria during amorphous silica precipitation in a quartzite cave environment

“…However, the 16S rRNA-based analysis is often not enough for deep taxonomy studies and the only attainment of the isolate would allow the certain definition of the new bacterial lineage possibly associated to the pioneering colonization of orthoquartzite cave surfaces. In the literature, only one strain was isolated for each of the two Ktedonobacterales genera Ktedonobacter 50 and Ktedonosporobacter 51 , while most of the Ktedonobacter genomes in the database are available as draft version and derive from metagenome-based reconstructions. Their filamentous structures resemble the microbial morphology that we observed in QP sample through FESEM, although no spore-like structures were evident in the Imawarì Yeuta sample 52 , 53 .…”

Reticulibacter mediterranei gen. nov., sp. nov., within the new family Reticulibacteraceae fam. nov., and Ktedonospora formicarum gen. nov., sp. nov., Ktedonobacter robiniae sp. nov., Dictyobacter formicarum sp. nov. and Dictyobacter arantiisoli sp. nov., belonging to the class Ktedonobacteria

“…1i). The spore surface was rough and covered with granules, similar to that of Ktedonosporobacter rubrisoli SCAWS-G2 T [6]. However, strain SCAWS-G2 T had spherical spores, which is differ from strain 150040 T .…”

Dictyobacter vulcani sp. nov., belonging to the class Ktedonobacteria, isolated from soil of the Mt Zao volcano

“…MK-9 was the major menaquinone of strain W12 T (). So far, among Ktedonobacteria , MK-9 has been reported as the major menaquinone only for Tengunoibacter tsumagoiensis Uno3 T [3], while all other described strains – including the reference Dictyobacter type strains – have MK-9(H 2 ) [2, 4, 5, 8, 9]. The cell-wall sugars of strain W12 T (mannose and xylose) also differed from D.…”

“…The class Ktedonobacteria was initially established in 2006 for the Gram-positive, aerobic, mycelia-and spore-forming branching lineage in the phylum Chloroflexi [1] and, at the time or writing, contains six genera and 13 formally proposed mesophilic and thermophilic species [1][2][3][4][5][6][7][8][9]. Strains belonging to this class were characterized with actinomycete-like morphologies [1][2][3][4][5][6][7][8][9], relatively large genomes (5.54-13.66 Mb) [10][11][12], ubiquity in various terrestrial environments [13][14][15][16][17][18] and having potential for secondary metabolism [12,[19][20][21].…”

“…strains -including the reference Dictyobacter type strainshave MK-9(H 2 )[2,4,5,8,9]. The cell-wall sugars of strain W12 T (mannose and xylose) also differed from D. aurantiacus S-27 T (arabinose), D. alpinus Uno16 T (mannose and glucose) and D. kobayashii Uno11 T (mannose, arabinose and xylose).…”