Thermolongibacillus altinsuensis gen. nov., sp. nov. and Thermolongibacillus kozakliensis sp. nov., aerobic, thermophilic, long bacilli isolated from hot springs

Abstract

Two novel endospore-forming, aerobic bacilli, strains E173aT and E265T, were isolated from soil and sediment samples from Kozakli and Altinsu hot springs, Nevsehir (Turkey). Their young cells in the exponential phase of growth were motile, Gram-stain-positive, straight rods, 0.6–1.1×3.0–8.0 µm in size, but they became strikingly long, approximately 0.6–1.2 by 9.0–35.0 µm, after the stationary phase of growth. Cells varied in tests for oxidase, and had a weakly positive reaction for catalase. Both strains could grow between 40 and 70 °C, with optimal growth at 60 °C (E173aT) and 55 °C (E265T). Growth occurred within the range pH 5.0–11.0 with optimal growth at pH 9.0 (E173aT) and pH 8.5 (E265T). Strain E173aT grew within a salinity range from 0 to1.5 % (w/v) NaCl with optimal growth at 0.5 %, while strain E265T grew within the range 0–5.0 % (w/v), with an optimum at 3.0 %. The new isolates differed from each other in some phenotypic and chemotaxonomic characters as well as repetitive extragenic palindromic element PCR (rep-PCR) fingerprints. 16S rRNA gene sequence similarities suggested distant relationships with other members of the family Bacillaceae (<95.8 %), although the two strains showed 97.5 % sequence similarity between them, and had 55 % relatedness by DNA–DNA hybridization. The DNA G+C contents were 44.8 (E173aT) and 43.5 mol% (E265T). Moreover, the chemotaxonomic data of E173aT and E265T [presence of low amounts of meso-diaminopimelic acid, A1γ to A1γ′ cross-linkage types in peptidoglycan, fatty acids including iso-C15 : 0 (>60 %), iso-C17 : 0 and C16 : 0] supported the consideration of these isolates as members of a novel genus. Based upon phenotypic, phylogenetic and chemotaxonomic characteristics, it is proposed that new isolates represent a novel genus, Thermolongibacillus gen. nov., with two novel species: Thermolongibacillus altinsuensis sp. nov. (type strain E265T = DSM 24979T = NCIMB 14850T) and Thermolongibacillus kozakliensis sp. nov. (type strain E173aT = DSM 24978T = NCIMB 14849T).

Melghiribacillus thermohalophilus gen. nov., sp. nov., a novel filamentous, endospore-forming, thermophilic and halophilic bacterium

“…In fact, by its optimum growth temperature of 55 °C, strain Nari2A T is distinguished from several genera of family Bacillaceae , including its closest phylogenetic relatives (). Thermophilic, aerobic members of the Bacillaceae with growth optima in the temperature range 45 to >70 °C are classified in the genera Bacillus , Alicyclobacillus , Brevibacillus , Aneurinibacillus , Sulfobacillus , Thermobacillus , Geobacillus and Thermolongibacillus (Sneath et al , 1986; Wisotzkey et al , 1992; Dufresne et al , 1996; Heyndrickx et al , 1998; Touzel et al , 2000; Coorevits et al , 2011; Cihan et al , 2014). In contrast to strain Nari2AT, these species are not halophilic.…”

Salipaludibacillus aurantiacus gen. nov., sp. nov. a novel alkali tolerant bacterium, reclassification of Bacillus agaradhaerens as Salipaludibacillus agaradhaerens comb. nov. and Bacillus neizhouensis as Salipaludibacillus neizhouensis comb. nov.

“…The family Bacillaceae is one of the largest taxa in the order Bacillales in which several novel genera have been reported. Some of these recently described genera include Streptohalobacillus (Wang et al, 2011), Allobacillus (Sheu et al, 2011), Natribacillus (Echigo et al, 2012), Domibacillus (Seiler et al, 2013), Saliterribacillus (Amoozegar et al, 2013), Fictibacillus (Glaeser et al, 2013), Sinibacillus (Yang & Zhou, 2014), Thermolongibacillus (Cihan et al, 2014), Aquibacillus (Amoozegar et al, 2014), Aureibacillus , Compostibacillus , Melghiribacillus (Addou et al, 2015) and Salibacterium (Reddy et al, 2015). In this study, we propose a novel species of a new genus in the family Bacillaceae, by characterizing two strains (S9 T and S12) based on the minimal standards (Logan et al, 2009) proposed for the description of new taxa of aerobic, endospore-forming bacteria.…”