%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Ben ali gam, Zouhaier
%A Thioye, A.
%A Cayol, J. L.
%A Postec, A.
%A Bartoli-Joseph, M.
%A Vandecasteele, C.
%A Erauso, G.
%A Labat, Marc
%T Thermospira aquatica gen. nov., sp. nov., a novel thermophilic spirochete isolated from a Tunisian hot spring, and description of the novel family Thermospiraceae
%D 2023
%L fdi:010088158
%G ENG
%J International Journal of Systematic and Evolutionary Microbiology
%@ 1466-5026
%K hot spring ; novel family ; novel genus ; thermophilic spirochaetota ; Thermospira
%K TUNISIE
%M ISI:001008263300026
%N 1
%P [10 ]
%R 10.1099/ijsem.0.005690
%U https://www.documentation.ird.fr/hor/fdi:010088158
%> https://www.documentation.ird.fr/intranet/publi/2023-08/010088158.pdf
%V 73
%W Horizon (IRD)
%X A novel thermophilic, anaerobic bacterium, strain F1F22T, was isolated from hot spring water collected in northern Tunisia. The cells were non-motile, Gram-negative and helical with hooked ends, 0.5x10-32 mu m in size. Growth of the strain was observed at 45-70 degrees C (optimum, 55 degrees C), in 0.0-1.0 % (w/v) NaCl (optimum without NaCl) and at pH 6.5-8.5 (optimum, pH 7.5). Yeast extract was required for growth, and the strain grew on glucose, sucrose and maltose. The major fatty acids were C16:0 (40.2 %), iso- C16: 0 (30.2 %) and C16 :0 DMA (14.5 %). The genome consisted of a circular chromosome (2.5 Mb) containing 2672 predicted protein -encoding genes with a G+C content of 43.15 mol %. Based on a comparative 16S rRNA gene sequence analysis, strain F1F22T formed a deeply branching lineage within the phylum Spirochaetota, class Spirochaetia, order Brevinematales, and had only low sequence similarity to other species of the phylum (lower than 83 %). Genome- based analysis of average nucleotide identity and digital DNA-DNA hybridization of strain F1F22T with Treponema caldarium DSM 7334T, Brevinema andersonii ATCC 43811T and Spirochaeta thermophila DSM 6578T showed values between 63.26 and 63.52 %, and between 20 and 25 %. Hence, we propose strain F1F22T as a representative of a novel family (Thermospiraceae fam. nov.), genus and species of Brevinematales: Ther-mospira aquatica gen. nov., sp. nov. (type strain F1F22T=JCM 31314T=DSM 101182T).
%$ 084 ; 034