Title |
Natronorubrum halophilum sp. nov. isolated from two inland salt lakes |
Author |
Cong-Qi Tao, Yi Ding, Yang-Jie Zhao, and Heng-Lin Cui* |
Address |
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P. R. China |
Bibliography |
Journal of Microbiology, 58(2),105-112, 2020,
|
DOI |
10.1007/s12275-020-9514-8
|
Key Words |
Natronorubrum halophilum sp. nov., halophilic
archaeon, salt lakes, genome, phylogenomic analyses |
Abstract |
Two halophilic archaeal strains, SHR37T and NEN6, were
isolated from salt lakes located in the Tibet and Xinjiang regions
of China. The two strains were found to form a single
cluster (99.9% and 99.3% similarity, respectively) separating
them from the six current members of Natronorubrum (94.7–
96.9% and 86.1–90.8% similarity, respectively) on the basis
of the 16S rRNA and rpoB gene sequence similarities and
phylogenetic analysis. Diverse phenotypic characteristics differentiate
strains SHR37T and NEN6 from current Natronorubrum
members. Their polar lipids are C20C20 and C20C25
glycerol diether derivatives of PG, PGP-Me, and a major glycolipid
chromatographically identical to disulfated mannosyl
glucosyl diether (S2-DGD). Four minor unidentified glycolipids
are also present. The OrthoANI and in silico DDH
values of the two strains were 97.3% and 76.1%, respectively,
which were much higher than the threshold values proposed
as a species boundary (ANI 95–96% and in silico DDH 70%),
which revealed that the two strains represent one species;
the two values (ANI 79.0–81.9% and in silico DDH 23.5–
25.7%) of the strains examined in this study and the current
members of Natronorubrum are much lower than the recommended
threshold values, suggesting that strains SHR37T
and NEN6 represent a genomically different species of Natronorubrum.
These results showed that strains SHR37T (=
CGMCC 1.15233T = JCM 30845T) and NEN6 (= CGMCC
1.17161) represent a novel species of Natronorubrum, for
which the name Natronorubrum halophilum sp. nov. is proposed. |