Published in:
Antonie Van Leeuwenhoek 113(11) , 1617-1632 (Nov 2020)
Author(s):
DOI:
10.1007/s10482-020-01468-5
Abstract:
In this study, two endophytic bacterial strains designated JS21-1(T) and S6-262(T) isolated from leaves of Elaeis guineensis and stem tissues of Jatropha curcas respectively, were subjected for polyphasic taxonomic approach. On R2A medium, colonies of strains JS21-1(T) and S6-262(T) are orange and yellow, respectively. Phylogenetic analyses using 16S rRNA gene sequencing and whole-genome sequences placed the strains in distinct clades but within the genus Sphingomonas. The DNA G + C content of JS21-1(T) and S6-262(T) were 67.31 and 66.95%, respectively. Furthermore, the average nucleotide identity and digital DNA-DNA hybridization values of strains JS21-1(T) and S6-262(T) with phylogenetically related Sphingomonas species were lower than 95% and 70% respectively. The chemotaxonomic studies indicated that the major cellular fatty acids of the strain JS21-1(T) were summed feature 8 (C18:1 omega7c and/or C18:1 omega6c), C16:0, and C14:0 2OH; strain S6-262(T) possessed summed feature 3 (C16:1 omega7c and/or iso-C15:0 2-OH) and summed feature 8 (C18:1 omega6c and/or C18:1 omega7c). The major quinone was Q10, and the unique polyamine observed was homospermidine. The polar lipid profile comprised of mixture of sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and certain uncharacterised phospholipids and lipids. Based on this polyphasic evidence, strains JS21-1(T) and S6-262(T) represent two novel species of the genus Sphingomonas, for which the names Sphingomonas palmae sp. nov. and Sphingomonas gellani sp. nov. are proposed, respectively. The type strain of Sphingomonas palmae sp. nov. is JS21-1(T) (= DSM 27348(T) = KACC 17591(T)) and the type strain of Sphingomonas gellani sp. nov. is S6-262(T) (= DSM 27346(T) = KACC 17594(T)).