Abstract
A novel actinobacterium, strain YIM 96748T, was isolated from a saline soil sample collected from the south bank of Aiding Lake in Xinjiang Province, Northwest China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YIM 96748T is closely related to Amycolatopsis cihanbeyliensis BNT52T (98.9%) and Amycolatopsis jiangsuensis KLBMP 1262T (97.2%). The DNA–DNA relatedness between strain YIM 96748T and its closest type strain A. cihanbeyliensis BNT52T was 59.6%. The average nucleotide identity between strain YIM 96748T and its neighbor strain was 88.97%. Based on the genotypic and phenotypic characteristics, it is concluded that strain YIM 96748T represents a novel species of the genus Amycolatopsis, whose name was proposed as Amycolatopsis aidingensis sp. nov. The type strain is YIM 96748T. To investigate the biosynthetic potential of producing secondary metabolites, the complete genome of YIM 96748T was sequenced and analyzed. The complete genome sequence of YIM 96748T consists of a 7,657,695-bp circular chromosome, comprising 7,162 predicted genes with a DNA G + C content of 70.21 mol%. Fifty-one putative biosynthetic gene clusters of secondary metabolites were found, including the antibacterial/antitumor agent TLN-05220, the antibacterial agent nocardicin A, the antifungal agent nystatin A1, and the osmolyte ectoine. The investigation of the secondary metabolites of A. aidingensis YIM96748T led to the discovery of two new phenylpropyl acetate enantiomers, amycoletates A (1) and B (2), and five known compounds: 4-hydroxy phenethyl acetate (3), 2-p-acetoxyphenylethanol (4), (S)-ethyl indole-3-lactate (5), (R)-ethyl indole-3-lactate (6), and p-hydroxybenzoic acid (7). One of the gene clusters 14, 36, and 43, which contain a single module of polyketide synthase, might be responsible for the biosynthesis of compounds 1 and 2 from compound 7 as a precursor. Further studies, including the one strain many compounds approach (OSMAC) and genetic modification, are needed to explore novel compounds from this talented halophilic Amycolatopsis strain.
Highlights
Strains of the genus Amycolatopsis are valuable sources, which could produce many active secondary metabolites
Strain YIM 96748T was isolated on cellulose–casein multi-salt (CCMS) medium (Tang et al, 2008) supplemented with 5% NaCl (w/v), which had been inoculated with a soil suspension and incubated at 37◦C for 4 weeks from soil samples isolated from a saline soil sample collected from the south bank of Aiding Lake, which is situated in the southern part of the Turpan Basin in Xinjiang Province, Northwest China
Phylogenetic analyses of the 16S ribosomal RNA (rRNA) gene sequences showed that strain YIM 96748T was a member of the genus
Summary
Strains of the genus Amycolatopsis are valuable sources, which could produce many active secondary metabolites. The ansamycin antibiotic rifamycin from Amycolatopsis mediterranei S699 is one of the first-line therapies used for the treatment of pathogenic Gram-positive cocci and mycobacteria infections for more than half a century (Sepkowitz et al, 1995). Many powerful antibiotics, such as barrymycin, balhimycin, chloroeremomycin, telavancin, oritavancin, and dethymicin, have been discovered from this genus. The earliest discovered species of Amycolatopsis is Streptomyces orientalis (Brigham and Pittenger, 1956). It was renamed as Amycolatopsis orientalis in 1986 (Lechevalier et al, 1986). Members of the genus Amycolatopsis are aerobic or facultative aerobic, Gram-positive, catalase-positive, non-acid-fast, non-motile actinomycetes that contain mesodiaminopimelic acid in the wall peptidoglycan (Lechevalier and Lechevalier, 1970). The predominant menaquinone type is MK9(H4), and the G + C content of the genomic DNA ranges from 66 to 75 mol%
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
