Abstract: In order to identify second metabolites and analyze the corresponding biosynthetic gene clusters, the strain GXIMD 03502, isolated from the Hainan Mangroves, was studied. The strain was identified by comparing 16S rDNA sequence. The secondary metabolites were separated by various chromatographic separation techniques, and their structures were determined by spectral data analysis and literature comparison. Five 2-hydroxyphenylthiazoline derivatives were isolated from this strain and identified as (+)-(S)-pulicatin G (1), pulicatin A (2), aerugine (3), pulicatin F (4), and (+)-(S)-dihydraeruginoic acid (5). At the same time, the genomic DNA of the strain was obtained by Illumina novaseq 6000 sequencing technology. Bioinformatics approach were employed to annotate the biosynthetic gene cluster and deduce the biosynthesis pathways of the compounds. The analysis results of the whole genome DNA sequence indicated that it contained 31 secondary metabolic biosynthetic gene clusters, and revealed that the cluster 11 may be responsible for the biosynthesis of 2-hydroxyphenylthiazoline derivatives. This study provided a mangroves-derived S. ardesiacus GXIMD 03502 to produce 2-hydroxyphenylthiazoline derivatives, and the whole genome sequence of this strain laid a foundation for the exploration of its secondary metabolites.

Key words: Mangrove-derived actinomycetes, Strepomyces ardesiacus, 2-hydroxyphenylthiazolineine, Biosynthetic gene cluster