We report here the biosynthesis of daidzein in Streptomyces sp. SS52, its genome sequence and the analysis of its genome for finding putative genes involved in daidzein biosynthesis. The Streptomyces sp. SS52 strain was isolated from the plant Phyllanthus urinaria in Tra Vinh province, Vietnam. This endophytic strain is capable of producing the isoflavone daidzein in the culture medium. Streptomyces sp. SS52 possesses a linear genome of 8,184,045 bp and the GC content of this genome is 72.5%. The preliminary genome analysis identified homologs of genes involved in the de novo biosynthesis of daidzein in the genome of Streptomyces sp. SS52. The genome sequencing of Streptomyces sp. SS52 was essential for the study of the biosynthesis of daidzein in Streptomyces bacteria.

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We isolated three strains of endophytic Streptomyces from Crinum latifolium. Preliminary screening of antimicrobial activity showed one strain (SS004) with antibacterial activity on SFM medium. SS004 was identified as Streptomyces diastaticus subsp. ardesiacusbased on 16S rRNA nucleotide sequence analysis. Antimicrobial activity produced by SS004 appeared merely after 18 hours of culture in SFM medium proving that the biosynthesis of the antimicrobial compounds was controlled in the same type as those as in other Streptomyces strains. SS004 produced more antimicrobial compound at 28 oC than at 37 oC. SS004 showed diversity in antimicrobial compound production on different media, notably on FM3 medium which has antibacterial activity against several antibioticresistant bacteria. In conclusion, endophytic Streptomyces strains are remarkable for their production of antimicrobial compounds.