3.6. Genome Sequencing of Streptomyces sp. RK44

The genome sequencing of Streptomyces sp. RK44 and the sequencing assembly service were provided by BGI-Shenzhen, China. A 300 bp paired-end genomic library of RK44 was prepared for Illumina sequencing. A total of 11,820,095 bp were obtained and assembled by SOAP denovo software. The assembled genome was submitted to the RAST server for annotation [40]. The open reading frames (ORFs) of the ahfa gene cluster was identified using the key enzymes encoded in the known mmf gene cluster as a sequence query. The 16s rDNA sequences and the ahfa cluster has been deposited in the NCBI ({"type":"entrez-nucleotide","attrs":{"text":"MN906804","term_id":"1805598995","term_text":"MN906804"}}MN906804).

Based on the partial 16s DNA gene sequence analysis it was identified that the strain belongs to the class Streptomyces and was most closely related to three strains with 82.49% sequence similarity: Streptomyces hoynatensis S1412, Streptomyces carpaticus NRRL B-16359, Streptomyces yeochonensis NBRC 100782. The strain formed a well-separated clade in the genus Streptomyces (Figure 4) based on the 16S rRNA gene analysis, indicating that Streptomyces sp. RK44 is a new Streptomyces species (MEGA 7, Neighbor-Joining method) [41,42]. The optimum pH for growth was determined to be 7.2. The DNA G+C content of the strain was determined to be 71.4 mol%.

Phylogenetic analysis of 16S rDNA sequences of Streptomyces sp. RK44 and other known Streptomyces species, indicating that Streptomyces sp. RK44 is a new Streptomyces species.