Streptomyces blattellae, a novel actinomycete isolated from the in vivo of a Blattella germanica.

During a screening for novel and useful actinobacteria in desert animal, a new actinomycete was isolated and designated strain TRM63209. The strain was isolated from in vivo of a Blattella germanica in Tarim University in Alar City, Xinjiang, north-west China. The strain was found to exhibit an inhibitory effect on biofilm formation by Candida albicans ATCC 18,804. The strain was observed to form abundant aerial mycelium, occasionally twisted and which differentiated into spiral spore chains. Spores of TRM63209 were observed to be oval-shaped, with a smooth surface. Strain TRM63209 was found to grow optimally at 28 °C, pH 8 and in the presence of 1% (w/v) NaCl. The whole-cell sugars of strain TRM63209 were rhamnose ribose, xylose, mannose, galactose and glucose, and the principal polarlipids were found to be diphosphatidylglycerol, phos-phatidylethanolamine, phosphatidylcholine, phosphatidylinositol mannoside, phosphatidylinositol and an unknown phospholipid(L). The diagnostic cell wall amino acid was identified as LL-diaminopimelic acid. The predominant menaquinone was found to be MK-9(H6) (14.64%), MK-9(H2) (19.65%), MK-9(H8) (22.34%), MK-10(H2) (25.37%). The major cellular fatty acids were identified as iso-C16:0, 16:0, anteiso-C15:0, anteiso-C17:0, iso-C15:0 and Sum in Feature 3. Analysis of the 16S rRNA sequence showed that strain TRM63209 exhibits high sequence similarity to Streptomyces bungoensis strain DSM 41781 98.20%. A multi-locus sequence analysis of five house-keeping genes (atpD, gyrB, rpoB, recA and trpB) and phylogenomic analysis also illustrated that strain TRM63209 should be assigned to the genus Streptomyces. The DNA G + C content of the strain was determined to be 70.2 mol%. Average nucleotide identity (ANI) between strain TRM63209 and S. bungoensis DSM 41781, Streptomyces phyllanthi PA1-07, Streptomyces longwoodensis DSM 41677 and Streptomyces caeruleatus NRRL B-24802 were 82.76%, 82.54%, 82.65%, 84.02%, respectively. Digtal DNA-DNA (dDDH) hybridization were 26.30%, 25.10%, 26.20%, 29.50%, respectively. Therefore, it is concluded that strain TRM63209 represents a novel species of the genus Streptomyces, for which the name Streptomyces blattelae is proposed. The type strain is TRM63209 (CCTCC AA 2018093 = LMG 31,403 = TRM63209).